Development of gas supply project of Dalnerechensky municipal district

Contents

Table of contents

Summary

The abstract

Table of contents

Introduction

1 General part

1.1 Characteristics of Dalnerechensky municipal district

1.2 Population Information

1.3 Analysis of fuel consumption

1.4 Current state of gas supply

1.5 Gas supply source. Main design solutions for gas supply

2 Design part

2.1 Determination of annual gas expenditures

2.2 Determination of gas hourly flow rates

2.3 Hydraulic calculation

2.4 Gas Distribution Station Design

2.5 Gas Control Station Design

3 Process Part

3.1 Preparation works for gas pipeline laying

3.2 Welding of gas pipelines

3.3 Earthworks

3.4 Laying of gas pipelines

3.5 Crossing artificial obstacles

3.6 Internal gas supply devices

3.6.1 Gas supply of residential buildings

3.6.2 Gas supply to production plants and boilers

3.7 Corrosion protection

4 Research and development

4.1 Comparative Characteristics of Gas Detectors

4.1.1 Causes of gas pollution

4.1.2 Requirements for control devices for carbon monoxide and methane content in the air of the working area

4.1.3 Characteristics of Carbon Monoxide (CO) Gas Gas Detectors/Analyzers

4.1.4 Requirements for maintenance, repair, verification of gas and gas detectors

4.1.5 Recommendations for arrangement of annunciators and safety systems

5 Life Safety

5.1 Analysis of hazardous and harmful production factors in accordance with GOST 12.0.003-99 and measures to prevent them

5.2 Safety requirements during gas hazardous operations

5.3 Calculation of lightning protection of gas distribution point

5.4 Environmental protection measures

6 Economic part

6.1 General provisions

6.2 Operating Costs

Conclusion

List of literature

Appendix A

Appendix B

Introduction

MINISTRY OF EDUCATION AND SCIENCE OF THE RUSSIAN FEDERATION

Federal State Autonomous Educational Institution

higher vocational education

Far Eastern Federal University

Engineering School

Department of Oil and Gas and Petrochemistry

Zelentsov Dmitry Andreevich

DEVELOPMENT OF GAS SUPPLY PROJECT OF DALNERECHENSKY

MUNICIPAL DISTRICT

DIPLOMA PROJECT

under the main training program for specialists

specialty 130501.65 - Design, construction and operation of oil and gas pipelines and storage facilities

Summary

In this diploma project, the gas supply design of the Dalnerechensky municipal district of 13,030 people was carried out.

The project displays general information about the object, terrain, and climatic conditions for the pipeline route.

In accordance with the initial design data, annual and hourly gas consumption was calculated (by household consumers; utility consumers and hospitals; agricultural enterprises), hydraulic calculation of the gas distribution network. Gas distribution point is designed.

The section of the technological part considers the construction technology and the construction organization process.

In the research part, a comparative characterization of gas pollution detectors of various manufacturers was carried out.

In the section "Life safety," the analysis of hazardous and harmful factors was carried out, the lightning protection of the gas distribution point was calculated, safety issues during gas hazardous work and the impact of the object on the environment were covered.

In the economic part, the project feasibility study was carried out, the project profitability was calculated.

The diploma project consists of an explanatory note on 112 sheets of A4 format, which contains 24 tables, 10 figures and 73 used sources, and a graphic part on 9 sheets of A1 format.

Improvement and automation of technological processes leads to the need to improve the quality of consumable heat carriers. Natural gas meets these requirements most than other fuels.

The rational use of gaseous fuel with the greatest realization of its technical advantages allows to obtain a significant economic effect, which is associated with an increase in the efficiency of the units and a decrease in fuel consumption. The use of natural gas as a fuel makes it possible to significantly improve the living conditions of the population, increase the sanitary and hygienic level of production and improve the air pool in settlements and industrial centers.

The purpose of natural gas supply to human settlements is:

improving the living conditions of the population;

replacing more expensive solid, liquid fuel or electricity in thermal processes at industrial enterprises, thermal power plants, at municipal enterprises, in medical institutions, public catering enterprises, etc.;

improving the ecological situation in cities and settlements, since natural gas during combustion practically does not emit harmful gases into the atmosphere.

Natural gas is supplied to cities and towns through main gas pipelines starting from gas production sites (gas fields) and ending at gas distribution stations (GRS) located near cities and towns.

To supply gas to all consumers, a gas distribution network is being built in the cities, gas control points or installations (GRP and GRU) are being equipped, and gas pipelines necessary for operation are being built

control points and other equipment.

On the territory of cities and villages, gas pipelines are laid above the ground.

On the territory of cities, towns, industrial enterprises and thermal power plants, gas pipelines are laid above the ground on separate supports, on overpasses, as well as on the walls and roofs of buildings.

Gas pipelines shall be laid in accordance with SNiP requirements.

Natural gas is used by the population for burning in household gas appliances: stoves, water gas heaters, in heating boilers.

At public utilities, gas is used to obtain hot water and steam, baking bread, cooking in canteens and restaurants, and heating rooms.

In medical institutions, natural gas is used for sanitary treatment, preparation of hot water, for cooking.

In agriculture, natural gas is used to prepare feed for animals, to heat agricultural buildings, and in production workshops.

The purpose of the diploma project is to design gas supply to the Dalnerechensky municipal district. To do this, you must:

1 Perform calculations of gas supply system:

determine the annual gas consumption by consumers;

Determine the hourly consumption of gas by consumers;

perform hydraulic calculation of low and medium pressure networks, intra-quarter and intra-house gas pipelines.

select gas equipment used by gas control stations (GRP), gas distribution station (GRS), enterprises, boiler houses.

2 The gas supply system shall ensure uninterrupted gas supply to consumers, be safe in operation, simple and convenient to maintain, shall provide for the possibility of disconnecting its individual elements or sections of gas pipelines for repair or emergency work.

3 Facilities, equipment and units in the gas supply system shall be of the same type. The adopted version of the system should have maximum economic efficiency and provide for the construction and commissioning of a gas supply system in parts.

4 A number of factors shall be taken into account:

nature of gas source, gas properties, degree of gas purification and humidity;

the size of the area, its climate and terrain, planning and development, population density;

the presence of natural or artificial obstacles to the laying of gas pipelines.

5 In order to prevent harm to a person, reduce the negative impact on the environment during the construction of a gas distribution network, programs for human labor protection and environmental protection should be developed.

The initial data for gas supply network design are:

composition and characteristics of natural gas or gas field;

climatic characteristics of the construction area;

development plan of the settlement;

characteristics of heat supply sources of the population and industrial enterprises;

The population of the district;

storey of development.

General part

1.1 Characteristics of Dalnerechensky municipal district

Dalnerechensky municipal district is located in the north of Primorsky Krai, in the valley of the Ussuri and Malinovka rivers. In the west it borders with the People's Republic of China, in the north with Pozharsky, in the east with Krasnoarmeysky, in the south with Chuguevsky and Kirovsky districts, as well as with the Lesozavodsky urban district. The total area of ​ ​ the district is 7290 km2.

The administrative center of the district is the city of Dalnerechensk. The district includes 6 rural settlements:

1 Vedenkinsky rural settlement: Vedenka, Mezhdurechye, Novotroitskoye, Solovyovka, Stretenka, Udarnoye, Malaya Vedenka.

2 Malinovsky rural settlement: Malinovo, Ariadnoye, Palm, Zimniki, Lyubitovka, Pozhiga, Savinovka.

3 Orekhovsky rural settlement: Orekhovo, Bogolyubovka, Martynova Polyana, Polyany.

4 Rakitnensky rural settlement: Rakitnoye, Lobanovka, Yasnaya Polyana.

5 Christmas rural settlement: Rozhdestvenka, Golubovka, Solnechnoye, Filino.

6 Salskoe rural settlement: Salskoe, Zvenigorodka, River, Sukhanovka, Chaldanka, Ebergard.

Agriculture and logging occupy a leading place in the region's economy. There are cooperatives and farms that grow soy, buckwheat, corn, oats, barley, wheat, potatoes, and a variety of vegetables. Animal husbandry is represented mainly by meat and dairy production. There is a beast industry, leading the fishing of river fish and taiga beast.

There are two leshozes in the area, two companies that harvest and process wood, such as spruce, fir, ash, oak, ilm, birch, wasp

on. Mineral deposits such as gold, ilmenite, rhodomite, coal, peat, limestone have been explored in the area. There are stocks of raw materials for the production of building materials.

Climatic data of the area.

The climate of the region is sharply continental temperate. Winters are cold, often snowy (the depth of snow cover can reach 7090 cm). Five months a year - from November to March, negative average monthly temperatures are observed, seven months - from April to October - positive. Ground freezing depth 190210 cm.

Of great importance for the climate of the Dalnerechensky municipal district is its location in the north of the Khankai lowland, fenced off from the sea by the SikhoteAlin ridge. Therefore, in the cold period, the masses of continental cold air when moving from Siberia to the ocean stagnate in front of the ridge, and the penetration of warm sea air is limited. As a result, very frosty dry sunny weather prevails in winter with rare precipitation and relatively weak winds.

In summer, wet air from the sea enters the territory, but its influence is not as great as on the coast. Summer is warm, the warmest month is July. The first half of summer is quite cloudy, but unlike the coast it is drier. The second half of summer from July to October is warm with frequent typhoons and heavy precipitation as a result of the arrival of marine tropical air. In October, sunny, rather warm weather is set.

The main climatic indicators are given in Table 1.

Table 1 - Main climatic indicators

Climatic characteristics

Value

Average temperature of the coldest five-day period (calculated for the design of heating systems), ° С

-31,0

Average temperature of coldest period (calculated for ventilation systems design), ° С

-8,5

0The average temperature of the coldest month (January), ° С

-20,5

Average temperature of hottest month (July), ° С

+21,1

Heating period duration, day

205

Seismicity in the Dalnerechensky municipal district at seismic hazard degree A (10%) is 6 points, at seismic hazard degree B (5%) is 7 points, at seismic hazard degree C (1%) is 8 points.

Relief characteristic

The area is located in the system of medium-low mountain and low mountain massifs and their groups, formed during the introduction of Upper Cretaceous granitoids and during local volcanic eruptions. The region is located in the northern part of the Prikhankai depression and in the valleys of the Bolshoi Ussurka and Malinovka rivers. Most of the region is occupied by low mountain massifs separated by an intragonal decrease in relief, drained by rivers of medium and high orders.

The dominant type of relief is low mountain ridges, with confined narrow river valleys flowing to the north-west, south-west and west.

The relief along the ridge is secondary, anthropogenic, there are local relief. Relief violations occurred in the past. The relief can be characterized as anthropogenic [5]. The engineering preparation of the territory is reduced only to the leveling of the relief [7]. Measures for the engineering protection of the territory are not required. During construction, the expansion of the range of anthropogenic relief will not occur. No significant exo and endogenous processes have been recorded; there is a sequential neotectonic elevation of the terrain with an amplitude of 2-6 mm/year.

Effects on the macro and mesorelief are excluded. Reclamation works at the end of construction will eliminate the negative impact on the microrelief of the area [5; 7, 4, 2]. Geomorphological conditions for construction are favorable.

Geotechnical characterization

The construction area falls on the Shmakov subzone of the zone of the Khankai massif of the Ussuri Khankai meganticlinory on the folded complexes of the base of the Khankai massif.

The area is composed of Karelian (early Proterozoic) tectonic structures of the Khankai massif covered by sedimentary Cenozoic structures. Intrusive rocks - granites, granodiorites, diorites - take part in the geological structure of the 72 m high area.

Engineering-geological mass of rocks is represented by crust of granites weathering with capacity up to 1 m covered with clays and loams [7]. Engineering-geological rock mass includes 3 engineering-geological elements [17].

According to the totality of geomorphological, geological, hydrogeological factors, the presence of geological processes negatively affecting the conditions of construction and operation of buildings and structures, the category of complexity of engineering and geological conditions of the work area should be considered I (simple) [18].

Eluvial deposits, represented by crushed clay soils, weathered granites from medium strength to strong, take part in the geological and olithological structure.

The degree of geodynamic risk is high, the activity of natural geoprocesses (up to 7-8 points) is increased. However, according to SNiP 11781 * [45], seismicity is determined at 6 points.

There are no deposits and manifestations of minerals in the described area. Geological monuments of nature are also absent. Engineering protection of the territory from hazardous geological processes is not required [57].

Thus, the geological, hydrogeological and engineering-geological conditions of the area are favorable for the planned construction, and the impact on the geological environment is defined as minimal and practically not significant. It is necessary to take into account the potential increased geodynamic activity of the region.

Characteristics of main water bodies

Dalnerechensky municipal district is an agricultural district. The main reservoirs are the Bolshaya Ussurka River and the Malinovka River.

There are many small lakes in the area. Not far from the village of Novotroitsky are the lakes of Fadeev and Denisov. Near the village of Stretenka, lakes Nechiporovo and Bolshoi. Near the village Solovyevka there are lakes Krugloye and Krasnoye. Near the village of Vedenka Lake Khutoryanskoye. Near the village Lobanovka there are lakes Kupalnaya, Khorkova and Stoilovoye.

Characteristics of the plant world

Sayan and Korean spruce grow in the dark-water forests of the Dalnerechensky municipal district, yellow birch, stone birch and blond fir, Daurian larch and Korean cedar. Botanical attractions of the district: microbiota - relict steaming coniferous shrub. Velvet (Amur cork tree) is bred. In the upper reaches of the rivers, a peculiar liana grows - lemon. Lians reach up to 15 m. Hundreds of legends have overgrown ginseng for its miraculous healing power - the root of life.

1.2 Population Information

In total, 13,030 people live in the Dalnerechensky municipal district. The population of the city of Dalnerechensk is 28,260 people. The residential development zone is represented by houses of different storeys. Information on the population of settlements included in the municipal district is given in Table 2.

1.3 Analysis of fuel consumption

At the moment, coal, firewood, and diesel fuel are used as boiler fuel in the Dalnerechensky municipal district, and firewood, coal and liquefied hydrocarbon gas (propanobutane mixture) are also used to provide household needs for the population. Information on the consumption of various types of fuels is given in Table 3.

1.4 Current state of gas supply

Currently, in the Dalnerechensky municipal district, natural gas is not used. The population uses liquefied gas in cylinders for cooking food and hot water for household needs in residential buildings of individual buildings. The number of apartments gasified with balloon gas is 3,412 pcs. There are no group tank plants in the Dalnerechensky municipal district. Information on the population and structure of the housing stock of the Dalnerechensky municipal district is presented in table 4.

1.5 Gas supply source. Main design solutions for gas supply

During the work, 3 versions of the gas supply system of the Dalnerechensky municipal district were designed:

1 variant with one GRSDalnerechenskaya, located between the village of Vedenka and the village of Malaya Vedenka; gas through inter-settlement high-pressure gas pipelines of the second category (0.6 MPa) is supplied to the FRG of settlements. From the GRSDalnerechenskaya pipe of the inter-settlement gas pipeline goes north to the fork, where it diverges in two directions:

northwest towards the mountains. Dalnerechensk. In the suburbs of the mountains. Dalnerechensk gas pipeline diverges in three directions:

to the northwest to supply gas to the mountains. Dalnerechensk;

to the north-east to provide the villages of Salskoye, Rechnoye, Sukhanovka, the LDK microdistrict and the Ebergard station;

southwest to supply villages: Lazo, Grushevoy, Rozhdestvenka, Golubovka, Nevsky and the village of Filino.

southeast to supply villages: Vedenka, Solovyovka, Stretenka, Novotroitskoye, Mezhdurechye, Lobanovka, Rakitnoye, Yasnaya Polyana, Orekhovo, Bogolyubovka, Malinovo, Lyubitovka.

Gas distribution network is made with maximum possible use of polyethylene pipelines.

2 variant with one GRSDalnerechenskaya located between the village of Vedenka and the village of Malaya Vedenka; gas through inter-settlement high-pressure gas pipelines of the second category (0.6 MPa) is supplied to the FRG of settlements.

From the GRSDalnerechenskaya pipe of the inter-settlement gas pipeline goes north to the fork, where it diverges in two directions:

northwest towards the city of Dalnerechensk. In the suburbs of the mountains. Dalnerechensk gas pipeline diverges in three directions:

to the north-west to supply gas to the city of Dalnerechensk.

to the northeast to provide the villages of Salskoye, Rechnoye, Sukhanovka, the LDK microdistrict and the Ebergard station.

southwest to supply villages: Lazo, Grushevoy, Rozhdestvenka, Golubovka, Nevsky and the village of Filino.

southeast to supply villages: Vedenka, Solovyovka, Stretenka, Novotroitskoye, Mezhdurechye, Lobanovka, Rakitnoye, Yasnaya Polyana.

Gas distribution network is made with maximum possible use of polyethylene pipelines.

3 variant with one GRSDalnerechenskaya located between the village of Vedenka and the village of Malaya Vedenka; gas through inter-settlement high-pressure gas pipelines of the second category (0.6 MPa) is supplied to the FRG of settlements.

From the GRSDalnerechenskaya pipe of the inter-settlement gas pipeline goes north to the fork, where it diverges in two directions:

northwest towards the city of Dalnerechensk. In the suburbs of the city of Dalnerechensk, the gas pipeline diverges in three directions:

to the northwest to supply gas to the mountains. Dalnerechensk.

to the northeast to provide the villages of Salskoye, Rechnoye, Sukhanovka, the LDK microdistrict and the Ebergard station.

southwest to supply villages: Lazo, Grushevoy, Solnechnoye, Rozhdestvenka, Golubovka, Nevsky and the village of Filino.

southeast to supply villages: Vedenka, Solovyovka, Stretenka, Novotroitskoye, Mezhdurechye, Lobanovka, Rakitnoye, Yasnaya Polyana, Orekhovo, Bogolyubovka, Polyany, Martynova Polyana, Zimniki, Malinovo, Lyubitovka, Ariadnoye, Pozhiga.

Gas distribution network is made with maximum possible use of polyethylene pipelines.

The third version of the gas supply system was preferred, since it has the largest coverage of network gas for consumers of the Dalnerechensky municipal district.

The supply of natural gas to the Dalnerechensky municipal district is provided through the Sakhalin Khabarovsk Vladivostok gas pipeline (pressure 4-10 MPa) through the gas distribution station (GRSDalnerechenskaya), the construction of which is provided for in the municipal district between the village of Vedenka and the village of Malaya Vedenka. The gas pressure at the outlet of the GPC is 0.6 MPa. The capacity of the GRS of the Dalnerechensky municipal district will be 39,196 m3/h (taking into account the approximate consumption of natural gas by the Krasnoarmeysky municipal district - 15,000 m3/h and the approximate consumption of natural gas by the Dalnerechensky urban district - 16,955 m3/h). According to the system of inter-village high-pressure gas pipelines of category II, gas enters the southeast to the settlements: Vedenka, Solovyovka, Stretenka, Novotroitskoye, Mezhdurechye, Lobanovka, Rakitnoye, Yasnaya Polyana, Orekhovo, Bogolyubovka, Polyana, Ziminovka, Malizniki. To the north-west, gas moves to the territory of the Dalnerechensky urban district, through which it transits south to the settlements: Solnechnoye, Filino, Nevsky (LGO), Rozhdestvenka, Golubovka and north to the settlements: Salskoye, Ebergard, River and Sukhanovka.

The gas supply system of the Dalnerechensky municipal district is two-stage - high-pressure gas pipelines of category II (P 0.6 MPa) and low-pressure (P 0.003 MPa). The scheme of high-pressure gas pipelines of the Dalnerechensky municipal district is adopted dead end.

The gas supply scheme guarantees the provision of the necessary parameters for the gas supply of heat sources, the population, housing and communal services and agricultural enterprises. The direction of gas use is shown in Table 5.

Table 5 - Directions of Natural Gas Use

Requirement

Purpose of the gas used

Population

Cooking, hot water for household and sanitary and hygienic needs and heating

Health-care institutions, children's, educational and communal enterprises and institutions

Cooking, hot water for household and sanitary and hygienic needs and heating

Local boiler houses, heating and district

Heating of housing and public funds

Agricultural enterprises

Heating, hot water supply, ventilation, technological needs

Design part

When designing a gas supply system, pipe sizes are selected based on a hydraulic calculation aimed at determining the internal diameter of pipes in each section. The diameter of the pipes is selected to provide the necessary amount of gas to the consumers connected to the gas supply network. The primary task is to determine the estimated gas hourly flow rates in all sections of the gas pipeline network. The costs at each site are calculated by adding the gas costs to the connected consumers.

Calculating the annual consumption of gas for household, communal and public needs is a difficult task, since the amount of gas consumed by these consumers depends on a large number of factors: gas equipment, improvement and population of apartments, equipment of urban institutions and enterprises, the degree of service by these institutions and enterprises, coverage of consumers with centralized hot water supply, climatic conditions. [54]

Most of these factors cannot be accurately accounted for, so annual gas consumption is calculated according to average standards developed as a result of many years of experience. It is especially difficult to determine the annual consumption of gas by apartments, since it depends on the availability of catering facilities, baths, laundry facilities and other institutions serving the population. The annual standards for gas consumption in apartments take into account that the population partially eats in buffets, canteens and restaurants, and also uses the services of utilities.

The region's annual gas consumption is the basis for the gas supply project.

The number of gas consumers in microdistricts is determined from the analysis of their population, storey and its main characteristics of the number and characteristics of enterprises and institutions of the district economy, the presence of centralized

hot water supply, characteristics of heating systems, fuel and heat balance of the city area.

This project envisages the use of gas for:

cooking in an individual low-rise building - 100%;

cooking in multi-storey buildings - 100%;

hot water supply in individual low-rise buildings - 100%, including: 100% use flowing gas water heaters.

Coverage of gas supply - 100%.

All natural gas consumers of the Dalnerechensky municipal district can be divided into the following categories:

population;

utility consumers;

agricultural enterprises.

2.1 Determination of annual gas expenditures

Determination of gas consumption for domestic consumption

Standards of gas consumption for utility needs are given in Table 6 [29].

Table 6 - Standards of gas consumption for utility needs

Gas consumers

Gas consumption indicator

Heat gas consumption rates,

thousand kcal

If there is a gas stove in the apartment and centralized hot water supply at gas supply:

For 1 person. per year

970

If there is a gas stove and a gas water heater in the apartment (if there is no centralized hot water supply) with gas supply:

For 1 person. per year

2400

If there is a gas stove in the apartment and there is no centralized hot water supply and gas water heater at gas supply:

For 1 person. per year

1430

Annual gas consumption for food preparation and hot water supply Vpischagod, m3/year, is determined by formula (1) [53]

Vpischagode = NYq1Qnr, (1)

where N is the population;

Y - the degree of coverage of gas supply of apartments, that is, the share of the population using gas;

q1 - heat consumption rate, kcal at presence of gas plate and MBT;

Qnr is the lowest combustion heat of one cubic meter of gas, kcal/m3.

Vpischagod = 13,030 * 2,400,000 * 17600 = 4,114,737 m3/year

Annual gas consumption for heating Votgod, m3/year, is determined by formula (2) [59]

Votgod=qotv-tcp.ot.NVn24∙notQnr, (2)

where qo is the specific heating characteristic, qo = 0.4 kcal/person;

tv is the average design temperature of internal air of the heated buildings, tv =18 C;

tcp. from. - average heating temperature, tcp.ot. = 8.5 C;

N is the number of inhabitants in the village covered by centralized hot water supply;

V - external construction volume of heated buildings, Vn = 90 m3;

not - duration of heating period, not = 205 days;

Qnr is the lowest calorific value of gas, kcal/m3;

- heating system efficiency.

Votgod=0.4∙18+8,5∙13 030∙90∙24∙2057600 ∙0,8=10 058 989 m3/year

The summary table of annual gas consumption by area for cooking, hot water and heating is given below.

Determination of gas consumption by utilities and hospitals

The group of utility consumers of DGO includes:

schools;

kindergartens;

farms;

hospitals.

The calculation of gas consumption by utility enterprises Vcom.hod, m3/year, was made based on the received initial data on the actual annual heat generation of each enterprise according to the formula (3)

Vcom.hod = QgodQnr, (3)

where Qgod - actual annual heat generation by the enterprise, kcal/year;

Qnr is the lowest calorific value of gas, kcal/m3;

- Efficiency of the enterprise heating system.

Vcom.hod = 15,937,265 0007600∙0,8=2 621,261 m3/year

The calculation of gas consumption by agricultural enterprises is reduced to the recalculation of the design loads of boiler houses obtained in the initial design data for the required amount of gas.

Calculation of annual gas consumption by agricultural enterprises Vc/Hg, m3/year, is determined by formula (4)

Vs/hop = Qs/hodQnr, (4)

where Qs/cold is the estimated annual heat production, kcal/year;

Qnr is the lowest calorific value of gas, kcal/m3;

- heating system efficiency.

Vs/Hg = 1,623,000 0007600∙0,8=266 941 m3/year

2.2 Determination of gas hourly flow rates

Determination of hourly gas consumption by household consumers .

Gas networks should be counted on maximum hourly expenses. The estimated hourly flow Vh, m3/h, is defined as a fraction of annual by formula (5) [55]

Vhr = Vgodk, (5)

where Vgod - annual gas flow rate, m3/h;

k is the hourly maximum factor [17].

A summary table of the hourly gas consumption by area for cooking and hot water supply is given in Table 8.

Determination of hourly gas consumption by utility consumers and hospitals

Calculation of hourly gas consumption by utilities is reduced to recalculation of design loads obtained in the initial data for gas supply system design for the required amount of gas.

Hourly gas consumption by utilities and hospitals Vkom hour, m3/h, is determined by formula (6)

Vkom hour =QchasQnr, (6)

where Qhour - actual hourly heat generation by the enterprise, kcal/hour;

Qnr is the lowest calorific value of gas, kcal/m3;

- Efficiency of the enterprise heating system.

The gas consumption of each utility is shown in Summary Table 9.

The total gas consumption of public utilities and hospitals is 955 m3/h.

Determination of hourly gas consumption by agricultural enterprises

The method of determining gas consumption by agricultural enterprises is similar to the method of determining the hourly gas consumption by utility enterprises.

Hourly consumption by agricultural enterprises Vc/hh, m3/h, is determined by formula (7)

Vs/hchas =qs/hchasqnr, (7)

where Qs/hh is the estimated hourly heat generation, kcal/h;

Qnr is the lowest calorific value of gas, kcal/m3;

- heating system efficiency.

Gas consumption by each agricultural enterprise of the Dalnerechensky municipal district is given in summary table 10.

The total hourly flow rate of gas by agricultural enterprises is 83 m3/h.

2.3 Hydraulic calculation

The purpose of hydraulic calculation is to select the diameters of gas pipelines and pressure losses in them. The capacity of gas pipelines is taken from the conditions of creation at maximum permissible gas pressure losses of the most economical and reliable system in operation, which ensures stability of operation of hydraulic fracturing and gas control plants (GRU), as well as operation of burners of consumers in permissible gas pressure ranges. The design internal diameters of gas pipelines are determined based on the condition of ensuring uninterrupted gas supply to all consumers during the hours of maximum gas consumption. Design pressure losses in high and medium pressure pipelines are accepted within the pressure category adopted for the gas pipeline. The initial information for the calculation is the physical properties of the transported gas, the configuration of the network and the description of the network sections. The calculated parameters are gas flows through the sections of the gas pipeline system, pressure in the units of the gas supply distribution system and gas velocity in the calculated sections.

Hydraulic calculation of gas pipelines is performed in accordance with the requirements of the following regulatory documents:

SNiP 42012002 "Gas distribution systems" [2];

SP 421012003 "General provisions for the design and construction of gas distribution systems made of metal and polyethylene pipes" [17];

SP 421022004 "Design and construction of gas pipelines from metal pipes" [25].

SP 421032003 "Design and construction of gas pipelines from polyethylene pipes and reconstruction of worn-out gas pipelines" [26].

The pressure drop in the gas network section can be determined by:

for medium and high pressure networks according to formula (8)

Pн2-Pк2=P0812Q02d50l=1,2687∙104Q02d50l, (8)

where Rn - absolute pressure at the beginning of the gas pipeline, MPa;

Rk - absolute pressure at the end of the gas pipeline, MPa;

P0 = 0.101325 MPa;

- hydraulic friction coefficient;

l - design length of gas pipeline of constant diameter, m;

d - internal diameter of gas pipeline, cm;

0 - gas density under normal conditions, kg/m3;

Q0 - gas flow rate, m3/h, under normal conditions.

for low pressure networks according to formula (9)

Pn-Pk = 1061622Q02d50l = 626, 1Q02d50l, (9)

where Rn - absolute pressure at the beginning of the gas pipeline, Pa;

Rk - absolute pressure at the end of the gas pipeline, Pa;

- hydraulic friction coefficient;

l - design length of gas pipeline of constant diameter, m;

d - internal diameter of gas pipeline, cm;

0 - gas density under normal conditions, kg/m3;

Q0 - gas flow rate, m3/h, under normal conditions.

The coefficient of hydraulic friction is determined depending on the mode of gas movement through the gas pipeline, characterized by the Reynolds number according to the formula (10)

Re=Q09πdν=0,0354Q0dν, (10)

where is the kinematic viscosity coefficient of the gas, m2/s, under normal conditions;

d - internal diameter of gas pipeline, cm;

Q0 - gas flow rate, m3/h, under normal conditions, and hydraulic smoothness of the internal wall of the gas pipeline, determined by condition (11)

Re=nd<23, (11)

where Re is the Reynolds number;

n is the equivalent absolute roughness of the inner surface of the pipe wall, taken equal to 0.01 cm for new steel ones, 0.1 cm for former steel ones, 0.0007 cm for polyethylene ones regardless of the operation time;

d - internal diameter of the gas pipeline, cm.

Depending on the value Re, the hydraulic friction coefficient is determined by:

for laminar gas flow mode Re2000

=64Re, (12)

for critical gas mode Re = 2000-4000

=0,0025Re0,333, (13)

at Re > 4000 - depending on condition fulfillment (13);

for hydraulically smooth wall (inequality (13) is true):

at 4,000 < Re < 100,000 by formula

=0,3164Re0,25, (14)

at Re > 100,000

=11,82lgRe1,642, (15)

for rough walls (inequality unfair) at Re > 4000

=0,11nd+68Re0,25, (16)

where n is the equivalent absolute roughness of the inner surface of the pipe wall, taken equal to 0.01 cm for new steel ones, 0.1 cm for former steel ones, 0.0007 cm for polyethylene ones regardless of operation time;

d - internal diameter of the gas pipeline, cm.

Hydraulic calculation was carried out using the ASPOGAZ 1.1 software complex designed for hydraulic calculation of newly constructed and reconstructed gas supply utilities of low, medium and high pressure, certified on the basis of the test report from 15.05.2010 No. 129 IL of the software of TsRIOIT LLC with certificate 0129388 in accordance with SP 421012003 [17].

The third version of the gas supply system was preferred, since it has the largest coverage of network gas for consumers of the Dalnerechensky municipal district.

In the third version, polyethylene gas pipes of GOST R 5083895 [46], PE polyethylene grade 100 and one section of steel from electric welded pipes of GOST 1070580 [47] are used.

The wall thickness of the polyethylene (including profiled) pipe is characterized by the standard dimension ratio of the nominal outer diameter to the nominal wall thickness (SDR), which should be determined depending on the pressure in the gas pipeline, polyethylene grade and safety factor according to formula (17) [26]

SDR=2MRSMOP∙C+1, (17)

where MRS⎯ the minimum long-term strength of polyethylene used for the manufacture of pipes and connectors is MPa (for PE 80 and PE 100, this is 8.0 and 10.0 MPa, respectively);

MOR⎯ operating pressure of gas, MPa, corresponding to the maximum pressure value for this category of gas pipeline, MPa;

C is the safety factor chosen depending on the operating conditions of the gas pipeline according to SNiP 42012002 "Gas distribution systems."

Select pipe material - PE 100.

SDR=2100,6∙2,8+1=12,9

Go downwards and accept the nearest SDR 11 pipe range.

Accepted calculation parameters, assumptions and simplifications.

The gas density under normal conditions is 0.73 kg/m3.

Kinematic viscosity of gas - 0.000014 sq.m/pages.

The method of laying throughout is underground.

The gas flow is considered isothermal.

The effect of local resistances is taken into account by increasing the actual length of the design area by 10%.

Changes in physical properties of natural gas within the design area are not taken into account.

Summary results of high pressure hydraulic calculation are given in Table 11. Detailed reports on the results of hydraulic calculations are available in Appendix A - for high pressure; in Appendix B - for low pressure.

2.4 Gas Distribution Station Design

Gas from the main gas pipelines enters the city, village and industrial gas supply systems through gas distribution stations, the schematic diagram of which is shown in Figure 1. They are the final sections of the main gas pipeline and are, as it were, the border between the city and main gas pipelines [56]. Initial data for gas distribution station design are given in Table 12.

1 - gas pipeline inlet to GRS; 2 - oil filter; 3 - heat exchanger; 4 - gate valve; 5 - pressure regulator; 6 - gas meter; 7 - gas odorizer; 8 - bypass; 9 - pressure gauges; 10 outlet of gas pipeline.

Figure 1 - GVC schematic diagram

Gas cleaning at GPU. Oil filters:

Capacity, Qm, m3/h, is determined by formula (18)

Qm=3,97∙105D2∙PTpzhpgpg0,5, (18)

where D is the inner diameter of the oil dust collector (filter),

P - gas pressure upstream the filter, MPa;

ρж - density of the moistening liquid under operating conditions, kg/m3

αg - gas density under operating conditions, kg/m3

T - gas temperature, To.

Qm=3,97∙1050,72∙7278,18000,730,730,5=162 020.91 m3/h

Determination of gas temperature at GPU outlet.

The gas temperature after the pressure regulator at small changes in linear velocity is the formula:

T2=T1-DiP1-P2, (19)

where T1, P1, - gas parameters to regulator,

T2, P2, - gas parameters after regulator,

Di = 5.5 - JoulyThompson coefficient, deg/MPa.

Q m=278,15,5∙5,10,6=251,2 K

The pressure regulator is selected in accordance with the initial data for the design of the GRS (Table 12) with the condition to ensure the necessary throughput, taking into account the reserve of 1520%.

The selected pressure regulator is 149 BV produced by the Gazprommash plant in Saratov.

2.5 Gas Control Station Design

To reduce pressure and maintain it at the specified levels, gas control points are provided in the gas supply systems, the fundamental diagram of the FRG is shown in Figure 2.

It is recommended to place separate GRP in settlements in the zone of green spaces, inside the quarters at a distance of at least those indicated in the SNiP 2.08.0189 * [10]. The starting data are shown in Table 13.

1 - inlet gas pipeline; 2 - flowmeter; 3 - gate valve; 4 - filter; 5 - pressure regulator; 6 - safety shut-off valve; 7 - bypass; 8 - sealing device (valve) on bypass; 9 - safety relief valve; 10 - recorder for measuring gas in the network; 11 - U-shaped pressure gauge; 12 - gas extraction tank; 13 - pressure gauge; 14 - pulse tube.

Figure 2 - Schematic diagram of hydraulic fracturing

Hydraulic operation mode of gas supply systems is controlled by means of pressure regulators, which automatically maintain constant pressure at the point of pulse extraction regardless of consumption mode.

The pressure regulator is selected in accordance with the initial data for the design of the GRP (Table 13) with the condition of ensuring the necessary throughput, taking into account the reserve of 1520%.

Depending on the gas flow rate, pressure regulators are selected at each FRG. The type of pressure regulator, the diameter of its seat and the type of gas control station are selected according to the catalog of the Gazprommash plant in Saratov.

A summary of the selected equipment is shown in Table 14 for pressure regulators with an input pressure of 0.6 MPa and an output pressure of 3 kPa.

Filter matching

Hair filters designed to clean gas from rust dust, resinous substances and other solid particles are used for gas cleaning at FRG.

The degree of purification depends on the filter element. The filter element is a cassette packed with horse hair and impregnated with viscin oil.

We accept a filter with a diameter of 100 mm for installation. Passport data: gas flow rate -

Process Part

3.1 Preparation works for gas pipeline laying

During the construction of gas networks in urban conditions, preparatory work includes obtaining permission to dig trenches and pits.

Routing preparatory works include:

breakdown and fixing of picket, geodetic breakdown of horizontal and vertical turning angles, marking of construction strip;

clearing the construction strip from the forest and shrub, stumps; removal and storage of a fertile layer of land in specially designated places;

building strip layout, boulder cleaning, arrangement of shelves on slopes;

arrangement of protective enclosures ensuring safety of works performance, installation of external lighting facilities;

erosion control measures.

The layout of the installation strip for the passage of construction equipment is recommended, as a rule, due to the arrangement of soil embankments from imported soil. The layout of the microrelief with cutting irregularities is allowed only on the strip of the future trench .

The breakdown of the gas pipeline route, i.e. the transfer of the projected gas pipeline route on city streets, is carried out from the permanent landmarks indicated in the route plan. In places of new development, gas pipeline bindings are applied from red lines, and in non-built-up places the route is transferred from urban polygonometry.

Route splitting is performed in compliance with the following requirements:

leveling of permanent benchmarks is performed with accuracy not less than 4 bits;

along the route, temporary benchmarks are installed, connected by leveling moves with permanent reliefs, layout axes and angles of route turns are fixed and tied to permanent objects on the ground (buildings, structures, supports, power transmission lines, communications, etc.);

the intersection of the gas pipeline route with existing underground structures is marked on the surface with special signs. The breakdown of the route by the customer and its acceptance in kind by the contractor is executed by an act with the application of fiducials and references.

Axis of gas pipeline is fixed in kind with metal pins, which are clogged in all angles of horizontal fractures of gas pipeline axis and in straight sections within the limits of pins visibility. In asphalt pavement, metal buttons are used instead of pins.

Insulated pipes or pipe sections are also delivered to the route.

When a batch of pipes or connecting parts enters the construction organization, their quality is checked by external inspection and measurement of the main geometric parameters of the products for compliance with the regulatory documentation.

External inspection and sizing of pipes or parts is performed according to the procedures specified in the regulatory documentation for the article.

Steel pipes.

Pipes with cracks, non-rectified dents and unacceptable corrosion damages shall be rejected.

Each pipe of a batch of insulated pipes is subjected to external inspection of the insulation coating.

In case of detection by external inspection of individual damages of insulation coating of pipe with area of more than 10% or several damages with total area of more than 20%, the pipe is completely re-isolated by mechanized method.

By the decision of the customer or the general contractor, in addition to external inspection of the insulation coating of pipes, at the input inspection, an instrument insulation check can be carried out as per GOST 9.6022005 [8].

During external inspection of the connecting parts, the presence of dents, nicks, burrs, cracks, corrosion damages, metal delamination, shells and thread quality, as well as compliance of geometric dimensions with GOST (TU) requirements are checked.

In the presence of cracks, through holes, shells, incomplete or clogged threads, deviations of geometric dimensions from the requirements of GOST (TU), unrecorded dents, connecting parts are rejected.

Polyethylene pipes.

Incoming quality control of pipes and connectors made of polyethylene is carried out in accordance with the requirements of SNiP 3.01.0185 [20] and PB 1252903 [23].

The quality certificate accompanying each batch of pipes (parts) contains the name and/or trademark of the manufacturer; Batch number and date of manufacture Pipe legend (part) lot size, m (pcs.); raw material grade; test results or confirmation of compliance of the test results with the requirements of the product standard; date of batch issue; signature and stamp of OTC.

The size of the pipe lot shall not exceed the value specified by GOST R 50838 [46] or other regulatory documents.

The appearance of the surface of pipes and parts is determined visually, without the use of magnifying instruments. Mechanical testing of pipes and connectors during incoming inspection is not provided.

In appearance the pipes shall have smooth outer and inner surfaces. Longitudinal strips and undulations are allowed that do not extend the thickness of the pipe wall beyond the permissible deviations. Bubbles, cracks, shells, foreign inclusions are not allowed on external, internal and end surfaces. Pipes are colored, black or black with colored longitudinal marking strips in an amount of at least three, evenly distributed around the circumference of the pipe. The characteristic color of the gas pipe or marking strips on it is from PE 80 ⎯ lemon yellow; from PE 100 ⎯ yellow-orange. Black pipes without marking strips with fuzzy manufacturer marking are not recommended for construction of gas pipelines.

The appearance of polyethylene pipes is shown in Table 16.

Internal and external surfaces of connecting parts shall have no signs of shrinkage, cracks, bloating and other damages that impair their operational properties. Minor traces from the forming tool, traces of machining and cold joints are allowed. The color of the connectors is yellow, orange, and black.

Dimensions (wall diameter and thickness) and ovality of pipes and parts are determined at temperature (23 ± 5) ° С. Before measurement, they are kept at the specified temperature for at least 2 hours.

Ovality of pipe ends is regulated by tolerances for ovality of connecting parts.

The average outer diameter is checked on each pipe at a distance of at least 150 mm from the ends in one section by measuring the perimeter of the pipe with an error of not more than 0.1 mm and division by 3.142. It is allowed to define the average outer diameter as the arithmetic mean of measurements in two mutually perpendicular directions.

Measurements are made by roulette according to GOST 750298 [27], caliper (GOST 16689 [49]) or micrometer (GOST 650790 [17]) with an error of not more than 0.1 mm.

The pipes are laid out on platforms along the route at a distance of approximately 1.5 m from the edge of the future trench and welded into a long section with a length corresponding to the length of the section. Pipe ends are closed with plugs.

Welding of gas pipelines

Steel gas pipelines.

To connect pipes, arc (manual, semi-automatic, automatic under flux) and gas welding, butt contact welding by melting, welding in CO medium and soldering are used.

Types, structural elements and dimensions of welded joints of steel gas pipelines shall comply with GOST 1603780 [43] and the recommendations of this section.

The technology of welding gas pipelines includes: preparation of pipes for welding, assembly of joints, basic welding of pipes in a section and welding of pipes or sections into a thread.

Preparation of edges for standard preparation (Figure 3) is performed by machining or gas cutting with subsequent grinding of the slip-machine.

Figure 3 - Edge machining diagram

Before assembling pipes, you must:

clean the internal cavity of pipes and parts from soil, dirt, snow and other contaminants;

clean the edges and adjacent internal and external surfaces of pipes, parts of gas pipelines, branch pipes, fittings for a width of not less than 10 mm up to metallic gloss;

check the geometric dimensions of the edges, straighten the smooth dents at the ends of the pipes up to 3.5% of the outer diameter of the pipe;

clean the edges to clean metal and the adjacent inner and outer surfaces of the pipes to a width of not less than 10 mm.

Ends of pipes having cracks, breaks, nicks, bevels with depth of more than 5 mm are cut.

Pipe joints are assembled on inventory beds using external or internal centralizers.

The permissible displacement of the edges of welded pipes shall not exceed 0.15S + 0.5 mm, where S is the smallest of the wall thicknesses of welded pipes.

Prior to welding operations of rotating and non-rotating joints of pipes, pipe ends and adjacent sections are dried or heated.

It is recommended to dry pipe ends by heating by 50 ° С:

if there is moisture on the pipes regardless of ambient temperature;

at ambient temperature below plus 5 ° С.

Welding work in the open air during rain, snowfall, fog and wind at a speed of more than 10 m/s can be carried out provided that the welding site is protected from moisture and wind.

Manual arc welding of non-rotating and rotary joints of pipes with wall thickness up to 6 mm is performed in at least two layers, with wall thickness more than 6 mm - in at least three layers. Each seam layer is thoroughly cleaned from slag and metal spatter before application of the subsequent seam layer.

Automatic arc welding under flux is carried out on the first layer welded by manual arc welding (the same electrodes with which joints were stuck) or welding in a carbon dioxide medium.

Welding materials used for welding of steel gas pipelines shall comply with GOST (TU) requirements.

At operating temperature of gas pipelines (design ambient temperature in the construction area for internal in unheated rooms and above-ground gas pipelines) up to minus 40 ° С arc welding of carbon steel pipes is carried out with electrodes of type E42, E46, from low-alloy - type E50.

Joints welded by arc or gas welding according to the results of external inspection shall comply with GOST 12.3.00386 [35] and meet the following requirements:

seams and adjacent pipe surfaces at a distance of at least 20 mm (on both sides of the seam) shall be cleaned of slag, splashes of molten metal, scale and other contaminants;

seams shall not have cracks, burns, uncontrolled craters coming to the surface of pores, as well as undercuts with a depth of more than 5% of the pipe wall thickness (more than 0.5 mm) and a length more than the perimeter of the joint (more than 150 mm).

According to the results of the radiographic test, joints should be rejected if there are the following defects:

cracks, burns, uncontrolled craters;

non-roving according to weld preparation;

non-roving in the root of the seam and between rollers with a depth of more than 10% of the pipe wall thickness;

Non-roving in the root of the seam and between the rollers over 25 mm for every 300 mm of weld length or over 10% of the perimeter with a weld length of less than 300 mm;

non-roving in the root of the seam in the joints of gas pipelines with a diameter of 920 mm and more, made with internal welding;

non-roving in the root of the seam in welded joints made with a lining ring;

if dimensions of joint defects (pores, slag and other inclusions) exceed those established for class 6 according to GOST 23055 [14].

Polyethylene gas pipelines.

Connections of polyethylene pipes to each other and to polyethylene connecting parts are made by two welding methods: butt welding with a heated tool and welding using connecting parts with embedded heaters (ZN). Connections of polyethylene pipes with steel pipes (or fittings) are made detachable (using flanges) or non-detachable, it is allowed to use "polyethylene steel" connections with threaded metal end for pipes of small diameters (up to 50 mm).

Welding operations can be carried out at ambient temperature from minus 15 ° С to plus 45 ° С. When performing welding operations at other temperatures in technical conditions, standards or certificates for materials, a special process mode of welding is determined, which must be certified in accordance with RD 03615. If a special welding mode is not set in these documents, then with a wider temperature range, it is recommended to perform welding work in rooms (shelters) that ensure compliance with the specified temperature range.

The welding site is protected from atmospheric precipitation, wind, dust and sand, and in summer and from intense solar radiation. During welding, the free end of the pipe or ply is closed to prevent through-holes inside the welded pipes.

It is recommended to cut pipe ends deformed above standard value or having nicks at right angles. Guillotines or telescopic pipe cutters are used to trim pipes with a diameter of more than 63 mm, for smaller diameters hand scissors are used.

Butt welding with a heated tool connects pipes and parts with a wall thickness at the ends of more than 5 mm. Butt welding of pipes with different wall thicknesses (SDRs) made of different grades of polyethylene and long-length pipes is not recommended.

It is recommended to assemble and weld pipes and parts on welding machines with a high and medium degree of automation of the welding process. It is also allowed to use machines with manual control of the welding process, but with the obligatory automatic maintenance of the set temperature of the heated tool.

The process of connecting pipes and parts by butt welding includes:

preparation of pipes and parts for welding (cleaning, assembly, alignment, machining of ends, checking of coincidence of ends and clearance in joint);

joint welding (melting, heating of ends, removal of heated tool, joint settlement, connection cooling).

Ends of pipes and parts are centered on outer surface so that maximum amount of displacement of outer edges does not exceed 10% of thickness of walls of pipes and parts. Fitting of pipes and parts during alignment is performed by turning of one of welded ends around their axis, rearrangement of supports along pipe length.

During butt welding, the departure of the pipe ends from the centering clamps is usually 15⎯30 mm, and the welded parts ⎯ not less than 5⎯15 mm.

The fixed and centered ends of the pipes and parts are machined ⎯ end-worked prior to welding in order to align the welded surfaces directly in the welding machine.

After machining, surface contamination of the ends is not allowed.

Chips are removed from pipe or part cavity by means of brush, and burrs are removed from sharp edges of end face ⎯ by means of knife.

After processing, alignment and absence of gaps in the joint are checked again. There shall be no clearances between the ends brought into contact, exceeding:

0.3 mm ⎯ for pipes up to 110 mm in diameter;

0.5 mm ⎯ for pipes with a diameter of 110 mm to 225 mm;

0.8 mm ⎯ for pipes from 250 mm to 315 mm inclusive;

1.0 mm ⎯ for pipes with a diameter of 355 mm and above.

Melting and heating of ends of welded pipes and parts is carried out simultaneously by means of their contact with working surfaces of heated tool.

Figure 4 shows the process of assembly and butt welding of polyethylene pipes.

a - alignment and fixation of ends of welded pipes in clamps of welding machine; b - mechanical treatment of pipe ends by means of end plate 1; c - check of coaxiality and accuracy of coincidence of ends by value of gap C; g - melting and heating of welded surfaces with heated tool 2; e - sediment of joint before formation of welded joint.

Figure 4 - Process sequence of assembly and butt welding of polyethylene pipes

During welding with heated tool, working surfaces of heater are covered with anti-adhesion layer preventing melt sticking to tool.

Welding joints (operator code) shall be marked with an indelible pencil-marker of bright color (for example: white or yellow ⎯ for black pipes, black and blue ⎯ for yellow pipes).

Marking (joint number and operator code) is applied next to the joint on the side nearest to the factory marking of pipes.

Earthworks

Digging trenches and pits. The depth of gas pipelines depends on the humidity of the transported gas and the presence of dynamic loads over the laid gas pipeline.

Soil dumps during excavation of pits and trenches are placed mainly on one side of excavation at a distance of not less than 0.5 m from the trench edge.

Trenches with laid gas pipelines are filled in two trenches: immediately - after laying the gas pipeline and testing for strength, they fall asleep and knock out the sinuses and sprinkle gas pipelines to a height of 0.2m with leveling of the soil in layers and compaction with manual electric tramways, then fill the rest of the trench. Backfilling of pits is performed after completion of works on arrangement of foundations and underground parts of structures.

When filling trenches, measures are taken against soil damage to insulation on gas pipelines. In places of crossings and intersections of trenches with road surfaces backfilling is performed with careful layer-by-layer compaction of soil up to 95% of its initial density and watered with water.

Laying of gas pipelines

Steel gas pipelines.

Laying is carried out by single pipes (sections) with their subsequent welding into trench or by long-length weaves pre-welded on trench berm.

Single insulated pipes (sections) are lowered into the trench depending on the diameter and thickness of the pipe wall (taking into account the length of the section) using self-propelled lifting means (pipe laying, boom cranes) or using manual rigging (belts, winches, polyspasts).

As load-gripping devices in mechanized operation with single pipes (sections), soft mounting towels or special elastic slings are used. It is not recommended to use open steel ropes, installation "jacks" and other devices for these purposes that do not have soft contact surfaces.

The trench is prepared for laying the gas pipeline immediately before its descent. The preparation of the trench consists in cleaning and planning the bottom, as well as checking the design elevations. Compliance with the basis of the project is carried out with the participation of technical supervision and the customer, according to the results of the inspection an act is drawn up.

Before laying in the trench, the pipes of the section and the weave are inspected and cleaned from the inside of foreign objects, dirt, ice, etc. After inspection and cleaning, pipe ends are closed with inventory plugs to prevent clogging.

One of the possible methods of laying the gas pipeline is the trenchless deepening method using a special machine - a knife pipe deepener, the method is shown in Figure 5

1 - tracked tractor; 2 - cutting knife; 3 - crankcase; 4 is a pipe raft; 5 - roller supports.

Figure 5 - Knife pipe depth

Soil is proportioned by tractor ripper.

The gas pipeline weave is laid out along the laying axis, then its free end is brought to roller supports using a pipe laying device, after which the movement of the pipe deepener begins, which cuts through the slot in the ground, where the weave is lowered. The final operation is the supply for backfilling of soil with the help of grader dumps of the slot-fill. The volume of soil that is pushed outward by the cutting knife when the slit is created is usually sufficient to completely fill it.

When using this method, insulation coating is applied on stacked sheet of steel pipes and its quality is checked [7].

The piping operations include the following operations:

pit fragment for initial deepening of the working element of the pipe-plunger;

installation of a conical blanking at the end of the pipe stack for its filling into the cassette;

deepening of the working element;

cleaning of the working element from roots, soil comas, etc.;

stacking of the weave;

pit passage for depressing the working member.

Cutting of steep shores for the passage of the pipe depth at crossings with a slope of more than 1:2 should be carried out by a bulldozer in the longitudinal direction.

Links of sections up to 40 m long are laid in trenches with the help of at least two pipe-laying or car cranes. Separate pipes of gas pipeline with length of up to 12 m are lowered into trench by one pipe-laying device or autocrane. If it is impossible to use cranes and pipe layouts, links of gas pipelines of small diameters are laid in trenches by installation of mounting trenches above the trench and laid link.

Gas pipelines, fittings and equipment are lowered into the trench smoothly, without jerking and striking the walls and bottom, without sharp differences in vertical and horizontal planes.

After laying in a trench, the gas pipeline must rest on a dense natural or artificial base along its entire length, after laying it is necessary to check the state of insulation, the actual distance between the gas pipeline and intersecting or adjacent structures and communications, as well as the correct location of the gas pipeline. Correctness of laying is checked by leveling of all nodal points of gas pipeline, as well as points of intersection with underground structures.

Pipe joints are assembled at the bottom of the trench and prepared for welding using a hoist suspended from the crossbar through a trench, tripods or a crane. After assembly, the joint is grabbed and then welded. Shaped parts of assemblies, reinforcement and other devices are welded directly into the trench to ensure their alignment with the main gas pipeline and without differences in vertical and horizontal planes.

Polyethylene gas pipelines.

It is recommended to perform works on laying of gas pipelines at ambient air temperature not lower than minus 15 ° С and not higher than plus 30 ° С.

When laying gas pipelines at a lower ambient temperature, it is necessary to organize their heating to the required temperature. This condition can be fulfilled by passing heated air through a gas pipeline prepared for laying. At that heated air temperature must not be more than plus 60 ° С.

When laying polyethylene gas pipelines, it is necessary to take into account the specific features of the pipe material: a high coefficient of linear elongation (1012 times higher than steel ones) and lower mechanical strength and rigidity compared to metal pipes, so it is recommended to lay gas pipelines in the coldest times of the day in summer, and in winter - in the warmest times.

Laying in the trench of gas pipelines is carried out, as a rule, after the end of the process of welding and cooling the connection, as well as the dismantling of welding equipment (positioners).

Before laying, the pipes shall be thoroughly inspected to detect cracks, undercuts, hairlines and other mechanical damages.

It is recommended to close the gas lines open from the ends with inventory plugs during the work. When laying gas pipelines in a trench, measures are taken to reduce stress in pipes from temperature changes during operation:

at the temperature of pipes (ambient air) above plus 10 ° С, the gas pipeline is laid with a free bend ("snake") with backfilling - in the coldest time of day;

at ambient air temperature below plus 10 ° C, it is possible to lay the gas pipeline rectilinear, including in narrow trenches, and fill the gas pipeline in this case at the warmest time of day.

In winter, the gas pipeline is laid on melted soil. In case of trench bottom freezing, trench bottom is filled with sand or fine-granulated melted soil while maintaining standard depth of gas pipeline laying.

When laying gas pipelines in rock and rocky soils and on the frozen bottom of the trench, it is recommended to use fine granulated soil, sand or polymer foam materials (WPT) to protect the gas pipeline from mechanical damage during laying and filling. Pipes with protective coating can be laid directly on the planned bottom of the trench.

The laying of gas pipelines with a diameter of 110 mm or less can be carried out using belts, textile slings, textile ropes, tarpaulin towels. Spans should be taken as per Table 17.

Table 17 - Values of span distances

Designation of distances (spans)

Distance values, m, depending on pipeline diameter, mm

In case of continuous method of gas pipeline laying with diameter more than 160 mm using two pipe layouts it is necessary to act in accordance with diagrams shown in Figure 6.

Note that the thickness of the pipe wall does not affect the selection of these distances, i.e. they should be the same for SDR 11 and SDR 17.6 pipes.

a - with head pipe laying cross-arm; b - with cross-arm at the rear pipe laying; c - with crossarms at both pipe-laying devices; 1 - rear pipe laying; 2 - head pipe laying; 3 is a pipe raft.

Figure 6 - Layouts of gas pipelines from the trench berm using

traverse

When laying gas pipelines in a narrow construction strip, it is recommended to use (in straight sections) the method of installation of the gas pipeline by pulling.

To do this, a storage pad is arranged at the starting point of the route section and a welding station is installed, and a pull winch is installed at the end point of this section. Then a trench is developed along which the weave is stretched as it grows. To reduce friction and traction (which allows increasing the length of the stretched web), as well as avoiding possible mechanical damage to the gas pipeline, guide rollers are installed at the bottom of the trench or a bed of polymeric foam materials is arranged along which the web slides.

Installation of facilities on gas networks.

Assembly assembled and tested in factory conditions, consisting of gate valve, compensator, branch pipes, cases, is installed in gas well and welded to laid gas pipeline.

External surfaces of wells are covered with bitumen insulation, internal surfaces are masked with cement mortar. Manhole neck is installed on well floor panel on cement mortar of 50 grade.

Installed reinforced concrete wells are filled on all sides evenly with the same compaction.

Brick wells are used only in cases when, according to local conditions, it is economically impractical to manufacture prefabricated reinforced concrete wells, as well as when connecting to existing gas pipelines without reducing gas pressure in them.

Manholes of wells on the roadway must be laid flush with the level of road surface, in not paved passages they are set above the level of passage by 5 cm.

Trenches in places of installation of protective carpets embedded in concrete base are filled with sand or extra soil with watering with water and layer-by-layer compaction. If the carpet is installed on the roadway of the street, then its cover should open against traffic .

In gas control stations, the equipment is installed from separate units manufactured and tested in factory conditions. GRP units delivered to the construction site shall have a factory test certificate.

Sealing of welds, flange and threaded joints into walls or foundations is not allowed. When passing the gas pipeline through the wall or foundation, the distance from the weld to the case must be at least 100mm .

3.5 Crossing artificial obstacles

At the underground intersection of railway tracks and roads, it should be provided, as a rule, at an angle of 90 °. It is allowed to reduce the angle of intersection to 45 ° with the corresponding feasibility study.

Horizontal distances from the points of intersection of underground gas pipelines of tram and railway tracks and roads shall be at least:

bridges and tunnels on public railways, tram tracks, roads of categories I-III, as well as pedestrian bridges, tunnels through them - 30 m, and for non-public railways, roads of categories IV-V and pipes - 15 m;

to the switch zone (beginning of points, tail of crosses, points of connection to the rails of suction cables and other intersections of the track) - 4 m for tram tracks and 20 m for railways;

to contact network supports - 3 m.

It is allowed to reduce the specified distances in agreement with the organizations in charge of the crossed structures.

Underground gas pipelines of all pressures at intersections with railway and tram tracks, highways of categories I-IV, as well as main streets of citywide significance should be laid in cases. In other cases, the issue of the need to install cases is decided by the project organization.

Cases must meet the conditions of strength and durability. At one end of the case, a test tube should be provided that extends under the protective device.

The ends of the cases when crossing the gas pipelines of public railways should be brought out at a distance from them not less than the installed SNiP 320195 [9]. When laying inter-village gas pipelines in constrained conditions and gas pipelines in the territory of settlements, it is allowed to reduce this distance to 10 m, provided that an exhaust candle with a sampling device is installed at one end of the case, which is taken at a distance of at least 50 m from the edge of the roadbed (axis of the extreme rail at zero elevations).

In other cases, the ends of the cases shall be located at a distance:

not less than 2 m from the extreme rail of the tram track and 750 mm gauge railways, as well as from the edge of the roadway of the streets;

not less than 3 m from edge of a drainage construction of roads (a ditch, a ditch, a reserve) and from an extreme rail of the railroads not of general use, but not less than 2 m from a sole of embankments.

When gas pipelines cross the 1520 mm gauge public railway lines, the depth of gas pipeline laying shall correspond to SNiP 3201.

In other cases, the depth of laying of the gas pipeline from the bottom of the rail or the top of the road cover, and if there is an embankment, from its bottom to the top of the case should meet safety requirements, but be at least:

when performing works using an open method -1.0 m;

during works performance by method of forcing or inclined-directional drilling and shield penetration - 1.5 m;

during works execution by puncture method - 2.5 m.

The wall thickness of the pipes of the steel gas pipeline when crossing the public railways should be 2-3 mm more than the design one, but not less than 5 mm at distances of 50 m each way from the edge of the roadway (the axis of the extreme rail at zero elevations).

Polyethylene pipes of not more than SDR 11 with a safety factor of not less than 2.8 shall be used for polyethylene gas pipelines in these sections and at the intersections of roads of categories I - III.

In the tubular space of the case, it is allowed to lay an operational communication cable, telemechanics, telephone, and an electrical protection drain cable intended for servicing the gas supply system.

The height of the above-ground gas pipelines at the intersection with electrified and non-electrified railway tracks, with tram tracks, roads, trolleybus contact network should be taken in accordance with the requirements of SNI8980 * [6].

When crossing the water barrier, the gas pipeline is laid above ground on a cable suspension below the automobile bridge along the river by 30 m. The gas pipeline is freely located on the cables, which ensures its movement in the longitudinal lines of the route in the directions. To prevent transverse movements and deformation, the gas pipeline is fixed on the bases of the suspension crossing. Before and after crossing to prevent accidents on the gas pipeline we install shutoff valves [24].

3.6 Internal gas supply devices

Residential buildings, utilities and industrial enterprises are supplied with gas from low or medium pressure gas pipelines through GRP or GRU. The gas supply scheme includes branches from the distribution gas pipeline, gas inlet to the consumer, inlet gas pipeline in the casing through the building wall, and internal gas pipelines.

Gas pipelines are introduced into residential and public buildings through non-residential rooms accessible for pipe inspection. At the gas pipeline inlet to the building, a disconnecting device is placed, which is mounted outside the building. The installation site shall be available for maintenance and quick shutdown of the gas pipeline.

The possibility of installing gas equipment and laying gas pipelines in specific buildings should be determined in accordance with the construction codes and rules for the design of the corresponding buildings.

Gas pipelines laid inside buildings and structures should be provided from steel pipes.

For connection of mobile units, portable gas burners, gas devices, instrumentation and automation devices it is allowed to provide rubber and rubber-fabric hoses. When selecting hoses, their resistance to the transported gas at the specified pressure and temperature should be taken into account.

Connection of pipes should be provided, as a rule, on welding. Detachable (carving and flange) connections are allowed only in installation sites of shutoff valves, gas devices, instrument, regulators of pressure and other equipment.

The installation of split connections of gas pipelines should be provided in places accessible for inspection and repair.

The laying of gas pipelines inside buildings and structures should be provided, as a rule, open.

It is not allowed to provide for laying of gas pipelines in rooms belonging to categories A and B for explosion and explosion-fire hazard; in explosive areas of all premises; in basements; in warehouses of explosive and combustible materials; in substation and switchgear rooms; through ventilation chambers, shafts and channels; elevator shafts; rooms of garbage collectors; chimneys; through rooms where the gas pipeline can be subject to corrosion, as well as in places where aggressive substances may be exposed and in places where the gas pipelines can be washed by hot combustion products or come into contact with heated or molten metal.

For internal gas pipelines with temperature effects, the possibility of compensation of temperature deformations should be provided.

Disconnecting devices on gas pipelines in the production premises of industrial enterprises, consumer service enterprises of a production nature should provide for:

at the inlet of the gas pipeline inside the room ;

on branches to each unit;

before burners and igniters;

on blowdown pipelines, at the points of their connection to gas pipelines.

If there is a gas meter or GRU inside the room located from the gas pipeline inlet at a distance of not more than 10 m, the gate valve or valve in front of the GRU or meter is considered as a disconnecting device at the inlet.

The need to take into account gas consumption and the choice of an accounting system at gas supply facilities should be determined in accordance with the instructions of the "Rules for the Use of Gas in the National Economy" approved by the Ministry of Gas Industry and the "General Provisions on the Procedure for Accounting and Control of Fuel Consumption, Electric and Thermal Energy for Industrial, Transport, Agricultural and Public Utilities Enterprises and Organizations."

By decision of the executive authorities of the constituent entities of the Russian Federation on the procedure for accounting for gas consumption by consumers and regulating gas prices in gasified residential buildings, it should be possible to take into account gas consumption by each subscriber by installing a gas flow meter on the gas pipeline (in an apartment, individual house).

Instruments for gas flow metering shall be located in FRG or gasified rooms. It is allowed to place instruments to take into account gas consumption in other rooms not lower than II degree of fire resistance, which have exhaust ventilation. It is allowed to install not more than two gas meters in parallel on one gas pipeline.

In existing and reconstructed residential buildings, it is allowed to provide for transit laying of low-pressure gas pipelines through living rooms in the absence of the possibility of another gasket.

Transit gas pipelines within residential premises shall not have threaded connections and fittings.

It is not allowed to provide for the laying of gas pipeline risers in residential rooms and sanitary units.

The installation of disconnecting devices on gas pipelines laid in residential buildings and public buildings (with the exception of catering enterprises and industrial consumer services enterprises) should include:

for disconnection of risers serving more than five floors;

before counters (if you cannot use the switch-off device at the input to disable the counter);

upstream of each gas device, furnace or plant;

on branches to heating furnaces or appliances.

On gas supply lines to heating furnaces and other similar equipment, two disconnecting devices should be installed in series: one for disconnection of the device (equipment) as a whole, the other for disconnection of burners.

On the gas supply lines to the gas devices, in which the disconnecting device in front of the burners is provided in their design, it is necessary to install one disconnecting device.

The need to install devices for disconnecting risers (entrances) of 5-storey and less residential buildings is decided by the design organization depending on local specific conditions, including the number of storeys of buildings and the number of apartments to be disconnected in case of emergency and other work.

Devices provided for disconnection of risers (entrances) should be installed as far as possible outside the building.

The distance from gas pipelines laid open and in the indoor floor to building structures, process equipment and pipelines of other purpose should be taken on the condition that it is possible to install, inspect and repair gas pipelines and fittings installed on them, while gas pipelines should not cross ventilation grids, window and door openings. In production rooms, it is allowed to cross light openings filled with glass blocks, as well as lay a gas pipeline along the bindings of non-opening windows.

Distances between gas pipelines and utilities of power supply located inside the premises in places of approach and intersection should be taken in accordance with PUE [50].

Laying of gas pipelines in places of people passage should be provided at a height of not less than 2.2 m from the floor to the bottom of the gas pipeline, and in the presence of thermal insulation - to the bottom of the insulation.

Installation of open gas pipelines to walls, columns and floors inside buildings, boiler frames and other production units should be provided by means of brackets, clamps, hooks or suspensions, etc., at a distance ensuring the possibility of inspection and repair of the gas pipeline and fittings installed on it.

The distance between the supporting fixtures of gas pipelines should be determined in accordance with the requirements of SNiP 42012002 [2].

Vertical gas pipelines at the intersection of building structures should be laid in cases. The space between the gas line and the case must be sealed with a ground pack, rubber sleeves or other elastic material. The end of the case shall extend no less than 3 cm above the floor and its diameter shall be assumed so that the annular gap between the gas pipeline and the case is not less than 5 mm for gas pipelines of nominal diameter not more than 32 mm and not less than 10 mm for gas pipelines of larger diameter.

Gas devices and gas burners should be connected to gas pipelines, as a rule, by a rigid connection.

Connection to the gas pipeline of gas devices, as well as portable and mobile gas-firing devices and units installed in the shops of industrial enterprises, can be provided after the disconnecting crane with rubber-fabric hoses. Rubber-fabric hoses for connection of domestic gas devices and laboratory burners shall not have butt joints [7].

On the gas pipelines of industrial (including boiler houses), agricultural enterprises, consumer service enterprises of a production nature, blowdown pipelines should be provided from the most remote sections of the gas pipeline from the injection point, as well as from the branches to each unit before the last disconnecting device in the gas flow.

The blowdown pipe diameter shall be at least 20 mm. After the disconnecting device, a nozzle with a sampling valve should be provided on the blowdown pipeline, if a nozzle for connecting the igniter cannot be used for this.

If the building is located outside the lightning protection area, the purge piping leads should be grounded.

3.6.1 Gas supply of residential buildings

Installation of gas stoves in residential buildings should be provided in kitchen rooms with a height of at least 2.2 m, having a window with a window (frame), an exhaust ventilation channel and natural lighting. We accept that gas stoves of "PG4" grade will be installed during gas supply. This is a four-burner stove consisting of a table, oven and drying cabinet. The heat load on each burner is 1600 kcal/h, and the oven is 3200 kcal/h. Supply is made from pipes D = 20.8 mm. At the same time, the internal volume of kitchen premises should be at least 15 m ³.

In existing residential buildings, gas stoves can be installed:

in rooms of kitchens not less than 2.2 m high and not less than the volume specified in the absence of a ventilation channel and the impossibility of using chimneys as such channel, but in the room there is a window with a window or frame in the upper part of the window;

in kitchens with inclined ceilings having a height in the middle part of at least 2 m, the installation of gas equipment should be provided in the part of the kitchen where the height is at least 2.2 m.

In existing residential buildings owned by citizens on personal property rights, it is allowed to install gas stoves in premises that meet the requirements, but have a height of less than 2.2 m up to 2 m inclusive, if these premises have a volume of at least 1.25 times the normative. At the same time, in houses that do not have a dedicated kitchen, the volume of the room where the gas stove is installed should be twice as large as specified.

If these requirements cannot be met, the installation of gas stoves in such premises may be allowed on a case-by-case basis, as agreed by the local sanitary supervision authority.

The possibility of installing gas stoves, heating and other devices in buildings located outside the residential building is decided by the design organization and operational organization of the gas economy, taking into account specific local conditions, including the availability of gas for these purposes. At the same time, the premises in which the installation of gas devices is provided must meet the requirements for the premises of residential buildings where the placement of such devices is allowed.

Wooden non-plastered walls and walls of other combustible materials at the places of installation of slabs should be insulated with non-combustible materials: plaster, roofing steel on asbestos sheet at least 3 mm thick, etc. The insulation shall extend beyond the plate dimensions by 10 cm on each side and not less than 80 cm on top.

The distance from the slab to the non-combustible insulated walls of the room shall be not less than 7 cm; the distance between the plate and the opposite wall shall not be less than 1 m.

For hot water supply, flow or capacitive gas water heaters should be provided, and for heating - capacitive gas water heaters, small-gauge heating boilers or other heating devices designed for gas fuel operation.

The storey of residential buildings in which the installation of the specified gas devices and devices is allowed should be accepted in accordance with SNiP 2.08.0189 * [10].

The arrangement of chimneys shall comply with the requirements of SNiP 2.04.0591 * [21] as for heating furnaces.

Installation of water heaters should be provided in kitchens and non-residential rooms intended for their placement. Installation of these devices in bathrooms is not allowed. The issue of the need to relocate gas water heaters from the bathrooms in which they were placed in accordance with previously existing standards to kitchens or other non-residential premises of a residential building during the reconstruction of a house or gas supply system should be decided on a case-by-case basis by the project organization in agreement with local operating organizations of the gas economy.

In existing residential buildings, it is allowed to provide for the installation of heating gas devices in individual corridors.

The distance from the protruding parts of gas burners or fittings to the opposite wall shall not be less than 1 m.

If there are no non-combustible materials walls in the room, it is allowed to provide for installation of a flow water heater on plastered, as well as on walls lined with non-combustible or hard-burning materials at a distance of at least 3 cm from the wall.

The surface of hard-burning walls should be insulated with roofing steel along an asbestos sheet with a thickness of at least 3 mm. The insulation shall extend beyond the dimensions of the water heater housing by 10 cm.

If there are no non-combustible walls in the room, it is allowed to install the above heating devices near the walls at a distance of not less than 10 cm from the wall.

A room designed to accommodate a gas water heater, as well as a heating boiler or heating apparatus, the removal of combustion products from which is provided for in the chimney, should have a height of at least 2 m. The volume of the room should be at least 7.5 m3 when installing one device.

All gas instruments shall not be placed in basements (basements).

3.6.2 Gas supply to production plants and boilers

When designing gas equipment of boiler houses or when converting existing boiler houses to gas fuel, in addition to the requirements of SNiP 2.04.0887 * [3], the requirements of SNiP II3576 [15] and PB 1057403 "Rules for the construction and safe operation of steam and water-fired boilers" approved by the USSR Gosgortekhnadzor should be followed. [24]

The gas supply source is designed high-pressure steel pipeline Ø1143.0 mm. The hourly flow rate of this boiler house is 2949 m3/h.

In the boiler room there are installed 3 steam boilers DE, which are equipped with gas-oil burners GM. [52]

Gas control unit is provided to reduce gas pressure from high to medium.

Combustion products removal from boilers is provided through designed individual chimneys (double insulated).

Blow-down and discharge pipelines shall be 1 m above the roof.

Check of shutoff valves prior to ignition for seal tightness shall be performed in accordance with the procedure established by the instruction developed by the operating organization.

Automation of gas supply to the boiler house.

Burner safety automation provides:

normative process of operation in automatic mode, excluding the need to intervene in this process of maintenance personnel.

control of safety parameters of combustion processes in automatic mode.

Burner safety automation stops fuel supply at:

increasing or decreasing the pressure of the gaseous fuel upstream of the burner;

reducing the air pressure upstream of the burner;

extinguishing of flares burned;

by the signal of failure of the boiler safety automation.;

faults of protection circuits, including voltage failure.

Safety automation of hot water boilers stops the fuel supply at:

increase of water temperature at boiler outlet;

increasing or decreasing the water pressure at the boiler outlet;

faults of protection circuits, including voltage failure.

Automation of hot water boilers provides:

maintaining a predetermined water temperature at the boiler outlet;

maintaining minimum set value of water temperature at boiler inlet (mixing valve);

control of boiler circulation pump.

The project provides for:

monitoring of process parameters using local display devices;

control of network water temperature depending on ambient air temperature;

automatic commissioning of boilers depending on the load of the heat network;

automatic control of heat network pumps by means of a logic controller;

control of CO (100mg/m ³) and methane (10% NCPR);

automatic closing of the solenoid valve on the gas pipeline and fuel pipeline at power outage, at the signal of the OPS device, at the signal of increase in the content of CO (100mg/m ³) and methane (10% of NCRM);

local light-and-sound alarm about violation of parameters of operation with storage of the root cause;

gas pressure recording (high pressure);

gas pressure recording (medium pressure);

gas temperature recording;

recording of liquid fuel level;

remote light-and-sound alarm in the room with permanent stay of people;

local light alarm in the pump room.

Gas burners of industrial plants, steam and hot water boilers using gas fuel shall comply with the requirements of SNiP 2.04.08-87 * [3]

Distance from protruding parts of gas burners or fittings to walls or other parts of the building, as well as to structures and equipment shall be not less than 1 m horizontally.

Gas-fuelled boilers and chimneys shall be provided with blast valves. Blast safety valves should be provided at the top of the furnace and chimneys, as well as in other places where gas accumulation is possible.

Ventilation of boiler houses, workshops of industrial and agricultural enterprises, buildings of consumer service enterprises of a production nature must comply with the requirements of building codes and rules for production located in them.

Gasified boilers shall be equipped with instrumentation, safety automation and automatic control in accordance with the requirements of SNiP II3576 [15].

Gasified production units shall be equipped with instrumentation for measurement:

gas pressure at the burner or group of burners after the last (downstream) disconnecting device and, if necessary, at the unit;

air pressure in the air duct at the burners after the last gate or throttle valve and, if necessary, at the fans;

vacuum in the furnace and, if necessary, in the chimney to the gate.

Instrument placement shall be provided at the measured parameter control point or on a special instrument panel.

When installing devices on the instrument board, it is allowed to use one device with a switch to measure parameters at several points.

3.7 Corrosion protection

For steel gas pipelines, protection against corrosion caused by the environment and wandering currents should be provided.

Corrosion protection of underground gas pipelines should be designed in accordance with the requirements of GOST 9.6022005 [8] and regulatory and technical documentation approved in accordance with the established procedure.

Material for protective coatings shall comply with the requirements of SNiP 2.04.0887 * [3].

On underground gas pipelines within settlements, it should be provided for the installation of checkpoints with intervals between them of no more than 200 m, outside the settlements - no more than 500 m, on arable land - established by the project. In addition, the installation of control points should be provided at the intersection of gas pipelines with underground gas pipelines and other underground metal engineering networks (except power cables), electric rail tracks (at the intersection of more than two rail tracks - on both sides of the intersection).

At the same time, at the crossings of gas pipelines between each other and with other underground networks, the need to install control and measurement points is decided by the design organization depending on corrosive conditions.

Disconnecting devices, condensate collectors and other equipment and structures on gas pipelines can be used to measure the protective electric potential of gas pipelines.

During electrochemical protection of gas pipelines it is necessary to provide insulating flange connections (IFS):

at the inlet and outlet of the gas pipeline from the ground and GRP, at the introduction of gas pipelines into buildings where electrical contact of the gas pipeline with the ground through metal structures of the building and engineering networks is possible, at the introduction of the gas pipeline to the object that is the source of wandering currents;

for partitioning of gas pipelines;

for electrical insulation of individual sections of the gas pipeline from the rest of the gas pipeline.

If the resistance to spreading of the GRP grounding loop is more than 50 m, it is allowed not to install IFS on gas pipelines.

Research Part

4.1 Comparative Characteristics of Gas Detectors

During the operation of boilers and other thermal devices using gaseous, liquid and solid fuel in the air of the premises, an excessive concentration of carbon monoxide CO and methane CH4 may occur, which can lead to poisoning of people or the threat of an explosive situation.

In 2002 The Gosgortekhnadzor of Russia made some changes to the Instruction on the control of carbon monoxide content in the premises of boiler houses RD1234100 [11], the main provisions and requirements of which are widely used in the operation of fuel combustion plants in boiler houses.

Gas detectors (gas detectors) are a device used to control the content of various gases in the atmosphere. They are designed to automatically control the gas content of hazardous gases in communal, domestic and industrial premises. If the specified value of concentration of hazardous gases is exceeded, sound and light signal are transmitted. Gas detectors can be a control element of shut-off valves.

4.1.1 Causes of gas pollution

The reasons for the occurrence of increased content of CO and CH4 in the air of the premises are violations in the operation of the unit, which occur as a result of:

inconsistent operation of blast fan and smoke pump;

vacuum fluctuations in the working volume due to the burner, burner tunnel destruction, violation of the process of mixing of fuel with air;

the mutual influence of pressures in the chimneys of installations having a common chimney when one of them is disconnected;

destruction of chimneys when groundwater (or water) enters them

from other communications );

leaks from pipes and other elements of boiler heating surface, economizers;

burning soot on the heating surface of boilers operating on solid and liquid fuel;

disturbances in the setting of devices and regulators of the ratio "gas air," rarefaction in the working volume, fluctuations in the value of thermal load ;

disturbances in density of heat fences and headset at positive pressure in the working chamber ;

changes in the heat of fuel combustion and, as a result, violation of the setting of devices for automatic control of combustion processes;

violations of the density of gas shutoff devices, as well as flange, threaded, welded connections of gas pipelines.

4.1.2 Requirements for control devices for carbon monoxide and methane content in the air of the working area

The following basic requirements apply to carbon monoxide and methane monitoring devices:

instruments (annunciators/gas analyzers) shall carry out continuous monitoring of CO content (in the working area) and CH4 (in the upper room volume) with signalling of excess of standard concentration thresholds;

the sensitivity of instruments (annunciators/gas analyzers) must be selective, not cross-sensitive to other toxic and combustible gases;

alarm is triggered at two thresholds (levels) of CO concentration in the working area. Alarm of the first level - when the CO concentration in the working zone reaches 20 ± 5 mg/m3 (MPC r.z.); in this case, the intermittent audio signal is turned on. Alarm of the second level - when the CO concentration reaches 100 ± 25 mg/m3 (5 MPC p.z.); at that continuous light and sound signals are switched on;

signalling by CH4 (natural gas) is triggered at the threshold level of 10% or 20% of the lower concentration flame propagation limit (LNFR), lower explosion limit (LFR);

instruments (annunciators/gas analyzers) shall have a program for actuation (disconnection) of emergency ventilation or automatic shutdown of fuel supply until provision of normal concentrations of CO and CH4 at permanent workplaces, in the upper volume of rooms;

alarm from several instruments (annunciators/gas analyzers) is output to the common panel;

safety of the structure shall comply with the requirements of GOST 12.2.007.075 [29];

instruments (annunciators/gas analyzers) must have a certificate of compliance with GOST R and permission to use the Gosgortekhnadzor of Russia;

service life of the hazardous components monitoring system is as long as possible, instruments (annunciators/gas analyzers) must work reliably at temperatures from -5 to + 50 С.

The great need for CO and CH4 concentration detectors in the atmosphere of production premises, primarily in boiler rooms, involves the use of inexpensive, reliable, compact devices (annunciators/gas analyzers) with a sufficient service life and adapted for regulated verification both in laboratory conditions and at the installation site.

4.1.3 Characteristics of Carbon Monoxide (CO) Gas Gas Detectors/Analyzers

The most widespread of domestic signaling devices WITH is a signaling device of SOU1. The signaling device of gas contamination of SOU1 is intended for the alarm system of excess of the maximum-permissible concentration (MPC) of carbon oxide (CO) in air and formations of the operating influence for turning on (shutdown) of actuation mechanisms by means of contacts of the relay. The signaling device of SOU1 carbon monoxide has the electrochemical principle of action, two thresholds of sensitivity (20 and 100) with an exit of the modulated signal to safety valve (gas cut-off) or the ventilation system. If necessary, the gas valve may be further installed. The competitiveness of the device reduces the relatively short service life of the sensor (3 years). Scope of SOO1 application: in boiler rooms; in the residential sector of public utilities, as well as in mines, wells, car parks, in covered garages and other facilities where carbon monoxide can be released and accumulated. SOU1 signaling device advantages: "dry" contacts by means of which it is possible to include and turn off ventilation and a siren and also other devices; small in size and mass; a good price.

The characteristics of carbon monoxide gas detectors/analyzers are shown in Table 18.

The ESSASO gas analyzers are relatively more reliable. ESSASO gas analyzers use durable cells of English production. Optimum on a ratio of price/quality it is possible to call SZTs2 signaling device for continuous control of contents WITH in air of the working area of industrial and utility companies. The NWC2 detector uses a Japanese-made thermocatalytic sensor.

Seitron gas detectors such as RGD and RGI have been used for several years to control the content of carbon monoxide in industrial and communal boiler houses, metallurgy, mechanical engineering, etc. These compact devices, already installed in more than 1,500 domestic boiler houses, fully meet the requirements of Gosgortekhnadzor: a stationary installation, a 2-threshold alarm system, access to the actuators of ventilation and gas supply disconnection systems, the possibility of configuration with proprietary gas valves, a relatively low price, long service life.

In boilers using natural gas as fuel, it is advisable to control CH4 methane in addition to carbon monoxide (CO). Control of methane and carbon monoxide content in the air of the working zone can be carried out in two ways:

two monogas instruments (the boiler room is equipped with two separate instruments: a switch on CO and a switch on CH4)

one switch that monitors carbon monoxide (CO) and methane (CH4). simultaneously.

In both cases, during installation, it should be taken into account that the sensors on CO and CH4 are attached at different heights. The sensor or indicator for methane should be mounted at a distance of 1020 cm from the ceiling, while the indicator for carbon monoxide should be hung at a height of 150180 cm from the floor. Therefore, the instrument (alarm/gas analyzer) monitoring both gases must be equipped with a remote sensor for methane. The characteristics of methane gas detectors/analyzers are given in

Seitron also produces methane (natural gas) annunciators tuned to operate at a CH4 concentration in the upper part of the workshop atmosphere (boiler room) of 10% NPV. Annunciators have the same dimensions and weight as instruments measuring CO concentration; sensor service life is not less than 5 years.

Characteristics of carbon monoxide and methane gas gas detectors/analyzers. In boilers using natural gas as fuel, annunciators controlling continuously and carbon monoxide and methane are more popular, their characteristics are shown in Table 20.

When choosing a gas analyzer or signaling device of gas contamination it is necessary to consider service life of the device and a measuring element (cells, the sensor, the sensor). But in any case, do not forget that anyone, whatever you choose the alarm, needs to be checked once a year. Annual mandatory state verification of gas detectors is carried out in specialized centers of CSM (Center for Standardization and Metrology), which can be found in every major city.

4.1.4 Requirements for maintenance, repair, verification of gas and gas detectors

Maintenance and repair of control devices shall be carried out in accordance with the procedure and within the time limits stipulated by the manufacturer's technical documentation for these devices. Testing and checks of instruments shall be carried out according to the manufacturer's methodology. Once a year it is necessary to perform state verification of annunciators with control mixtures at actuation levels. Repair and maintenance of monitoring devices shall be carried out by trained personnel who have passed certification in the qualification commission of a specialized organization or manufacturer. The participation of a representative of the body of the State Gortekhnadzor of Russia in the work of the commission on certification of these personnel is not necessary. At the end of the service life of the monitoring device (sensor), its diagnostics are carried out in order to establish the possibility of further operation or replacement. The boiler room personnel shall ensure the serviceability of the monitoring devices with the mark in the watch log every day.

Many enterprises operating fuel-using thermal equipment already at the design stage require a sufficient number of detectors for CO and CH4 in the workshop to guarantee the safety of the units and maintenance personnel.

The choice of gas detectors is not only necessary, but also responsible. Therefore, in this case, it is necessary to contact specialized organizations with experience in working with gas safety devices.

The appearance of methane gas detectors/analyzers is shown in Table 21.

4.1.5 Recommendations for arrangement of annunciators and safety systems

Selection of the location of the annunciator (system), valve (or other devices), DRC (if any) shall be performed in accordance with the following requirements:

for a signaling device on CH4 methane the block of the sensor of a signaling device to arrange in the place of the most probable congestion of gas, on a wall, in vertical position, at distance not less than 1 meter from edge of the gas equipment and at distance of 1020 cm from a ceiling;

for LNG detector the sensor unit is located on the wall, in vertical position and at a distance of 1020 cm from the floor;

for annunciator on CO install the detector unit on the wall in vertical position at a distance of 1.5-1.8 m from the floor in the immediate vicinity of the place of installation of gas-using equipment, but not closer than 2 m from the places of supply air supply and open windows.

Do not install the annunciator in the immediate vicinity of heat sources (heating devices). Figure 7 shows the option of placing the gas detector in a private house.

Figure 7 - Variant of gas content detector in a private house

Safety of life

5.1 Analysis of hazardous and harmful production factors in accordance with GOST 12.0.00399 and measures to prevent them

During installation of gas supply systems, a number of hazardous and harmful production factors affect the body and general working condition of workers, which by the nature of their action are divided into the following groups: [19]

physical;

chemical;

biological;

psychophysiological.

Physical factors:

1 Moving machines and mechanisms (lifting and transportation equipment, drilling rigs, cars, pipe laying), unprotected moving parts of production equipment, moving products, blanks, materials (pipelines, heat pumps, fittings), collapsing earthen bed (edges of trenches and pits) - during loading, installation and earthworks.

Activities:

Occupational safety training in accordance with GOST 12.0.00490 (as amended in 2010) [33] "System of occupational safety standards. Organization of occupational safety training. General provisions "; preparation and organization of work sites and fencing of hazardous areas in accordance with GOST 2340778 (as amended 2010) [18] "Fencing inventory of construction sites and construction and installation work areas. Specifications "; use of safety signs to designate hazardous areas according to GOST R 12.4.0262001 "Signal colors, safety signs and signal markings" [48]; medical examination and training of persons admitted to work; mechanization and automation of loading and unloading operations; correct placement and stacking

loading of goods in work areas and in vehicles according to GOST 12.3.00976 (as amended 2010) "System of occupational safety standards. Loading and unloading works. General safety requirements "[33]; operation of production equipment in accordance with GOST 12.2.00391 "Production equipment. General safety requirements "and operational documents; compliance with requirements for power transmission protection zones, utility and power supply units according to GOST R 12.1.0192009 (as amended in 2011) "Electrical safety. General requirements and nomenclature of protection types "[42]; personal protective equipment (PPE) - overalls according to GOST 12.4.01683 (with revision 2010) "Special protective clothing. Nomenclature of quality indicators "[32], sleeves or gloves GOST 2884690 (with amendments 2010) [22], building helmets GOST 12.4.08784 (with amendments 2010) [31], overalls GOST 12.4.10080 (with amendments 2010) [13]. Excavation during the construction of gas pipelines should be carried out in accordance with the requirements of GOST R 12.3.0482002 (as amended in 2011) "SSBT. Construction. Excavation by hydromechanization. Safety requirements "[40].

2 Increased dust and gas content of the working zone air (operation: electric welding).

Activities:

As personal protective equipment, protective cascades are provided, GOST R 12.4.2452007 (with revision 2010) [30].

3 Increased value of voltage in electrical circuit, closure of which can occur through human body (welding cables, welding unit, electrical equipment) - during welding operations and operation of electrical equipment.

Activities:

In electric welding devices and their power sources, reliable fences of energized elements are installed, in accordance with GOST 2340778 (with revision 2010) [9]; application of safety signs according to GOST R 12.4.0262001 (as amended in 2010) [48] during the entire period of operation of electrical installations; only personnel authorized to work with electrical installations are allowed to connect the equipment to the electrical network; collective protection means (protective grounding) are used, according to GOST 12.1.03081 (with revision 2010) [41]; automatic disconnection of electrical equipment according to SNiP 12032001; personal protective equipment of electric welders is used: protective helmets as per GOST 12.4.12883 (with revision 2000) [39], protective hoses with crags as per GOST 12.4.01075 (with revision 2010) [36], shield as per GOST 12.4.11982 (with revision 2010) [38]; electrical lighting of construction sites and sections shall be supplied from AC and DC mains:

a) for lighting devices (searchlights and lighting fixtures) of general lighting with a voltage of not more than 220 V (in agreement with the bodies of the State Energy Supervision, the use of special lighting devices with a voltage of more than 220 V is allowed);

b) for fixtures of stationary local lighting installed at the height of 42 V available for accidental touches;

c) for hand-held portable lamps - 12 V.

4 Increased temperature of equipment surfaces, materials (welding) - during welding operations.

Activities:

Workers for hand protection are provided with hoses and crags as per GOST 12.4.01075 (with revision 2010) [36], workwear as per GOST 12.4.01683 (with revision 2010) [32].

Chemical factors:

1 Toxic (welding aerosol, evaporation from corrosion insulation, 10% ethylene glycol solution) - during welding and insulation works. Pathways of penetration into the human body through respiratory organs, gastrointestinal tract, skin and mucous membranes.

Activities:

Welders and workers are supplied with respiratory protection devices according to GOST 12.4.0342001 (with amendments 2010) [37] and respiratory air isolating devices according to GOST R 12.4.18697 (with amendments 2010) [28].

Psychophysiological factors:

1 Physical overloads during installation work (transfer of tools and devices of great gravity, excessive transitions, uneven distribution of muscle load in constrained conditions) - during operation and transfer of weights.

Activities:

The use of automatic and semi-automatic mechanisms and devices for the movement and transfer of goods.

2 Neuropsychiatric factors (monotonicity of labor, emotional overload, mental overvoltage, overvoltage of analyzers).

Activities:

Work breaks are arranged, rooms for rest and psychological unloading are equipped.

5.2 Safety requirements during gas hazardous operations

In order to eliminate these hazards and hazards from affecting human health, a set of protection measures is being developed.

All works on installation of gas pipelines begin after acceptance of the facility for installation according to the act and are carried out in accordance with safety rules of PB 1252903 [23] gas distribution and gas consumption systems.

Managers, specialists and workers trained in gas hazardous work technology, rules for using personal protective equipment (gas masks and rescue belts), methods of providing first (pre-medical) assistance, certified and verified knowledge in the field of industrial safety [23] are allowed to perform gas hazardous work.

Initial training of workers in safe methods and methods of work, including those allowed for gas hazardous work, should be carried out in accredited organizations (subdivisions of organizations) engaged in training personnel in the field of activity.

Persons with an appropriate (work profile) secondary or higher education can undergo a primary knowledge test without additional training.

Practical skills should be developed at training sites with existing gas pipelines and gas equipment or at workplaces in compliance with safety measures, according to programs agreed with the territorial bodies of the Gosgortekhnadzor of Russia [23]

The regulation on quality control and safe performance of works (production control) should provide for:

Frequency and scope of inspections;

measures taken to address the violations identified;

analysis of the causes of violations with a view to their elimination and prevention;

verification of the activities of the organization's departments to ensure that they comply with the requirements of the Rules and Instructions at the workplace.

Gas hazardous works include:

connection (tie-in) of newly built external and internal gas pipelines to the existing ones, disconnection (cutting off) of gas pipelines;

start-up of gas in gas pipelines when commissioning, degreasing, after repair (reconstruction), commissioning of GRP, GRPB, SRP and GRU;

maintenance and repair of the operating external and internal gas pipelines, the gas equipment of GRP, GRPB, SRP and GRU, gas-using installations;

blowing of gas pipelines when gas-using plants are switched off or on;

round of external gas pipelines, GRP, GRPB, SRP and GRU, repair, survey and airing of wells, check and pumping of condensate from kondensatosbornik;

rupture in places of gas leaks until their elimination;

repair with performance of hot (welding) work and gas cutting (including mechanical) on functioning gas pipelines, the equipment of GRP, GRPB, SRP and GRU.

Gas hazardous works must be performed by a team of workers consisting of at least 2 people under the guidance of a specialist.

Gas hazardous work in wells, tunnels, headers, as well as in trenches and pits with a depth of more than 1 m shall be carried out by a team of workers consisting of at least 3 people.

For the performance of gas hazardous works, a work permit of the established form is issued, providing for the development and subsequent implementation of a set of measures for the preparation and safe conduct of these works.

Persons who have the right to issue work permits for the performance of gas hazardous works are appointed by order of a gas distribution organization or organization with its own operational gas service, from among senior employees and specialists who passed the exam and have experience in the gas industry for at least one year.

Periodically repeated gas hazardous work, carried out, as a rule, by a constant composition of workers, can be carried out without issuing a work permit according to approved production instructions.

Gas start-up in gas networks of settlements during primary gasification, in high-pressure gas pipelines; works on connection of high and medium pressure gas pipelines; repair work in GRP, GRPB, SRP and GRU with application of welding and gas cutting; repair works on medium and high pressure pipelines (under gas) using welding and gas cutting; reduction and restoration of gas pressure in medium and high pressure gas pipelines associated with disconnection of consumers; disconnection and subsequent switching on of gas supply to industrial production are carried out according to a special plan approved by the technical head of the gas distribution organization.

The plan indicates the sequence of operations; the placement of people; technical equipment; measures to ensure maximum safety; persons responsible for carrying out gas hazardous works (separately in each work area) and for general management and coordination of actions.

According to the plan, a separate work permit is issued to each person responsible for gas hazardous works.

As-built documentation (drawing or copy of as-built documentation) shall be attached to the plan and work permits indicating the place and nature of the work to be performed.

Before the start of gas hazardous works, the person responsible for their performance shall check the compliance of the documentation with the actual location of the gas pipeline.

Work permits for gas hazardous works shall be issued in advance for necessary preparation for operation.

The work permit indicates the duration of its validity, the time of start and end of work.

If it is impossible to complete it within the prescribed period, the permit for gas hazardous work shall be extended by the person issuing it.

The person responsible for carrying out gas hazardous works, receiving a work permit, is signed in the registration log of work permits.

Work permits must be stored for at least one year from the moment of its closure.

Permit orders issued for the initial gas start-up, tie-in to the existing gas pipeline, disconnection of gas pipelines with brewing tightly at the branch points are kept permanently in the executive and technical documentation for this gas pipeline.

Prior to the start of gas hazardous works, the responsible person must instruct all workers about the technological sequence of operations and the necessary safety measures. After that, each employee who received the instruction must sign in the permit.

Gas hazardous work shall normally be performed during the day.

In areas of the northern climatic zone, gas hazardous work is carried out regardless of the time of day.

Gas pipelines not put into operation within 6 months from the date of testing shall be re-tested for tightness.

The operation of electrochemical protection units, the state of smoke removal and ventilation systems, the completeness and serviceability of gas equipment, valves, measuring and automation tools are additionally checked.

The connection of the newly constructed gas pipelines to the existing ones is made only before the gas start-up.

All gas pipelines and gas equipment shall be externally inspected and tested (by air or inert gases) by the gas start-up team prior to connection to the existing gas pipelines and after repair.

Excess air pressure in the connected gas pipelines must be maintained until the work on their connection (tie-in) begins.

When repairing in a gas-laden environment, a non-ferrous metal tool should be used that excludes sparking.

The working part of the black metal tool must be abundantly lubricated with solidol or other similar lubricant.

The use of electric tools giving a spark is not allowed.

Footwear at the persons performing gas dangerous works in wells, rooms of GRP, GRPB, GRU should not have steel horseshoes and nails.

When performing gas hazardous works, use portable lamps in explosion-proof design with a voltage of 12 volts.

Welding works and gas cutting on gas pipelines in wells, tunnels, headers, technical underground, rooms of FRG, FRG and GRU without their disconnection, blowing with air or inert gas and installation of blankings are not allowed.

Prior to the start of welding (cutting) of the gas pipeline, as well as replacement of valves, compensators and insulating flanges in wells, tunnels, headers, the ceilings shall be removed (dismantled).

Prior to commencement of works, air is checked for gas content. The volume fraction of gas in the air shall not exceed 20% of the lower concentration limit of flame propagation. Samples shall be taken in the most poorly ventilated locations.

Work on connection of gas equipment to the existing internal gas pipelines using welding (cutting) should be carried out with disconnection of gas pipelines and their blowing with air or inert gas.

The reduction of the gas pressure in the existing gas pipeline should be carried out using disconnecting devices or pressure regulators.

To avoid gas overpressure in the gas pipeline, the overpressure should be released to the plug using the available condensate collectors or to the plug specially installed at the site.

The discharged gas should be burned if possible.

Leak check of gas pipelines, valves and instruments by open fire is not allowed.

The presence of unauthorized persons, the use of open fire sources, as well as smoking in places of gas hazardous work is not allowed.

Work areas shall be protected.

Pits shall have dimensions convenient for work and evacuation of workers.

Warning signs "Flammable - Gas" are posted or displayed near gas hazardous work sites.

Gas pipelines shall be blown by air or inert gas when released from gas.

The volume fraction of gas in the sample of air (inert gas) shall not exceed 20% of the lower concentration limit of flame propagation.

When purging gas pipelines, it is forbidden to release the gas-air mixture into rooms, ventilation and smoke removal systems, as well as in places where it can enter buildings or ignite from a fire source.

The person responsible for the availability of personal protective equipment, their serviceability and use is the work manager, and during the work, without technical guidance, the person who issued the task.

Availability and serviceability of the necessary personal protective equipment are determined when issuing a permit for gas hazardous works.

When organizing work, the manager must provide for the possibility of quickly withdrawing workers from the hazardous area.

Everyone participating in gas hazardous works shall have a hose or oxygen-insulating gas mask prepared for operation. The use of filtering gas masks is not allowed.

Permission to switch on oxygen-insulating gas masks is given by the work manager.

When operating in an oxygen-insulating gas mask, it is necessary to monitor the residual oxygen pressure in the gas mask bottle, which ensures the return of the operating gas to the gas-free zone.

Duration of gas mask operation without interruption shall not exceed 30 min.

Time of operation in oxygen-insulating gas mask should be recorded in its passport.

Air intake branch pipes of hose gas masks shall be located from windward side and attached. In the absence of forced air supply by the fan, the length of the hose should not exceed 15 m.

The hose must not have inflections and pinches.

Gas masks are checked for tightness before works are performed by clamping the end of corrugated breathing tube.

In a properly selected gas mask, it is impossible to breathe.

5.3 Calculation of lightning protection of gas distribution point

The gas distribution point belongs to the 1st category of buildings and structures or their part with production facilities, the premises of which according to the Rules for the arrangement of electrical installations (PUE) belong to classes B-1 and B-2. Protection area type - A (explosion and fire hazard for combustible gases. flammable liquids with a flash-point of not more than 25 ° C in such an amount that vapour-air mixtures can form; for substances and materials capable of exploding and burning when interacting with water, air oxygen or with each other). [50]

Dimensions of the GRP: length 2.4 m, width 2 m, height GRP2.55 m. Soil resistance sound= 100 Ohm (loam).

In accordance with the requirements of JI 15334.21.1222003 "Instruction on lightning protection of buildings, structures and industrial communications" [12] lightning protection of FRG is performed according to the II category of lightning protection. Protection against direct lightning strikes is carried out by installing a rod lightning rod.

Source Data:

Height of protected area at the level of GRP height hx1 = 2.55 m;

Height of protected area at level of blowdown plug hx2 = 4.0 m;

Height of lightning receptacle = 9.0m;

Calculation of a zone of the GRP core interception rod (reliability of protection of Rz =0.999):

Height of protection cone vertex h0, m, is determined by formula (24)

h0=0,7h (24)

h0=0,7∙9 = 6.3 m

Radius of protection circle at ground level r0, m, is determined by formula (25)

r0=0,6h (25)

r0=0,6∙9=5,4 m

Radius of protection circle at level of blowdown plug rx2, m, is determined by formula (26)

rх2=r0h0-hx2h0 (26)

rx2 = 5.46.34 6.3 = 1.97 m

Radius of protection circle at the level of GRP altitude rx1, m, is determined by formula (27)

rх1=r0h0-hx1h0 (27)

rx1 = 5.46.32.55 6.3 = 3.21 m

To protect against direct lightning strikes, a lightning bolt consisting of the following parts is designed:

The lightning receptacle installed at the GRP wall is made of round steel with a diameter of 16 mm, is attached to the GRP wall through corners.

Current leads are made of round steel with a diameter of 12 mm, welded to the lower part of the lightning receptacle and laid to the grounding conductor (2 pcs. from one lightning receptacle).

Lightning protection grounding conductor consists of vertical electrodes with length of 3 m each, made of round steel with diameter of 16 mm, combined by horizontal grounding conductor (strip 40· 4 mm), laid at depth of 0.8 m and ground resistance Rz = 9.1 Ohm

To protect against high-potential drift, on external above-ground and underground metal communications on the above-ground gas pipeline, IFS are installed, as well as connection to the ground loop of the lightning protection of the PGB foundation frame, armor of the supply cable at the entrance to the PGB, support of the incoming and outgoing gas pipelines is provided. Lightning protection diagram and grounding diagram of lightning receptacle are shown in Figures 8 and 9 respectively.

The resistance of the grounding device shall not exceed 10 ohms.

Figure 8 - Lightning protection diagram

Figure 9 - Grounding diagram of lightning receptacle

5.4 Environmental protection measures

When performing the work, it is necessary to comply with the requirements for protecting the environment, maintaining a sustainable ecological balance and not violate the land use conditions established by the federal law on environmental protection.

The objects of environmental protection from pollution, depletion, degradation, damage, destruction and other negative effects of economic and other activities are:

land, subsoil, soil;

surface and groundwater;

forests and other vegetation, animals and other organisms and their genetic foundation;

atmospheric air, the ozone layer of the atmosphere and near-Earth space.

At all stages of the work, measures should be taken to prevent:

development of adverse relief processes;

Change natural surface runoff

sunbathing of natural vegetation;

landfill of the territory with construction and other waste;

Fuel and lubricants spill.

Direct impacts on the soil cover are associated with preparatory excavation and are expressed as follows:

violation of the established forms of natural relief as a result of various types of earthworks (digging trenches and other excavations, filling embankments, planning work, etc.);

deterioration of physical-mechanical and chemical-biological properties of the soil layer;

destruction and deterioration of crops and hayfields;

landfilling of soils with waste of building materials, debris, etc.;

man-made microrelief disorders caused by multiple passage of heavy construction equipment.

Upon completion of construction, most of these violations are eliminated during organizational and technical measures and restoration of disturbed lands.

In order to protect and rational use of land resources, the following main requirements for their implementation, which are reflected in the project for the performance of works, must be met during construction and installation works:

carrying out preparatory work at the facilities within the time limits strictly agreed with the land user in accordance with the construction schedule;

Work should be carried out strictly within the limits of the territory allocated for construction, preventing unauthorized seizure of additional space related to the irrational organization of construction production;

during the construction of temporary roads to construction and installation sites, existing driveways should be used as much as possible;

Strict compliance with all design decisions taken, especially with regard to the depth of utilities; compliance with environmental measures such as erosion control measures, technical reclamation;

mandatory loading and transportation work to soil storage sites removed from the spots of permanent ground structures development, less the volume of said soil used for landscaping and strengthening works. Exported soil can be used to land low-productivity land or to create new areas of agricultural development on inconvenience;

mandatory and timely implementation of anti-weather and anti-erosion measures to protect the soil layer from wind and rain erosion;

reduction of production waste volumes with their disposal and neutralization;

timely elimination of soil contamination stains with fuel and lubricants with removal of contaminated soil to an organized landfill and mandatory replacement with high-quality soil;

prevention of soil cover entrainment with remnants of building materials with organization of their collection and disposal.

All land damaged during the construction period should be rehabilitated through technical and biological reclamation.

The source of air basin pollution during construction are:

exhaust gases of construction machines and mechanisms, vehicles, boiler houses and mobile power plants with liquid and gas fuel;

smoke from diesel engines, burning wood residues and building materials;

dust from traffic, facilities of the production base, development, movement and transportation of soil;

welding aerosols from pipe welding units and manual welding;

hydrocarbons from fuel and lubricants warehouses, petrol stations, fuel tanks, diesel power plants.

To reduce the negative effect of pollutant emissions during construction, it is necessary to:

Take into account the mutual location of pipe welding bases and fuel and lubricants warehouses;

Provide local control over the condition of vehicles;

regularly water access roads and the site of the facility itself in dry and hot weather;

Prohibit incineration of garbage and construction waste in undisclosed locations .

The main source of pollution of water bodies during construction are household, industrial and storm drains from sites of temporary facilities, from sites of technological facilities.

In order to avoid contamination of ponds silting, it is necessary to provide for the construction of drainage ditches, guide rollers for the removal of surface and drainage water from the site and a temporary construction base.

The sources of acoustic environmental pollution during construction are concentrated on the construction site:

vehicles;

construction machinery and equipment.

The direct effect is the noise of vehicles, the concentration of a significant number of builders in a limited construction area [27].

Economic part

6.1 General provisions

Main parameters of the gas pipeline:

total length of the route with all taps 253,185 m;

tariff for 1 kWh of consumed power 4.5 rub.;

operating pressure 0.6 MPa;

the diameters of the gas pipeline pipes vary, they are shown in Table 23.

The amount of costs for construction and installation of the linear part of the gas pipeline, including EHZ and materials, is shown in Table 22.

6.2 Operating Costs

Operating costs are the full range of costs associated with transporting gas through a gas pipeline during the year.

Operating costs included in the cost are determined in accordance with the legislation of the Russian Federation. The composition of costs is established in accordance with chapter 25 of the Tax Code of the Russian Federation "Income Tax" with additions and amendments.

Operating costs include:

labour costs;

Depreciation deductions

energy costs;

maintenance;

other costs.

Labor costs

Wage fund planning aims to determine the total amount of funds for the remuneration of employees of the production association.

The payroll fund includes the entire amount of accrued wages without taxes, as well as without deduction of other deductions made in accordance with the current legislation. The salary fund includes the following:

salary accrued for the worked time at tariff rates, salaries, basic rates;

cash premiums from the payroll fund.

The number of personnel of the operating organization is as follows:

ITR - 30 people;

workers - 90 people.

The average salary of ITR is 20,000 rubles. per month, workers - 10,000 rubles. per month.

Then the cost of wages will be:

(30· 30,000 + 90· 90,000)· 12 = 18 million rubles per year.

Deductions for social insurance are accepted in the amount of 34.9% of the annual FWP, they will amount to:

18 ∙ 0.349 = 6.3 million rubles per year.

Depreciation deductions

Depreciation rate is 5% of capital investments. In monetary terms, depreciation deductions are:

A = 700 005.2· 0.05 = 35 000.26 thousand rubles. per year.

Electricity costs Ze, RUB per year, determined by formula (28)

Conclusion

The result of supplying natural gas to the Delnerechensky municipal district is:

improving the living conditions of the population;

replacement of more expensive coal, fuel oil or electricity in thermal processes at agricultural enterprises, municipal enterprises, in medical institutions, public catering enterprises;

improved environmental situation in settlements, since natural gas during combustion practically does not emit harmful gases into the atmosphere.

As a result of the design of the gas distribution network, gas consumption by consumers was calculated. During hydraulic calculations, pipe diameters were selected, equipment was selected for FRG.

Hazardous and harmful production factors were analyzed during the pipeline construction period. As a result of the design, the main environmental measures at the construction stage were selected.

In the diploma project, a feasibility study was made of the project, in which the cost of building gas pipelines and the profitability of the project were calculated.

List of literature

Regulations

Occupational safety in construction: SNiP 12032001.

Combustible natural gases for industrial and utility purposes. GOST 554287.

Industrial Master Plans: SNiP II8980 *.

Urban planning. Planning and development of urban and rural settlements: SNiP 2.07.0189 *. - M.: ZITP Gosstroy of the USSR, 1989.

Unified corrosion and aging protection system. Underground structures. General requirements for corrosion protection: GOST 9.6022005.

Railways gauge 1520 mm: SNiP 320195.

Residential buildings: SNiP 2.08.0189 *.

Instructions for control of carbon monoxide content in boiler rooms: RD 1234100.

Instructions for lightning protection of buildings, structures and industrial communications.: CO 15334.21.1222003.

Men's overalls for protection against non-toxic dust, mechanical effects and general industrial pollution. Specification: GOST 12.4.10080 (rev. 2010).

Nondestructive testing. Welding of metals by melting. Classification of welded joints according to the results of radiographic inspection: GOST 2305578.

Boiler units: SNiP II3576.

Micrometers. Specification: GOST 650790.

General provisions for the design and construction of gas distribution systems made of metal and polyethylene pipes: SP 421012003.

Fences inventory of construction sites and construction and installation work areas. Specification: GOST 2340778 (rev.2010).

Hazardous and harmful production factors. Classification: GOST 12.0.00391 SSBT..

Organization of construction production: SNiP 3.01.01-85 *

Heating, ventilation and air conditioning: SNiP 2.04.0591 *.

Gloves and sleeves. General specifications: GOST 2884690 (rev. 2010).

Safety rules for gas distribution and gas consumption systems. PB 1252903

Rules for arrangement and safe operation of steam and hot water boilers: PB 1057403.

Design and construction of gas pipelines from metal pipes: SP 421022004.

Design and construction of gas pipelines from polyethylene pipes and reconstruction of worn-out gas pipelines: SP 421032003.

Metal measuring roulettes. Specification: GOST 750298.

Occupational safety standards system. Respiratory air isolating devices. General technical requirements and test methods: GOST R 12.4.18697 (rev. 2010).

Occupational safety standards system. Electrical products. General safety requirements: GOST 12.2.007.075.

Occupational safety standards system. Cascets are protective. General technical requirements. Test methods: GOST R 12.4.2452007 (rev. 2010).

Occupational safety standards system. Helmets are protective. General specifications: GOST 12.4.12883 (rev. 2010).

Occupational safety standards system. Special protective clothing. Nomenclature of quality indicators: GOST 12.4.01683 (ed. 2010).

Occupational safety standards system. Organization of occupational safety training. General provisions: GOST 12.0.00490 (rev. 2010).

Occupational safety standards system. Loading and unloading works. General safety requirements: GOST 12.3.00976 (rev. 2010).

Occupational safety standards system. Electric welding works. Safety requirements: GOST 12.3.00386.

Occupational safety standards system. Personal protective equipment. The sleeves are special. Specification: GOST 12.4.01075 (rev. 2010).

Occupational safety standards system. Personal respiratory protection equipment. Classification and marking: GOST 12.4.0342001 (rev. 2010).

Occupational safety standards system. Personal respiratory protection equipment. Method for evaluation of protective equipment by aerosols: GOST 12.4.11982 9 (rev. 2010).

Occupational safety standards system. Construction. Helmets construction. Specification: GOST 12.4.08784 (rev. 2010).

Occupational safety standards system. Construction. Excavation by hydromechanization. Safety requirements: GOST R 12.3.0482002 (rev. 2011).

Occupational safety standards system. Electrical safety. Protective grounding, grounding: GOST 12.1.03081 (rev. 2010).

Occupational safety standards system. Electrical safety. General requirements and nomenclature of protection types: GOST R 12.1.0192009 (rev. 2011).

Welded joints of steel pipelines. Main types, structural elements and dimensions: GOST 1603780.

Construction climatology: SNiP 230199 *.

Construction in seismic areas: SNiP II-7-81 *

Polyethylene pipes for gas pipelines. Specification: GOST R 5083895.

Electric welded steel pipes. Specification: GOST 1070580.

Signal colors, safety signs and signal markings. Purpose and application rules. General technical requirements and specifications. Test methods: GOST R 12.4.0262001 SSBT.

Calipers. Specification: GOST 16689.

Textbooks and tutorials

Electrical Installation Rules. - M.: Energoatomizdat, 1985.

Russia's energy strategy for the period up to 2030. November 13, 2009

Handbook on low-capacity boiler plants/Ed. K.F. Roddatisa.- M.: Energoatomizdat, 1989. - 488 s.

Golyanov A.I. Gas networks and gas reservoirs. - Ufa: Monograph, 2004. – 303 pages.

Golik V.G. Gas supply of the settlement: Textbook. - Saratov, 1995. – 68 pages.

Ionin A.A. Gas supply. - M.: Stroyizdat, 1989. – 439 pages.

Zemenkov Yu.D. Gas networks and gas reservoirs: Tutorial. - Tyumen: Vector Buk, 2004. – 208 pages.

Mustafin F.M., Kuznetsov M.V., Vasiliev G.G. and others. Corrosion protection of pipelines: Volume 1. - S.-P.: Nedra, 2005. – 620 pages.

Mustafin. F.M., Blekherova N.G., Kvyatkovsky O.P. and others. Piping Welding: Tutorial. - M.: NedraBusinesscenter, 2002. – 350 pages.

Orlov M.E. Calculation and design of urban gas supply systems: Methodological guidelines for the course project. - Ulyanovsk: UlGTU, 2005. - 52 s.

Filter selection - Faleev Yu.P., Klokov A.A., Marukhin A.I. Gas supply systems. Material, pipes and valves used in the construction of gas supply systems. Selection of GRP and GRU equipment. Training manual for specialists involved in gas supply design. - Nizhny Novgorod: NGASU, 1993. – 100 pages.

Skaftymov N.A. Fundamentals of gas supply. For students of universities and technical schools. L.: Nedra, 1975. 343 pages.

Ternigoryeva L.M., Oleinik N.I. Methodological guidelines for the implementation of the organizational and economic part of the diploma project for students of full-time and correspondence forms of training in specialty 0907 "Design, construction and operation of gas and oil pipelines and gas and oil storage facilities." - Tyumen.: 1989.

Shantarin V.D., Starikova G.V. Life safety. -Tymen.: TSNGU, 1997.

Shur I. A. - Gas regulatory points and installations - L.: Nedra, 1985. - 288 p .

Electronic resources

Security of supply and related investments. Report of Alexei Miller at the XXIV World Gas Congress. 06.10.2009. [Electronic Resource]. - Access mode: http://gazprom.ru/press/news/2009/october/article68793/, free.

Gas Group [Electronic Resource]. - Access mode: http://gazovik.ru/, free.

Gazprom Sakhalin. Liquefaction and storage. [Electronic Resource]. - Access mode: http://gazpromsh.nl/ru/lng/technology/liquefaction/, free.

Ivantsov O., Twins A. Solid step of liquid gas//Science and life. 1988. №7. [Electronic Resource]. - Access mode:

www.n-t.ru/nj/nz/1988/0703/htm free.

Kurbanov Y. In 10 years, Russia may become one of the key players in the LNG// Oil&GasEurasia market. 2008. №6. [Electronic Resource]. - Access mode: http://www.oilandgaseurasia.ru/articles/p/77/article/654/, free.

Meta news. Foreign gas engine news .//Non-profit partnership "National Gas Engine Association" (NGA). 10.11.2007. № 49. [Electronic Resource]. - Access mode: http://www.ngvrus.ru/metnews49.shtml, free.

Gas supply design [Electronic resource]. - Access mode: http:// proektgaz.ru

Turgiev M. Japanese energy companies are switching to liquefied natural gas ,//RIA Novosti. 19.05.2007. [Electronic Resource]. - Access mode: http://www.rian.ru/economy/20070519/65735842.html, free.

Free Encyclopedia Wikipedia [Electronic Resource]. - Access mode: http://ru.wikipedia.org, free.

Simonov I.V. Perspectives of Liquefied Natural Gas//Academy of Energy. 2009. №5. [Electronic Resource]. - Access mode: http://www.energoacademy.ru/ru/index.php?PAGE_CODE=MAGAZINE&PAGE_TYPE=M&article_id=231, free.

Sycheva V. On water aki sushu//Totals. 2009. №8. [Electronic Resource]. - Access mode: http://www.itogi.ru/delo/2009/8/137587.html, free.

Tomberg I.R. Terminal or pipe: risks of choice//NGenergia. 13.01.2009. [Electronic Resource]. - Access mode: http://www.ng.ru/energy/20090113/9_riski.html, free.

Appendix A

Hydraulic calculation of the high-pressure network of the Dalnerechensky municipal district in the ASPOGAZ 1.1 program

Object cipher

DP.RD56.3-47.130501.65

Object name

Development of gas supply project of Dalnerechensky municipal district

Calculation completed

Zelentsov D.A.

Network Information

Network Feature - High Pressure Network Calculation