Refrigerant recovery system and recovery method thereof, compressor test device and air conditioning system

Abstract

The present invention provides a refrigerant recovery system and its recovery method, a compressor test device and an air-conditioning system, wherein the refrigerant recovery system includes: a tested compressor, an air intake pipe, an exhaust pipe, a vacuum gauge, an oil separator, a recovery compressor and a control unit, the vacuum gauge is arranged in the air intake pipe, one end of the air intake pipe and the exhaust pipe are both connected to the tested compressor, the other ends of the air intake pipe and the exhaust pipe are both connected to the recovery end, and the oil separator is arranged between the suction port and the recovery end of the recovery compressor. In the refrigerant recovery system and its recovery method, the compressor test device and the air-conditioning system provided in the present application, by arranging an oil separator between the recovery end of the refrigerant and the suction port of the recovery compressor, the oil in the refrigerant will not accumulate in the recovery compressor, thereby reducing the failure rate of the recovery compressor, and in addition, the control system can be used to cleanly recover the refrigerant, further improving the refrigerant recovery efficiency.

Description

Technical Field

[0001] The present application relates to the technical field of compressors, and in particular to a refrigerant recovery system and a recovery method thereof, a compressor testing device and an air conditioning system. Background Art

[0002] The existing air conditioning system usually includes a compressor, an oil separator, a four-way reversing valve, a liquid storage device, an outdoor heat exchanger, a throttling device and an indoor heat exchanger. Among them, the compressor is the core equipment of the air conditioning system, which can compress the refrigerant to make it participate in the circulation.

[0003] In order to reuse the refrigerant and avoid direct discharge and pollution of the environment, the compressor test bench (such as the endurance bench or the cooling bench, etc.) usually needs to recover the refrigerant of the tested compressor and its connecting pipes after the compressor test is completed. Currently, the refrigerant recovery of the compressor test bench is generally carried out through an external recovery compressor, and the recovered refrigerant is sent to the liquid storage tank of the tested compressor or an external recovery tank.

[0004] However, in the actual recycling process, it was found that due to the short operating time of the recycling compressor (generally within 10 seconds), the refrigerant in the tested compressor and pipeline could not be completely recovered. Moreover, after a long period of operation, the oil dissolved in the refrigerant will slowly accumulate in the recycling compressor, causing the oil level of the recycling compressor to continue to rise, causing the coil current to increase until the coil burns out. Therefore, existing recycling compressors often fail and cannot work. In addition, for refrigerants with certain flammability such as R32 and R290, if they are not recycled cleanly and leak on site, there will be certain safety hazards. Summary of the invention

[0005] In view of the defects in the prior art, the purpose of the present invention is to provide a refrigerant recovery system and its recovery method, a compressor testing device and an air-conditioning system, which overcome the difficulties of the prior art, can avoid the problem of unclean refrigerant recovery, improve the refrigerant recovery efficiency, and reduce the failure rate of the recovery compressor.

[0006] According to one aspect of the present invention, there is provided a refrigerant recovery system, the refrigerant recovery system comprising: a compressor to be tested, an air intake pipe, an air discharge pipe, a vacuum gauge, an oil separator, a recovery compressor and a control unit;

[0007] One end of the air intake pipe and the air exhaust pipe are both connected to the compressor under test, and the other ends of the air intake pipe and the air exhaust pipe are both connected to a recovery end, the recovery compressor is connected to the recovery end, the oil separator is arranged between the suction port of the recovery compressor and the recovery end, and the vacuum gauge is arranged in the air intake pipe;

[0008] The control unit includes a first solenoid valve, a second solenoid valve, a third solenoid valve, a fourth solenoid valve and a fifth solenoid valve, the first solenoid valve is arranged between the intake pipe and the external evaporator, the second solenoid valve is arranged between the exhaust pipe and the external condenser, the third solenoid valve is arranged between the intake pipe and the recovery end, the fourth solenoid valve is arranged between the recovery end and the oil separator, and one end of the fifth solenoid valve is connected to the discharge port of the recovery compressor.

[0009] Optionally, in the refrigerant recovery system, the control unit also includes a main control system, the first solenoid valve to the fifth solenoid valve are all connected to the main control system, and the main control system is used to control the opening and closing of the first solenoid valve to the fifth solenoid valve.

[0010] Optionally, in the refrigerant recovery system, it further includes: a low pressure control and a high pressure control;

[0011] The low pressure control is arranged in the air intake duct, and is used to detect whether the pressure of the air intake duct exceeds a set lower limit and send a signal to the main control system;

[0012] The high pressure control is arranged in the exhaust pipe, and is used to detect whether the pressure of the exhaust pipe exceeds a set upper limit and send a signal to the main control system.

[0013] Optionally, the refrigerant recovery system further includes: a first sensing unit and a second sensing unit;

[0014] The first sensing unit includes a first temperature sensor and a first pressure sensor, both of which are arranged in the air intake duct and are used to sense the temperature and pressure of the air intake duct respectively;

[0015] The second sensing unit includes a second temperature sensor and a second pressure sensor, and the second temperature sensor and the second pressure sensor are both disposed in the exhaust pipe and are used to respectively sense the temperature and the pressure of the exhaust pipe.

[0016] Optionally, the refrigerant recovery system further includes: an air intake hose and an air exhaust hose;

[0017] The compressor under test is connected to the intake pipe via the intake hose, and the compressor under test is connected to the exhaust pipe via the exhaust hose.

[0018] Optionally, in the refrigerant recovery system, the other end of the fifth solenoid valve is connected to the condenser, and an oil drain valve is provided on the oil separator.

[0019] Optionally, the refrigerant recovery system further includes a recovery tank, which is connected to the discharge port of the recovery compressor through the other end of the fifth solenoid valve.

[0020] According to another aspect of the present invention, a refrigerant recovery method is provided, the refrigerant recovery method comprising:

[0021] Step 1: providing the refrigerant recovery system as described above;

[0022] Step 2: close the first solenoid valve, and recover the refrigerant in the suction pipe to the condenser through the compressor under test until the reading of the vacuum gauge reaches a first set value;

[0023] Step 3, close the second solenoid valve and the compressor under test;

[0024] Step 4, opening the third solenoid valve, the fourth solenoid valve and the fifth solenoid valve, and starting the recovery compressor until the reading of the vacuum gauge reaches the second set value;

[0025] Step 5, close the recovery compressor, the fourth solenoid valve and the fifth solenoid valve, and obtain the reading of the vacuum gauge; if the reading of the vacuum gauge does not rise within the predetermined time, the recovery is ended; if the reading of the vacuum gauge rises within the predetermined time, repeat steps 4 and 5.

[0026] According to another aspect of the present invention, a compressor testing device is provided, wherein the compressor testing device comprises the refrigerant recovery system as described above.

[0027] According to another aspect of the present invention, an air conditioning system is provided, comprising the refrigerant recovery system as described above.

[0028] In the refrigerant recovery system and its recovery method, compressor testing device and air-conditioning system provided by the present invention, an oil separator is arranged between the recovery end of the refrigerant and the suction port of the recovery compressor, so that the oil in the refrigerant will not accumulate in the recovery compressor, thereby reducing the failure rate of the recovery compressor. In addition, the control system can further improve the refrigerant recovery efficiency, recover the refrigerant cleanly, and thus avoid environmental pollution and safety hazards caused by refrigerant leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The technical solution of the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments to make the characteristics and advantages of the present invention more obvious.

[0030] Figure 1 It is a structural schematic diagram of a refrigerant recovery system according to an embodiment of the present invention;

[0031] Figure 2 It is a structural schematic diagram of a refrigerant testing machine according to an embodiment of the present invention;

[0032] Figure 3 It is a structural schematic diagram of a refrigerant recovery system according to another embodiment of the present invention. DETAILED DESCRIPTION

[0033] The following is a detailed description of the embodiments of the present invention. Although the present invention will be described and illustrated in conjunction with some specific embodiments, it should be noted that the present invention is not limited to these embodiments. On the contrary, modifications or equivalent substitutions made to the present invention should all be included in the scope of the claims of the present invention.

[0034] In addition, in order to better illustrate the present invention, numerous specific details are provided in the following specific embodiments. It will be understood by those skilled in the art that the present invention can be implemented without these specific details. In other examples, well-known structures and components are not described in detail in order to highlight the main purpose of the present invention.

[0035] The technical solution of the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments to make the characteristics and advantages of the present invention more obvious.

[0036] Please refer to Figure 1 , which is a schematic diagram of the structure of the refrigerant recovery system of an embodiment of the present invention. Figure 1 As shown, the refrigerant recovery system 10 includes: a tested compressor 1, an air intake pipe (the number is not shown in the figure), an exhaust pipe (the number is not shown in the figure), a vacuum gauge 2, an oil separator 3, a recovery compressor 4 and a control unit; the control unit includes a first solenoid valve EV1, a second solenoid valve EV2, a third solenoid valve EV3, a fourth solenoid valve EV4 and a fifth solenoid valve EV5, the first solenoid valve EV1 is arranged between the air intake pipe and the external evaporator 21, the second solenoid valve EV2 is arranged between the exhaust pipe and the external condenser 22, the third solenoid valve EV3 is arranged between the air intake pipe and the recovery end R, the fourth solenoid valve EV4 is arranged between the recovery end R and the oil separator 3, and the fifth solenoid valve EV5 is arranged between the discharge port of the recovery compressor 4 and the condenser 22.

[0037] Specifically, the suction port of the tested compressor 1 is connected to one end of the suction pipe, the exhaust port of the tested compressor 1 is connected to one end of the exhaust pipe, the vacuum gauge 2 is arranged in the suction pipe, the other end of the suction pipe and the other end of the exhaust pipe are both connected to the recovery end R, the suction port of the recovery compressor 4 is connected to the recovery end R, and the oil separator 3 is arranged between the suction port of the recovery compressor 4 and the recovery end R.

[0038] The oil separator 3 is provided with an oil drain valve NV3, and the oil in the oil separator 3 can be manually or automatically drained through the oil drain valve NV3.

[0039] like Figure 1 As shown, the refrigerant recovery system 10 further includes: an air intake hose 5 and an air exhaust hose 6 , the compressor 1 under test is connected to the air intake pipe via the air intake hose 5 , and the compressor 1 under test is connected to the air exhaust pipe via the air exhaust hose 6 .

[0040] like Figure 1 As shown, the refrigerant recovery system 10 also includes a first sensing unit and a second sensing unit, the first sensing unit includes a first temperature sensor T1 and a first pressure sensor P1, the first temperature sensor T1 and the first pressure sensor P1 are both arranged in the intake duct, the first temperature sensor T1 is used to sense the temperature of the intake duct, the first pressure sensor P1 is used to sense the pressure of the intake duct, the second sensing unit includes a second temperature sensor T2 and a second pressure sensor P2, the second temperature sensor T2 and the second pressure sensor P2 are both arranged in the exhaust duct, the second temperature sensor T2 is used to sense the temperature of the exhaust duct, and the second pressure sensor P2 is used to sense the pressure of the exhaust duct.

[0041] Please continue to refer to Figure 1 The control unit also includes a main control system (not shown in the figure), the first solenoid valve EV1 to the fifth solenoid valve EV5 are all connected to the main control system, and the main control system is used to control the opening and closing of the first solenoid valve EV1 to the fifth solenoid valve EV5. The refrigerant recovery system 10 also includes a low-pressure pressure control LC and a high-pressure pressure control HC. The low-pressure pressure control LC is arranged in the intake duct to detect whether the pressure of the intake duct exceeds the set lower limit and sends a signal to the main control system. The high-pressure pressure control is arranged in the exhaust duct to detect whether the pressure of the exhaust duct exceeds the set upper limit and sends a signal to the main control system.

[0042] Accordingly, this embodiment also provides a refrigerant recovery method. Figure 1 , the refrigerant recovery method comprises:

[0043] Step 1: providing the refrigerant recovery system 10 as described above;

[0044] Step 2: Close the first solenoid valve EV1 and recycle the refrigerant in the suction pipe to the condenser 22 through the compressor 1 under test until the reading of the vacuum gauge 2 reaches the set value.

[0045] Step 3, close the second solenoid valve EV2 and the tested compressor 1;

[0046] Step 4: Open the third solenoid valve EV3, the fourth solenoid valve EV4 and the fifth solenoid valve EV5, and start the recovery compressor 4 until the reading of the vacuum gauge 2 reaches the set value;

[0047] Step 5, close the recovery compressor 4, the fourth solenoid valve EV4 and the fifth solenoid valve EV5, and obtain the reading of the vacuum gauge 2; if the reading of the vacuum gauge 2 does not rise within the predetermined time, the recovery is ended; if the reading of the vacuum gauge 2 rises within the predetermined time, repeat steps 4 and 5.

[0048] Specifically, first, the refrigerant recovery system 10 as described above is provided. When the compressor system test is finished, refrigerant recovery is started through the refrigerant recovery system 10. At this time, the compressor 1 under test does not stop.

[0049] Next, the first solenoid valve EV1 (i.e., the suction valve) is closed, and the refrigerant in the suction pipe is recovered to the condenser 22 through the tested compressor 1 until the reading of the vacuum gauge 2 reaches the first set value (e.g., 500 Pa);

[0050] Then, close the second solenoid valve EV2 (i.e., the exhaust valve) and the tested compressor 1;

[0051] Afterwards, the third solenoid valve EV3 (balancing valve), the fourth solenoid valve EV4 and the fifth solenoid valve EV5 are opened, and the recovery compressor 4 is started until the reading of the vacuum gauge 2 reaches the second set value (e.g., 500 Pa);

[0052] Thereafter, the recovery compressor 4 , the fourth solenoid valve EV4 and the fifth solenoid valve EV5 are closed, and the reading of the vacuum gauge 2 is obtained.

[0053] If the reading of the vacuum gauge 2 does not rise within the predetermined time (5 seconds), the recovery is terminated; if the reading of the vacuum gauge 2 rises within the predetermined time (5 seconds), repeat the above steps 4 and 5. That is, reopen the third solenoid valve EV3 (balance valve), the fourth solenoid valve EV4 and the fifth solenoid valve EV5, and start the recovery compressor 4 until the reading of the vacuum gauge 2 reaches the second set value (for example, 500Pa). After that, close the recovery compressor 4, the fourth solenoid valve EV4 and the fifth solenoid valve EV5. Wait for a certain period of time (for example, 5 seconds) and check the reading of the vacuum gauge 2 until the reading of the vacuum gauge 2 does not rise within the predetermined time (5 seconds).

[0054] The first setting value, the second setting value and the scheduled time are only examples and not limitations. Those skilled in the art may set the first setting value, the second setting value and the scheduled time according to actual needs.

[0055] In this embodiment, the first set value and the second set value are both 500Pa, and the predetermined time is 5 seconds. In other embodiments, the first set value and the second set value may also be 300Pa, 400Pa, 600Pa or other pressure set values, and the predetermined time may also be 3 seconds, 4 seconds, 6 seconds or other predetermined time, which are not limited here.

[0056] Correspondingly, this embodiment further provides an air conditioning system, which includes the refrigerant recovery system 10 as described above.

[0057] Accordingly, this embodiment further provides a compressor test device, which includes the above-mentioned refrigerant recovery system 10. The compressor test device includes a refrigerant test machine, a durability bench, a cooling capacity bench or other test equipment.

[0058] The compressor testing device provided in this embodiment is described below by taking a refrigerant testing machine as an example. The refrigerant testing machine can simulate the operation of the compressor air conditioning refrigeration and heating conditions.

[0059] Please refer to Figure 1 and Figure 2 , which is a schematic diagram of the structure of a refrigerant testing machine according to an embodiment of the present invention. Figure 1 and Figure 2 As shown, the refrigerant testing machine 100 includes: a vacuum system, a machine system under test, a refrigerant recovery system 10 and a four-way reversing valve 9. The machine system under test is connected to the refrigerant recovery system 10 through the four-way reversing valve 9, the vacuum system is connected to the intake pipe of the refrigerant recovery system 10, and is connected to the exhaust pipe of the refrigerant recovery system 10 through the third solenoid valve EV3.

[0060] Specifically, the vacuum pumping system includes a vacuum pump 31, and the vacuum pump 31 is connected to the refrigerant recovery system 10 through a second stop valve NV2. The machine system under test includes an evaporator 21, a condenser 22, a first fan 23, a second fan 24, a system reservoir 25, a dry filter 26, a throttling device and four one-way valves. The evaporator 21, the system reservoir 25, the dry filter 26, the throttling device and the condenser 22 are connected in sequence, the first fan 23 is aimed at the evaporator 21, the second fan 24 is aimed at the condenser 22, the first one-way valve CK1 and the second one-way valve CK2 are arranged in the same direction, and the first one-way valve CK1 is connected between the throttling device and the condenser 22, and the refrigerant is discharged through the first one-way valve CK 1 flows to the condenser 22, the second one-way valve CK2 is connected between the throttling device and the evaporator 21, and the refrigerant flows to the evaporator 21 via the second one-way valve CK2, the third one-way valve CK3 and the fourth one-way valve CK4 are arranged in the same direction, and the third one-way valve CK3 is connected between the condenser 22 and the system reservoir 25, and the refrigerant flows to the system reservoir 25 via the third one-way valve CK3, the fourth one-way valve CK4 is connected between the evaporator 21 and the system reservoir 25, and the refrigerant flows to the system reservoir 25 via the fourth one-way valve CK4.

[0061] The throttling device includes a capillary tube 27, a sixth electromagnetic valve EV6 and a bidirectional electronic expansion valve EXV1 arranged in parallel, and the throttling unit composed of the capillary tube 27 and the sixth electromagnetic valve EV6 is arranged in parallel with the bidirectional electronic expansion valve EXV1. A first ball valve BV1 is arranged between the throttling device and the drying filter 26, and a second ball valve BV2 is arranged between the drying filter 26 and the system reservoir 25.

[0062] In this embodiment, the wind speeds of the first fan 23 and the second fan 24 are adjustable, and both have three wind speed levels (high speed, medium speed, and low speed).

[0063] In this embodiment, the system liquid reservoir 25 has a sight glass, through which the refrigerant condition of the system liquid reservoir 25 can be directly observed.

[0064] Please continue to refer to Figure 1 and Figure 2The recovery compressor 4 of the refrigerant recovery system 10 is connected to the first end of the four-way reversing valve 9 through the fifth solenoid valve EV5, the exhaust pipe of the refrigerant recovery system 10 is also connected to the first end of the four-way reversing valve 9 through the second solenoid valve EV2, the intake pipe of the refrigerant recovery system 10 is connected to the second end of the four-way reversing valve 9 through the first solenoid valve EV1, the evaporator 21 of the machine system under test is connected to the third end of the four-way reversing valve 9, and the condenser 22 of the machine system under test is connected to the fourth end of the four-way reversing valve 9.

[0065] Please continue to refer to Figure 2 The machine system under test also includes a first liquid filling port AL1, a second liquid filling port AL2 and an emptying port EL1. The first liquid filling port AL1 is connected to the system liquid reservoir 25 through a first stop valve NV1, the second liquid filling port AL2 is connected to the suction pipe of the refrigerant recovery system 10 through a second stop valve NV2, and is connected to the exhaust pipe of the refrigerant recovery system 10 through a second stop valve NV2 and a third solenoid valve EV3. The emptying port EL1 is connected to the suction pipe of the refrigerant recovery system 10 through a seventh solenoid valve EV7, and is connected to the exhaust pipe of the refrigerant recovery system 10 through the seventh solenoid valve EV7 and the third solenoid valve EV3.

[0066] In this embodiment, liquid can be added to the system liquid reservoir 25 through the first liquid filling port AL1, and the liquid adding operation is generally performed in a liquid state. Liquid can be added to the tested compressor 1 in the refrigerant recovery system 10 through the second liquid filling port AL2, and the liquid adding operation is generally performed in a gas state.

[0067] In the refrigerant tester 100 provided in this embodiment, due to the use of the refrigerant recovery system 10, the refrigerant in the tested compressor and pipeline can be completely recovered, and there is no need to frequently stop the machine to replenish the refrigerant in the system, and there will be no situation of environmental pollution due to refrigerant leakage when the machine is disassembled. It is particularly suitable for compressor test systems or air conditioning systems that use refrigerants with certain flammability such as R32 and R290, and the flammable refrigerant will not cause safety problems due to leakage.

[0068] In addition, since the refrigerant has passed through the oil separator 3 before entering the recovery compressor 4, the oil in the refrigerant is separated and will not accumulate in the recovery compressor 4, so the failure rate of the recovery compressor 4 is reduced.

[0069] Please refer to Figure 3 , which is a schematic diagram of the structure of a refrigerant recovery system according to another embodiment of the present invention. Figure 3As shown, the refrigerant recovery system 20 of another embodiment further includes a recovery tank 7, and the recovery tank 7 is connected to the discharge port of the recovery compressor 4 through a fifth solenoid valve EV5.

[0070] In this embodiment, the refrigerant recovery system is connected to the system reservoir connected thereto, and the refrigerant recovered by the recovery compressor 4 is transported to the system reservoir via a pipeline. In another embodiment, the refrigerant recovery system 20 is not connected to the system reservoir, and the refrigerant recovered by the recovery compressor 4 is directly transported to the recovery tank 7 via the fifth solenoid valve EV5.

[0071] In summary, the refrigerant recovery system and its recovery method, compressor testing device and air-conditioning system of the present invention, by setting an oil separator between the recovery end of the refrigerant and the suction port of the recovery compressor, prevent the oil in the refrigerant from accumulating in the recovery compressor, thereby reducing the failure rate of the recovery compressor. In addition, the control system can further improve the refrigerant recovery efficiency, recover the refrigerant cleanly, and thus avoid environmental pollution and safety hazards caused by refrigerant leakage.

[0072] The above content is a further detailed description of the present application in combination with specific preferred implementation methods, and it cannot be determined that the specific implementation of the present application is limited to these descriptions. For ordinary technicians in the technical field to which the present application belongs, several simple deductions or substitutions can be made without departing from the concept of the present application, which should be deemed to fall within the scope of protection of the present application.

Claims

1. A refrigerant recovery system, characterized in that: include: The tested compressor, the suction pipe, the exhaust pipe, the vacuum gauge, the oil separator, the recovery compressor and the control unit, as well as a suction hose and an exhaust hose; One end of the suction pipe and the exhaust pipe are both connected to the compressor under test, the suction port of the compressor under test is connected to one end of the suction pipe, the compressor under test is connected to the suction pipe through the suction hose, the compressor under test is connected to the exhaust pipe through the exhaust hose, the other ends of the suction pipe and the exhaust pipe are both connected to a recovery end, the recovery compressor is connected to the recovery end, the oil separator is arranged between the suction port of the recovery compressor and the recovery end, and the vacuum gauge is arranged in the suction pipe; The control unit includes a first solenoid valve, a second solenoid valve, a third solenoid valve, a fourth solenoid valve and a fifth solenoid valve, the first solenoid valve is arranged between the intake pipe and the external evaporator, the second solenoid valve is arranged between the exhaust pipe and the external condenser, the third solenoid valve is arranged between the intake pipe and the recovery end, the fourth solenoid valve is arranged between the recovery end and the oil separator, one end of the fifth solenoid valve is connected to the discharge port of the recovery compressor, the other end of the fifth solenoid valve is connected to the condenser, and an oil drain valve is arranged on the oil separator.

2. The refrigerant recovery system according to claim 1, characterized in that: The control unit further includes a main control system, and the first to fifth solenoid valves are all connected to the main control system, and the main control system is used to control the opening and closing of the first to fifth solenoid valves.

3. The refrigerant recovery system according to claim 2, characterized in that: Also includes: A low voltage control and a high voltage control; The low pressure control is arranged in the air intake duct, and is used to detect whether the pressure of the air intake duct exceeds a set lower limit and send a signal to the main control system; The high pressure control is arranged in the exhaust pipe, and is used to detect whether the pressure of the exhaust pipe exceeds a set upper limit and send a signal to the main control system.

4. The refrigerant recovery system according to claim 1, characterized in that: Also includes: a first sensing unit and a second sensing unit; The first sensing unit includes a first temperature sensor and a first pressure sensor, both of which are arranged in the air intake duct and are used to sense the temperature and pressure of the air intake duct respectively; The second sensing unit includes a second temperature sensor and a second pressure sensor, and the second temperature sensor and the second pressure sensor are both disposed in the exhaust pipe and are used to respectively sense the temperature and the pressure of the exhaust pipe.

5. The refrigerant recovery system according to claim 1, characterized in that: It also includes a recovery tank, which is connected to the discharge port of the recovery compressor through the other end of the fifth solenoid valve.

6. A refrigerant recovery method, characterized in that: include: Step 1: providing a refrigerant recovery system as described in any one of claims 1 to 5; Step 2, closing the first solenoid valve, and recovering the refrigerant in the suction pipe to the condenser through the compressor under test until the reading of the vacuum gauge reaches a first set value; Step 3, close the second solenoid valve and the compressor under test; Step 4, opening the third solenoid valve, the fourth solenoid valve and the fifth solenoid valve, and starting the recovery compressor until the reading of the vacuum gauge reaches the second set value; Step 5, close the recovery compressor, the fourth solenoid valve and the fifth solenoid valve, and obtain the reading of the vacuum gauge; if the reading of the vacuum gauge does not rise within the predetermined time, the recovery is terminated; if the reading of the vacuum gauge rises within the predetermined time, repeat steps 4 and 5.

7. A compressor testing device, characterized in that: include: A refrigerant recovery system according to any one of claims 1 to 5.

8. An air conditioning system, characterized in that: include: A refrigerant recovery system according to any one of claims 1 to 5.

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