Course work on gas supply to the microdistrict

Contents

1. Source Data

2. Characteristics of natural gas composition

3. Gas supply to the city

3.1. Determination of annual gas consumption for individual consumer groups

3.2. Determination of estimated gas hourly flow rates in medium-sized networks

and low pressure

3.3. Calculation of the optimal number of gas control points

(PWG) for urban gas supply system

4. Drawing up of design diagrams of low-pressure gas networks and placement of PRG on the city plan

5. Urban Gas Distribution Design and Calculation

low- and medium-pressure networks

6. Gas supply to the settlement quarter

7. Laying and calculation of internal gas pipelines of the house gas network

8. To Create a Gas Pipeline Profile

9. Selection of PRG equipment

10. Selection of the type of anti-corrosion insulation

List of literature

Applications

3. Gas supply to the city.

Modern city distribution systems are a complex complex of structures consisting of the following main elements: low-pressure gas networks, medium and high-pressure gas networks, gas distribution stations, gas control stations, gas control points and installations. In these stations and installations, the gas pressure is reduced to the required value and maintained constantly using automation. They have automatic safety devices that exclude the possibility of increasing the pressure in the networks above the standards. For the management and operation of these systems, special services are available to enable uninterrupted gas supply.

Gas supply projects are developed on the basis of schemes for the development and placement of sectors of the national economy and regional planning projects, master plans of cities taking into account their development for the future .

Consumers of medium-pressure gas in our case are: mineral fertilizer plant No. 1, oil and fat plant No. 2, bath and laundry plant, bakery, gas control points. Low-pressure gas after reduction at FRG is used by small municipal consumers, for household purposes and heating .

4. Compilation of design diagrams of low-pressure gas networks and location of GRP on the city plan.

It is recommended to adopt a two-stage scheme for gas supply to the city, since medium and low pressure gas is used. High-pressure gas distribution networks transport gas from GDC to GRP. In FRG, the pressure is reduced to low and through low pressure distribution networks the gas is sent to consumers. It is advisable to place EMG on the city plan in a staggered order, and so that EMG are located in the centers of the zones that they feed.

The route of medium pressure gas distribution networks is planned in the shortest way from GDS to medium pressure consumers (industrial enterprises, large utilities and GRP). The choice of ring or dead end schemes is agreed with the project management.

The area connecting the low-pressure gas distribution network with the FRG should not exceed 100 m. To increase the reliability of the network, it is necessary to loop around gas pipelines (especially main gas pipelines), and is also recommended for multi-storey development .

It is advisable to lay gas pipelines along low-speed streets and roads. Underground laying of gas pipelines is recommended in the city. It is recommended to provide gas valves in aboveground design.

In accordance with the recommendations above, the route of low-pressure city gas distribution networks is selected.

The design diagram of this network is compiled. The direction of gas movement from the supply points to the zero points along the shortest path is selected. Zero points are assigned in the most remote sections of the network and dead-end branches. The network points are numbered. The calculation scheme is given in the explanatory note.

8. To Create a Gas Pipeline Profile

The profile of the gas pipeline is built for one of the longest inputs of the quarterly network. In this project: 36373839404142. On the block plan, on the selected gas pipeline, pickets are placed every 100 m, at the places where gas equipment is installed (gate valves, passages, cases), at the corners of turns, at the exit from the ground, branches .

The longitudinal profile of the gas pipeline is shown as a sweep along the axis of the gas pipeline .

Since the gas pipeline in the selected direction is less than 150 mm in diameter, it is shown in one line .

Elevations of the bottom of the trench under the gas pipeline are placed at characteristic points, for example, at intersections with roads, railway and tram tracks, engineering communications and structures that affect the laying of designed gas pipelines. The type of soil is a natural sand pad, the level of groundwater is below the depth of gas pipelines.

9. Selection of FRG equipment

For consumers of low-pressure gas, the installation of gas control points of the RGW cabinet type is provided. The PSGs are placed on separate supports, taking into account the exclusion of their damage from the impact of transport, natural disasters, a hurricane, etc. Within the PSGSH protection area, fences made of metal mesh with a height of 1.6 m are installed.

Distances from separate PSGSh to buildings must be at least 10 m, to the side of roads - at least 5 m.

Selection and calculation of PSGN equipment is performed in accordance with technical characteristics. When selecting the equipment, the operating pressure of the gas to which the object is connected is taken into account; gas composition, its density; pressure loss from the point of connection to the input to the PSGN.

10. Selection of the type of anti-corrosion insulation

The risk of soil corrosion of underground metal gas pipelines is determined by the corrosive aggressiveness of the soil to the metal.

Specific electrical resistance of the soil UES = 23 Ohm * m, the degree of corrosion activity of the soil is medium. Insulation type - reinforced. Anti-corrosion insulation is used in metal areas at the entrance to the building, and in areas where reinforcement is located.