Installation of RVG G-160 metering unit

Contents

Designation

Name

Note

Explanatory Note

1. GENERAL PART

2. GAS SUPPLY SYSTEM

2.1. Gas Supply Diagram

2.2. Incoming quality control of pipes and parts

2.3. Quality control of welded joints and testing of gas pipelines

3. AUTOMATION

4. MEASURES TO ENSURE INDUSTRIAL SAFETY, PREVENTION OF ACCIDENTS AND LOCALIZATION OF THEIR CONSEQUENCES AT HAZARDOUS PRODUCTION FACILITY

5. HEALTH AND SAFETY MEASURES

6. OPERATION OF THE GAS FARM

7. INPUT DATA

1. common part

The working project "Modernization of the gas metering unit in the boiler house" was carried out in accordance with the specifications issued by the trust and with the requirements of regulatory documents.

The gas pipeline shall be installed by a specialized installation organization in accordance with the requirements of SNiP 42012002, PB 1252903.

The measuring system is installed on the low-pressure gas pipeline in the boiler room, in the place of outdated metering unit RG600.

The boiler room is classified as "D" by fire hazard.

The fire resistance of the building is II.

The boiler house operates with the constant presence of maintenance personnel. The boiler room is seasonal, i.e. heat is generated only for heating.

Gas supply system

2.1. Gas supply diagram.

The design provides for the installation of a measuring complex instead of the RG600 meter in the boiler room.

As a measuring complex it is accepted SGEKVzR0.2250/1.6 on the basis of the rotational RVG G160 counter (measurement range 1:20). The throughput of the counter Bmax = 250.0 nm ³/h Bmin = 13.0 nm ³/h.

Three water heating boilers B-1 are installed in the boiler room.

Boiler House Input:

- gas flow rate: max - 231.0 nm ³/h;

min - 20.8 nm ³/h;

- gas overpressure: max - 250 mm water;

min - 160 mm water.

The maximum gas flow to the boiler house is taken based on the maximum power of all installed boilers.

The minimum gas flow to the boiler house is accepted according to the mode cards to the boiler house.

Range of a consumption of gas which measuring SGEKVzR0.2250/1.6 complex is capable to count at operating parameters:

nm3/h

nm3/h

According to the calculation, the adopted measuring complex is able to take into account the necessary gas flow through the heating boiler house.

SGEK complex is designed to account for natural gas consumption as per GOST 5542 in units of volume reduced to standard conditions (quantities) by means of automatic electronic correction of the readings of the rotary gas counter RVG by the temperature, pressure and compressibility coefficient of the measured medium, taking into account the manual values ​ ​ of the relative gas density, the content of nitrogen, hydrogen and carbon dioxide in the gas, the specific heat of gas combustion in accordance with GOST 30319 and PR50.2.019.

SGEK complex provides the following procedures:

a) input and change of initial conditions and data (setting procedure);

b) periodic survey and calculation of all gas flow parameters;

c) calculation of gas flow rate and volume reduced to standard conditions;

d) displaying on the display of the corrector information on the current values ​ ​ of the measured and calculated parameters (volume, flow rate, pressure, temperature, etc.);

e) display on call of current values of sensors readings, as well as reduced flow rate and volume and values of all entered and calculated parameters;

f) remote transmission using an additional modem (not part of the complex) of all calculated, entered and stored in the memory of the parameter corrector on request or a given program;

g) reporting on emergency situations, accidents and unauthorized interventions;

h) hourly archiving of the main parameters for the last 9 months of the EGEC complex operation;

and) diagnostics of functional units operability of SGEK complex;

k) display of maximum and minimum readings of measured parameters with indication of time and date; consumption and maximum gas consumption of the current and past month;

l) display of readings of daily counters of corrector;

m) displaying serial numbers of component parts of the complex.

Communication of the EGEC complex with the higher level systems is carried out through the standard RS232 interface (RS485).

The SODEC software complex is designed to read and process current data (operating and standard volumes, flow rates, pressure, temperature, gas compressibility factor, correction factor) from an electronic corrector.

At the inlet of the gas pipeline to the boiler room, install the KTZ thermal intake valve to automatically stop the gas supply in case of fire.

To automatically stop the gas supply in cases of gas contamination (CO and CH4 monitoring), install an electromagnetic valve of HV type.

A filter for cleaning gas from mechanical impurities is installed on the gas pipeline in front of the complex. The filter is not included in the scope of supply of the complex and is necessary if the measured gas does not meet the requirements of GOST 5542.

Monitoring of the technical condition and degree of contamination on the measuring complex and filter is provided with a switch indicating differential pressure gauge DSP80RASCO.

2.2. Incoming quality control of pipes and parts

Pipes, parts, gas fittings and equipment supplied to the construction site are subjected to external inspection in order to determine compliance with their design documentation and detect mechanical damages during their transportation; in addition, incoming quality control is carried out according to their main dimensions and characteristics.

Incoming quality control of pipes and parts at the construction site should be carried out by specialists of a certified laboratory in accordance with the established procedure.

For incoming quality control of pipes in terms of appearance and dimensions from the received batch, the customer takes at least five samples in the form of pipe sections. If the number of received pipes and parts is less than five pieces, then all are monitored.

2.3. Quality control of welded joints and testing of gas pipelines

Welded joints shall be visually and measurably inspected in order to detect external defects of all types, as well as deviations in geometric dimensions and mutual arrangement of elements. NDT of welded joints shall be performed with positive results of visual and measuring inspection.

For physical inspection, weld joints approved by visual inspection shall be selected.

Tests of the gas pipeline shall be carried out by the construction and installation organization in the presence of a representative of the operational organization.

Gas pipelines shall be held under test pressure for the time required to equalize the air temperature in the gas pipeline prior to the start of the leak test.

Test results shall be documented in the construction certificate.

Gas pipelines are tested for tightness by feeding compressed air into gas pipeline.

Tests of the designed gas pipeline shall be carried out in accordance with the design of SNiP 421012002 item 10.5, developed by the construction organization.

The gas pipeline should be considered to have passed the leak test if the actual pressure drop during the test does not exceed the value regulated by SNiP 421012002 "Gas distribution systems" and SP 421012003 "General provisions for the design and construction of gas distribution systems made of metal and polyethylene pipes."

Number of joints to be checked is:

- above-ground and internal natural gas pipelines with a diameter of 50 mm and more, with a pressure of up to 0.005 MPa - are not subject to control.

Joints of steel pipelines shall be monitored by radiographic method as per GOST 751282.

Control of radiographic images of welded steel joints welded by each welder should be carried out at the hardware and software complex of automated decryption of radiographic images in the amount of 20% PB 1252903 item 3.2.27.

For physical inspection, weld joints approved by visual inspection shall be selected.

Automation

An solenoid valve shall be installed at the gas pipeline inlet to ensure gas cut-off when the room is gas-free. Monitoring of CO carbon monoxide and CH4 methane is provided by the existing STG11D10 annunciator (in). The annunciator, which includes a carbon monoxide sensor, is installed on the automation and alarm board in the boiler room, at el. 1.6m from the floor surface and a remote sensor for methane is installed under the floor, 200mm below the ceiling.

When the CO content in the room increases to 20mg/m3 (I threshold) or CH4 to 10%, the LPSD is activated by light and sound alarm, when the CO content further increases to 100 mg/m3 (II threshold) or the CH4 increases to more than 10%, the LPSD is cut off at the entry into the room. Gas cut-off is accompanied by light and sound alarm. The alarm is output to the instrumentation board installed in the boiler room and transmitted to the board in the room with permanent personnel (control room).

The instrument panel is powered by ~ 220V voltage from the electrical power panel. The dispatcher board is powered by ~ 220V voltage from the local power panel.

Grounding and protective electrical safety measures are performed in accordance with the requirements of SNiP 3.05.06.87 and PuE7.

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