Pressurizing separation system for large tank air exhaust

Abstract

The invention discloses a pressurization separation system for large tank air exhaust. The device comprises a gas inlet separation unit, a compression conveying unit, a pressurization separation unit, a quick discharge emptying unit connected with gas phase pipelines of the gas inlet separation unit, the compression conveying unit and the pressurization separation unit, and a two-stage gas supply unit connected with gas phase pipelines of the gas inlet separation unit and the pressurization separation unit. The urgent discharge emptying unit comprises an oil distribution safety valve and a gas distribution safety valve; the two-stage air supply unit comprises a first-stage air supply adjusting valve and a second-stage air supply adjusting valve. According to the oil and gas recovery device, through combination of pressurization separation recovery and compression conveying, resistance in the fluid conveying process can be effectively overcome, oil and gas can be conveyed more rapidly and remotely, and the oil and gas recovery efficiency is greatly improved.

Description

Technical Field

[0001] The invention belongs to the technical field of oil and gas recovery in oil fields, and in particular relates to a pressurized separation system for pumping gas from a large tank. Background Art

[0002] During oilfield production operations, large oil storage tanks usually volatilize a large amount of oil and gas, which not only contains valuable hydrocarbon components, but also may contain harmful gases such as hydrogen sulfide. Therefore, it is of great significance to use oil and gas recovery technology to recover and treat these volatile gases.

[0003] With the continuous deepening of oil field development and increasingly stringent environmental protection requirements, the problem of oil and gas volatilization has become increasingly prominent. Traditional oil and gas treatment methods have problems such as resource waste and environmental pollution. For example: the saturation of activated carbon adsorbents will affect its adsorption effect during long-term operation, and it needs to be replaced or regenerated regularly, which is costly; the membrane separation method is relatively expensive, and the selection and replacement of membrane materials are highly professional... Therefore, there is an urgent need to adopt more advanced oil and gas recovery technologies and processes to solve the above problems or optimize existing technologies.

[0004] At the same time, by recycling hydrocarbon components in oil and gas, we can reduce resource waste, improve resource utilization, help reduce air pollution and greenhouse gas emissions, reduce environmental pollution, and help promote the sustainable development of oil field production and environmental protection. Summary of the invention

[0005] Purpose of the invention: In order to overcome the deficiencies in the prior art, the present invention provides a pressurized separation system for large tank vacuuming.

[0006] Technical solution: The present invention provides a pressurized separation system for extracting gas from a large tank, comprising an air intake separation unit (100), a compression and delivery unit (200) connected to a gas phase pipeline of the air intake separation unit (100), a pressurized separation unit (300) connected to a gas phase pipeline of the compression and delivery unit (200), an emergency air discharge unit (400) connected to the gas phase pipelines of the air intake separation unit (100), the compression and delivery unit (200) and the pressurized separation unit (300), and a two-stage air supply unit (500) connected to the gas phase pipelines of the air intake separation unit (100) and the pressurized separation unit (300);

[0007] The emergency air discharge unit (400) comprises an oil safety valve (402) and a gas safety valve (403);

[0008] The two-stage air supply unit (500) comprises a primary air supply regulating valve (501) and a secondary air supply regulating valve (502).

[0009] Preferably, the air intake separation unit (100) comprises an air intake shut-off valve (101), an air intake flame arrester (102) connected to the air outlet end of the air intake shut-off valve (101), an air intake separation tank (104) connected to the air outlet end of the air intake flame arrester (102), an inlet liquid discharge valve (107) connected to the liquid outlet end of the air intake separation tank (104), and an infusion pump (105) connected to the outlet end of the inlet liquid discharge valve (107).

[0010] Preferably, the gas inlet of the large tank of the system is connected to the inlet end of the air intake cut-off valve (101);

[0011] An intake pressure transmitter (106) is provided on a pipeline connecting the gas inlet of the large tank and the inlet end of the intake cut-off valve (101); an oxygen content detector (103) is provided on a pipeline connecting the outlet of the intake flame arrester (102) and the gas inlet of the intake separation tank (104).

[0012] Preferably, the gas phase pipeline of the compression and delivery unit (200) comprises an air intake filter (201), a loading valve (202) connected to the outlet end of the air intake filter (201), a gas compressor (203) connected to the outlet end of the loading valve (202), an oil-gas separator (204) connected to the outlet end of the gas compressor (203), an oil-gas check valve (205) connected to the first air outlet end of the oil-gas separator (204), a reflux cut-off valve (214) connected to the second air outlet end of the oil-gas separator (204), and an air-cooled heat exchanger (206H) connected to the outlet end of the oil-gas check valve (205);

[0013] The other end of the backflow cut-off valve (214) is connected to the inlet end of the loading valve (202).

[0014] Preferably, the outlet end of the air-cooled heat exchanger (206H) is connected to the inlet end of the air outlet separation tank (301); and the inlet end of the air intake filter (201) is connected to the first air outlet end of the air intake separation tank (104).

[0015] Preferably, an oil temperature transmitter (213) is provided on the pipeline connecting the outlet of the gas compressor (203) and the inlet of the oil-gas separator (204); an air-cooled temperature transmitter (207) and an outlet air pressure transmitter (208) are provided on the outlet pipeline of the air-cooled heat exchanger (206H).

[0016] Preferably, a liquid level transmitter (210) is provided at the liquid storage portion at the lower portion of the oil-gas separator (204).

[0017] Preferably, the oil phase pipeline of the compression and conveying unit (200) includes an oil-gas separator (204), an oil-cooled heat exchanger (209H) connected to the oil outlet end of the oil-gas separator (204), an oil filter (211) connected to the outlet end of the oil-cooled heat exchanger (209H), and an oil shut-off valve (212) connected to the outlet end of the oil filter (211); the other end of the oil shut-off valve (212) is connected to the oil return port of the gas compressor (203).

[0018] Preferably, the pressurized separation unit (300) comprises a gas outlet separation tank (301), a gas outlet flame arrester (302) connected to a first gas outlet end of the gas outlet separation tank (301), a gas outlet cut-off valve (303) connected to an outlet end of the gas outlet flame arrester (302), and an outlet liquid discharge valve (304) connected to a liquid outlet end of the gas outlet separation tank (301);

[0019] The outlet end of the gas outlet cut-off valve (303) is connected to the user-side pipe network; the other end of the outlet liquid discharge valve (304) is connected to the liquid discharge outlet.

[0020] Further preferably, the emergency discharge air-release unit (400) further comprises an emergency discharge valve (401);

[0021] The inlet end of the emergency vent valve (401) is connected to the second outlet end of the air inlet separation tank (104);

[0022] The inlet end of the oil safety valve (402) is connected to the third outlet end of the oil-gas separator (204);

[0023] The inlet end of the gas separation safety valve (403) is connected to the second gas outlet end of the gas outlet separation tank (301);

[0024] The outlet end of the emergency vent valve (401), the outlet end of the oil safety valve (402) and the outlet end of the gas safety valve (403) are all connected to the emergency vent pipe.

[0025] Further preferably, the two-stage air supply unit (500) further comprises an air supply cut-off valve (503) connected to the inlet end of the secondary air supply regulating valve (502);

[0026] The inlet end of the gas supply cut-off valve (503) is connected to the natural gas pipeline;

[0027] The outlet end of the secondary air supply regulating valve (502) is connected to the inlet end of the air intake cut-off valve (101);

[0028] The outlet end of the first-stage air supply regulating valve (501) is connected to the inlet end of the air intake cut-off valve (101);

[0029] The inlet end of the primary air supply regulating valve (501) is connected to the third air outlet end of the air outlet separation tank (301).

[0030] More preferably, the air-cooled heat exchanger (206H) is equipped with an air-cooled fan (206F);

[0031] The oil-cooling heat exchanger (209H) is equipped with an oil-cooling fan (209F);

[0032] The gas compressor (203) adopts a variable frequency single screw.

[0033] Preferably, when the gas compressor (203) is in a powered-on loading state, or the gas compressor (203) is in a powered-off unloading state, the reflux cut-off valve (214) is opened;

[0034] When the gas compressor (203) is started up and loaded, or when the gas compressor (203) is shut down and unloaded, the reflux cut-off valve (214) is closed;

[0035] When the gas compressor (203) is running, the gas outlet shut-off valve (303) is opened;

[0036] When the gas compressor (203) is turned off, the gas outlet shut-off valve (303) is closed;

[0037] When the secondary air supply regulating valve (502) is opened, the air supply cut-off valve (503) is opened; when the secondary air supply regulating valve (502) is closed, the air supply cut-off valve (503) is closed.

[0038] Further preferably, the air inlet shut-off valve (101), the air outlet shut-off valve (303) and the return shut-off valve (214) are all interlocked with the gas compressor (203) for control.

[0039] Further preferably, the air-cooling temperature transmitter (207) is interlockedly controlled with the air-cooling fan (206F).

[0040] Further preferably, the oil temperature transmitter (213) is interlockedly controlled with the oil cooling fan (209F).

[0041] Further preferably, the outlet pressure transmitter (208) and the liquid level transmitter (210) are both interlocked with the gas compressor (203).

[0042] Further preferably, the oxygen content detector (103) is interlocked with the emergency vent valve (401) and the gas compressor (203).

[0043] Further preferably, the primary air supply regulating valve (501) and the secondary air supply regulating valve (502) are both interlocked with the air intake pressure transmitter (106) for control.

[0044] Further preferably, the infusion pump (105) is interlockedly controlled with the air intake separation tank (104).

[0045] Further preferably, the outlet liquid discharge valve (304) is interlocked with the gas outlet separation tank (301).

[0046] Preferably, it also includes a hand valve (215) with adjustable opening.

[0047] Further preferably, the manual valve (215) and the loading valve (202) pipeline are arranged in parallel.

[0048] More preferably, the ratio of the flow volume of the hand valve (215) to the flow volume of the loading valve (202) is 1:8-10.

[0049] More preferably, when the gas compressor (203) is started and loaded, the air intake cut-off valve (101) is opened, the loading valve (202) is closed, and the return cut-off valve (214) is opened;

[0050] When the gas compressor (203) is loaded, the air intake cut-off valve (101) is opened, the loading valve (202) is opened, and the reflux cut-off valve (214) is closed;

[0051] When the gas compressor (203) is shut down for unloading, the air intake cut-off valve (101) is closed, the loading valve (202) is closed, and the return cut-off valve (214) is opened until the gas compressor (203) is shut down after unloading is completed.

[0052] Beneficial effects: The pressurized separation system for large tank air extraction provided by the present invention combines air intake separation, compression transportation and pressurized separation, and has the following advantages over the prior art:

[0053] (1) In the large tank vacuum pressurization separation system provided by the present invention, a two-stage air supply unit connected to the gas phase pipelines of the air intake separation unit and the pressurization separation unit can realize the system's all-weather stable operation, greatly improving the stability and reliability of the system operation.

[0054] (2) In the large tank vacuum pressurization separation system provided by the present invention, a three-stage emergency discharge system is provided, which eliminates the risk of overpressure and has high safety.

[0055] (3) The pressurized separation system for large tank gas extraction provided by the present invention is a compressed pressure conveying system. Through two gas-liquid separations and compressed pressure conveying, long-distance conveying can be achieved, and the conveying distance can be as long as several thousand meters.

[0056] (4) Based on the structure and construction provided by the present invention, the large tank air after the first gas-liquid separation can be filtered and separated by the air intake filter, and then enters the gas compressor for compression and pressurization at room temperature. The pressurized gas is separated into gas and oil, and the separated gas is transmitted to the air-cooled heat exchanger for air-cooled heat exchange and cooled to room temperature. The pressurized room-temperature gas is subjected to the second gas-liquid separation and then output to the outside. The pressurized gas (such as pressurized 6 bar gas) output by the pressurized separation system of the large tank air extraction provided by the present invention can be directly introduced into the pipeline network, without exhaust gas emission into the atmosphere, which is green and environmentally friendly.

[0057] (5) The pressurized separation in the pressurized separation system for large tank gas extraction provided by the present invention can be configured to use thinner transmission pipelines, effectively saving system equipment costs.

[0058] (6) Furthermore, in the pressurized separation system for large tank extraction provided by the present invention, combined with oil injection and exhaust cooling, the exhaust temperature is no higher than 45°C, and the system is safe and reliable for normal temperature transportation.

[0059] In general, the present invention can effectively overcome the resistance in the fluid transportation process by combining pressurized separation recovery and compression transportation, so that oil and gas can be transmitted faster and over longer distances, greatly improving the efficiency of oil and gas recovery. The combination of large tank gas extraction recovery and pressurized separation compression transportation makes the entire operation process relatively more convenient, and the equipment cost and maintenance cost are effectively reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 This is a schematic diagram of the structure of a pressurized separation system for extracting gas from a large tank provided in this embodiment.

[0061] In the figure, 100-intake separation unit, 200-compression and delivery unit, 300-pressurization separation unit, 400-urgent air discharge unit, 500-two-stage air supply unit;

[0062] 101-intake cut-off valve, 102-intake flame arrester, 103-oxygen content detector, 104-intake separation tank, 105-infusion pump, 106-intake pressure transmitter, 107-inlet drain valve;

[0063] 201-intake filter, 202-loading valve, 203-gas compressor, 204-oil-gas separator, 205-oil-gas check valve, 206F-air-cooling fan, 206H-air-cooling heat exchanger, 207-temperature transmitter, 208-outlet pressure transmitter, 209F-oil-cooling fan, 209H-oil-cooling heat exchanger, 210-liquid level transmitter, 211-oil filter, 212-oil cut-off valve, 213-oil temperature transmitter, 214-return cut-off valve, 215-hand valve;

[0064] 301-gas outlet separation tank, 302-gas outlet flame arrester, 303-gas outlet cut-off valve, 304-export drain valve;

[0065] 401- Emergency vent valve, 402- Oil safety valve, 403- Gas safety valve;

[0066] 501-first-stage air supply regulating valve, 502-second-stage air supply regulating valve, 503-air supply cut-off valve. DETAILED DESCRIPTION

[0067] The present invention will be further described in detail below in conjunction with the embodiments and drawings, and the following embodiments do not limit the present invention.

[0068] This embodiment provides a large tank vacuum pressure separation system, such as Figure 1 As shown, it includes an air intake separation unit 100, a compression and conveying unit 200 connected to the gas phase pipeline of the air intake separation unit 100, a pressurization separation unit 300 connected to the gas phase pipeline of the compression and conveying unit 200, an emergency air discharge unit 400 connected to the gas phase pipelines of the air intake separation unit 100, the compression and conveying unit 200 and the pressurization separation unit 300, and a two-stage air replenishment unit 500 connected to the gas phase pipelines of the air intake separation unit 100 and the pressurization separation unit 300.

[0069] like Figure 1 As shown, the emergency air discharge unit 400 includes an oil safety valve 402 and a gas safety valve 403 .

[0070] like Figure 1 As shown, the two-stage air supply unit 500 includes a primary air supply regulating valve 501 and a secondary air supply regulating valve 502 .

[0071] In this embodiment, specifically, the air intake separation unit 100 includes an air intake cut-off valve 101, an air intake separation tank 104 connected to the air outlet end of the air intake cut-off valve 101, an inlet discharge valve 107 connected to the liquid outlet end of the air intake separation tank 104, and an infusion pump 105 connected to the outlet end of the inlet discharge valve 107;

[0072] It also includes an air intake flame arrester 102; the air intake end of the air intake flame arrester 102 is connected to the air outlet end of the air intake cut-off valve 101, and the air outlet end of the air intake flame arrester 102 is connected to the gas inlet (i.e., the air intake end) of the air intake separation tank 104. That is, an air intake flame arrester 102 is also provided between the air outlet end of the air intake cut-off valve 101 and the gas inlet of the air intake separation tank 104.

[0073] It can also be said that: the air intake separation unit 100 includes an air intake shut-off valve 101, an air intake flame arrester 102 connected to the air outlet end of the air intake shut-off valve 101, an air intake separation tank 104 connected to the air outlet end of the air intake flame arrester 102, an inlet drain valve 107 connected to the liquid outlet end of the air intake separation tank 104, and an infusion pump 105 connected to the outlet end of the inlet drain valve 107.

[0074] In this embodiment, the gas inlet of the large tank of the system is connected to the inlet end of the air intake cut-off valve 101;

[0075] An intake pressure transmitter 106 is provided on the pipeline connecting the gas inlet of the large tank and the inlet end of the intake cut-off valve 101; an oxygen content detector 103 is provided on the pipeline connecting the outlet of the intake flame arrester 102 and the gas inlet of the intake separation tank 104.

[0076] In this embodiment, specifically, the gas phase pipeline of the compression and delivery unit 200 includes an air intake filter 201, a loading valve 202 connected to the outlet end of the air intake filter 201, a gas compressor 203 connected to the outlet end of the loading valve 202, an oil-gas separator 204 connected to the outlet end of the gas compressor 203, an oil-gas check valve 205 connected to the first gas outlet end of the oil-gas separator 204, a reflux cut-off valve 214 connected to the second gas outlet end of the oil-gas separator 204, and an air-cooled heat exchanger 206H connected to the outlet end of the oil-gas check valve 205;

[0077] The other end of the reflux cut-off valve 214 is connected to the inlet end of the loading valve 202. In other words, the other end of the reflux cut-off valve 214 is connected to the inlet end of the loading valve 202 and the outlet end (i.e., the gas outlet end) of the air intake filter 201, and the gas is output from the other end of the reflux cut-off valve 214 and / or the outlet end of the air intake filter 201 to the inlet end of the loading valve 202.

[0078] In this embodiment, the outlet end of the air-cooled heat exchanger 206H is connected to the inlet end of the air outlet separation tank 301 ; the inlet end of the air intake filter 201 is connected to the first air outlet end of the air intake separation tank 104 .

[0079] In some preferred embodiments, an oil temperature transmitter 213 is provided on the pipeline connecting the outlet of the gas compressor 203 and the inlet of the oil-gas separator 204. In some preferred embodiments, an air-cooled temperature transmitter 207 and an outlet gas pressure transmitter 208 are provided on the outlet pipeline of the air-cooled heat exchanger 206H.

[0080] In certain preferred embodiments, a liquid level transmitter 210 is provided at the liquid storage portion (also referred to as a liquid storage portion) at the lower portion of the oil-gas separator 204 .

[0081] In this embodiment, specifically, the oil phase pipeline of the compression and delivery unit 200 includes an oil-gas separator 204, an oil-cooled heat exchanger 209H connected to the oil outlet end of the oil-gas separator 204, an oil filter 211 connected to the outlet end of the oil-cooled heat exchanger 209H, and an oil cut-off valve 212 connected to the outlet end of the oil filter 211; the other end of the oil cut-off valve 212 is connected to the oil return port (also called the oil phase pipeline inlet) of the gas compressor 203.

[0082] In this embodiment, specifically, the pressurized separation unit 300 includes a gas outlet separation tank 301, a gas outlet flame arrester 302 connected to the first gas outlet end of the gas outlet separation tank 301, a gas outlet cut-off valve 303 connected to the outlet end of the gas outlet flame arrester 302, and an outlet liquid discharge valve 304 connected to the liquid outlet end of the gas outlet separation tank 301.

[0083] In this embodiment, specifically, the outlet end of the gas outlet cut-off valve 303 is connected to the user-side pipe network; the other end (i.e., the liquid outlet end) of the outlet drain valve 304 is connected to the drain outlet. In this embodiment, the liquid outlet end of the outlet drain valve 304 is connected to the drain outlet provided in the air intake separation unit 100.

[0084] In this embodiment, specifically, the emergency discharge air unit 400 includes an emergency discharge valve 401, an oil safety valve 402 and a gas safety valve 403;

[0085] The inlet end of the emergency vent valve 401 is connected to the second outlet end of the air inlet separation tank 104;

[0086] The inlet end of the oil safety valve 402 is connected to the third outlet end of the oil-gas separator 204;

[0087] The inlet end of the gas separation safety valve 403 is connected to the second gas outlet end of the gas outlet separation tank 301;

[0088] The outlet end of the emergency vent valve 401, the outlet end of the oil safety valve 402 and the outlet end of the gas safety valve 403 are all connected to the emergency vent pipe.

[0089] In this embodiment, specifically, the two-stage air supply unit 500 includes a primary air supply regulating valve 501, a secondary air supply regulating valve 502, and an air supply cut-off valve 503 connected to the inlet end of the secondary air supply regulating valve 502;

[0090] The inlet end of the gas supply cut-off valve 503 is connected to the natural gas pipeline (that is, connected to the user-side natural gas pipeline for natural gas supply);

[0091] The outlet end of the secondary air supply regulating valve 502 is connected to the inlet end of the air intake cut-off valve 101;

[0092] The outlet end of the primary air supply regulating valve 501 is connected to the inlet end of the air intake cut-off valve 101;

[0093] The inlet end of the primary air supply regulating valve 501 is connected to the third outlet end of the air outlet separation tank 301. The third outlet end of the air outlet separation tank 301, also called the air supply outlet end, is used to output supplementary gas to the primary air supply regulating valve 501 in the two-stage air supply unit 500.

[0094] In certain preferred embodiments, the air-cooled heat exchanger 206H is equipped with an air-cooled fan 206F.

[0095] In certain preferred embodiments, the oil-cooled heat exchanger 209H is equipped with an oil-cooled fan 209F.

[0096] In some preferred embodiments, the gas compressor 203 uses a variable frequency single screw.

[0097] In certain preferred embodiments, when the gas compressor 203 is in the on-load state, or the gas compressor 203 is in the off-load state, the reflux shut-off valve 214 is opened;

[0098] When the gas compressor 203 is started and loaded, or the gas compressor 203 is shut down and unloaded, the reflux cut-off valve 214 is closed;

[0099] When the gas compressor 203 is running, the gas outlet shut-off valve 303 is opened;

[0100] When the gas compressor 203 is turned off, the gas outlet shut-off valve 303 is closed;

[0101] When the secondary air supply regulating valve 502 is opened, the air supply cut-off valve 503 is opened; when the secondary air supply regulating valve 502 is closed, the air supply cut-off valve 503 is closed.

[0102] In certain preferred embodiments, the air inlet shut-off valve 101 , the air outlet shut-off valve 303 , and the return shut-off valve 214 are all interlocked with the gas compressor 203 .

[0103] In certain preferred embodiments, the air-cooling temperature transmitter 207 is interlockedly controlled with the air-cooling fan 206F.

[0104] In certain preferred embodiments, the oil temperature transmitter 213 is interlockedly controlled with the oil cooling fan 209F.

[0105] In certain preferred embodiments, both the outlet gas pressure transmitter 208 and the liquid level transmitter 210 are interlocked with the gas compressor 203 .

[0106] In certain preferred embodiments, the oxygen content detector 103 is interlocked with the emergency vent valve 401 and the gas compressor 203 .

[0107] In certain preferred embodiments, both the primary air supply regulating valve 501 and the secondary air supply regulating valve 502 are interlocked with the intake air pressure transmitter 106 for control.

[0108] In certain preferred embodiments, the infusion pump 105 is interlockedly controlled with the high and low liquid level indicators of the air intake separation tank 104 .

[0109] In certain preferred embodiments, the outlet liquid discharge valve 304 is interlockedly controlled with the high and low liquid level indicators of the gas outlet separation tank 301 .

[0110] In some preferred embodiments, a hand valve 215 with adjustable opening is further included, and the hand valve 215 is connected in parallel with the loading valve 202. The hand valve 215 is always open when the gas compressor 203 is started for loading, after loading is completed, when the gas compressor 203 is shut down for unloading, and after unloading is completed.

[0111] The hand valve 215 is arranged in parallel with the loading valve 202 (parallel here also includes physical pipeline parallel, that is, pipeline parallel arrangement), and the ratio of the diameter of the hand valve 215 to the diameter of the loading valve 202 is 1:8 to 10. One end of the hand valve 215 is connected to the inlet end of the loading valve 202, and the other end of the hand valve 215 is connected to the outlet end of the loading valve 202.

[0112] Taking one of the large tank air extraction pressurization separation systems provided in the above embodiments as an example, the relevant working principle / workflow thereof is explained by way of example:

[0113] In the air intake separation unit 100: the gas drawn from the large tank passes through the air intake cut-off valve 101 and the air intake flame arrester 102 in sequence, and then enters the air intake separation tank 104 for buffering and first gas-liquid separation to separate free water and / or some heavy hydrocarbons;

[0114] In the compression and delivery unit 200: the large tank gas after the first gas-liquid separation in the air intake separation unit 100 enters the compression and delivery unit 200, first passes through the air intake filter 201 for high-efficiency filtration and separation (to protect the gas compressor from impurities, high-efficiency filtration and separation also requires a filtration level of not less than 10μm), and then enters the moving equipment gas compressor 203 through the loading valve 202 for normal temperature compression and pressurization to the first compression and pressurization threshold (such as: 0.6MPa), the pressurized gas enters the oil-gas separator 204 for gas and oil separation, the separated gas is discharged from the first gas outlet end of the oil-gas separator 204, and is unidirectionally discharged through the oil-gas one-way valve 205 and is output to the air-cooled heat exchanger 206H for air-cooled heat exchange and cooling to room temperature, and then output to the pressurized separation unit 300;

[0115] In the pressurized separation unit 300: the pressurized gas at room temperature after being pressurized by the compression and delivery unit 200 enters the pressurized separation unit 300, first enters the gas outlet separation tank 301 for the second gas-liquid separation, and after the supersaturated water and / or part of the light hydrocarbons are separated, it is then output to the outside through the gas outlet flame arrester 302 and the gas outlet shut-off valve 303 in sequence; if the output gas is transported to the outside to the gas transmission network, that is, Figure 1 The main process of the system gas circuit includes the above-mentioned process / steps of gas intake separation, the process / steps of compression and transportation, and the process / steps of pressurization separation, completing the main process of the system gas circuit;

[0116] In the emergency air discharge unit 400: when the oxygen content measured by the oxygen content detector 103 in the air intake separation unit 100 is higher than the first preset oxygen content threshold (the first preset oxygen content threshold is adjustable, such as set to 5%), the emergency vent valve 401 in the emergency air discharge unit 400 is opened to discharge air urgently; when the pressure of the oil safety valve 402 in the emergency air discharge unit 400 exceeds its set pressure, the oil safety valve 402 is opened to discharge air urgently; when the pressure of the gas safety valve 403 in the emergency air discharge unit 400 exceeds its set pressure, the gas safety valve 403 is opened to discharge air urgently;

[0117] In the two-stage air supply unit 500: after the system is turned on, the first-stage air supply is turned on first (at this time, when the two-stage air supply unit 500 is in the first-stage air supply: the first-stage air supply regulating valve 501 is opened, and the second-stage air supply regulating valve 502 is closed), and the opening of the first-stage air supply regulating valve 501 is adjusted to stabilize the pressure value measured by the intake pressure transmitter 106 near the first preset pressure stable value; when the opening of the first-stage air supply regulating valve 501 is adjusted to the maximum and is still insufficient, open the second-stage air supply regulating valve 502 to start the second-stage air supply (when the second-stage air supply: the first-stage air supply regulating valve 501 and the second-stage air supply regulating valve 502 are both opened, and the opening of the first-stage air supply regulating valve 501 reaches the maximum value), and the opening of the second-stage air supply regulating valve 502 is adjusted to stabilize the pressure value measured by the intake pressure transmitter 106 near the second preset pressure stable value.

[0118] In this example, the gas compressor 203 is the system's dynamic equipment. While compressing the gas, it also realizes the extraction of volatile oil and gas from the oil storage tank. The large tank extraction mentioned in this article refers to the volatile oil and gas being pumped into the oil storage tank by the system's dynamic equipment gas compressor.

[0119] In this example, the following are also included:

[0120] The compressor is started and loaded; specifically, the following steps are performed: when the measured value of the intake pressure transmitter 106 rises to a first preset pressure threshold (the first preset pressure threshold is adjustable, such as being set to 500Pa), the intake shut-off valve 101 is opened, and the gas compressor 203 is started for loading (the default time for startup loading is 15S), and after loading is completed, the loading valve 202 is opened;

[0121] Compressor shutdown unloading; specifically, including: when the measured value of the intake pressure transmitter 106 drops to the second preset pressure threshold (the second preset pressure threshold is adjustable, such as set to 200Pa), the intake shut-off valve 101 is closed, the loading valve 202 is closed, and then the gas compressor is unloaded (the shutdown unloading is 15s by default), and after the unloading is completed, the gas compressor 203 is closed;

[0122] Liquid collection and recovery; specifically, the liquid separated from the first gas-liquid separation in the gas inlet separation tank 104 and the liquid separated from the second gas-liquid separation in the gas outlet separation tank 301 are transported to a designated liquid storage tank for liquid collection and recovery.

[0123] In this example, when the gas compressor 203 is in the on-load state, or the gas compressor 203 is in the off-load state, the reflux cut-off valve 214 is opened;

[0124] When the gas compressor 203 is started up and loaded, or when the gas compressor 203 is shut down and unloaded, the reflux cut-off valve 214 is closed.

[0125] Specifically, when the gas compressor 203 is started and loaded, the air intake shut-off valve 101 is opened, the loading valve 202 is closed, and the reflux shut-off valve 214 is opened. At this time, the gas from the air intake separation unit 100 is input into the gas compressor 203 through the air intake filter 201 and the manual valve 215, and / or the return air from the oil-gas separator 204 is input into the gas compressor 203 through the reflux shut-off valve 214 and the manual valve 215, to ensure the continuous operation of the gas compressor 203.

[0126] When the gas compressor 203 is loaded, the air intake cut-off valve 101 is opened, the loading valve 202 is opened, and the reflux cut-off valve 214 is closed. At this time, the gas compressor 203 operates normally to achieve the extraction of volatile oil and gas from the oil storage tank and gas compression.

[0127] When the gas compressor 203 is shut down and unloaded, the air intake shut-off valve 101 is closed, the loading valve 202 is closed, and the reflux shut-off valve 214 is opened. At this time, the return air from the oil-gas separator 204 is input into the gas compressor 203 through the reflux shut-off valve 214 and the manual valve 215 to reduce the pressure in the oil-gas separator 204 until the gas compressor 203 is shut down after the unloading is completed.

[0128] An additional flow path is provided by providing a hand valve 215 with an adjustable opening, which is arranged in parallel with the loading valve 202 and has a flow ratio range of 1:8 to 10 with respect to the loading valve 202. In other words, a bypass arranged in parallel with the loading valve 202 and the pipeline therein is provided by the hand valve 215 with an adjustable opening and the pipeline therein, and the hand valve 215 and the pipeline therein have a flow ratio range of 1:8 to 10 with respect to the loading valve 202 and the pipeline therein.

[0129] Based on the parallel arrangement of the loading valve 202 and its pipeline (relatively the main pipeline) and the hand valve 215 and its pipeline (relatively the bypass, referred to as the hand valve 215 bypass or bypass hand valve 215 in the text), and the structure and construction formed by the limitation of the above-mentioned diameter ratio range, in this scheme / system / method / example, when the loading valve 202 is opened, the gas mainly flows to the gas compressor 203 through the loading valve 202, and when the gas compressor 203 is started for loading or shut down for unloading and the loading valve 202 is closed, it can be ensured that a trace amount of gas can enter the gas compressor 203 through the bypass where the hand valve 215 is located. By setting the bypass hand valve 215, the loading and unloading performance of the entire scheme / system / method can be optimized, the stability of the opening and closing of the gas compressor 203 can be ensured, the system stability can be improved, the operation efficiency can be optimized, the energy consumption can be reduced, the service life can be extended, etc.

[0130] At the same time, the bypass structure formed by the hand valve 215 and its pipeline relative to the loading valve 202 and its pipeline allows the present solution / system to adjust the opening of the hand valve 215 as needed, which is more conducive to flexibly, efficiently and reliably maintaining a stable pressure in the system.

[0131] In this example, when the gas compressor 203 is running, the gas outlet shut-off valve 303 is opened; when the gas compressor 203 is shut down, the gas outlet shut-off valve 303 is closed.

[0132] In this embodiment, the loading and unloading time of the gas compressor is very short (15s by default). The purpose of startup loading and shutdown unloading is to protect the pressure stabilization and oil return of the compressor and play a buffering role (that is, start slowly and shut down slowly).

[0133] In this example, the following are also included:

[0134] Air cooling start and stop; specifically, when the temperature measured by the air cooling temperature transmitter 207 is higher than the first preset air cooling threshold (the first preset air cooling threshold is adjustable, such as set to 40°C), the air cooling fan 206F is turned on; when the temperature measured by the air cooling temperature transmitter 207 is lower than the second preset air cooling threshold (the second preset air cooling threshold is adjustable, such as set to 25°C), the air cooling fan 206F is turned off;

[0135] Oil cooling start and stop; specifically, when the temperature measured by the oil temperature transmitter 213 is higher than the first preset oil cooling threshold (the first preset oil cooling threshold is adjustable, such as set to 60°C), the oil cooling fan 209F is turned on; when the temperature measured by the oil temperature transmitter 213 is lower than the second preset oil cooling threshold (the second preset oil cooling threshold is adjustable, such as set to 50°C), the oil cooling fan 209F is turned off;

[0136] In some preferred embodiments, this example specifically also includes:

[0137] Interlocking alarm; specifically including: when the pressure measured by the outlet pressure transmitter 208 is higher than the third preset pressure threshold (the third preset pressure threshold is adjustable, such as set to 0.66MPa), the interlocking alarm is triggered and the compressor is shut down (and shutting down the compressor is also: shutting down the compressor to stop the compressor from running); when the liquid level measured by the liquid level transmitter 210 is lower than the first preset liquid level threshold (the first preset liquid level threshold is adjustable, such as set to 50mm), the interlocking alarm is triggered and the compressor is shut down; when the oxygen content measured by the oxygen content detector 103 is higher than the first preset oxygen content threshold (the first preset oxygen content threshold is adjustable, such as set to 5%), the emergency vent valve 401 is opened for emergency venting, and the interlocking alarm is triggered and the compressor is shut down.

[0138] In this example, in the compression and delivery unit 200, the temperature of the gas pressurized by the gas compressor 203 is between 60 and 80°C, and then it is cooled to a normal temperature of about 45°C by the air-cooled heat exchanger 206H.

[0139] In this example, in the above-mentioned compression and delivery unit 200: the first compression pressurization threshold is set to 0.6 MPa.

[0140] In this example, in the above-mentioned compression and delivery unit 200: the oil and gas one-way valve 205 is a mechanical one, and its pressure setting value is 0.4 MPa.

[0141] In this example, the gas compressor used is a variable frequency single-screw compressor. Combined with oil injection and exhaust cooling, the exhaust temperature is no higher than 45°C, and the system's normal temperature transportation is safe and reliable.

[0142] In this example, the adjustable opening of the first-stage air supply regulating valve 501 is 0-X%; the adjustable opening of the second-stage air supply regulating valve 502 is 0-Y%;

[0143] Specifically, in this example, after the system is turned on, the first-level air supply is turned on (during the first-level air supply: the first-level air supply regulating valve 501 is opened, and the second-level air supply regulating valve 502 is closed), and the opening of the first-level air supply regulating valve 501 is adjusted and controlled according to the pressure value measured by the intake pressure transmitter 106, so that the pressure value measured by the intake pressure transmitter 106 is stabilized near the first preset pressure stable value (such as the first preset pressure stable value is set to 150Pa, and the first preset pressure stable value is such as 150±5Pa);

[0144] When the opening feedback of the primary air supply regulating valve 501 is greater than the setting value of the secondary air supply regulating valve 502 (that is, when the primary air supply is insufficient, it can also be said that when the opening of the primary air supply regulating valve 501 reaches X%), the secondary air supply regulating valve 502 opens, and the secondary air supply is started (during the secondary air supply: the primary air supply regulating valve 501 and the secondary air supply regulating valve 502 are both opened, and the opening of the primary air supply regulating valve 501 reaches the maximum value X%);

[0145] When the secondary air supply regulating valve 502 is opened and the secondary air supply is performed, the opening degree of the secondary air supply regulating valve 502 is adjusted and controlled according to the pressure value measured by the intake air pressure transmitter 106, so that the pressure value measured by the intake air pressure transmitter 106 is stabilized near the second preset pressure stable value (for example, the second preset pressure stable value is set to 100Pa, and the second preset pressure stable value is such as 100±5Pa);

[0146] When the opening feedback of the first-stage air supply regulating valve 501 is less than the closing setting value of the second-stage air supply regulating valve 502, the second-stage air supply regulating valve 502 is closed;

[0147] When the secondary air supply regulating valve 502 is opened, the air supply cut-off valve 503 is opened; when the secondary air supply regulating valve 502 is closed, the air supply cut-off valve 503 is closed.

[0148] In this example, the first preset pressure stability value is set to 150 Pa. The vicinity of the first preset pressure stability value is 150±5 Pa.

[0149] In this example, the second preset pressure stability value is set to 100 Pa. The second preset pressure stability value is around 100±5Pa.

[0150] In this example, the opening setting value of the secondary air supply regulating valve 502 is set to 100Pa.

[0151] In this example, the closing setting value of the secondary air supply regulating valve 502 is set to 150Pa;

[0152] In this example, the set pressure of the oil safety valve 402 is set to 0.72Mpa; the set pressure of the gas safety valve 403 is set to 0.72Mpa. In case of overpressure, that is, when the pressure of the oil safety valve 402 and / or the gas safety valve 403 exceeds their respective set pressures, the corresponding safety valve is opened, and the gas will be urgently discharged from the exhaust port of the corresponding safety valve, and the excess pressure of the entire compression, transportation and pressurization separation system will be discharged in time to prevent the entire system from continuing to increase pressure, effectively preventing accidents. Of course, in some examples, the set pressure of the oil safety valve 402 can be set to 0.72±0.03Mpa, and the set pressure of the gas safety valve 403 can be set to 0.72±0.03Mpa.

[0153] Specifically, when the pressure of the oil safety valve 402 exceeds its set pressure, the oil safety valve 402 is opened, and the gas is discharged from the exhaust port of the safety valve, and the excess pressure of the entire compression and delivery system / compression and delivery unit is discharged in time to prevent the entire system from continuing to increase pressure, effectively preventing accidents. When the pressure of the gas safety valve 403 exceeds its set pressure, the gas safety valve 403 is opened, and the gas is discharged from the exhaust port of the safety valve, and the excess pressure of the entire pressurized separation system / pressurized separation unit is discharged in time to prevent the entire system from continuing to increase pressure, effectively preventing accidents.

[0154] In this example, the first preset pressure threshold is adjustable, and in this example, the first preset pressure threshold is set to 500Pa.

[0155] In this example, the second preset pressure threshold is adjustable. In this example, the second preset pressure threshold is set to 200Pa.

[0156] In this example, the third preset pressure threshold is adjustable. In this example, the third preset pressure threshold is set to 0.66 MPa.

[0157] In this example, the first preset air cooling threshold is adjustable. In this example, the first preset air cooling threshold is set to 40°C.

[0158] In this example, the second preset air cooling threshold is adjustable. In this example, the second preset air cooling threshold is set to 25°C.

[0159] In this example, the first preset oil cooling threshold is adjustable. In this example, the first preset oil cooling threshold is set to 60°C.

[0160] In this example, the second preset oil cooling threshold is adjustable. In this example, the second preset oil cooling threshold is set to 50°C.

[0161] In this example, the first preset liquid level threshold is adjustable, and in this example, the first preset liquid level threshold is set to 50 mm.

[0162] In this example, the first preset oxygen content threshold is adjustable. In this example, the first preset oxygen content threshold is set to 5%.

[0163] In this example, in the above-mentioned liquid collection recovery: the liquid separated from the first gas-liquid separation by the air inlet separation tank 104 is passed through the infusion pump 105, and the liquid separated from the second gas-liquid separation by the air outlet separation tank 301 is passed through the outlet discharge valve 304, and then combined and transported to the designated liquid storage tank.

[0164] In this example, the infusion pump 105 is started and stopped according to the high and low liquid level indications (such as a liquid level sensor) of the air intake separation tank 104.

[0165] In this example, the outlet liquid discharge valve 304 is started and stopped according to the high and low liquid level indications (such as a liquid level sensor) of the gas outlet separation tank 301.

[0166] In the present invention, the interlocking control between the components, the opening / closing / starting / stopping of the components, the switching / conversion / adjustment of the operation modes, the opening / closing or opening adjustment of the related valves can be performed manually, or the automatic switching / control / adjustment can be realized through the PLC control logic. The automatic switching / control / adjustment here can be realized by the conventional control logic in the prior art, which will not be described in detail. In some preferred embodiments, various transmitters and / or sensors can be further combined to realize the automatic switching / conversion / adjustment of the related operation modes.

[0167] The gas pipelines described herein are connected, which can also be referred to as gas lines; the gas pipelines described herein can also be referred to as gas pipelines. The oil pipelines described herein can also be referred to as oil pipelines. The interlocking control described herein can also be referred to as interlocking control. The inlet / outlet described herein can also be referred to as inlet / outlet, or inlet / outlet end.

[0168] The pressurized separation system for large tank gas extraction described in the article may also be called a compressed conveying pressurized separation system for large tank gas extraction, or a pressurized separation compression conveying system for large tank gas extraction, or a pressurized separation system for / based on large tank gas extraction, or a pressurized separation system for / based on compressed conveying pressurized separation system for large tank gas extraction, or a pressurized separation compression conveying system for / based on large tank gas extraction. The pressurized separation compression conveying method for large tank gas extraction described in the article may also be called a pressurized separation compression conveying method for / based on large tank gas extraction. The pressurized separation compression conveying system described in the article may also be called a pressurized separation compression conveying device. The " / " described in the article represents or.

[0169] The above embodiments do not limit the present invention. Various changes and modifications made by relevant personnel without departing from the technical concept of the present invention are all within the protection scope of the present invention.

Claims

1. A pressurized separation system for large tank extraction, characterized in that: The invention comprises an air intake separation unit (100), a compression and delivery unit (200) connected to the gas phase pipeline of the air intake separation unit (100), a pressurization separation unit (300) connected to the gas phase pipeline of the compression and delivery unit (200), an emergency air discharge unit (400) connected to the gas phase pipelines of the air intake separation unit (100), the compression and delivery unit (200) and the pressurization separation unit (300), and a two-stage air supply unit (500) connected to the gas phase pipelines of the air intake separation unit (100) and the pressurization separation unit (300); The emergency air discharge unit (400) comprises an oil safety valve (402) and a gas safety valve (403); The two-stage air supply unit (500) comprises a primary air supply regulating valve (501) and a secondary air supply regulating valve (502).

2. The pressurized separation system for large tank gas extraction according to claim 1 is characterized in that: The air intake separation unit (100) comprises an air intake cut-off valve (101), an air intake flame arrester (102) connected to the air outlet end of the air intake cut-off valve (101), an air intake separation tank (104) connected to the air outlet end of the air intake flame arrester (102), an inlet liquid discharge valve (107) connected to the liquid outlet end of the air intake separation tank (104), and an infusion pump (105) connected to the outlet end of the inlet liquid discharge valve (107).

3. The pressurized separation system for large tank gas extraction according to claim 2 is characterized in that: The gas inlet of the large tank of the system is connected to the inlet end of the air intake cut-off valve (101); An intake pressure transmitter (106) is provided on a pipeline connecting the gas inlet of the large tank and the inlet end of the intake cut-off valve (101); an oxygen content detector (103) is provided on a pipeline connecting the outlet of the intake flame arrester (102) and the gas inlet of the intake separation tank (104).

4. The pressurized separation system for large tank gas extraction according to claim 1 is characterized in that: The gas phase pipeline of the compression and delivery unit (200) comprises an air intake filter (201), a loading valve (202) connected to the outlet end of the air intake filter (201), a gas compressor (203) connected to the outlet end of the loading valve (202), an oil-gas separator (204) connected to the outlet end of the gas compressor (203), an oil-gas check valve (205) connected to the first air outlet end of the oil-gas separator (204), a reflux cut-off valve (214) connected to the second air outlet end of the oil-gas separator (204), and an air-cooled heat exchanger (206H) connected to the outlet end of the oil-gas check valve (205); The other end of the backflow cut-off valve (214) is connected to the inlet end of the loading valve (202).

5. The pressurized separation system for large tank gas extraction according to claim 4 is characterized in that: The outlet end of the air-cooled heat exchanger (206H) is connected to the inlet end of the air outlet separation tank (301); the inlet end of the air intake filter (201) is connected to the first air outlet end of the air intake separation tank (104); and / or An oil temperature transmitter (213) is provided on the pipeline connecting the outlet of the gas compressor (203) and the inlet of the oil-gas separator (204); an air-cooled temperature transmitter (207) and an outlet air pressure transmitter (208) are provided on the outlet pipeline of the air-cooled heat exchanger (206H); A liquid level transmitter (210) is provided at the liquid storage portion at the lower part of the oil-gas separator (204).

6. The pressurized separation system for large tank gas extraction according to claim 1 is characterized in that: The oil phase pipeline of the compression and delivery unit (200) comprises an oil-gas separator (204), an oil-cooling heat exchanger (209H) connected to the oil outlet end of the oil-gas separator (204), an oil filter (211) connected to the outlet end of the oil-cooling heat exchanger (209H), and an oil cut-off valve (212) connected to the outlet end of the oil filter (211); the other end of the oil cut-off valve (212) is connected to the oil return port of the gas compressor (203).

7. The pressurized separation system for large tank gas extraction according to claim 1 is characterized in that: The pressurized separation unit (300) comprises a gas outlet separation tank (301), a gas outlet flame arrester (302) connected to a first gas outlet end of the gas outlet separation tank (301), a gas outlet cut-off valve (303) connected to an outlet end of the gas outlet flame arrester (302), and an outlet liquid discharge valve (304) connected to a liquid outlet end of the gas outlet separation tank (301); The outlet end of the gas outlet cut-off valve (303) is connected to the user-side pipe network; the other end of the outlet liquid discharge valve (304) is connected to the liquid discharge outlet.

8. The pressurized separation system for large tank gas extraction according to claim 1 is characterized in that: The emergency discharge and emptying unit (400) further comprises an emergency discharge valve (401); The inlet end of the emergency vent valve (401) is connected to the second outlet end of the air inlet separation tank (104); The inlet end of the oil safety valve (402) is connected to the third outlet end of the oil-gas separator (204); The inlet end of the gas separation safety valve (403) is connected to the second gas outlet end of the gas outlet separation tank (301); The outlet end of the emergency vent valve (401), the outlet end of the oil safety valve (402) and the outlet end of the gas safety valve (403) are all connected to the emergency vent pipe.

9. The pressurized separation system for large tank gas extraction according to claim 1 is characterized in that: The two-stage air supply unit (500) further comprises an air supply cut-off valve (503) connected to the inlet end of the secondary air supply regulating valve (502); The inlet end of the gas supply cut-off valve (503) is connected to the natural gas pipeline; The outlet end of the secondary air supply regulating valve (502) is connected to the inlet end of the air intake cut-off valve (101); The outlet end of the first-stage air supply regulating valve (501) is connected to the inlet end of the air intake cut-off valve (101); The inlet end of the primary air supply regulating valve (501) is connected to the third air outlet end of the air outlet separation tank (301).

10. The pressurized separation system for large tank gas extraction according to claim 1, characterized in that: The air-cooled heat exchanger (206H) is equipped with an air-cooled fan (206F); The oil-cooling heat exchanger (209H) is equipped with an oil-cooling fan (209F); The gas compressor (203) adopts a variable frequency single screw.

11. The pressurized separation system for large tank gas extraction according to claim 1 is characterized in that: When the gas compressor (203) is in a powered-on loading state, or the gas compressor (203) is in a powered-off unloading state, the reflux cut-off valve (214) is opened; When the gas compressor (203) is started up and loaded, or when the gas compressor (203) is shut down and unloaded, the reflux cut-off valve (214) is closed; When the gas compressor (203) is running, the gas outlet shut-off valve (303) is opened; When the gas compressor (203) is turned off, the gas outlet shut-off valve (303) is closed; When the secondary air supply regulating valve (502) is opened, the air supply cut-off valve (503) is opened; when the secondary air supply regulating valve (502) is closed, the air supply cut-off valve (503) is closed.

12. The large tank gas extraction pressurization separation system according to claim 1, characterized in that: The air inlet shut-off valve (101), the air outlet shut-off valve (303) and the return shut-off valve (214) are all interlocked with the gas compressor (203); and / or The air-cooling temperature transmitter (207) is interlocked with the air-cooling fan (206F); and / or The oil temperature transmitter (213) is interlocked with the oil cooling fan (209F); and / or The outlet pressure transmitter (208) and the liquid level transmitter (210) are both interlocked with the gas compressor (203); and / or The oxygen content detector (103) is interlocked with the emergency vent valve (401) and the gas compressor (203); and / or The primary air supply regulating valve (501) and the secondary air supply regulating valve (502) are both interlocked with the air intake pressure transmitter (106); and / or The infusion pump (105) is interlocked with the air inlet separation tank (104); and / or The outlet liquid discharge valve (304) is interlocked with the gas outlet separation tank (301) for control.

13. The pressurized separation system for large tank gas extraction according to claim 4, characterized in that: Also includes a hand valve (215) with adjustable opening; and / or The hand valve (215) is arranged in parallel with the loading valve (202) pipeline; and / or The ratio of the flow volume of the hand valve (215) to the flow volume of the loading valve (202) is 1:8-10.

14. The pressurized separation system for large tank gas extraction according to claim 11, characterized in that: When the gas compressor (203) is started and loaded, the air intake cut-off valve (101) is opened, the loading valve (202) is closed, and the return flow cut-off valve (214) is opened; When the gas compressor (203) is loaded, the air intake cut-off valve (101) is opened, the loading valve (202) is opened, and the reflux cut-off valve (214) is closed; When the gas compressor (203) is shut down for unloading, the air intake cut-off valve (101) is closed, the loading valve (202) is closed, and the return cut-off valve (214) is opened until the gas compressor (203) is shut down after unloading is completed.

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