Method of returning cycle air to operating cycle of gas pumping unit

Abstract

FIELD: gas industry.SUBSTANCE: invention can be used on gas pumping units (GPU) with gas turbine engines (GTE) having a cycle air discharge, dry gas-dynamic seals (SGDS) of a centrifugal compressor (CC) and an air heating system for the GPU hangar. The objective of the invention is to reduce emissions of harmful substances into the atmosphere from a gas turbine engine and a modular air heating gas unit (AHGU), thermal pollution of the atmosphere and the amount of energy resources spent on supplying barrier air entering the barrier air system and heating the supply air entering the ventilation system of an individual shelter. The stated problem is solved, and the technical result is achieved by supplying heat with air discharged from the air-air heat exchanger to the barrier air receiver and to the intake of the modular gas air heating unit, by installing additional air ducts and installing a pressure fan with a constant rotation speed and a pressure fan with frequency regulation connected to the automatic control system (ACS).EFFECT: return of heat discharged with cycle air from the gas turbine engine to the operating cycle of the gas compressor unit by supplying it to the barrier air and heating the gas compressor unit hangar.1 cl, 1 dwg

Description

[0001] The invention relates to the field of gas industry and can be used on gas pumping units (hereinafter referred to as GPU) with gas turbine engines (hereinafter referred to as GTE) having a cycle air discharge, dry gas-dynamic seals (hereinafter referred to as SGDS) of a centrifugal compressor (hereinafter referred to as CBC) and an air heating system for the GPU hangar.

[0002] In accordance with the operating manual [Operating Manual for the Gas Pumping Unit GPA-25 Ural. Part 1. Technical Description. Iskra-Turbogaz LLC, 2008], the barrier air of the CBC is designed to prevent oil from entering the cavities of the front and rear bearings onto the SGDU. The flow rate of the barrier air is from 240 to 400 m 3 / h. The barrier air temperature must be no lower than +5°C. Barrier air is drawn from stage 7 of the high-pressure compressor (HPC), then throttled and supplied to the seals.

[0003] In accordance with the technical requirements of the standard [VRD 39-1.8-055-2002. Standard technical requirements for the design of compressor stations, booster compressor stations, and underground gas storage compressor stations. - OAO Gazprom, Moscow, 2002], three air exchanges per hour must be ensured in individual GPA shelters. The temperature of the supply air entering the individual shelter of an operating GPA must be maintained at a level of at least +15°C [Gas pumping unit GPA-25M-02 "Ural". Operation manual. - OAO NPO Iskra, 2010].

[0004] A heating device for individual gas compressor unit (GPU) shelters is known [Russian Federation Patent for Utility Model No. 100196, F24H 3 / 00, 2010], consisting of a prefabricated box-type housing, fans, an automatic control system, an air intake unit installed at the entrance, a heating unit, and collectors. A disadvantage of this device is the method for maintaining the temperature in the individual GPU shelter, which involves burning natural gas and indirectly heating the supply air. As a result, some of the heat and harmful substances generated during the gas combustion process are released into the atmosphere with the exhaust gases.

[0005] A known air heating system [Russian Federation Patent for Invention No. 2230259, F24D 5 / 00, 2004] consists of an air intake shaft, fans, supply and exhaust air ducts, a mixing air heater installed in the supply air duct, and an automatic fuel supply regulator. The disadvantages of this system are:

[0006] - emissions of harmful substances formed during gas combustion into the atmosphere;

[0007] - the entry of harmful substances formed during gas combustion into the working area;

[0008] - the possibility of natural gas entering the working area when the burner goes out.

[0009] A barrier air preparation system for a gas turbine plant is known [Russian Federation Patent for Utility Model No. 184580, F24F 7 / 00, 2018], comprising at least two screw compressors connected in parallel to the discharge line, air filters with a technical condition monitoring sensor connected to the discharge line, a condensate drain device, a drying and cleaning unit, as well as a compressed air accumulator with a pressure sensor, check and shut-off valves, characterized in that the system contains an electromagnetic valve additionally installed after the compressed air accumulator and connected in series to the discharge line, connected to a pressure sensor, a fine filter, a drying and cleaning device, a pressure regulator and a temperature sensor, wherein the air filters are connected in series to the discharge line, and the condensate drain device is connected to the first filter. The disadvantages of this device are:

[0010] - Low system reliability. If one screw compressor fails, it takes time for the backup compressor to start up. During this time, there is a high risk of oil spilling onto the compressor and damaging the seals;

[0011] - the absence of barrier air heaters, which, when atmospheric air is taken in during winter, leads to a decrease in the barrier air temperature below permissible values.

[0012] A method for heating supply ventilation air is known [Russian Federation Patent for Invention No. 2753094, C1, 2020]. In this method, heat normally discharged from the gas turbine engine with purge air from the air-to-air heat exchanger unit (hereinafter referred to as the ATHE) through an installed air duct is redirected to an air duct connecting the ATHE and the modular gas air heating unit (hereinafter referred to as the AGHU). To regulate the amount of heat supplied to the individual GPU shelter, a two-position air valve and a frequency-controlled fan are installed in the air duct. The amount of heat discharged with the ATHE purge air is regulated by varying the fan speed. A disadvantage of this method is the incomplete use of the air discharged from the ATHE at outside temperatures ranging from +5°C to -30°C.

[0013] The technical result of the invention is the return of heat discharged with the cycle air from the gas turbine engine to the operating cycle of the gas compressor unit by supplying it to the barrier air and heating the gas compressor unit hangar.

[0014] The stated problem is solved, and the technical result is achieved by supplying heat with air discharged from the BVVT to the barrier air receiver and to the intake of the modular gas air heating unit by installing additional air ducts, installing a pressure fan with a constant rotation speed and a pressure fan with frequency regulation, connected to the automatic control system (hereinafter - ACS).

[0015] Scheme of heat supply, discharged with the air blowing off the BVVT into the barrier air system and into the ventilation system of the individual shelter of the GPA (figure) consisting of: 1 - BVVT; 2 - air duct for heat discharge from the GTE; 3 - air valve; 4 - fan with frequency control; 5 - air duct connecting the BVVT and the AVGM; 6 - AVGM; 7 - supply ventilation duct; 8 - fire damper; 9 - individual shelter of the GPA; 10 - GPA shelter resistance thermometer; 11 - thermometer measuring channel with the automatic control system (hereinafter referred to as ACS); 12 - ACS; 13, 14 - control channels; 15 - pressure measuring sensor; 16 - pressure measuring sensor channel; 17 - GPA; 18 - air duct for supplying heat to the receiver of the barrier air system; 19 - receiver of the barrier air system; 20 - constant flow fan.

[0016] Heat normally discharged from the gas turbine engine with purge air from the BVVT is redirected to the AVGM and the barrier air system receiver, where it is then fed through standard air ducts to the supercharger. To regulate the amount of heat entering the individual GPA shelter, a two-position air valve and a frequency-controlled fan are installed in the air duct. The amount of heat discharged with the BVVT purge air is controlled by varying the fan speed. The amount of heat supplied to the AVGM from the BVVT is directly proportional to the fan speed. Completely shutting off the heat supply with the BVVT purge air to the AVGM is accomplished by closing the air valve. To supply fresh air to the individual GPA shelter in the AVGM, atmospheric air is taken in, purified, directly heated by the heat released with the BVVT purge air, and pumped into the standard installed supply ventilation duct.To monitor the temperature (hereinafter referred to as Ta) inside the individual GPA shelter, a resistance thermometer is installed, linked to the control system. The control system controls the position of the two-position air valve and the rotation speed of the AVGM fan.

[0017] The effect of the invention is that during the operation of the gas pumping unit, the consumption of fuel gas by the gas turbine engine and the automatic gas turbine engine is minimized.

[0018] The advantages of the invention are:

[0019] - reduction of economic costs due to the reduction of gas consumption in gas turbine engines and automatic gas turbine engines;

[0020] - reduction of harmful emissions into the atmosphere from gas turbine engines and automatic gas turbine engines;

[0021] - reduction of thermal pollution emissions into the atmosphere from gas turbine engines and AWGMs.

Claims

A method for returning cyclic air to the operating cycle of a gas pumping unit, which consists of returning air discharged from an air-to-air heat exchanger unit to the barrier air system and the heating system of the hangar of the gas pumping unit by installing air ducts from the air heat exchanger unit to the receiver of the barrier air system and the modular gas air heating unit of the hangar heating system of the gas pumping unit, containing a two-position air valve, a frequency-controlled fan, a constant pressure fan, a pressure measuring sensor, and supplementing the automatic control system with a cyclic algorithm for maintaining the temperature of the measured air by changing the amount of warm air supplied from the air-to-air heat exchanger unit by changing the rotation speed of the fan, characterized in that a more complete return of the cyclic air discharged into the atmosphere is carried out,achieved through its secondary use in barrier air systems and heating of the gas pumping unit hangar, thereby reducing the amount of harmful emissions into the atmosphere from the gas turbine engine and the modular air-heating gas unit, thermal pollution of the atmosphere and the amount of energy resources spent on supplying barrier air and heating the supply air.

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