Refrigerant recovery device of refrigerant compressor

Abstract

The invention relates to a refrigerant compressor refrigerant recovery device which comprises an original separator, a front coarse filter, a front fine filter, an adsorption tank and a dust filter and is connected with a refrigerant recovery port. The adsorption tank is connected with a regenerated gas feeding pipeline and a regenerated gas emptying pipeline, and is provided with a corresponding valve; and a thermometer and a differential pressure gauge are also arranged on the pipeline. On the premise that safety is guaranteed, the content of compressor oil stains and impurities in the recycled refrigerant is greatly reduced, and downstream equipment is not affected any more. And the normal working process and the regeneration process are completely separated through the control valve, so that the two process flows are ensured not to interfere with each other, the refrigerant can be well prevented from being influenced by the regeneration gas during recovery, and the mixed refrigerant can be recovered and reused after reaching the standard.

Description

Technical Field

[0001] The present invention relates to the field of natural gas mixed refrigerant recovery, in particular to a refrigerant compressor refrigerant recovery device. Background Art

[0002] The statements in this section only provide background information related to the present disclosure, and these statements may constitute prior art. In the process of implementing the present invention, the inventors found that there are at least the following problems in the prior art.

[0003] LNG plants are used to liquefy produced natural gas for transportation and storage. The MRC or C3+MRC processes are commonly used in LNG plants both domestically and internationally. These processes utilize a mixed refrigerant to cool the natural gas in stages, ultimately reducing the pressure to atmospheric pressure through a throttle valve for liquefied storage. However, during the refrigerant circulation process, small amounts of leakage are inevitable. These leaks contain compressor oil and impurities, which can lead to material waste if flared. Furthermore, mixed refrigerants are relatively expensive, so refrigerant recovery is generally practiced.

[0004] Mixed refrigerants contain six recyclable components and require removal of oil, solid impurities, and other contaminants before they can be recycled. Currently, refrigerant recovery solutions typically utilize refrigerant recovery pumps or compressors. The main components of the mixed refrigerant in LNG refrigerant compressor refrigerant recovery units are: 22.73 mol% methane, 32.75 mol% ethylene, 20.5 mol% propane, 13.1 mol% isopentane, 10.93 mol% nitrogen, and 5 ppm compressor lubricant. Because mixed refrigerants can form explosive mixtures with air or oxidants, when the natural gas content in air reaches 5-15%, exposure to high heat, sparks, or open flames poses a risk of combustion and explosion. The highly flammable nature of mixed refrigerants (minimum ignition energy of 0.28 MJ) ensures that natural gas processing environments always present potential fire and explosion hazards. Overpressure can cause physical explosions, potentially leading to secondary chemical explosions and fire hazards. When mixed refrigerants in pipelines are exposed to high heat, the internal pressure of the container increases, posing a risk of cracking and physical explosion. Its internal pressure will increase with the increase of temperature. When it exceeds the actual pressure limit of the pipeline, cracking and physical explosion will occur, which may lead to combustion and explosion.

[0005] Due to the above-mentioned characteristics of the mixed refrigerant, when using a refrigerant recovery compressor for refrigerant recovery, generally only a simple filter is designed before the LNG refrigerant compressor (liquid phase refrigerant in the outlet separator tank) for simple filtration. However, according to on-site production feedback, it was found that the processing capacity, efficiency and accuracy of the original refrigerant filtration and separation system could no longer meet the actual needs, resulting in excessive compressor oil and impurity content in the recovered refrigerant. The peak oil content even reached 5ppm, causing a certain impact on downstream equipment. In response to this problem, the applicant proposed a technical rectification to remove the oil and other impurities in the refrigerant recovery gas, thereby achieving standard refrigerant recovery and reuse of the refrigerant compressor.

[0006] However, how to achieve efficient removal of oil and impurities from mixed refrigerants while ensuring safety is a problem that needs to be solved in this field. Summary of the Invention

[0007] In view of the above problems, the present invention aims to solve some of the problems in the prior art, or at least alleviate these problems.

[0008] The refrigerant recovery device of the refrigerant compressor includes an original separator and a filtering device, which are connected through a pipeline; the filtering device is connected to the refrigerant recovery port, and the refrigerant recovery port is used to connect to the LNG refrigerant compressor; the filtering device includes a pre-filter, an adsorption tank and a dust filter connected in sequence through pipelines; the pipeline between the pre-filter and the adsorption tank is connected to the regeneration gas inlet pipeline and the sewage pipeline; the pipeline between the adsorption tank and the dust filter is connected to the regeneration gas venting pipeline; a thermometer and a differential pressure gauge are provided on the pipeline to observe the temperature and pressure of the pipeline; the sewage pipeline is located at the bottom of the adsorption tank, and is provided with a sewage valve.

[0009] The refrigerant recovery device of the refrigerant compressor also includes a safety valve front valve, a safety valve rear valve, a regeneration gas flow valve, a bypass valve, a first pipeline valve and a second pipeline valve; the safety valve front valve and the safety valve rear valve are arranged on one of the pipelines between the adsorption tank and the regeneration gas vent pipeline, and the bypass valve is arranged on the other pipeline between the adsorption tank and the regeneration gas vent pipeline; the first pipeline valve is arranged at the outlet pipeline of the pre-filter; the regeneration gas flow valve is arranged at the regeneration gas inlet pipeline; the second pipeline valve is arranged at the inlet pipeline of the dust filter.

[0010] Furthermore, when the regeneration gas inlet pipeline is connected to the adsorption tank for regeneration, the first pipeline valve and the second pipeline valve are closed; the regeneration gas flow valve and the bypass valve are slowly opened; the valve before the safety valve and the valve after the safety valve are kept in a normally open state; the valve before the safety valve is used for system isolation and maintenance or replacement of the spare safety valve; the valve after the safety valve is used to isolate the discharge side; the sewage valve is kept in a normally closed state for system sewage discharge.

[0011] Preferably, the two pressure taking points of the pressure differential gauge are respectively located at the inlet pipe and the outlet pipe of the adsorption tank, and are respectively provided with root valves.

[0012] Preferably, the thermometer is provided at the outlet pipe of the adsorption tank, and the regeneration gas temperature is controlled by controlling the opening of the regeneration gas flow valve; the regeneration temperature is 120°C to 150°C, the regeneration time is 6h to 12h; the regeneration pressure is normal pressure; the operating temperature during normal operation is 40°C and the operating pressure is 0.3MPa.

[0013] Furthermore, the pre-filter includes a pre-coarse filter and a pre-fine filter; the filtration accuracy of the pre-coarse filter is: oil removal accuracy 1ppm, dust removal accuracy 1μm; the filtration accuracy of the pre-fine filter is: oil removal accuracy 0.01ppm, dust removal accuracy 0.01μm.

[0014] The dust filter is used to filter the abrasive dust generated by the adsorbent when the process gas passes through the adsorbent in the adsorption tank; the filtration accuracy is: oil removal accuracy 1ppm, dust removal accuracy 1μm; the maximum static pressure of the differential pressure gauge is 2.5MPa, and the accuracy is ±1.6%FS.

[0015] Furthermore, a regeneration gas flare is provided at the regeneration gas venting pipeline.

[0016] A refrigerant recovery method for a refrigerant compressor, which uses the refrigerant recovery device for a refrigerant compressor to recover refrigerant, comprises the following steps:

[0017] Keep the valves before and after the safety valve in the normally open state; keep the sewage valve in the normally closed state; keep the two root valves of the differential pressure gauge in the normally open state;

[0018] Close the first pipeline valve and the second pipeline valve;

[0019] Slowly open the regeneration gas flow valve and bypass valve, and control the opening of the regeneration gas flow valve to control the flow of regeneration gas, and finally control the regeneration gas temperature at 120℃~150℃, so as to activate and regenerate the adsorbent in the adsorption tank; the regeneration time is 6h~12h;

[0020] After regeneration is completed, open the first pipeline valve and the second pipeline valve, and close the regeneration gas flow valve and the bypass valve;

[0021] After checking that the switch status of the above valves is correct, open the valve between the original separator and the refrigerant recovery port, so that the mixed refrigerant output from the original separator passes through the pre-coarse filter, pre-fine filter, adsorption tank and dust filter in sequence, and finally enters the LNG refrigerant compressor through the refrigerant recovery port.

[0022] The present invention has the following beneficial effects:

[0023] 1. This application passes the refrigerant output from the original separator through a pre-filter, an adsorption tank, and a dust filter in sequence, and sets a thermometer and a differential pressure gauge in the pipeline. This can greatly reduce the content of compressor oil and impurities in the recovered refrigerant while ensuring safety, and no longer affect downstream equipment, thus achieving the recovery and reuse of mixed refrigerant that meets standards;

[0024] 2. In order to prevent the refrigerant filtration process from being affected by the regeneration gas, the applicant installed multiple valves and strictly controlled the opening and closing of the valves to completely separate the normal working process from the regeneration process, ensuring that the two processes do not interfere with each other, which can effectively prevent the refrigerant filtration from being affected by the regeneration gas;

[0025] 3. This application changes the pre-filter into a pre-coarse filter and a pre-fine filter, so that it can better cooperate with the adsorption tank and the dust filter. The adsorption efficiency of the adsorption tank is further improved by the staged filtration method, and the overall refrigerant recovery and reuse rate is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The above structure of the present invention can be further illustrated by the following non-limiting embodiments given in the accompanying drawings.

[0027] Figure 1 It is a process pipeline flow chart of the present invention.

[0028] Among them: 1-original separator; 2-pre-coarse filter; 3-pre-fine filter; 4-differential pressure gauge; 5-adsorption tank; 6-dust filter; 7-thermometer; 8-regeneration gas inlet pipeline; 9-refrigerant recovery port; 10-regeneration gas vent pipeline; 11-sewage pipeline; 104-first pipeline valve; 105-second pipeline valve; 111-valve before safety valve; 112-bypass valve; 113-valve after safety valve; 115-regeneration gas flow valve; 116-sewage valve. DETAILED DESCRIPTION

[0029] The present invention will be further described below in conjunction with the accompanying drawings. The embodiments of the present invention are only used to illustrate the present invention and are not intended to limit the present invention. Without departing from the technical concept of the present invention, various substitutions and modifications can be made based on common technical knowledge and customary means in the field, and all should be included in the scope of the present invention.

[0030] To address the aforementioned issues, this application adds a refrigerant recovery device capable of meeting existing production capacity to the existing refrigerant recovery system and the existing refrigerant compressor outlet separator tank skid. This device is used in conjunction with the LNG refrigerant compressor (liquid-phase refrigerant in the outlet separator tank) filtration device. The specific solution is as follows.

[0031] like Figure 1 As shown, the refrigerant recovery device for the refrigerant compressor includes an original separator 1 and a filter device, which are connected by pipes. The filter device is connected to a refrigerant recovery port 9, which is used to connect to the LNG refrigerant compressor. The filter device includes a pre-filter, an adsorption tank 5, and a dust filter 6, which are connected in sequence by pipes. The pipe between the pre-filter and the adsorption tank 5 is connected to the regeneration gas supply pipe 8 and the sewage pipe 11. The pipe between the adsorption tank 5 and the dust filter 6 is connected to the regeneration gas vent pipe 10. The pipe is equipped with a thermometer 7 and a differential pressure gauge 4 for observing the temperature and pressure of the pipe. The sewage pipe 11 is located at the bottom of the adsorption tank 5 and is equipped with a sewage valve 116.

[0032] The original separator 1 is used to output the mixed refrigerant. The pre-filter performs a preliminary oil and dust removal process before the adsorption tank 5, enhancing the adsorption efficiency of the adsorption tank 5. The adsorption tank 5 contains an adsorbent that absorbs tiny oil molecules and other impurities in the gas, thereby completely removing oil and impurities from the gas. Because the activated carbon in the adsorbent must be regenerated upon initial use to remove moisture and activate the adsorbent, a regeneration gas inlet pipe 8 is connected to the adsorption tank 5. The regeneration gas is used to dry the adsorption tank 5, thereby activating the adsorbent. After activation, the regeneration gas is discharged through the regeneration gas vent pipe 10. The dust filter 6 primarily filters solid impurities from the gas. It is located after the adsorption tank 5 to filter dust generated by adsorption in the adsorption tank 5. The thermometer 7 and differential pressure gauge 4 monitor the temperature and pressure of the mixed refrigerant within the device, ensuring operation at safe temperatures and pressures and ensuring the safety of the mixed refrigerant recovered within the device.

[0033] Through the above design, the present application can greatly reduce the content of compressor oil and impurities in the recovered refrigerant while ensuring safety, no longer affecting downstream equipment, and achieve the recovery and reuse of mixed refrigerant that meets the standards.

[0034] In order to avoid the refrigerant recovery process being affected by the regeneration gas, the applicant set up multiple valves to completely separate the normal working process from the regeneration process, so that the regeneration operation process is only used for the activation of the adsorbent in the adsorption tank 5 before it is put into use. Figure 1 As shown, the refrigerant recovery device for the refrigerant compressor also includes a safety valve pre-valve 111, a safety valve post-valve 113, a regeneration gas flow valve 115, a bypass valve 112, a first pipeline valve 104, and a second pipeline valve 105. The safety valve pre-valve 111 and the safety valve post-valve 113 are located on one of the pipelines between the adsorption tank 5 and the regeneration gas vent pipeline 10, and the bypass valve 112 is located on the other pipeline between the adsorption tank 5 and the regeneration gas vent pipeline 10. The first pipeline valve 104 is located at the outlet pipeline of the prefilter; the regeneration gas flow valve 115 is located at the regeneration gas inlet pipeline 8; and the second pipeline valve 105 is located at the inlet pipeline of the dust filter 6. Using this valve design, the corresponding valves can be opened and closed separately during the normal working process and the regeneration process, ensuring that the two processes do not interfere with each other and effectively preventing the refrigerant recovery from being affected by the regeneration gas. The specific valve opening and closing methods are shown in the subsequent process flow.

[0035] When the regeneration gas inlet pipe 8 is connected to the adsorption tank 5 for regeneration, the first pipe valve 104 and the second pipe valve 105 must be closed. The regeneration gas flow valve 115 and the bypass valve 112 are then slowly opened, and the opening of the regeneration gas flow valve 115 is controlled to control the flow of the regeneration gas and ultimately the regeneration gas temperature. During this process, the temperature reading of the thermometer 7 should be monitored at all times to maintain the temperature between 120°C and 150°C. The opening of the regeneration gas flow valve 115 should be adjusted based on the changes in the thermometer reading.

[0036] The valve before the safety valve 111 and the valve after the safety valve 113 are kept in a normally open state; the valve before the safety valve 111 is used for system isolation and maintenance or replacement of the spare safety valve; the valve after the safety valve 113 is used to isolate the discharge side; the sewage valve 116 is kept in a normally closed state for system sewage discharge.

[0037] Furthermore, if the mixed refrigerant is exposed to high temperatures in the pipeline, the internal pressure of the container increases, posing a risk of cracking and physical explosion. This internal pressure increases with temperature, and when it exceeds the actual pressure limit of the pipeline, cracking and physical explosion will occur, potentially leading to combustion and explosion. Since the adsorbent in the adsorption tank 5 can reach temperatures as high as 280°C during regeneration, the differential pressure gauge 4 and thermometer 7 are preferably located near the adsorption tank 5 to ensure that the temperature and pressure values ​​in the dangerous area are immediately measured, ensuring that the temperature and pressure during refrigerant recovery and adsorbent activation remain within a safe range.

[0038] For this reason, Figure 1 As shown, the two pressure points of the differential pressure gauge 4 are located at the inlet and outlet pipes of the adsorption tank 5, respectively, and are each equipped with a root valve. The two root valves are provided to isolate the system during inspection and replacement of the differential pressure gauge. During normal operation and regeneration, the root valves are always open to measure the bed pressure differential of the adsorption tank 5.

[0039] In addition, if Figure 1 As shown, the thermometer 7 is installed at the outlet pipe of the adsorption tank 5 and controls the regeneration gas temperature by controlling the opening of the regeneration gas flow valve 115. The regeneration temperature is 120°C to 150°C, the regeneration time is 6 hours to 12 hours, and the regeneration pressure is atmospheric pressure. During normal operation, the operating temperature is 40°C and the operating pressure is 0.3 MPa. The maximum static pressure of the differential pressure gauge 4 is 2.5 MPa, with an accuracy of ±1.6% FS.

[0040] In order to further improve the adsorption efficiency of the adsorption tank 5, the present application also makes certain improvements to the pre-filter. Figure 1 As shown, the pre-filter includes a pre-coarse filter 2 and a pre-fine filter 3; the pre-coarse filter 2 is used for further oil removal and dust removal, and its filtration accuracy is: oil removal accuracy 1ppm, dust removal accuracy 1μm. The pre-fine filter 3 is used for fine filtration for oil removal and dust removal, and its filtration accuracy is: oil removal accuracy 0.01ppm, dust removal accuracy 0.01μm. The above-mentioned staged filtration method can effectively filter out oil molecules and impurities in the gas except for tiny oil molecules and other tiny impurities before the mixed refrigerant enters the adsorption tank 5, further improving the adsorption efficiency of the adsorption tank 5, thereby improving the overall refrigerant recovery and reuse rate. According to actual tests, the adsorption rate of the adsorption tank 5 can thus reach 99.9%.

[0041] In addition, the dust filter 6 is used to filter the abrasion dust generated by the adsorbent when the process gas passes through the adsorbent in the adsorption tank 5, so that the dust carried by the refrigerant passing through the adsorption tank 5 can also be effectively removed. The filtration accuracy of the dust filter 6 is: oil removal accuracy 1ppm, dust removal accuracy 1μm.

[0042] The regeneration gas venting pipe 10 may be provided with a regeneration gas flare.

[0043] The following is the process design of adsorption tank 5:

[0044] Design pressure: 2.0MPa

[0045] Design temperature: 55℃

[0046] Working pressure: 0.3MPa (normal operation), normal pressure (regeneration)

[0047] Working temperature: 40℃ (normal operation), 280℃ (regeneration)

[0048] Processing capacity: 300Nm 3 / h.

[0049] All pipelines are made of No. 20 seamless steel pipes. All instrument pipelines are made of 06Cr19Ni10 seamless steel pipes.

[0050] A refrigerant recovery method for a refrigerant compressor, which uses the refrigerant recovery device for a refrigerant compressor to recover refrigerant, comprises the following steps:

[0051] Keep the valve 111 before the safety valve and the valve 113 after the safety valve in the normally open state; keep the sewage valve 116 in the normally closed state; keep the two root valves of the pressure differential gauge 4 in the normally open state;

[0052] Close the first pipeline valve 104 and the second pipeline valve 105;

[0053] Slowly open the regeneration gas flow valve 115 and the bypass valve 112, and control the opening of the regeneration gas flow valve 115 to control the flow of the regeneration gas, and finally control the regeneration gas temperature at 120°C to 150°C, thereby activating and regenerating the adsorbent in the adsorption tank 5; the regeneration time is 6h to 12h;

[0054] After regeneration is completed, the first pipeline valve 104 and the second pipeline valve 105 are opened, and the regeneration gas flow valve 115 and the bypass valve 112 are closed;

[0055] After checking that the switch status of the above valves is correct, open the valve between the original separator 1 and the refrigerant recovery port 9, so that the mixed refrigerant output from the original separator 1 passes through the pre-coarse filter 2, the pre-fine filter 3, the adsorption tank 5 and the dust filter 6 in sequence, and finally enters the LNG refrigerant compressor through the refrigerant recovery port 9.

[0056] The following are the design parameters of the entire equipment:

[0057] 1) The operating pressure of the LNG refrigerant compressor refrigerant recovery device is P: 0.3MPa, the operating temperature is T: 40℃, and the processing capacity is Q: 300Nm3 / h; the operating pressure of the LNG refrigerant compressor (liquid phase refrigerant in the outlet separator tank) filter device is P: 4.1MPa, the operating temperature is T: 40℃, and the processing capacity is Q: 20m3 / h.

[0058] 2) Design pressure of LNG refrigerant compressor refrigerant recovery device: 2.0MPa; design pressure P of LNG refrigerant compressor (liquid phase refrigerant in outlet separator tank) filtration device: 4.6MPa.

[0059] 3) Design temperature of LNG refrigerant compressor refrigerant recovery device: 55℃; design temperature of LNG refrigerant compressor (liquid phase refrigerant in outlet separator tank) filtration device: 60℃.

[0060] Here's how the whole set is connected:

[0061] From the refrigerant recovery port of the refrigerant compressor to the original separator 1, then to the pre-coarse filter 2, then to the pre-fine filter 3, followed by the adsorption tank 5, then to the dust filter 6, and finally to the inlet pipes of the A machine filter system and the B machine filter system of the original refrigerant compressor.

[0062] The following is the complete process flow of the whole set of equipment:

[0063] The LNG refrigerant compressor refrigerant recovery device uses the normal "discharge" gas from the sealing packing of the LNG refrigerant compressor as the gas recovery source, separates most of the oil and impurities in the gas through the original separator 1, and then performs fine filtration for oil removal and dust removal through the pre-coarse filter 2, and then performs fine filtration for oil removal and dust removal through the pre-fine filter 3, and then uses the adsorption tank 5 to adsorb tiny oil molecules and other tiny impurities in the gas, thereby completely removing the oil and impurities in the gas, and finally filters the solid impurities in the gas through the dust filter 6 and returns to the inlet of the A machine filtration system and the B machine filtration system of the original refrigerant compressor for reuse; the LNG refrigerant compressor (outlet separator liquid refrigerant) filtration device uses the liquid refrigerant in the liquid phase outlet N5 of the outlet separator D-1404 as the processing object, and filters and separates the impurities in the liquid phase refrigerant through the filter separator, thereby completely removing the impurities contained in the refrigerant medium, and then transmits the qualified refrigerant medium to the back-end equipment.

[0064] Upon initial use, the adsorbent should be regenerated to remove moisture. The regeneration pressure is atmospheric pressure, the regeneration temperature is 120°C to 150°C, and the regeneration time is 6 to 12 hours. During regeneration, the first and second pipeline valves 104 and 105 must be closed. Then, the regeneration gas flow valve 115 and bypass valve 112 must be slowly opened. The opening of the regeneration gas flow valve 115 must be controlled to control the flow rate of the regeneration gas and, ultimately, the regeneration gas temperature. During this process, the temperature reading on thermometer 7 should be monitored at all times. The temperature should be maintained between 120°C and 150°C, and the opening of the regeneration gas flow valve 115 should be adjusted based on the changes in the thermometer reading.

[0065] During normal use, the valves before and after the safety valve must be fully open (not closed), and the bypass valve 112 must be closed (not opened). Note: Before and after each regeneration of the adsorbent, the valve 111 before the safety valve, the bypass valve 112, the valve 113 after the safety valve, as well as the first pipeline valve 104, the second pipeline valve 105, the regeneration gas flow valve 115, the sewage valve 116, and the two root valves at the pressure point of the differential pressure gauge 4 must be checked for their open and closed status. Only after ensuring that their open and closed status are correct can the next operation be carried out.

[0066] The fixed connection not specifically mentioned above may be a connection method such as riveting, welding, bolt connection, etc., and the movable connection may be a connection method such as hinged connection.

Claims

1. A refrigerant recovery device for a refrigerant compressor, comprising an original separator (1) and a filter device, which are connected via a pipeline; the filter device is connected to a refrigerant recovery port (9), and the refrigerant recovery port (9) is used to connect to an LNG refrigerant compressor; characterized in that: The filtering device comprises a pre-filter, an adsorption tank (5) and a dust filter (6) connected in sequence through a pipeline; the pipeline between the pre-filter and the adsorption tank (5) is connected to a regeneration gas inlet pipeline (8) and a sewage discharge pipeline (11); the pipeline between the adsorption tank (5) and the dust filter (6) is connected to a regeneration gas exhaust pipeline (10); a thermometer (7) and a differential pressure gauge (4) are provided on the pipeline for observing the temperature and pressure of the pipeline; the sewage discharge pipeline (11) is located at the bottom of the adsorption tank (5) and is provided with a sewage discharge valve (116).

2. The refrigerant recovery device for a refrigerant compressor according to claim 1, characterized in that: The invention also includes a safety valve front valve (111), a safety valve rear valve (113), a regeneration gas flow valve (115), a bypass valve (112), a first pipeline valve (104) and a second pipeline valve (105); the safety valve front valve (111) and the safety valve rear valve (113) are arranged on one of the pipelines between the adsorption tank (5) and the regeneration gas venting pipeline (10), and the bypass valve (112) is arranged on the other pipeline between the adsorption tank (5) and the regeneration gas venting pipeline (10); the first pipeline valve (104) is arranged at the outlet pipeline of the pre-filter; the regeneration gas flow valve (115) is arranged at the regeneration gas inlet pipeline (8); and the second pipeline valve (105) is arranged at the inlet pipeline of the dust filter (6).

3. The refrigerant recovery device for a refrigerant compressor according to claim 2, characterized in that: When the regeneration gas inlet pipeline (8) is connected to the adsorption tank (5) for regeneration, the first pipeline valve (104) and the second pipeline valve (105) are closed; the regeneration gas flow valve (115) and the bypass valve (112) are slowly opened; the valve before the safety valve (111) and the valve after the safety valve (113) are kept in a normally open state; the valve before the safety valve (111) is used for system isolation and maintenance or replacement of the spare safety valve; the valve after the safety valve (113) is used for isolating the discharge side; and the sewage valve (116) is kept in a normally closed state for system sewage discharge.

4. The refrigerant recovery device for a refrigerant compressor according to claim 1 or 2, characterized in that: The two pressure points of the pressure differential gauge (4) are respectively located at the inlet pipe and the outlet pipe of the adsorption tank (5), and are respectively provided with root valves.

5. The refrigerant recovery device for a refrigerant compressor according to claim 2, characterized in that: The thermometer (7) is arranged at the outlet pipe of the adsorption tank (5) and controls the temperature of the regeneration gas by controlling the opening of the regeneration gas flow valve (115); the regeneration temperature is 120°C to 150°C, the regeneration time is 6h to 12h; the regeneration pressure is normal pressure; the operating temperature during normal operation is 40°C and the operating pressure is 0.3MPa.

6. The refrigerant recovery device for a refrigerant compressor according to claim 1, characterized in that: The pre-filter comprises a pre-coarse filter (2) and a pre-fine filter (3); the filtering accuracy of the pre-coarse filter (2) is: oil removal accuracy 1 ppm, dust removal accuracy 1 μm; the filtering accuracy of the pre-fine filter (3) is: oil removal accuracy 0.01 ppm, dust removal accuracy 0.01 μm.

7. The refrigerant recovery device for a refrigerant compressor according to claim 1, characterized in that: The dust filter (6) is used to filter the abrasion dust generated by the adsorbent when the process gas passes through the adsorbent in the adsorption tank (5); the filtering accuracy is: oil removal accuracy 1ppm, dust removal accuracy 1μm; the maximum static pressure of the differential pressure gauge (4) is 2.5MPa, and the accuracy is ±1.6%FS.

8. The refrigerant recovery device for a refrigerant compressor according to claim 1, characterized in that: The regeneration gas venting pipeline (10) is provided with a regeneration gas flare.

9. A refrigerant recovery method for a refrigerant compressor, comprising: recovering refrigerant using the refrigerant recovery device for a refrigerant compressor according to any one of claims 1 to 8; wherein: The following steps are involved: Keep the safety valve front valve (111) and the safety valve rear valve (113) in a normally open state; keep the sewage valve (116) in a normally closed state; and keep the two root valves of the pressure differential gauge (4) in a normally open state; Close the first pipeline valve (104) and the second pipeline valve (105); Slowly opening the regeneration gas flow valve (115) and the bypass valve (112), and controlling the opening of the regeneration gas flow valve (115) to control the flow of the regeneration gas, and finally controlling the regeneration gas temperature at 120° C. to 150° C., thereby activating and regenerating the adsorbent in the adsorption tank (5); the regeneration time is 6 hours to 12 hours; After the regeneration is completed, the first pipeline valve (104) and the second pipeline valve (105) are opened, and the regeneration gas flow valve (115) and the bypass valve (112) are closed; After checking that the switch status of the above valves is correct, open the valve between the original separator (1) and the refrigerant recovery port (9), so that the mixed refrigerant output from the original separator (1) passes through the pre-coarse filter (2), the pre-fine filter (3), the adsorption tank (5) and the dust filter (6) in sequence, and finally enters the LNG refrigerant compressor through the refrigerant recovery port (9).

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