Gas control station. Course

1.2.1. Determination of total gas flow, distribution of annual gas flow by months, determination of monthly and hourly maximum and minimum gas flow

Annual consumption of natural gas by the gas supply facility:

Annual gas consumption for production needs is calculated in tabular form (Table 2.1).

When filling in table 2.1, consider the following:

1. Operation mode of production shops;

2. When calculating, use the current year calendar;

3. Consider summer natural gas consumption:

The annual gas costs for heating and utility needs shall be distributed by months in tabular form (Table 2.2).

Distribution of annual gas costs for heating and utilities

Distribution of production gas consumption shall be performed in tabular form (Table 2.3).

Distribution of gas production flow

Based on the obtained results, we plot the annual gas consumption of gas supply objects (Figure 1 in the calculation explanatory note and the graphic part of the first sheet).

Determination of maximum-hour natural gas consumption by gas supply facilities:

- for heating:

Determination of minimum-hour natural gas consumption by gas supply facilities:

- for heating:;

- for utility needs:;

where: - minimum (August) gas consumption for utility needs (as per Table 2);

- minimum daily consumption factor within a week;

- coefficient of minimum hourly consumption within the day of August (night hours);

- the number of calendar days of August.

The obtained data of maximum and minimum-hour expenses are recorded in

Hydraulic calculation of gas pipelines

Hydraulic calculation of gas pipelines includes:

• hydraulic calculation of the section of the medium pressure gas pipeline to the FRG (Table 5);

• hydraulic calculation of sections of low pressure gas pipelines after FRG. At that, pipeline diameters are accepted at the beginning of calculation approximately based on the equation of continuity:

For each section of the gas pipeline, the calculation is carried out according to three versions - one stage higher and one stage lower than the flow continuity estimated by the equation.

The sum of the pressure losses in the sections of the low pressure gas pipeline shall be:

If the condition of equality of total pressure losses in the gas pipeline is met, the hydraulic calculation is considered completed.

Natural gas flow rate in the section of the gas pipeline to GRP is selected according to Table

The value of the coefficient "A" is determined by the formula:

where D is the accepted diameter of the gas pipeline, see.

As a result of the calculation (Table 6), several values ​ ​ of Rk are obtained. It is recommended to select the smallest of them, since the condition of economic feasibility is met.

In this case, it is necessary to take into account the condition under which the ratio of pressure before the GRP regulator to pressure after the GRP regulator should be within the limits, which affects the calmer operation of the GRP regulators and ensures the minimum wear of the regulator.

The input pressure to the GRP regulator is determined by the expression:

Hydraulic calculation of low pressure gas pipeline section

Selection of FRG equipment

1.2.3.1. Gas filter selection

Using Table 4, the flow rate of natural gas through the filter is:

Using a nomogram to select a gas filter (from the reference literature), losses of it are determined and a filter is selected indicating its main characteristics.

The actual resistance of the clean filter is determined by the formula:

After the calculation, it is necessary to clarify the gas pressure at the inlet to the pressure regulator:

As well as checking the gas pressure ratio at the inlet and outlet of the FRG. After comparison, it is necessary to make a conclusion about the operability of the pressure regulator accepted for installation in the FRG. After that, it is necessary to accept the installation of the hair filter of the welded structure (from the reference literature) of the FG type for cleaning gas from mechanical impurities with the indication of its operating parameters, overall dimensions, weight and capacity.

1.2.3.2. Selection of pressure regulator

Currently, universal pressure regulators of the RDUK2 type are installed everywhere at GRP (GRU) of industrial enterprises, boiler houses, etc.

Based on the gas flow rate, it is necessary to determine the design capacity of the RD selected for the installation:

RDC2with the valve of the corresponding diameter, which will provide the final pressure corresponding to the design one, is accepted for installation on the FRG.

On GRP, they strive to limit themselves to one - maximum two parallel RDs of the same type. Their size can be different. They should be chosen so that with the maximum hourly gas flow per year (in winter during peak hours) they would be loaded no more than 75%, and with the minimum (in summer at night) at least 10% of their estimated throughput. In these cases, RDC2 regulators operate in a stable control mode.

Maximum RD load:

Minimum RD load:

After the final decision on the installation of the appropriate pressure regulator, it is necessary to write out the characteristic dimensions of RDUK2 with the indication of its weight.

1.2.3.3. Selection of safety valve

SZK is selected by the nominal pipe diameter and setting limits (s).

The BSV setting limit is defined as:

Based on the calculated pressure value, it is accepted to the installation of PKV-type PKV (N) with indication of the maximum pressure in the housing, adjustment limits, overall dimensions and weight.

1.2.3.4. Selection of safety relief valve.

The UCS is installed on the gas outlet line from the FRG. The amount of gas to be discharged by the UCS, if there is a BSV pressure in front of the regulator, is determined by;

Based on the obtained data, the UCS is accepted for installation with indication of the valve adjustment limits with low pressure spring, diameter and weight.

1.2.3.5. Selection of bypass line.

The diameter of the bypass line is not less than the diameter of the pressure regulator valve.

1.2.3.6. Selection of shutoff valves.

Based on the conditions of gas pipelines and climatic data of the area, it is necessary to select shutoff valves for each design area, as well as for GRP. When describing the selected type, it is necessary to indicate the marking of the shutoff valves with decryption, the diameter of the flow section, overall dimensions and mass.

1.2.3.7. Selection of pipes for GRP binding

When selecting pipes for design areas and GRP binding, it is necessary to be guided by the gas network laying conditions, the purpose of pipelines and external temperature. Describe the pipes selected for installation in the Pipe selection table form

Heating and

ventilation calculation

Heat consumption for FRG heating:

The diameter of the deflector is determined by:

Fire extinguishing equipment and protection of gas pipelines

Carbon dioxide GGs and foam fire extinguishers, as well as a box with sand (Table 8) shall be installed to extinguish GRP. Explosion-proof lamps shall be used for lighting. The GRP door shall open to the outside.

The calculated sections of gas pipelines at above ground about underground laying are subject to various factors that are corrosive. Based on this, it is necessary to provide for measures to protect them.

Project Gas Supply System Graphic Design

The graphics part is made on two sheets of A1 format and three sheets of A4 format.

On the first sheet, it is necessary to depict the design scheme of gas supply of the enterprise on a scale, the schedule of annual gas consumption by the industrial enterprise as a whole, and by individual consumers (heating, utility and production needs) and the profile of gas pipelines.

On the second sheet on a scale, a longitudinal section of the GRP is drawn indicating the equipment placed in it, selected as a result of the calculation.

In the calculation explanatory note on millimetre paper it is necessary to draw the sections selected for installation of gas filter, pressure regulator and safety shutoff to