Diploma project Development of gas network of Martyanovo district (village)

Contents

INTRODUCTION

1. GENERAL PART

1.1 Location, regional and climatic characteristics

1.2 Determination of physicochemical parameters of gas

1.3 Selection of gas supply flow chart

2. DETERMINATION OF ESTIMATED GAS CONSUMPTION BY INDIVIDUAL CONSUMERS AND HYDRAULIC CALCULATION

2.1 Annual Gas Consumption

2.2 Hydraulic calculation

3.PATENT SEARCH AND FEASIBILITY STUDY

3.1 Patent Search

3.2 Project Feasibility Study

4. ORGANIZATION OF CONSTRUCTION

4.1 Selection of work methods

4.2 Calculation of Commodity Requirements

4.3 Safety Solutions

4.4 Technical and economic indicators

5. ERGONOMIC FOUNDATIONS FOR SAFE OPERATION OF GAS SUPPLY SYSTEM

5.1 Analysis of possible hazardous and harmful factors during operation of the gas supply system

5.2 Development of organizational and technical measures to ensure safe operation of the gas supply system

5.3 Safety and Fire Safety

6. CONSTRUCTION ECONOMY AND ENVIRONMENTAL EXPERTISE OF THE PROJECT

6.1 Construction Economics

6.2 Project Environmental Review

CONCLUSION

LIST OF LITERATURE

Introduction

Natural gas supply to cities and settlements aims to:

• improvement of living conditions of the population;

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

• improvement of 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, control points and other equipment necessary for the operation of gas pipelines are being built. On the territory of cities and towns, gas pipelines are laid only underground. Modern urban and rural distribution systems are a complex structure consisting of the following main elements: gas networks of low, medium and high pressure; gas distribution stations, control and regulatory points, gas control points and installations; in the above stations and installations gas pressure is reduced to the required value and automatically kept constant. They have automatic safety devices that exclude the possibility of increasing the pressure in the networks above normal; communication and telemechanization systems. 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. Facilities, equipment and units in the gas supply system should 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. The main element of rural gas supply systems are gas networks. According to the number of pressure degrees used in gas networks, gas supply systems are divided into: 1. two-stage, consisting of low and medium or high (up to 0.6 MPa) pressure networks; 2. three-stage, including low, medium and high pressure pipelines (up to 0.6 MPa); 3. multistage, in which gas is supplied through gas pipelines of low, medium and high (up to 0.6 and up to 1.2 MPa) pressure. Gas supply systems of cities and towns differ in the principles laid down in the distribution networks, the nature of the supply of the rural network, the type of equipment and structures used in networks, communication and telemechanization systems. A number of factors influence the choice of the village gas supply system. The main ones are: 1) the nature of the gas source, the properties of the gas, the degree of its purification and humidity; 2) the size of the village, the peculiarities of its layout and development, population density;

3) number and nature of industrial consumers; 4) the presence of natural or artificial obstacles to the laying of gas pipelines. Gas is supplied to the village through several main gas pipelines, which end with gas distribution stations (GRS). Gas pressure decreases in GPC and it enters the high-pressure network. Underground gas storage is connected to high-pressure ring through control and control station. To equalize the daily schedule of gas consumption in the city there are gas golder stations. Medium and high pressure gas pipelines (up to 0.6 MPa) serve to supply rural low pressure distribution networks through gas control stations (GRP). They also supply gas through GRP and local gas control plants (GRU) to gas pipelines of industrial and municipal enterprises. Low-pressure gas pipelines serve to transport gas to residential and public buildings, as well as small public utilities, and small heating boilers can also join them. The number of FRG supplying the low pressure network is determined by technical and economic calculation. The FRG is located in the center of the zones that they feed, the zones of action do not overlap. Gas pipeline routes are designed with minimum network length. Distribution networks consist of main lines and subscriber branches.

1. common part

1.1 Location, regional climatic characteristics

Suksunsky district is one of the largest in the Perm Territory, where 14 percent of the population of the entire region is concentrated .

The climate is sharply continental, arid with hot and dry summers and cold winters. In summer, dry and dust storms are frequent, in winter - snowstorms. The average air temperature in July is 22.5 ° C, and the average air temperature in January is − 15.5 ° C. Rainfall averages 125-200 mm per year. The population of the district center is about 8,500 people. For calculations, one of the districts of the village of Martyanovo was taken.

1.3 Selection of gas supply flow chart

Currently, intensive gasification of rural areas begins almost throughout the Perm Territory. In order for this process to be most efficient, it is necessary to choose the most economical, rational gas distribution scheme for settlements with the lowest costs for the construction, operation, repair of gas networks. This choice should be characterized by ensuring a reliable, safe supply of gas to the consumer. The selection of gas pipeline laying conditions and horizontal and vertical distance from the gas pipeline to associated utilities, as well as buildings, structures, natural and artificial barriers should be provided taking into account building codes and rules approved by the federal executive body, specially authorized in the field of construction, as well as other regulatory and technical documents approved and (or) agreed by the Gosgortekhnadzor of Russia. The design should provide, as a rule, for underground laying of gas pipelines. Ground and above-ground laying of gas pipelines shall be carried out with appropriate justification.

Deepening of gas pipelines should be provided at least 0.8 m to the top of the pipe.

For steel gas pipelines in places where there is no traffic and agricultural machinery (inter-village gas pipelines) - at least 0.6 m.

Ground and above-ground laying of gas pipelines, including on-site combined with other engineering communications, is allowed in cases where there are no contradictions with other regulatory documents approved in the established manner.

Distances between pipelines are accepted on the condition of processability and convenience of works during construction and operation.

When laying gas pipelines on the walls of buildings and structures, the distance (in light) to the enclosing structures should be taken at least half of the diameter of the gas pipeline.

The earth diversion for the gas pipeline shall have a width equal to the transverse dimension of the structures on the underground gas pipeline and the longest length of the crossbeam (crossbeam), including supports consoles, racks, passages.

When laying above ground, it is not allowed to place reinforcement, detachable connections within the dimensions of automobile and pedestrian bridges, as well as over railway and road roads.

The arrangement of compensators due to the rotation angles of the gas pipeline route within the dimensions of roads and railways is allowed when justifying their safety.

Calculations of gas pipeline structures for strength and stability, as well as hydraulic calculation of gas pipelines, should be carried out according to the relevant methodological documents approved in the established manner.

Gas pipelines shall be calculated for a combination of loads acting on the gas pipeline, according to the time of action, direction, as well as for loads caused by soil and natural conditions (beam, subsidence, seismic impacts, subworking of territories, etc.).

When calculating the loads acting on the gas pipeline, take into account the own weight of the pipe and valves, the preliminary stress state of the gas pipelines, temperature differences, the possible impact of additional loads in landslide and flood events.

For above-ground gas pipelines in the presence of vibration loads or located in seismic areas, fasteners should be provided that ensure their movement and prevent the discharge of the gas pipeline from supports.

When laying gas pipelines above ground, standard movable and fixed support parts or made according to standard or separate designs should be provided.

The span between the supports should be determined taking into account the deformations of the supports caused by natural influences. With predicted soil deformations, the support structure, as a rule, should provide for the possibility of restoring the design position of the gas pipeline.

Above-ground gas pipelines shall be laid on supports, racks, passages made of non-combustible materials.

The pitch of the gas pipeline supports should be determined taking into account the loads from the gas pipelines, the impact of soils on the supports, as well as natural impacts. Gasket height shall be accepted in accordance with building codes and regulations.

Sections of the above-ground gas pipeline between fixed supports should be calculated taking into account the effects of changes in pipe wall temperature and pressure on them. To compensate for these effects, self-compensation of gas pipelines should be used due to the angles of rotation of the route or factory-made compensators (lens, bellows).

When selecting pipe materials, fittings, connectors and products for gas pipelines and technical devices for gas consumption systems, the approved nomenclature should be followed, taking into account pressure, design temperatures and other conditions.

The wall thickness of the pipe shall be at least 3 mm for underground and ground in the collapse of gas pipelines and 2 mm for above-ground and ground without collapse.

The pipe wall thickness for underwater transitions should be taken 2 mm more than the design one, but not less than 5 mm, at crossings through the railways of the common network - 3 mm more than the design one, but not less than 5 mm.

Steel pipes shall contain not more than 0.25% carbon, 0.056% sulphur, 0.046% phosphorus.

Carbon equivalent for carbon and low alloy steels shall not exceed 0.46%.

Requirements for polyethylene pipe material, marking and testing methods of polyethylene pipes for gas pipelines shall comply with state standards.

The use of secondary polyethylene for the manufacture of gas pipes is not allowed.

Polyethylene pipes used in the construction of gas pipelines must be made of polyethylene with a minimum long-term strength (MRS) of at least 8.0 MPa.

Pipes and connectors having different MRS values may be used in the construction of polyethylene gas lines.

Laying of underground gas pipelines from polyethylene pipes is allowed:

- in the territory of settlements with pressure up to 0.3 MPa;

- outside the territory of settlements (inter-settlement) with a pressure of up to 0.6 MPa.

Safety factor shall be accepted at least 2.5.

It is allowed to provide for the laying of underground gas pipelines from polyethylene pipes with a pressure of more than 0.3 MPa to 0.6 MPa in the territory of settlements with one-two-story and cottage buildings with a safety factor of at least 2.8.

For settlements of up to 200 inhabitants, it is allowed to lay underground gas pipelines from polyethylene pipes with a pressure of up to 0.6 MPa with a safety factor of at least 2.5.

It is not allowed to lay gas pipelines from polyethylene pipes:

- at possible decrease of pipe wall temperature during operation below minus 15 ° С;

- for transportation of gases containing aromatic and chlorinated hydrocarbons, as well as liquid phase of liquefied hydrocarbon gases;

- in areas with seismicity over 7 points in the territory of settlements made of pipes with safety factor below 2.8 dimensional length without 100% control by ultrasonic method of welded butt joints;

- above ground, inside buildings, as well as in tunnels, headers and channels;

- at crossings through artificial and natural barriers (through railways of the common network and roads of category IIII, under highways, main streets and city-wide roads, as well as through water barriers with a width of more than 25 m with low horizon and type III swamps with a safety factor of less than 2.8 and with a ratio of the nominal outer diameter of the pipe to the nominal thickness of the pipe wall (SDR) of more than 11.

At the intersection of underground gas pipelines with other communications, protective measures should be provided to prevent gas penetration and movement along the communications.

Above-ground gas pipelines at the intersection of high-voltage power lines must have protective devices that prevent electric wires from falling onto the gas pipeline in the event of a break.

The grounding resistance of the gas pipeline and its protective device shall not exceed 10 ohms.

The distances between the gas pipeline and the electrical conductors at the intersections and during parallel laying shall be taken in accordance with the rules of the electrical installations.

Gas pipelines when laid through walls shall be made in steel cases. The inner diameter of the case shall be determined on the basis of possible deformations of buildings and structures, but not less than 100 mm more than the diameter of the gas pipeline. The gaps between the gas line and the case shall be sealed with an elastic material.

Wells for arrangement of shutoff valves and compensators shall have dimensions ensuring their installation and operation.

The structure of the wells shall be water resistant to groundwater.

When choosing a gas distribution scheme for a settlement, three main gas distribution schemes can be considered: - With a gas distribution system or a cabinet unit common to the entire village and low pressure networks; - With cabinet control stations per group of houses and with low and medium pressure networks; - With individual cabinet control stations from which gas with low pressure is supplied to only one house.

The diploma project uses a combined gas distribution scheme from the Suksunsky district of the Perm Territory. The gas supply scheme of the Martyanovo district center is determined based on the location of the gas supply source and the nature of the development of the district center. It includes low and medium pressure networks. The gas is supplied through the medium pressure pipeline to: - GRPSH-1, GRPSH2, GRPSH-3, GRPSH4, GRPSH-5, where the gas is cleaned, distributed to consumers through low pressure gas pipelines with R3 kPa. The supply of natural gas to consumers in the residential area is provided from the main gas pipeline under construction from Kungur. From MG, to connect the residential sector, it is enough to bring a medium pressure branch with parameters: Ru 0.3 MPa, Du 63. Odorized natural gas is provided as the main fuel, which will be transported by MG from Kungur.