Exchange rate project for gas supply of the settlement with drawings and explanations

Contents

Introduction

1. Thermophysical properties of gas and calculation of combustion process

2. Population definition

3. Determination of annual gas consumption

3.1. Determination of annual gas consumption in apartments and small enterprises

3.2. Determination of annual gas consumption during gas consumption at consumer service enterprises

3.3. Determination of annual gas consumption at public catering facilities

3.4. Determining Annual Gas Consumption in Health Facilities

3.5. Determination of annual gas consumption at bakeries and bakeries

3.6. Determination of annual gas consumption for heating, ventilation, hot water supply of residential and public buildings

3.7. Drawing up the final table of gas consumption by the city

4. Construction of annual and daily schedules of gas consumption by the city

4.1. Underground Storage Storage Capacity

4.2. Determine the storage capacity required to equalize the daily gas consumption schedule

5. Determination of the optimal amount of GRP

6. Hydraulic calculation of gas pipelines

6.1. Hydraulic calculation of low pressure gas networks

6.2. Hydraulic calculation of low pressure dead end gas pipelines

6.3. Hydraulic calculation of high and medium pressure ring networks

6.3.1. Calculation in emergency modes

6.3.2. Calculation of flow distribution in normal hydraulic mode

6.4. Hydraulic calculation of internal house gas pipelines

7. Selection and justification of gas supply system

8. Safety in the gas industry

Appendix I

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) are being equipped, control points and other equipment necessary for the operation of gas pipelines are being built.

On the territory of cities and villages, gas pipelines are laid only underground.

On the territory of 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 production buildings.

Gas pipelines shall be laid in accordance with the requirements of SNiP [1].

Natural gas is used by the population for burning in domestic 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.

At industrial enterprises, gas is burned primarily in boilers and industrial furnaces. It is also used in technological processes for heat treatment of products manufactured by the enterprise.

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

In this course project, the gas supply system of Blagoveshchensk, Far Eastern Region, was designed. Source Data:

1. Population density: 353 people/ha.

2. Domestic gas consumption:

- cooking with central hot water supply - 30%;

-preparation of food with water heater - 35%;

-feed food and water on the farm. needs if there is only a slab - 35%;

3. Industrial enterprises, gas consumption:

- Food - 10,000 m3/day;

- Brewing - 9330 m3/day;

- Wine and vodka - 7660 m3/day.

4. Big Utilities:

- mechanical laundry - 45%;

-baking standard for bakery products per 1000 inhabitants per day - 0.7;

- number of beds per 1000 inhabitants in hospitals: n, pcs. - 8;

- Baths - 43%.

- Canteens, restaurants - 28%.

5. Gas pressure after GPC is 0.7 MPa.

6. Consumers - 0.34 MPa

7. After FRG - 3 kPa.

8. Nominal pressure upstream of household appliances is 1.9 kPa.

9. The number of floors is 7.

10. The number of plate locks is 2.

11. The type of water heater is flowing.

Gas field: Komi Republic (Igrim - Nizhny Tagil)

Gas composition:

CH4 - 95.9%

C2H6 - 1.9%

C3H8 - 0.6%

C4H10 - 0.3%

C5H12 - 0.1%

CO2 - 0%

N2 - 1,3%

Density - 0.741 kg/m3

= 36.47 MJ/m3

7. Selection and justification of gas supply system

Gas supply systems are a complex complex of structures. The choice of the gas supply system of the city is influenced by a number of factors. This is primarily: the size of the gasified territory, the features of its layout, population density, the number and nature of gas consumers, the presence of natural and artificial obstacles to the laying of gas pipelines (rivers, dams, ravines, railways, underground structures, etc.). When designing a gas supply system, a number of options are developed and their technical and economic comparison is made. For construction, the best option is used.

Depending on the maximum gas pressure, city gas pipelines are divided into the following groups:

- high pressure of category 1 with pressure from 0.6 to 1.2 MPa;

- average pressure from 5 kPa to 0.3 MPa;

- low pressure up to 5 kPa;

High and medium pressure gas pipelines serve to supply medium and low pressure urban distribution networks. They are the bulk of the gas to all consumers of the city. These gas pipelines are the main arteries supplying the city with gas. They are made in the form of rings, the floor of rings or rays. Gas is supplied to high and medium pressure gas pipelines from gas distribution stations.

Modern systems of urban gas networks have a hierarchical construction system, which is associated with the above classification of gas pipelines by pressure. The upper level consists of high-pressure gas pipelines of the first and second categories, and lower low-pressure gas pipelines. The gas pressure during the transition from a high level to a lower level gradually decreases. This is done using pressure regulators installed on the FRG.

8. Safety in the gas industry

Designed gas supply systems of cities, settlements and individual gas consumers should provide uninterrupted, safe gas supply, as well as the possibility of operational disconnection of gas pipelines, microdistricts, industrial, agricultural and municipal enterprises.

Welding, insulation and other construction and installation works during the construction of gas supply systems shall be carried out in accordance with the requirements of SNiP 3.05.02 - 88 * (control and test standards are specified in Annexes 33 - 34).

Construction of gas supply facilities is carried out, as a rule, by specialized construction and installation organizations.

Each enterprise shall carry out a set of measures, including a maintenance and repair system, ensuring the maintenance of the gas farm in good condition

Process diagrams indicating the places of installation of shutoff valves and instrumentation shall be attached to the instructions for maintenance and repair of the equipment of GRP, GRU, GNS, HNP, AGPC and boiler houses. The PID and PID shall be reviewed and re-approved after reconstruction, re-equipment and process change before the equipment is put into operation.

For each external gas pipeline, electric protection, tank and group balloon plant, GRP (GRU), GNS (HNS), AGSE, an operational passport must be prepared containing the main technical characteristics, as well as data on repairs carried out.

The reinforcement flywheels shall indicate the direction of rotation when the reinforcement is opened and closed.

Gas pipelines shall be painted periodically during operation.

The gas flow directions shall be indicated on the gas pipelines of the GNS (HNP), AGDC.

Detection and elimination of corrosion hazardous areas on underground steel gas pipelines and liquefied gas tanks, maintenance and repair of electrochemical protection units shall be carried out only by organizations specializing in the performance of work on protection of underground metal structures and communications against corrosion .

Natural gases supplied to gas pipelines shall comply with the requirements of GOST 5542 - 87. Gas odor intensity shall be checked by gas and gas supply organizations in accordance with GOST 22387.5-77. Control points and sampling periodicity are established depending on the gas supply system and gas flow rates. Check results must be recorded in a special log.

The control of gas pressure in the networks of the city and the settlement should be carried out by measuring at different points at least once a year (in winter) during the hours of maximum gas consumption.

Checking the presence of moisture and condensate in gas pipelines, their removal should be carried out with a periodicity that excludes the possibility of blockages. The frequency of inspection is determined by the gas company.

Valves and compensators installed on gas pipelines shall be subject to annual maintenance and, if necessary, repair. Information on replacement of gate valves, cranes, compensators, as well as works performed during overhaul should be entered in the gas pipeline passport, and on maintenance - in the log book.

Technical condition of external gas pipelines and structures shall be controlled by periodic bypass. When bypassing above-ground gas pipelines, gas leaks, damage to disconnecting devices, attachment violations and sagging of pipes should be detected. The bypass should be conducted at least 1 times every three months. When bypassing underground gas pipelines, gas pipeline routes should be inspected and gas leaks should be detected by external signs; all wells and control tubes, as well as wells and chambers of other underground communications, basements of buildings, mines, collectors, underground passages located at a distance of up to 15 m from the gas pipeline; check the safety, condition of wall indicators and landmarks of gas facilities; inspect the state of the area along the gas pipeline route in order to detect the collapse of the soil, its erosion with melted or rainwater.

The results of the bypass of gas pipelines should be reflected in a special journal .

Building owners are responsible for the serviceability of the sealing of underground utility lines, the maintenance of basements and technical subholes in a state that ensures the possibility of their constant ventilation and gas testing.

Underground gas pipelines in operation shall be subjected to technical inspection with the help of special instruments. Technical inspection of underground steel gas pipelines shall be carried out at least 1 times per 5 years. Gas pipelines included in the overhaul or replacement plan should be examined at least 1 times a year.

The operation mode of FRG, GRU and combined regulators shall be set in accordance with the design.

The settings of the equipment of the city and village GRP are set by the chief engineer of the gas enterprise, while for domestic consumers: the maximum operating gas pressure after the regulator should not exceed 300 daPa; safety relief valves, including those built into pressure regulators, shall provide gas discharge when maximum operating pressure after the regulator is exceeded by not more than 15%; upper limit of actuation of safety shut-off valves shall not exceed maximum operating gas pressure downstream the regulator by more than 25%.

The gas pressure at the outlet of the FRG (GRU) exceeding 10% of the operating pressure is not allowed. Malfunctions of regulators causing increase or decrease of operating pressure, malfunctions in operation of safety valves, as well as gas leaks, shall be eliminated in emergency order.

During operation of GRP and GRU, the following shall be performed:

- inspection of the technical condition within the terms established by the instruction, ensuring safety and reliability of operation;

- check of parameters of operation of safety shut-off and waste valves at least 1 time in 2 months and also upon termination of repair of the equipment ;

-technical maintenance - at least 1 times per 6 months;

- ongoing repair - at least 1 times a year, if the manufacturer of pressure regulators, safety valves, telemechanical devices does not require repairs in a shorter time;

- capital repair - during replacement of equipment, measuring instruments, heating, lighting and restoration of building structures of the building on the basis of defective lists compiled as a result of inspections.

Rooms in which gas pipelines are laid and gas-using plants and valves are installed shall be accessible to maintenance personnel. Do not load gas pipelines and use them as supporting structures and grounding.

Internal gas pipelines and gas equipment of the units shall be subject to maintenance at least 1 times a month, current repair - at least 1 times a year.

Gas supply to the unit shall be immediately stopped by protection at:

- increase or decrease of gas pressure before burners;

- reducing rarefaction in the furnace;

- lowering of air pressure upstream burners for boilers equipped with burners with forced air supply;

- extinguishing of burner flares, disconnection of which is not allowed during boiler operation;

- failure of protection circuits, including voltage loss, only for boiler rooms of the second category.

In addition, the service personnel shall immediately stop the gas supply at:

- detection of loopholes in frosting, in places of installation of explosive valves and gas ducts;

- failure of burners, gas-using plants;

- failure of instrumentation, automation and alarm equipment;

- occurrence of gas contamination, detection of gas leaks on gas equipment and gas pipelines;

- explosion in the furnace space, gas explosion or ignition of combustible deposits in gas ducts;

- fire threatening personnel or equipment, as well as protection and remote control circuits of shutoff valves.

Smoke and ventilation channels are subject to periodic inspection and cleaning: before the heating season - chimneys of seasonally operating heating and heating-cooking furnaces, capacitive water heaters, heating apartment boilers, regardless of their design.