Refrigerant recovery system and control method thereof

Abstract

The application provides a refrigerant recovery system and a control method thereof. The refrigerant recovery system comprises a liquid cooling circuit and a refrigerant circuit. The refrigerant circuit is connected with an air conditioner to be recovered. The refrigerant of the air conditioner to be recovered can flow into the refrigerant circuit, and the liquid cooling circuit can exchange heat with the refrigerant circuit. The refrigerant circuit comprises a compressor, a condenser, a throttling device and a first heat exchanger. The compressor, the condenser, the throttling device and the first heat exchanger are sequentially connected to form a first circulation circuit. The throttling device is connected with the air conditioner to be recovered. The first heat exchanger is further connected with a liquid storage tank. The refrigerant of the air conditioner to be recovered sequentially passes through the throttling device, the first heat exchanger, the compressor and the condenser, and then flows into the liquid storage tank through the first heat exchanger. According to the application, the high and low pressure ratio of the refrigerant recovery system in the prior art is overcome, the slow recovery speed and low efficiency of the refrigerant are improved, and the recovery efficiency is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of air conditioners, in particular to a refrigerant recovery system and a control method thereof. BACKGROUND

[0002] With the increasing seriousness of environmental protection trend, the demand for refrigerant recovery in the market is becoming more and more prosperous. The working process of the conventional refrigerant recovery system is that the gaseous refrigerant passes through the drying filter, the compressor, the oil separator and the condenser in turn, and enters the liquid storage tank. During the refrigerant recovery, the liquid refrigerant remaining in the system to be recovered continues to vaporize, and its temperature continues to decrease (usually below 0℃). The low-temperature gaseous refrigerant has low pressure and small density. Since the system temperature is higher than the ambient temperature, the liquid storage tank contains high-temperature high-pressure liquid refrigerant, thereby increasing the high-low pressure ratio of the compressor. The high-low pressure ratio will reduce the compression efficiency of the compressor, and the low-temperature gaseous refrigerant with small density will reduce the recovery speed, efficiency and quality of the compressor.

[0003] Since the refrigerant recovery system in the prior art has the defect of large high-low pressure ratio, which leads to slow refrigerant recovery speed and low efficiency, the present application researches and designs a refrigerant recovery system and a control method thereof. SUMMARY

[0004] Therefore, the technical problem to be solved by the present application is to overcome the defect of large high-low pressure ratio of the refrigerant recovery system in the prior art, which leads to slow refrigerant recovery speed and low efficiency, thereby providing a refrigerant recovery system and a control method thereof.

[0005] In order to solve the above problems, the present application provides a refrigerant recovery system, which comprises:

[0006] a liquid cooling circuit and a refrigerant circuit, the refrigerant circuit being connected with an air conditioner to be recovered, the refrigerant of the air conditioner to be recovered being capable of flowing into the refrigerant circuit, and the liquid cooling circuit being capable of exchanging heat with the refrigerant circuit;

[0007] the refrigerant circuit comprising a compressor, a condenser, a throttling device and a first heat exchanger, the compressor, the condenser, the throttling device and the first heat exchanger being connected in sequence to form a first circulation circuit, the throttling device being connected with the air conditioner to be recovered, the first heat exchanger further being connected with a liquid storage tank, the refrigerant of the air conditioner to be recovered passing through the throttling device, the first heat exchanger, the compressor and the condenser in turn, and then flowing into the liquid storage tank through the first heat exchanger.

[0008] In some embodiments, the refrigerant circuit further comprises a filter and an oil separator, the filter is located between the compressor and the first heat exchanger, one end of the filter is connected to the compressor and the other end is connected to the first heat exchanger, the oil separator is located between the compressor and the condenser, the oil separator has a first end and a second end, the first end is connected to the condenser, and the second end is connected to the condenser.

[0009] In some embodiments, a second heat exchanger is provided between the first heat exchanger and the liquid storage tank, one end of the second heat exchanger is connected to the first heat exchanger, and the other end is connected to the liquid storage tank, the refrigerant flowing out of the condenser passes through the first heat exchanger and then flows into the liquid storage tank through the second heat exchanger.

[0010] In some embodiments, the second heat exchanger is connected to the air conditioner to be recovered, a first stop valve is provided between the second heat exchanger and the air conditioner to be recovered, one end of the first stop valve is connected to the second heat exchanger, and the other end is connected to the air conditioner to be recovered.

[0011] In some embodiments, a second stop valve is provided between the second heat exchanger and the first heat exchanger, one end of the second stop valve is connected to the first heat exchanger, and the other end is connected to the second heat exchanger, and the second heat exchanger is connected to the liquid storage tank through a third stop valve.

[0012] In some embodiments, the refrigerant recovery system further comprises a semiconductor refrigeration sheet, the third heat exchanger is opposite to the second heat exchanger, the semiconductor refrigeration sheet is located between the third heat exchanger and the second heat exchanger, and the third heat exchanger, the semiconductor refrigeration sheet and the second heat exchanger are coupled.

[0013] In some embodiments, the semiconductor refrigeration sheet has a cold end and a hot end, the cold end faces the second heat exchanger, and the hot end faces the third heat exchanger.

[0014] The present application also provides a first control method of a refrigerant recovery system, comprising any one of the refrigerant recovery systems described above, when the refrigerant recovery system comprises the compressor, the semiconductor refrigeration sheet, the throttling device, the first stop valve, the second stop valve, the pump body, the fan and the third stop valve.

[0015] The judging step judges whether the refrigerant flowing out of the air conditioner to be recovered is clean or not.

[0016] The control step controls to close the compressor, the throttling device, and the second stop valve, and controls to open the first stop valve, the third stop valve, the semiconductor refrigeration sheet, the pump body, and the fan when the refrigerant flowing out of the air conditioner to be recycled is in a clean state; and controls to open the throttling device, the second stop valve, and the third stop valve, and controls to open the compressor, the semiconductor refrigeration sheet, the pump body, and the fan, and controls to close the first stop valve when the refrigerant flowing out of the air conditioner to be recycled is not in the clean state.

[0017] In some embodiments, the control method of the refrigerant recycling system further comprises a preparation step of opening the semiconductor refrigeration sheet and working the semiconductor refrigeration sheet for not less than 2 minutes before entering the judgment step.

[0018] In some embodiments, the preparation step, when the liquid reservoir and the pressure gauge are included,

[0019] judging whether the refrigerant exists in the liquid reservoir,

[0020] when the refrigerant exists in the liquid reservoir, controlling to open the throttling device and the first stop valve, and controlling to close the third stop valve, and performing vacuumizing on the refrigerant circuit, and stopping the vacuumizing when the pressure value detected by the pressure gauge is lower than 40 Pa, and controlling to close the throttling device and the first stop valve;

[0021] when the refrigerant does not exist in the liquid reservoir, controlling to open the throttling device, the first stop valve, and the third stop valve, and stopping the vacuumizing when the pressure value detected by the pressure gauge is lower than 40 Pa, and controlling to close the throttling device and the first stop valve.

[0022] In some embodiments, when the refrigerant recycling system further comprises a sight glass,

[0023] judging whether the refrigerant flows out of the air conditioner to be recycled through the sight glass;

[0024] when the refrigerant flows out of the air conditioner to be recycled, and the refrigerant flowing out of the air conditioner to be recycled is in a clean state, controlling to close the compressor, the throttling device, and the second stop valve, and controlling to open the first stop valve, the third stop valve, the semiconductor refrigeration sheet, the pump body, and the fan;

[0025] when the refrigerant does not flow out of the air conditioner to be recycled, and the refrigerant flowing out of the air conditioner to be recycled is in a clean state, controlling to close the first stop valve.

[0026] In some embodiments, when the outlet of the air conditioner to be recovered has refrigerant flowing, and the refrigerant flowing out of the air conditioner to be recovered is not in a clean state, the control opens the throttling device, the second stop valve and the third stop valve, while opening the compressor, the semiconductor refrigeration sheet, the pump body and the fan, and closing the first stop valve.

[0027] When the outlet of the air conditioner to be recovered has no refrigerant flowing, and the refrigerant flowing out of the air conditioner to be recovered is not in a clean state, the control first closes the third stop valve, the throttling device and the first stop valve, and then controls to close the compressor, stop the semiconductor refrigeration sheet, stop the pump body and stop the fan.

[0028] The application also provides a second control method of a refrigerant recovery system, comprising the refrigerant recovery system of any one of the preceding claims, when the refrigerant recovery system comprises the compressor, the semiconductor refrigeration sheet, the throttling device, the first stop valve, the second stop valve, the pump body and the fan, the sight glass and the third stop valve.

[0029] The judgment step judges whether the refrigerant flowing out of the air conditioner to be recovered is in a liquid state according to the sight glass.

[0030] The control step controls to close the compressor, the throttling device and the second stop valve when the refrigerant flowing out of the air conditioner to be recovered is in a liquid state, and controls to open the first stop valve, the third stop valve, the semiconductor refrigeration sheet, the pump body and the fan; and controls to open the throttling device, the second stop valve and the third stop valve while opening the compressor, the semiconductor refrigeration sheet, the pump body and the fan, and closing the first stop valve when the refrigerant flowing out of the air conditioner to be recovered is not in a liquid state.

[0031] In some embodiments, the control method of the refrigerant recovery system further comprises a preparation step of opening the semiconductor refrigeration sheet, and entering the judgment step after the semiconductor refrigeration sheet works for no less than 2 minutes.

[0032] In some embodiments, when the refrigerant recovery system comprises the liquid storage tank and the pressure gauge,

[0033] The judgment step judges whether the refrigerant recovery system further comprises the liquid storage tank and the pressure gauge.

[0034] When the liquid storage tank contains refrigerant, the control opens the throttling device and the first stop valve, and closes the third stop valve, and performs vacuumizing on the refrigerant circuit, and stops vacuumizing when the pressure value detected by the pressure gauge is lower than 40 Pa, and controls to close the throttling device and the first stop valve.

[0035] When there is no refrigerant in the liquid storage tank, the throttle, the first stop valve and the third stop valve are controlled to be opened, and the vacuumizing is stopped when the pressure value detected by the pressure gauge is lower than 40 Pa, and the throttle and the first stop valve are controlled to be closed.

[0036] The refrigerant recovery system and the control method thereof have the following beneficial effects:

[0037] The to-be-recovered air conditioner is connected with the refrigerant circuit, and the refrigerant of the to-be-recovered air conditioner can flow into the refrigerant circuit, so that the refrigerant in the to-be-recovered air conditioner flows into the refrigerant circuit, and the refrigerant of the to-be-recovered air conditioner sequentially passes through the throttle, the first heat exchanger, the compressor and the condenser, and then flows into the liquid storage tank through the first heat exchanger, so that the refrigerant of the to-be-recovered air conditioner is recovered, and the liquid cooling circuit can exchange heat with the refrigerant circuit, so as to increase the temperature of the refrigerant circuit, increase the low-pressure recovery pressure, reduce the high-low pressure ratio of the compressor, improve the efficiency of the compressor, and improve the recovery efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 The figure is a structural schematic diagram of the refrigerant recovery system of the embodiment of the present application.

[0039] The figure is a structural schematic diagram of the refrigerant recovery system of the embodiment of the present application.

[0040] 1, to-be-recovered air conditioner; 2, compressor; 3, condenser; 4, first heat exchanger; 5, second heat exchanger; 6, third heat exchanger; 7, semiconductor refrigeration piece; 8, liquid storage tank; 9, filter; 10, oil separator; 11, sight glass; 12, throttle; 13, first stop valve; 14, second stop valve; 15, pump body; 16, radiator; 17, fan; 18, pressure gauge; 19, third stop valve. DETAILED DESCRIPTION

[0041] The figure is a structural schematic diagram of the refrigerant recovery system of the embodiment of the present application. Figure 1As shown, according to the embodiment of the present application, a refrigerant recovery system is provided, comprising: a liquid cooling circuit and a refrigerant circuit, the refrigerant circuit being connected with an air conditioner 1 to be recovered, refrigerant of the air conditioner 1 to be recovered being able to flow into the refrigerant circuit, and the liquid cooling circuit being able to exchange heat with the refrigerant circuit; the refrigerant circuit comprising a compressor 2, a condenser 3, a throttling device 12 and a first heat exchanger 4, the compressor 2, the condenser 3, the throttling device 12 and the first heat exchanger 4 being connected in sequence to form a first circulation circuit, the throttling device 12 being connected with the air conditioner 1 to be recovered, the first heat exchanger 4 being further connected with a liquid storage tank 8, refrigerant of the air conditioner 1 to be recovered being able to flow into the liquid storage tank 8 through the first heat exchanger 4 after sequentially passing through the throttling device 12, the first heat exchanger 4, the compressor 2 and the condenser 3. In this technical solution, the refrigerant circuit is connected with the air conditioner 1 to be recovered, refrigerant of the air conditioner 1 to be recovered is able to flow into the refrigerant circuit, refrigerant in the air conditioner 1 to be recovered flows into the refrigerant circuit, refrigerant of the air conditioner 1 to be recovered is able to flow into the liquid storage tank 8 through the first heat exchanger 4 after sequentially passing through the throttling device 12, the first heat exchanger 4, the compressor 2 and the condenser 3, so that refrigerant of the air conditioner 1 to be recovered is recovered, the liquid cooling circuit is able to exchange heat with the refrigerant circuit, so that the refrigerant in the refrigerant circuit is effectively cooled by the coolant in the liquid cooling circuit, thereby effectively reducing the temperature of the refrigerant in the liquid storage tank, and further reducing the pressure of the refrigerant in the liquid storage tank, i.e. effectively reducing the high-low pressure ratio of the compressor (the exhaust end of the compressor 2 is connected to the liquid storage tank 8, so that the pressure at the liquid storage tank 8 is approximately equivalent to the high pressure end of the compressor, and the suction end of the compressor is connected to the air conditioner to be recovered, so that the pressure at the air conditioner to be recovered is approximately equivalent to the low pressure end of the compressor), because the pressure at the air conditioner to be recovered is increased, and the pressure at the liquid storage tank is reduced, so that the refrigerant is more favorably able to flow from the air conditioner to be recovered to the liquid storage tank, thereby effectively improving the recovery efficiency of the refrigerant.

[0042] thereby increasing the temperature of the refrigerant circuit, increasing the low pressure recovery pressure, further reducing the high-low pressure ratio of the compressor, improving the efficiency of the compressor, and improving the recovery efficiency.

[0043] In some embodiments, the refrigerant circuit further comprises a filter 9 and an oil separator 10, the filter 9 is located between the compressor 2 and the first heat exchanger 4, one end of the filter 9 is connected to the compressor 2, and the other end is connected to the first heat exchanger 4, and the oil separator 10 is located between the compressor 2 and the condenser 3, the oil separator 10 has a first end and a second end, the first end is connected to the condenser 3, and the second end is connected to the condenser 3. In this technical solution, according to the state of the refrigerant flowing out of the air conditioner 1 to be recovered, when the refrigerant flowing out of the air conditioner 1 to be recovered needs to be recovered through the first circulating loop, the refrigerant flows into the first circulating loop, the impurities in the refrigerant are filtered through the filter 9, and the oil in the refrigerant is separated through the oil separator 10, thereby improving the quality of the recovered refrigerant and ensuring the recovery effect.

[0044] In some embodiments, the first heat exchanger 4 and the liquid storage tank 8 are provided with a second heat exchanger 5, one end of the second heat exchanger 5 is connected to the first heat exchanger 4, and the other end is connected to the liquid storage tank 8, and the refrigerant flowing out of the condenser 3 flows into the liquid storage tank 8 through the second heat exchanger 5 after passing through the first heat exchanger 4. In this technical solution, according to the state of the refrigerant flowing out of the air conditioner 1 to be recovered, when the refrigerant flowing out of the air conditioner 1 to be recovered does not need to be recovered through the first circulating loop, the refrigerant is directly heat-exchanged through the second heat exchanger 5 and then recovered into the liquid storage tank 8, thereby completing the recovery.

[0045] In some embodiments, the second heat exchanger 5 is connected to the air conditioner 1 to be recovered, a first stop valve 13 is provided between the second heat exchanger 5 and the air conditioner 1 to be recovered, one end of the first stop valve 13 is connected to the second heat exchanger 5, and the other end is connected to the air conditioner 1 to be recovered. In this technical solution, the first stop valve 13 is provided between the second heat exchanger 5 and the air conditioner 1 to be recovered, and the refrigerant flowing out of the air conditioner 1 to be recovered can be controlled to determine whether it needs to be recovered through the first circulating loop according to the state of the refrigerant flowing out of the air conditioner 1 to be recovered, thereby improving the efficiency of refrigerant recovery.

[0046] In some embodiments, a second stop valve 14 is provided between the second heat exchanger 5 and the first heat exchanger 4, one end of the second stop valve 14 is connected to the first heat exchanger 4, and the other end is connected to the second heat exchanger 5, and the second heat exchanger 5 is connected to the liquid storage tank 8 through a third stop valve 19. In this technical solution, the second stop valve 14 is provided between the second heat exchanger 5 and the first heat exchanger 4, and the second heat exchanger 5 is connected to the liquid storage tank 8 through the third stop valve 19, and the third stop valve 19 and the second stop valve 14 control the disconnection or connection of the flow path, thereby controlling the operation of the refrigerant recovery system according to the state of the refrigerant flowing out of the air conditioner 1 to be recovered, and improving the recovery efficiency.

[0047] In some embodiments, the liquid cooling circuit comprises a third heat exchanger 6, a radiator 16 and a pump body 15, which are sequentially connected to form a second circulation circuit, the radiator 16 is provided with a fan 17, and the second circulation circuit is located outside the first circulation circuit. In this technical solution, the pump body 15 is preferably a water pump, the radiator 16 is preferably an air-cooled radiator, the third heat exchanger 6, the radiator 16 and the pump body 15 are sequentially connected to form a second circulation circuit, the radiator 16 is provided with a fan 17, and the second circulation circuit is located outside the first circulation circuit. Thus, the second circulation circuit heats the first circulation circuit through the third heat exchanger 6 and the radiator 16, increases the low-pressure recovery pressure, thereby reducing the compressor high-low pressure ratio, improving the compressor efficiency, and improving the recovery efficiency. Preferably, the radiator is spaced apart from the to-be-recovered air conditioner 1, and the radiator is located upstream of the to-be-recovered air conditioner 1 along the direction of air flow, so that the air heated by the radiator flows to the to-be-recovered air conditioner 1 to heat the refrigerant in the to-be-recovered air conditioner 1. The fan is spaced apart from the radiator, and the fan is arranged upstream or downstream of the radiator in the direction of air flow, so that the fan can drive air to flow into the radiator to exchange heat with the refrigerant in the radiator. This is a further preferred structure of the present application, which can effectively drive the air flow to flow through the radiator and exchange heat with the refrigerant in the radiator by the arrangement of the fan structure.

[0048] This is a further preferred structure between the radiator and the to-be-recovered air conditioner of the present application, that is, the radiator is an air-cooled radiator, which is arranged upstream of the to-be-recovered air conditioner in the direction of air flow, so that the radiator first heats the air flowing through it, and then the heated air flows through the to-be-recovered air conditioner, thereby effectively heating the refrigerant in the to-be-recovered air conditioner, thereby increasing the temperature (pressure) of the refrigerant at the to-be-recovered air conditioner, that is, increasing the pressure at the low-pressure end of the compressor, which is beneficial to the recovery of the refrigerant.

[0049] In some embodiments, the refrigerant recovery system further comprises a semiconductor refrigeration sheet 7, the third heat exchanger 6 is opposite to the second heat exchanger 5, the semiconductor refrigeration sheet 7 is located between the third heat exchanger 6 and the second heat exchanger 5, and the third heat exchanger 6, the semiconductor refrigeration sheet 7 and the second heat exchanger 5 are coupled. In this technical solution, the third heat exchanger 6 is filled with heat storage material, preferably water or paraffin, the second heat exchanger 5 is filled with cold storage material, preferably water, the cold end of the semiconductor refrigeration sheet 7 is used to pre-cool and lower the temperature of the cold storage material before refrigerant recovery, and the hot end of the semiconductor refrigeration sheet 7 is used to pre-heat and raise the temperature of the heat storage material. The saturation temperature of the recovered refrigerant is further reduced by the cold storage material, the high-pressure pressure of the recovered refrigerant is reduced, the heat recovered from the hot end of the semiconductor refrigeration sheet 7 is recovered by a liquid cooling system, the system to be recovered is heated by the third heat exchanger 6, the low-pressure recovery pressure is increased, the high-low pressure ratio of the compressor is reduced, the efficiency of the compressor is improved, the recovery efficiency is improved, the cold end of the semiconductor refrigeration sheet can effectively absorb heat from the refrigerant in the second heat exchanger, the hot end of the semiconductor refrigeration sheet can release heat to the heat storage material in the third heat exchanger, the cold end of the semiconductor refrigeration sheet can pre-cool and lower the temperature of the cold storage material, and the hot end of the semiconductor refrigeration sheet can pre-heat and raise the temperature of the heat storage material. The saturation temperature of the recovered refrigerant is further reduced by the cold storage material, the high-pressure pressure of the recovered refrigerant is reduced, the pressure of the refrigerant at the storage tank is effectively reduced, the heat recovered from the hot end of the semiconductor refrigeration sheet is recovered by a liquid cooling system, the system to be recovered is heated by the third heat exchanger 6, the low-pressure recovery pressure is increased, the pressure of the refrigerant at the system to be recovered is effectively increased, the refrigerant can flow from the system to be recovered to the storage tank, the high-low pressure ratio of the compressor is further reduced, the efficiency of the compressor is further improved, and the recovery efficiency is further improved.

[0050] In some embodiments, the semiconductor refrigeration sheet 7 has a cold end and a hot end, the cold end faces the second heat exchanger 5, and the hot end faces the third heat exchanger 6. In this technical solution, the cold end of the semiconductor refrigeration sheet 7 is used to pre-cool and lower the temperature of the second heat exchanger 5, and the hot end of the semiconductor refrigeration sheet 7 is used to pre-heat and raise the temperature of the third heat exchanger 6 before refrigerant recovery. The saturation temperature of the recovered refrigerant is further reduced by the second heat exchanger 5, the high-pressure pressure of the recovered refrigerant is reduced, the heat recovered from the hot end of the semiconductor refrigeration sheet 7 is recovered by a liquid cooling system, the system to be recovered is heated by the third heat exchanger 6, the low-pressure recovery pressure is increased, the high-low pressure ratio of the compressor is reduced, the efficiency of the compressor is improved, and the recovery efficiency is improved.

[0051] In the refrigerant recovery, the temperature of the liquid refrigerant remaining in the air conditioner 1 to be recovered continuously decreases (usually below 0°C) as the liquid refrigerant continuously vaporizes, the low-temperature gaseous refrigerant has a low pressure and a small density, and the liquid refrigerant in the liquid accumulator 14 has a high temperature (the temperature of the conventional system is higher than the ambient temperature) and a high pressure, so that the high-low pressure ratio of the compressor is large. The large high-low pressure ratio reduces the compression efficiency of the compressor, and the low-temperature gaseous refrigerant with a small density reduces the recovery speed (reduces the mass flow rate) of the compressor.

[0052] Therefore, the refrigerant recovery system of the present application preferably pre-cools and pre-heats the cold storage material by the cold end of the semiconductor refrigeration sheet before refrigerant recovery. The cold storage material further reduces the saturation temperature of the recovered refrigerant, reduces the high-pressure pressure of the recovered refrigerant, and recovers the heat from the hot end of the semiconductor refrigeration sheet through the liquid cooling system. The heat exchanger heats the air conditioner to be recovered, increases the low-pressure recovery pressure, and further reduces the high-low pressure ratio of the compressor, improves the efficiency of the compressor, and improves the recovery efficiency.

[0053] In some embodiments, the air conditioner 1 to be recovered has an outlet through which the refrigerant of the air conditioner 1 to be recovered flows, and a pressure gauge 18 and a sight glass 11 are arranged at the outlet. In this technical solution, the pressure in the refrigerant recovery system can be detected in real time according to the pressure gauge 18, so that the system is vacuumized to ensure the pressure in the system, and the amount of refrigerant can be detected in real time according to the sight glass 11. When no refrigerant is observed to flow out through the sight glass 11, it indicates that the refrigerant recovery is completed, the refrigerant recovery system is closed, the recovery efficiency is improved, and resource waste is avoided.

[0054] In one embodiment, the present application also provides a control method of a refrigerant recovery system, comprising the refrigerant recovery system of any one of the preceding embodiments;

[0055] When the refrigerant recovery system comprises the compressor 2, the semiconductor refrigeration sheet 7, the throttling device 12, the first stop valve 13, the second stop valve 14, the pump body 15, the fan 17, and the third stop valve 19;

[0056] A judging step of judging whether the refrigerant flowing out of the air conditioner 1 to be recovered is clean;

[0057] The control step is to control to close the compressor 2, the throttling element 12 and the second stop valve 14 when the refrigerant flowing out of the air conditioner 1 to be recycled is in a clean state, and to control to open the first stop valve 13, the third stop valve 19, the semiconductor refrigeration sheet 7, the pump body 15 and the fan 17; and to control to open the throttling element 12, the second stop valve 14 and the third stop valve 19 while starting the compressor 2, the semiconductor refrigeration sheet 7, the pump body 15 and the fan 17 and closing the first stop valve 13 when the refrigerant flowing out of the air conditioner 1 to be recycled is not in a clean state. In the technical solution, whether the refrigerant flowing out of the air conditioner 1 to be recycled is clean is judged; the standard is to judge whether it is qualified according to the standard of the refrigerant model, the qualified one is the clean refrigerant, and the unqualified one is the unclean refrigerant. Taking R32 refrigerant as an example, the qualified product specified in the standard of HG / T4634-2014 industrial difluoromethane HFC-32 is considered to be clean refrigerant. When the refrigerant flowing out of the air conditioner 1 to be recycled is in a clean state, the compressor 2, the throttling element 12 and the second stop valve 14 are controlled to be closed, and the first stop valve 13, the third stop valve 19, the semiconductor refrigeration sheet 7, the pump body 15 and the fan 17 are controlled to be opened. Due to the existence of the pressure difference and the temperature of the second heat exchanger 5 being lower than the ambient temperature, the refrigerant flows from the air conditioner 1 to be recycled to the second heat exchanger 5, is cooled by the pre-cooled cold storage material and then flows into the liquid storage tank 8. At the same time, the pump body 15 and the fan 17 are started, so that the cooling liquid circulates in the liquid cooling system. The cooling liquid takes away the heat of the heat storage material preheated by the third heat exchanger 6, discharges the heat under the fan 17 through the air cooling radiator 16, the discharged heat heats the refrigerant recovery system, increases the pressure in the refrigerant recovery system and promotes the refrigerant to further flow to the liquid storage tank 8.

[0058] When the refrigerant flowing out of the air conditioner 1 to be recycled is not in a clean state, the throttling element 12, the second stop valve 14 and the third stop valve 19 are controlled to be opened while the compressor 2, the semiconductor refrigeration sheet 7, the pump body 15 and the fan 17 are started and the first stop valve 13 is closed. The compressor 2, the semiconductor refrigeration sheet 7, the pump body 15 and the fan 17 continuously work, and the heat discharged by the air cooling radiator 16 continuously heats the refrigerant recovery system. The refrigerant throttled by the throttling element 12 into low-temperature and low-pressure refrigerant enters the first heat exchanger 4 to evaporate and absorb heat, then enters the compressor 2 after passing through the drying filter 9. The high-temperature and high-pressure refrigerant coming out of the compressor 2 passes through the oil separator 10, enters the condenser 3, and the condensed refrigerant releases heat and cools through the first heat exchanger 4. The refrigerant cooled from the first heat exchanger 4 passes through the second stop valve 14, flows to the second heat exchanger 5, is cooled by the pre-cooled cold storage material in the second heat exchanger 5 and then flows into the liquid storage tank 8 through the third stop valve 19.

[0059] In some embodiments, the control method of the refrigerant recovery system further comprises a preparation step, opening the semiconductor refrigerating sheet 7, and making the semiconductor refrigerating sheet 7 work for not less than 2 minutes before entering the judgment step. In this technical solution, the semiconductor refrigerating sheet 7 is made to work in advance before the refrigerant recovery system recovers the refrigerant. The cold end of the semiconductor refrigerating sheet 7 cools the second heat exchanger 5 filled with the internal storage material, and the hot end of the semiconductor refrigerating sheet 7 heats the third heat exchanger 6 filled with the internal storage material. Therefore, before the refrigerant is recovered, the temperature in the refrigerant recovery system is ensured, and the initial refrigerant entering the refrigerant recovery system can be effectively recovered, thereby improving the recovery efficiency.

[0060] In some embodiments, when the preparation step includes the liquid storage tank 8 and the pressure gauge 18,

[0061] judging whether there is refrigerant in the liquid storage tank 8,

[0062] when there is refrigerant in the liquid storage tank 8, controlling to open the throttling device 12 and the first stop valve 13, controlling to close the third stop valve 19, performing vacuumizing on the refrigerant circuit, stopping vacuumizing when the pressure value detected by the pressure gauge 18 is lower than 40 Pa, and controlling to close the throttling device 12 and the first stop valve 13;

[0063] when there is no refrigerant in the liquid storage tank 8, controlling to open the throttling device 12, the first stop valve 13, and the third stop valve 19, stopping vacuumizing when the pressure value detected by the pressure gauge 18 is lower than 40 Pa, and controlling to close the throttling device 12 and the first stop valve 13. In this technical solution, the liquid storage tank 8 and the refrigerant circuit need to be vacuumized before the refrigerant is recovered. This avoids the influence of the pressure in the system on the high and low pressure when the refrigerant is recovered, thereby improving the recovery quality. When there is no refrigerant in the liquid storage tank 8, the throttling device 12, the first stop valve 13, and the third stop valve 19 are controlled to be opened. Vacuumizing is stopped when the pressure value detected by the pressure gauge 18 is lower than 40 Pa, and the throttling device 12 and the first stop valve 13 are controlled to be closed.

[0064] In some embodiments, when the refrigerant recovery system further includes the sight glass 11,

[0065] judging whether there is refrigerant flowing out of the air conditioner 1 to be recovered through the sight glass 11;

[0066] when there is refrigerant flowing out of the air conditioner 1 to be recovered, and the refrigerant flowing out of the air conditioner 1 to be recovered is in a clean state, controlling to close the compressor 2, the throttling device 12, and the second stop valve 14, and controlling to open the first stop valve 13, the third stop valve 19, the semiconductor refrigerating sheet 7, the pump body 15, and the fan 17;

[0067] When the outlet of the air conditioner to be recycled 1 has no refrigerant flow, and the refrigerant flowing out of the air conditioner to be recycled 1 is in a clean state, the first stop valve 13 is controlled to be closed. In this technical solution, when the outlet of the air conditioner to be recycled 1 has no refrigerant flow, and the refrigerant flowing out of the air conditioner to be recycled 1 is in a clean state, the first stop valve 13 is controlled to be closed. The recovery progress of the refrigerant recovery system is detected in real time, and when the refrigerant recovery is completed and there is no refrigerant flow, the first stop valve 13 is controlled to be closed, thereby improving the recovery efficiency and avoiding energy waste.

[0068] In some embodiments, when the outlet of the air conditioner to be recycled 1 has refrigerant flow, and the refrigerant flowing out of the air conditioner to be recycled 1 is not in a clean state, the throttling element 12, the second stop valve 14 and the third stop valve 19 are controlled to be opened, and the compressor 2, the semiconductor refrigeration piece 7, the pump body 15 and the fan 17 are turned on, and the first stop valve 13 is closed.

[0069] When the outlet of the air conditioner to be recycled 1 has no refrigerant flow, and the refrigerant flowing out of the air conditioner to be recycled 1 is not in a clean state, the third stop valve 19, the throttling element 12, the first stop valve 13 are first controlled to be closed, and then the compressor 2 is controlled to be closed, the semiconductor refrigeration piece 7 is stopped, the pump body 15 is stopped, and the fan 17 is stopped. In this technical solution, when the outlet of the air conditioner to be recycled 1 has no refrigerant flow, and the refrigerant flowing out of the air conditioner to be recycled 1 is not in a clean state, and the absolute pressure of the pressure gauge 18 is lower than 1 bar, the third stop valve 19, the throttling element 12, the first stop valve 13 are first controlled to be closed, and then the compressor 2 is controlled to be closed, the semiconductor refrigeration piece 7 is stopped, the pump body 15 is stopped, and the fan 17 is stopped, thereby ensuring the stability of the refrigerant recovery system, improving the service life of the refrigerant recovery system, and effectively protecting the safety and stability of each component.

[0070] In another embodiment, the present application also provides a control method of a refrigerant recovery system, comprising the refrigerant recovery system of any one of the preceding embodiments;

[0071] When the refrigerant recovery system comprises the compressor 2, the semiconductor refrigeration piece 7, the throttling element 12, the first stop valve 13, the second stop valve 14, the pump body 15 and the fan 17, the sight glass 11 and the third stop valve 19;

[0072] A judging step is provided to judge whether the refrigerant flowing out of the air conditioner to be recycled is in a liquid state according to the sight glass 11;

[0073] The control step is to control to close the compressor 2, the throttling element 12 and the second stop valve 14 when the refrigerant flowing out of the air conditioner to be recycled is liquid, and to control to open the first stop valve 13, the third stop valve 19, the semiconductor refrigeration sheet 7, the pump body 15 and the fan 17; when the refrigerant flowing out of the air conditioner to be recycled is not liquid, control to open the throttling element 12, the second stop valve 14 and the third stop valve 19, and to open the compressor 2, the semiconductor refrigeration sheet 7, the pump body 15 and the fan 17, and to close the first stop valve 13. In the technical solution, when the refrigerant flowing out of the air conditioner to be recycled is liquid, the compressor 2, the throttling element 12 and the second stop valve 14 are controlled to be closed, and the first stop valve 13, the third stop valve 19, the semiconductor refrigeration sheet 7, the pump body 15 and the fan 17 are controlled to be opened; due to the existence of the pressure difference and the temperature of the second heat exchanger 5 being lower than the ambient temperature, the refrigerant flows from the air conditioner to be recycled 1 to the second heat exchanger 5, and after being cooled by the pre-cooled cold storage material, flows into the liquid storage tank 8; at the same time, the pump body 15 and the fan 17 are opened, so that the cooling liquid circulates in the liquid cooling system. The cooling liquid takes away the heat of the preheated heat storage material of the third heat exchanger 6, and under the fan 17, the heat is dissipated through the air cooling radiator 16, and the dissipated heat heats the refrigerant recovery system, increases the pressure in the system, and promotes the refrigerant to further flow to the liquid storage tank 8.

[0074] When the refrigerant flowing out of the air conditioner to be recycled is not liquid, the throttling element 12, the second stop valve 14 and the third stop valve 19 are controlled to be opened, and the compressor 2, the semiconductor refrigeration sheet 7, the pump body 15 and the fan 17 are opened, and the first stop valve 13 is closed. The compressor 2, the semiconductor refrigeration sheet 7 and the pump body 15 and the fan 17 continue to work, and the heat dissipated by the air cooling radiator 16 continues to heat the refrigerant recovery system. The refrigerant throttled by the throttling element 12 into low-temperature and low-pressure refrigerant enters the first heat exchanger 4 to evaporate and absorb heat, and then enters the compressor 2 after passing through the drying filter 9. The high-temperature and high-pressure refrigerant coming out of the compressor 2 passes through the oil separator 10, enters the condenser 3, and the condensed refrigerant passes through the first heat exchanger 4 to release heat and cool. The refrigerant cooled from the first heat exchanger 4 passes through the second stop valve 14 and flows to the second heat exchanger 5, and after being cooled by the pre-cooled cold storage material in the second heat exchanger 5, flows into the liquid storage tank 8 through the third stop valve 19.

[0075] In some embodiments, the control method of the refrigerant recovery system further comprises a preparation step, opening the semiconductor refrigeration piece 7, and making the semiconductor refrigeration piece 7 work for not less than 2 minutes before entering the judgment step. In this technical solution, the semiconductor refrigeration piece 7 is made to work in advance before the refrigerant recovery system recovers the refrigerant. The cold end of the semiconductor refrigeration piece 7 cools the second heat exchanger 5 filled with internal storage materials, and the hot end of the semiconductor refrigeration piece 7 heats the third heat exchanger 6 filled with internal storage materials. Therefore, before the refrigerant is recovered, the temperature in the refrigerant recovery system is ensured, and the initial refrigerant entering the recovery system can be effectively recovered, thereby improving the recovery efficiency.

[0076] In some embodiments, the preparation step, when including the liquid storage tank 8 and the pressure gauge 18,

[0077] judging whether there is refrigerant in the liquid storage tank 8,

[0078] when the liquid storage tank 8 contains refrigerant, controlling to open the throttling device 12 and the first stop valve 13, controlling to close the third stop valve 19, and performing vacuumizing on the refrigerant circuit. When the pressure value detected by the pressure gauge 18 is lower than 40 Pa, stop vacuumizing, and control to close the throttling device 12 and the first stop valve 13.

[0079] when the liquid storage tank 8 contains refrigerant, controlling to open the throttling device 12 and the first stop valve 13, controlling to close the third stop valve 19, and performing vacuumizing on the refrigerant circuit. When the pressure value detected by the pressure gauge 18 is lower than 40 Pa, stop vacuumizing, and control to close the throttling device 12 and the first stop valve 13.

[0080] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, and improvement within the spirit and principle of the present application shall be included in the protection scope of the present application. The above only describes the preferred embodiments of the present application, and it should be noted that for ordinary skilled in the art, without departing from the technical principles of the present application, a number of improvements and modifications can be made, and these improvements and modifications shall be regarded as the protection scope of the present application.

Claims

1. A refrigerant recovery system characterized by comprising: The application relates to a refrigerant recovery system. The refrigerant recovery system comprises a liquid cooling circuit and a refrigerant circuit, the refrigerant circuit is connected with a to-be-recovered air conditioner (1), refrigerant of the to-be-recovered air conditioner (1) can flow into the refrigerant circuit, and the liquid cooling circuit can exchange heat with the refrigerant circuit. The refrigerant circuit comprises a compressor (2), a condenser (3), a throttling device (12) and a first heat exchanger (4), the compressor (2), the condenser (3), the throttling device (12) and the first heat exchanger (4) are sequentially connected to form a first circulating circuit, the throttling device (12) is connected with the to-be-recovered air conditioner (1), the first heat exchanger (4) is further connected with a liquid storage tank (8), and refrigerant of the to-be-recovered air conditioner (1) sequentially passes through the throttling device (12), the first heat exchanger (4), the compressor (2) and the condenser (3), and then flows into the liquid storage tank (8) through the first heat exchanger (4). A second heat exchanger (5) is arranged between the first heat exchanger (4) and the liquid storage tank (8), one end of the second heat exchanger (5) is connected with the first heat exchanger (4), the other end of the second heat exchanger (5) is connected with the liquid storage tank (8), and refrigerant flowing out of the condenser (3) flows into the liquid storage tank (8) through the second heat exchanger (5) after passing through the first heat exchanger (4). The liquid cooling circuit comprises a third heat exchanger (6), a radiator (16) and a pump body (15), the third heat exchanger (6), the radiator (16) and the pump body (15) are sequentially connected to form a second circulating circuit, a fan (17) is arranged on the radiator (16), and the second circulating circuit is located outside the first circulating circuit. The refrigerant recovery system further comprises a semiconductor refrigeration sheet (7), the third heat exchanger (6) is opposite to the second heat exchanger (5), the semiconductor refrigeration sheet (7) is located between the third heat exchanger (6) and the second heat exchanger (5), and the third heat exchanger (6), the semiconductor refrigeration sheet (7) and the second heat exchanger (5) are coupled.

2. The refrigerant recovery system of claim 1, wherein: The refrigerant circuit further comprises a filter (9) and an oil separator (10), the filter (9) is located between the compressor (2) and the first heat exchanger (4), one end of the filter (9) is connected with the compressor (2), and the other end of the filter (9) is connected with the first heat exchanger (4), the oil separator (10) is located between the compressor (2) and the condenser (3), the oil separator (10) has a first end and a second end, the first end of the oil separator (10) is connected with the condenser (3), and the second end of the oil separator (10) is connected with the condenser (3).

3. The refrigerant recovery system of claim 1, wherein: The second heat exchanger (5) is connected with the to-be-recovered air conditioner (1), a first stop valve (13) is arranged between the second heat exchanger (5) and the to-be-recovered air conditioner (1), one end of the first stop valve (13) is connected with the second heat exchanger (5), and the other end of the first stop valve (13) is connected with the to-be-recovered air conditioner (1).

4. The refrigerant recovery system of claim 3, wherein: The second heat exchanger (5) is provided with a second stop valve (14) between the first heat exchanger (4), one end of the second stop valve (14) is connected with the first heat exchanger (4), the other end is connected with the second heat exchanger (5), and the second heat exchanger (5) is connected with the liquid storage tank (8) through a third stop valve (19).

5. The refrigerant recovery system of claim 1, wherein: The semiconductor refrigeration piece (7) has a cold end and a hot end, the cold end faces the second heat exchanger (5), and the hot end faces the third heat exchanger (6).

6. The refrigerant recovery system of claim 4, wherein: The to-be-recovered air conditioner (1) has an outlet, the refrigerant of the to-be-recovered air conditioner (1) flows out from the outlet, and a pressure gauge (18) and a sight glass (11) are arranged at the outlet.

7. The control method of the refrigerant recovery system according to any one of claims 1-6, wherein: when the refrigerant recovery system comprises a second stop valve (14) provided between the second heat exchanger (5) and the first heat exchanger (4); a judging step of judging whether the refrigerant flowing out of the to-be-recovered air conditioner (1) is clean; a control step of, when the refrigerant flowing out of the to-be-recovered air conditioner (1) is clean, controlling to close the compressor (2), the throttling device (12) and the second stop valve (14), and controlling to open the first stop valve (13), the third stop valve (19), the semiconductor refrigeration piece (7), the pump body (15) and the fan (17); and when the refrigerant flowing out of the to-be-recovered air conditioner (1) is not clean, controlling to open the throttling device (12), the second stop valve (14) and the third stop valve (19), and simultaneously controlling to start the compressor (2), the semiconductor refrigeration piece (7), the pump body (15) and the fan (17), and to stop the first stop valve (13).

8. The control method of the refrigerant recovery system according to claim 7, characterized by: The control method of the refrigerant recovery system further comprises a preparation step of starting the semiconductor refrigeration piece (7) and working the semiconductor refrigeration piece (7) for not less than 2 minutes before entering the judging step.

9. The control method of the refrigerant recovery system according to claim 8, characterized by: The preparation step, when comprising the pressure gauge (18), judging whether there is refrigerant in the liquid storage tank (8), when there is refrigerant in the liquid storage tank (8), controlling to open the throttling device (12) and the first stop valve (13), and controlling to close the third stop valve (19), and performing vacuumizing on the refrigerant circuit, stopping the vacuumizing when the pressure value detected by the pressure gauge (18) is lower than 40 Pa, and controlling to close the throttling device (12) and the first stop valve (13); when there is no refrigerant in the liquid storage tank (8), controlling to open the throttling device (12), the first stop valve (13) and the third stop valve (19), and stopping the vacuumizing when the pressure value detected by the pressure gauge (18) is lower than 40 Pa, and controlling to close the throttling device (12) and the first stop valve (13).

10. The control method of the refrigerant recovery system according to claim 7, characterized by: when the refrigerant recovery system further comprises a sight glass (11), judging whether there is refrigerant flowing out of the outlet of the to-be-recovered air conditioner (1) through the sight glass (11); When the outlet of the air conditioner (1) to be recovered has refrigerant flowing, and the refrigerant flowing out of the air conditioner (1) to be recovered is in a clean state, the compressor (2), the throttling device (12) and the second stop valve (14) are controlled to be closed, and the first stop valve (13), the third stop valve (19), the semiconductor refrigeration sheet (7), the pump body (15) and the fan (17) are controlled to be opened. When the outlet of the air conditioner (1) to be recovered has no refrigerant flowing, and the refrigerant flowing out of the air conditioner (1) to be recovered is in a clean state, the first stop valve (13) is controlled to be closed.

11. The control method of the refrigerant recovery system according to claim 10, wherein: When the outlet of the air conditioner (1) to be recovered has refrigerant flowing, and the refrigerant flowing out of the air conditioner (1) to be recovered is not in a clean state, the throttling device (12), the second stop valve (14) and the third stop valve (19) are controlled to be opened, and the compressor (2), the semiconductor refrigeration sheet (7), the pump body (15) and the fan (17) are controlled to be started, and the first stop valve (13) is controlled to be closed. When the outlet of the air conditioner (1) to be recovered has no refrigerant flowing, and the refrigerant flowing out of the air conditioner (1) to be recovered is not in a clean state, the third stop valve (19), the throttling device (12) and the first stop valve (13) are controlled to be closed first, and then the compressor (2) is controlled to be closed, the semiconductor refrigeration sheet (7) is controlled to stop working, the pump body (15) is controlled to stop, and the fan (17) is controlled to stop working.

12. The control method of the refrigerant recovery system according to any one of claims 1-6, wherein: When the refrigerant recovery system comprises a sight glass (11); A judging step is provided to judge whether the refrigerant flowing out of the air conditioner to be recovered is in a liquid state according to the sight glass (11); When the refrigerant flowing out of the air conditioner to be recovered is in a liquid state, the compressor (2), the throttling device (12) and the second stop valve (14) are controlled to be closed, and the first stop valve (13), the third stop valve (19), the semiconductor refrigeration sheet (7), the pump body (15) and the fan (17) are controlled to be opened; when the refrigerant flowing out of the air conditioner to be recovered is not in a liquid state, the throttling device (12), the second stop valve (14) and the third stop valve (19) are controlled to be opened, and the compressor (2), the semiconductor refrigeration sheet (7), the pump body (15) and the fan (17) are controlled to be started, and the first stop valve (13) is controlled to be closed.

13. The control method of the refrigerant recovery system according to claim 12, characterized by: The control method of the refrigerant recovery system further comprises a preparation step of opening the semiconductor refrigeration sheet (7) and making the semiconductor refrigeration sheet (7) work for not less than 2 minutes before entering the judging step.

14. The control method of the refrigerant recovery system according to claim 13, characterized by: When the refrigerant recovery system comprises the liquid storage tank (8) and the pressure gauge (18), the preparation step comprises: judging whether there is refrigerant in the liquid storage tank (8), When the refrigerant exists in the liquid storage tank (8), the throttle (12) and the first stop valve (13) are controlled to be opened, the third stop valve (19) is controlled to be closed, the refrigerant circuit is vacuumized, and the vacuumization is stopped when the pressure value detected by the pressure gauge (18) is lower than 40 Pa, and the throttle (12) and the first stop valve (13) are controlled to be closed. When the refrigerant does not exist in the liquid storage tank (8), the throttle (12), the first stop valve (13) and the third stop valve (19) are controlled to be opened, the vacuumization is stopped when the pressure value detected by the pressure gauge (18) is lower than 40 Pa, and the throttle (12) and the first stop valve (13) are controlled to be closed.

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