Refrigerant recovery equipment and control method thereof

Abstract

The invention discloses refrigerant recovery equipment and a control method thereof, and relates to the technical field of refrigerant recovery. The system comprises a recovery unit and a refrigeration and purification device, the recovery unit comprises a purification pipeline, the refrigeration and purification device is embedded in the purification pipeline, the refrigeration and purification device comprises a low-temperature container, a filter assembly, a refrigeration unit and a purification pump, the filter assembly is arranged in the low-temperature container, and the cold end of the refrigeration unit is matched with the filter assembly; the cooling device is used for cooling the filtering assembly and condensing a gaseous refrigerant flowing into the filtering assembly into a liquid refrigerant, and impurities in the liquid refrigerant are solidified in the filtering assembly. The purification pump communicates with the space, located below the filtering assembly, in the low-temperature container and communicates with the recycling unit so that the purified liquid refrigerant can be recycled. The characteristic that the freezing point of water and lubricating oil is higher than that of a refrigerant can be utilized, the solidified water and lubricating oil are captured in the filtering assembly, and therefore the purity of the recycled refrigerant is greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of refrigerant recovery, and particularly to a refrigerant recovery device and its control method. Background Art

[0002] A refrigerant is a greenhouse gas, and its recovery meets the requirements of the renewable utilization of resources. With the gradual enhancement of environmental awareness, the demand for refrigerant recovery has also gradually increased. When a refrigerant recovery system recovers a refrigerant, it usually uses a filter to remove impurities and moisture, and an oil separator to remove oil. However, the purity of the refrigerant recovered by the above recovery method is relatively low, thereby reducing the refrigeration efficiency of the refrigerant that can be reused subsequently. Summary of the Invention

[0003] In view of the problem that the purity of the refrigerant recovered by a refrigerant recovery device is reduced, affecting the refrigeration efficiency that can be reused subsequently, the present invention is proposed to provide a refrigerant recovery device and its control method that can overcome or at least partially solve the above problems.

[0004] Based on the first aspect of the present invention, a refrigerant recovery device is provided. The refrigerant recovery device includes: a recovery unit, the recovery unit includes a purification pipeline; a refrigeration purification device, the refrigeration purification device is embedded in the purification pipeline, and the refrigeration purification device includes: a low-temperature container; a filtration component, the filtration component is arranged in the low-temperature container; a refrigeration unit, the cold end of the refrigeration unit cooperates with the filtration component to cool the filtration component, so as to condense the gaseous refrigerant flowing into the filtration component into a liquid refrigerant, and impurities in the liquid refrigerant solidify in the filtration component; a purification pump, the purification pump is communicated with the space below the filtration component in the low-temperature container and is communicated with the recovery unit to recover the purified liquid refrigerant.

[0005] An optional summary of the invention, the filtration component includes a porous structure for generating a capillary effect to lock the liquid refrigerant in the porous structure.

[0006] An optional summary of the invention, when the refrigeration unit operates, the temperature in the low-temperature container is controlled between -40 °C and -90 °C to solidify impurities in the liquid refrigerant located in the porous structure.

[0007] An optional invention content, the recovery unit further includes: a recovery pipeline, the recovery pipeline is communicated with the purification pipeline, and the recovery pipeline includes a recovery inlet for communicating with the equipment to be recovered; a liquid storage tank communicated with the recovery pipeline for storing refrigerant; a cooling component for cooling the liquid storage tank to make the liquid storage tank generate negative pressure to suck the refrigerant in the equipment to be recovered; the refrigerant recovery equipment further includes a valve assembly arranged in the recovery pipeline and the purification pipeline for switching the pipelines between the recovery pipeline and the purification pipeline.

[0008] An optional invention content, the recovery unit further includes a drying filter, a distillation tank, a compressor and a first heat exchanger. The air outlet of the drying filter is communicated with the air inlet of the distillation tank. The air outlet of the distillation tank is communicated with the refrigerant inlet of the low-temperature container. The refrigerant outlet of the low-temperature container is communicated with the compressor. The air outlet of the compressor is communicated with the air inlet of the first heat exchanger. The liquid outlet of the first heat exchanger is communicated with the liquid storage tank. Wherein, the liquid inlet of the purification pump is communicated with the air inlet of the compressor, and the liquid outlet of the purification pump is communicated with the liquid outlet of the first heat exchanger; the valve assembly includes: a first purification valve arranged at the liquid inlet of the purification pump to control the on-off of the liquid path of the purification pump; a second purification valve arranged at the air inlet of the compressor to control the on-off of the air path of the compressor.

[0009] An optional invention content, the recovery pipeline includes a first recovery outlet and a second recovery outlet. The valve assembly further includes: a first recovery valve arranged at the inlet of the liquid storage tank to control the opening and closing of the liquid storage tank; a second recovery valve arranged between the first recovery outlet and the liquid storage tank; a third purification valve arranged in the purification pipeline communicated with the second recovery outlet, and the second recovery outlet is communicated with the drying filter; a fourth purification valve arranged in the purification pipeline between the liquid storage tank and the first heat exchanger; wherein, if the first recovery valve and the second recovery valve are opened, and the third purification valve and the fourth purification valve are closed, the refrigerant flowing in from the recovery inlet flows into the liquid storage tank through the first recovery outlet; if the first recovery valve, the second purification valve, the third purification valve and the fourth purification valve are opened, and the first purification valve and the second recovery valve are closed, the refrigerant flowing in from the recovery inlet flows into the drying filter through the second recovery outlet, and sequentially flows through the distillation tank, the compressor and the first heat exchanger and then flows into the liquid storage tank.

[0010] An optional invention content, the refrigerant recovery unit further includes a refrigerant detection device, the refrigerant detection device is arranged in the recovery pipeline for detecting the purity of the refrigerant; the valve assembly further includes a fifth purification valve, the fifth purification valve is located in the purification pipeline connecting the recovery inlet and the purification pump. When the fifth purification valve is opened and the fourth purification valve is closed, the refrigerant flowing out of the purification pump passes through the refrigerant detection device for purity detection.

[0011] An optional invention content, the refrigerant recovery device further includes a distillation heat exchange device, the distillation heat exchange device includes: a heat exchange pipeline; a second heat exchanger, the second heat exchanger is in contact with the hot end of the refrigeration unit and is embedded in the heat exchange pipeline; a circulation pump, the circulation pump is embedded in the heat exchange pipeline for providing heat exchange power; a third heat exchanger, the third heat exchanger is embedded in the heat exchange pipeline and is in contact with the distillation tank to transfer the heat of the refrigeration unit to the distillation tank for distillation heating of the refrigerant.

[0012] Based on the second aspect of the present invention, there is also provided a control method for a refrigerant recovery device, the refrigerant recovery device includes the refrigerant recovery device as described in any one of the above invention contents, and the control method includes: obtaining purity data of the refrigerant; when it is determined that the preset purification conditions are met according to the purity data, controlling the refrigerant recovery device to execute a purification mode, and executing the purification mode includes: controlling the refrigeration unit to work to cool down the filtration component so that the gaseous refrigerant flowing into the filtration component condenses into a liquid refrigerant, so that impurities in the liquid refrigerant solidify in the filtration component; controlling the purification pump to work to provide pressure to send the liquid refrigerant purified by the filtration component into the refrigerant recovery unit for recovery.

[0013] An optional invention content, controlling the refrigeration unit to work to cool down the filtration component includes: controlling the refrigeration unit to work to cool down the filtration component and keeping the temperature of the filtration component between -40 degrees Celsius and -90 degrees Celsius.

[0014] An optional invention content, executing the purification mode further includes: when it is detected that the purification switching conditions are met, stopping the purification pump from working and controlling the valve assembly to work so that the gaseous refrigerant flowing out of the low-temperature container flows into the compressor; controlling the compressor and the first heat exchanger to work to condense the gaseous refrigerant into a liquid refrigerant.

[0015] An optional invention content, performing the purification mode further includes: performing a refrigerant detection step, the refrigerant detection step including: controlling the valve assembly to act so that the liquid refrigerant flowing out of the first heat exchanger or the purification pump flows through the refrigerant detection device, so that the refrigerant detection device detects the purity data of the refrigerant; obtaining the purity data of the refrigerant; if it is determined that the preset purification conditions are met according to the purity data, repeating the refrigerant detection step; if it is determined that the preset purification conditions are not met according to the purity data, controlling the valve assembly to act so that the liquid refrigerant flowing out of the first heat exchanger or the purification pump flows into the liquid storage tank.

[0016] An optional invention content, performing the purification mode further includes starting the circulation pump to work, so as to transfer the heat of the refrigeration unit to the distillation tank for distillation heating of the refrigerant.

[0017] An optional invention content, the control method further includes: in the case where it is determined that the preset purification conditions are not met according to the purity data, controlling the refrigerant recovery device to execute the recovery mode, and performing the recovery mode including: controlling the valve assembly to act and the cooling assembly to work, so that the refrigerant flowing in from the recovery inlet flows into the liquid storage tank; in the case where the pressure supply switching conditions are detected, controlling the valve assembly to work and the compressor to work, so that the compressor provides pressure, and the refrigerant flowing in from the recovery inlet sequentially flows through the drying filter, the distillation tank, the compressor and the first heat exchanger and then flows into the liquid storage tank.

[0018] Compared with the prior art, the present invention includes a recovery unit and a refrigeration purification device. The recovery unit includes a purification pipeline, and the refrigeration purification device is embedded in the purification pipeline. The refrigeration purification device includes a low-temperature container, a filtration component, a refrigeration unit and a purification pump. The filtration component is arranged in the low-temperature container, and the cold end of the refrigeration unit cooperates with the filtration component to cool the filtration component, so as to condense the gaseous refrigerant flowing into the filtration component into a liquid refrigerant, and the impurities in the liquid refrigerant solidify in the filtration component. The purification pump is communicated with the lower space of the filtration component in the low-temperature container and is communicated with the recovery unit to recover the purified liquid refrigerant. Thus, by utilizing the characteristics that the freezing points of water and lubricating oil are higher than that of the refrigerant, a low-temperature environment can be created in the filtration component by the refrigeration unit, and the solidified water and lubricating oil can be captured in the filtration component to perform deep water and oil removal. Thereby, the purity of the recovered refrigerant is greatly improved, and the refrigeration efficiency of the subsequent recyclable refrigerant is improved.

[0019] The above description is only an overview of the technical solution of the present invention. In order to be able to understand the technical means of the present invention more clearly, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features and advantages of the present invention more obvious and understandable, the following specifically illustrates the specific embodiments of the present invention. Brief Description of the Drawings

[0020] By reading the detailed description of the preferred embodiments below, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present invention. Moreover, throughout the drawings, the same reference numerals are used to represent the same components.

[0021] In the drawings: Figure 1 is a schematic structural diagram of a refrigerant recovery device provided by an embodiment of the present invention; Figure 2 is a schematic diagram of the first refrigerant flow direction when another refrigerant recovery device provided by an embodiment of the present invention operates in a purification mode; Figure 3 is a schematic diagram of the second refrigerant flow direction when another refrigerant recovery device provided by an embodiment of the present invention operates in a purification mode; Figure 4 is a schematic diagram of the third refrigerant flow direction when another refrigerant recovery device provided by an embodiment of the present invention operates in a purification mode; Figure 5 is a schematic diagram of the first refrigerant flow direction when another refrigerant recovery device provided by an embodiment of the present invention operates in a recovery mode; Figure 6 is a schematic diagram of the second refrigerant flow direction when another refrigerant recovery device provided by an embodiment of the present invention operates in a recovery mode; Figure 7 is a block diagram of the electrical connection structure of a refrigerant recovery device provided by an embodiment of the present invention; Figure 8 is a schematic flow chart of the steps of a control method for a refrigerant recovery device provided by an embodiment of the present invention; Figure 9 is a schematic flow chart of the steps of another control method for a refrigerant recovery device provided by an embodiment of the present invention; Reference numerals: 1, recovery unit; 11, purification pipeline; 12, recovery pipeline; 13, liquid storage tank; 14, cooling assembly; 15, drying filter; 16, distillation tank; 17, compressor; 18, first heat exchanger; 19, flow regulating valve; 2, refrigeration and purification device; 21, low-temperature container; 22, filtration assembly; 23, refrigeration unit; 24, purification pump; 3, valve assembly; 31, first purification valve; 32, second purification valve; 33, first recovery valve; 34, second recovery valve; 35, third purification valve; 36, fourth purification valve; 37, fifth purification valve; 38, sixth purification valve; 4, refrigerant detection device; 5, distillation heat exchange device; 51, heat exchange pipeline; 52, second heat exchanger; 53, circulation pump; 54, third heat exchanger; 6, sight glass; 7, controller; 8, equipment to be recovered. Detailed implementation mode

[0022] The exemplary embodiments of the present invention will be described in more detail below with reference to the drawings. Although the exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present invention can be more thoroughly understood and the scope of the present invention can be fully conveyed to those skilled in the art.

[0023] Refrigerant is a greenhouse gas, and its recovery conforms to the development of renewable utilization of resources. With the gradual enhancement of environmental awareness, the demand for refrigerant recovery has also gradually increased. When the refrigerant recovery system recovers refrigerant, it usually uses a filter to remove impurities and moisture and an oil separator to remove oil. However, the purity of the refrigerant recovered by the above recovery method is relatively low, thus reducing the subsequent refrigeration efficiency of the refrigerant that can be reused.

[0024] Based on the above technical problems, embodiments of the present invention are proposed. The embodiments of the present invention may include a recovery unit 1 and a refrigeration and purification device 2. The recovery unit 1 includes a purification pipeline 11, and the refrigeration and purification device 2 is embedded in the purification pipeline 11. The refrigeration and purification device 2 includes a low-temperature container 21, a filtration component 22, a refrigeration unit 23, and a purification pump 24. The filtration component 22 is disposed in the low-temperature container 21, and the cold end of the refrigeration unit 23 cooperates with the filtration component 22 to cool the filtration component 22, so as to condense the gaseous refrigerant flowing into the filtration component 22 into a liquid refrigerant, and the impurities in the liquid refrigerant solidify in the filtration component 22. The purification pump 24 is communicated with the space below the filtration component 22 in the low-temperature container 21 and is communicated with the recovery unit 1 to recover the purified liquid refrigerant. Thus, by utilizing the characteristic that the freezing points of water and lubricating oil are higher than that of the refrigerant, a low-temperature environment can be created in the filtration component 22 by the refrigeration unit 23, and the solidified water and lubricating oil can be captured in the filtration component 22 to perform deep water and oil removal. Thereby, the purity of the recovered refrigerant is greatly improved, and the refrigeration efficiency of the subsequent reusable refrigerant is also improved.

[0025] Referring to Figures 1-7 As shown, embodiments of the present invention provide a refrigerant recovery device. The refrigerant recovery device may include a recovery unit 1 and a refrigeration and purification device 2. The recovery unit 1 includes a purification pipeline 11, and the refrigeration and purification device 2 is embedded in the purification pipeline 11. The refrigeration and purification device 2 includes a low-temperature container 21, a filtration component 22, a refrigeration unit 23, and a purification pump 24. The filtration component 22 is disposed in the low-temperature container 21, and the cold end of the refrigeration unit 23 cooperates with the filtration component 22 to cool the filtration component 22, so as to condense the gaseous refrigerant flowing into the filtration component 22 into a liquid refrigerant, and the impurities in the liquid refrigerant solidify in the filtration component 22. The purification pump 24 is communicated with the space below the filtration component 22 in the low-temperature container 21 and is communicated with the recovery unit 1 to recover the purified liquid refrigerant.

[0026] In the embodiments of the present invention, the recovery unit 1 can be understood as a collection of a series of devices and pipelines required for recovering refrigerant. It is used to communicate with the device 8 to be recovered to recover the refrigerant. Among them, the device 8 to be recovered can be understood as including related electrical equipment with refrigerant. For example, the device 8 to be recovered may include, but is not limited to, refrigerators, freezers, air-conditioning equipment, refrigeration units, cold drink machines, ice-making machines, and other related equipment with refrigeration requirements.

[0027] The purification pipeline 11 can be understood as the relevant pipeline that constitutes the purification channel during the process of recovering the refrigerant. It can be composed of at least two connecting pipelines connected end to end. The refrigeration purification device 2 is embedded in the purification pipeline 11, that is, the refrigerant flowing through the purification pipeline 11 can flow through the refrigeration purification device 2, so that the refrigerant can be deeply purified by the refrigeration purification device 2. The refrigeration purification device 2 can include a low-temperature container 21, a filtration component 22, a refrigeration unit 23, and a purification pump 24. The low-temperature container 21 refers to a sealed container that can store or maintain the refrigerant in a low-temperature environment. For example, the low-temperature container 21 can be a low-temperature container 21 with a liquid level gauge, etc. The filtration component 22 is arranged in the low-temperature container 21, and it is provided with fine pores for the refrigerant to pass through. The cold end of the refrigeration unit 23 cooperates with the filtration component 22. For example, the cold end of the refrigeration unit 23 is in surface contact with the filtration component 22, so that the refrigerant passing through the filtration component 22 can be quickly cooled, and the gaseous refrigerant condenses to form a liquid refrigerant with a lower temperature.

[0028] In the low-temperature environment provided by the refrigerant unit, considering that the impurities in the refrigerant usually include water and the lubricating oil of the compressor 17, since the freezing points of water and the lubricating oil of the compressor 17 are higher than that of the refrigerant. Therefore, when the refrigeration unit 23 operates to lower the temperature in the low-temperature container 21 below the freezing points of water and the lubricating oil of the compressor 17 and higher than the freezing point of the refrigerant, the impurities (water and the lubricating oil of the compressor 17) in the liquid refrigerant solidify in the filtration component 22, and the deeply purified liquid refrigerant passes through the filtration component 22 and flows to the bottom of the low-temperature container 21 for storage. The purification pump 24 pumps the purified liquid refrigerant in the low-temperature container 21 outside the low-temperature container 21 and introduces it into the recovery unit 1, so that the deeply purified liquid refrigerant can be recovered by the recovery unit 1. Utilizing the physical property that the freezing points of the impurities in the refrigerant are higher than that of the refrigerant, the refrigerant is deeply purified, which can greatly improve the purity of the recovered refrigerant. And it improves the refrigeration efficiency of the subsequent recyclable refrigerant.

[0029] In the embodiment of the present invention, the filtration component 22 can be detachably connected to the low-temperature container 21, so that the filtration component 22 can be taken out from the low-temperature container 21. After flushing the impurities and drying the filtration component 22, the filtration component 22 can be reused.

[0030] In an alternative embodiment of the invention, the filtration component 22 includes a porous structure for generating a capillary effect to lock the liquid refrigerant in the porous structure.

[0031] In the embodiment of the present invention, the capillary effect can be understood as that when the liquid refrigerant is in the fine pores of the porous structure and there is no external pressure, it spontaneously rises along the porous structure. Thus, after the impurities in the liquid refrigerant solidify in the porous structure, the solidified impurities will be captured in the porous structure due to the capillary effect and will not fall downward. Thereby, a highly purified liquid refrigerant is obtained in the lower space of the cryogenic container 21.

[0032] In an alternative embodiment of the invention, when the refrigeration unit 23 operates, the temperature in the cryogenic container 21 is controlled between -40 °C and -90 °C to solidify the impurities in the liquid refrigerant located in the porous structure.

[0033] In the embodiment of the present invention, when the refrigeration unit 23 operates, the temperature in the cryogenic container 21 can be controlled between -40 °C and -90 °C. For example, the temperature in the cryogenic container 21 can be -40 °C, -50 °C, -70 °C, -80 °C, -90 °C, etc., which is not limited here too much. Considering that the freezing point of the lubricating oil of the compressor 17 is generally higher than -40 °C, the full solidification of the lubricating oil can be ensured within this temperature range. And the water content in the refrigerant is inversely proportional to the temperature, that is, the lower the temperature, the less the water content in the refrigerant. For example, within the above temperature range, the water content in the refrigerant can be controlled to be less than or equal to 0.0079 Or even the water content in the refrigerant can be controlled to be less than or equal to 0.001 Thereby, the recovery purity of the refrigerant can be greatly improved.

[0034] In some embodiments, the refrigeration unit 23 may include a Stirling refrigerator. A Stirling refrigerator is a thermodynamic cycle refrigerator that operates based on the reverse Stirling cycle principle and uses the expansion and compression of gas at different temperatures to achieve the refrigeration effect. For example, the cold finger (cold output end) of the refrigeration unit 23 can be in surface contact with the porous structure, so as to quickly reduce the temperature of the gaseous refrigerant passing through the pores of the porous structure, liquefy it quickly, and make the impurities in the liquid refrigerant solidify quickly.

[0035] In an alternative embodiment of the invention, refer to Figures 1-6As shown, the recovery unit 1 may further include a recovery pipeline 12, a liquid storage tank 13, and a cooling assembly 14. The recovery pipeline 12 is communicated with the purification pipeline 11, and the recovery pipeline 12 includes a recovery inlet for communicating with the device 8 to be recovered. The liquid storage tank 13 is communicated with the recovery pipeline 12 for storing refrigerant. The cooling assembly 14 is used to cool the liquid storage tank 13 so that the liquid storage tank 13 generates negative pressure to suck the refrigerant in the device 8 to be recovered. The refrigerant recovery device further includes a valve assembly 3 disposed in the recovery pipeline 12 and the purification pipeline 11 for switching the pipeline between the recovery pipeline 12 and the purification pipeline 11.

[0036] In an embodiment of the present invention, the recovery pipeline 12 can be understood as the relevant pipeline constituting the recovery channel during the process of recovering refrigerant, which can be composed of at least two connecting pipes connected. The difference between the recovery pipeline 12 and the purification pipeline 11 is that no relevant devices for purifying refrigerant are provided on the recovery pipeline 12. The recovery pipeline 12 is communicated with the purification pipeline 11 so that the purified refrigerant flows through the recovery pipeline 12 and then into the liquid storage tank 13 for storage.

[0037] The recovery pipeline 12 at least includes a recovery inlet for communicating with the device 8 to be recovered. The liquid storage tank 13 is communicated with the recovery pipeline 12 for storing the recovered refrigerant. The cooling assembly 14 is in surface contact with the liquid storage tank 13 for cooling the refrigerant in the liquid storage tank 13. Refer to Figure 4 As shown, the cooling assembly 14 may be located at the bottom or the side of the liquid storage tank 13, so as to condense the gaseous refrigerant entering the liquid storage tank 13 to obtain liquid refrigerant, and a negative pressure can be formed in the recovery pipeline 12, so that the refrigerant in the device 8 to be recovered can be sucked into the liquid storage tank 13 by relying on the negative pressure. And through gas-liquid conversion, the liquid storage capacity of the liquid storage tank 13 can be improved. The preliminary recovery of the refrigerant is completed under the condition of pressure balance.

[0038] The valve assembly 3 includes at least one valve. The valve assembly 3 is disposed in the recovery pipeline 12 and the purification pipeline 11, and can make the valve assembly 3 work to switch the connection channel between the recovery pipeline 12 and the purification pipeline 11. For example, refer to Figure 5As shown, when the refrigerant recovery device operates in the recovery mode and reaches pressure balance and cannot continue the recovery, the valve assembly 3 can be controlled to act, so that the recovery pipeline 12 communicates with the purification pipeline 11, enabling the relevant devices located in the purification pipeline 11 in the recovery unit 1 to work, thereby generating a pressure difference, causing the refrigerant flowing in from the recovery inlet to flow into the purification pipeline 11 and then flowing into the liquid storage tank 13 through the purification pipeline 11.

[0039] In an optional embodiment of the invention, as shown in Figures 2-6 shown, the recovery unit 1 further includes a drying filter 15, a distillation tank 16, a compressor 17, and a first heat exchanger 18. The outlet of the drying filter 15 communicates with the inlet of the distillation tank 16. The outlet of the distillation tank 16 communicates with the refrigerant inlet of the low-temperature container 21. The refrigerant outlet of the low-temperature container 21 communicates with the compressor 17. The outlet of the compressor 17 communicates with the inlet of the first heat exchanger 18. The liquid outlet of the first heat exchanger 18 communicates with the liquid storage tank 13. Among them, the inlet of the purification pump 24 communicates with the inlet of the compressor 17, and the outlet of the purification pump 24 communicates with the liquid outlet of the first heat exchanger 18. The valve assembly 3 may include a first purification valve 31 and a second purification valve 32. The first purification valve 31 is disposed at the inlet of the purification pump 24 to control the on-off of the liquid path of the purification pump 24. The second purification valve 32 is disposed at the inlet of the compressor 17 to control the on-off of the gas path of the compressor 17.

[0040] In the embodiment of the present invention, on the one hand, the drying filter 15 is used to adsorb the moisture in the refrigerant, and on the other hand, it can also filter the impurities in the refrigerant. For example, the impurities may include substances such as oil stains, dust, and acidic substances. The distillation tank 16 can remove the lubricating oil of the compressor 17 according to the different boiling points of the refrigerant and the lubricating oil. Considering that the boiling point of the lubricating oil is much higher than that of the refrigerant, the temperature inside the distillation tank 16 can be controlled above the boiling point of the refrigerant and lower than the boiling point of the lubricating oil, so that the lubricating oil remaining in a liquid state can be left at the bottom of the distillation tank 16. The gaseous refrigerant enters the low-temperature container 21 through the inlet of the low-temperature container 21, and the refrigerant outlet of the low-temperature container 21 communicates with the compressor 17. That is, the refrigerant outlet of the low-temperature container 21 communicates with the purification pump 24 and the compressor 17 respectively.

[0041] The first purification valve 31 is arranged at the liquid inlet of the purification pump 24 (which can also be understood as the connection between the refrigerant outlet of the low-temperature container 21 and the purification pump 24), so that the on-off of the liquid path of the purification pump 24 can be controlled by adjusting the first purification valve 31. The second purification valve 32 is arranged at the air inlet of the compressor 17 (which can also be understood as the connection between the refrigerant outlet of the low-temperature container 21 and the compressor 17), so that the on-off of the air path of the compressor 17 can be controlled by adjusting the second purification valve 32.

[0042] In one example, referring to Figure 2 and Figure 3 as shown, when the first purification valve 31 is opened and the second purification valve 32 is closed, the refrigerant flowing out of the low-temperature container 21 flows to the purification pump 24.

[0043] In another example, referring to Figure 5 as shown, when the first purification valve 31 is closed and the second purification valve 32 is opened, the refrigerant flowing out of the low-temperature container 21 flows to the compressor 17. When the refrigerant recovery device operates in the recovery mode and the pressure balance is reached and the recovery cannot continue, the valve assembly 3 can be controlled to act so that the recovery pipeline 12 is connected to the purification pipeline 11, and the refrigerant flowing in from the recovery inlet sequentially flows to the drying filter 15, the distillation tank 16, the compressor 17, and the first heat exchanger 18. Through the operation of the compressor 17, a pressure difference is provided, and the low-temperature and low-pressure gaseous refrigerant is compressed into a high-temperature and high-pressure gaseous refrigerant. The first heat exchanger 18 condenses the high-temperature and high-pressure gaseous refrigerant to obtain a liquid refrigerant, and under the pressure of the compressor 17, the liquid refrigerant flowing out of the first heat exchanger 18 is sent into the liquid storage tank 13. Among them, the first heat exchanger 18 can adopt devices such as an air-cooled heat exchanger.

[0044] In an optional embodiment of the invention, referring to Figure 4 and Figure 5As shown, the recovery pipeline 12 includes a first recovery outlet and a second recovery outlet. The valve assembly 3 further includes a first recovery valve 33, a second recovery valve 34, a third purification valve 35, and a fourth purification valve 36. The first recovery valve 33 is arranged at the inlet of the liquid storage tank 13 to control the opening and closing of the liquid storage tank 13. The second recovery valve 34 is arranged between the first recovery outlet and the liquid storage tank 13. The third purification valve 35 is arranged in the purification pipeline 11 communicated with the second recovery outlet, and the second recovery outlet is communicated with the drying filter 15. The fourth purification valve 36 is arranged in the purification pipeline 11 between the liquid storage tank 13 and the first heat exchanger 18. Wherein, when the first recovery valve 33 and the second recovery valve 34 are opened, and the third purification valve 35 and the fourth purification valve 36 are closed, the refrigerant flowing in from the recovery inlet flows into the liquid storage tank 13 through the first recovery outlet. When the first recovery valve 33, the second purification valve 32, the third purification valve 35, and the fourth purification valve 36 are opened, and the first purification valve 31 and the second recovery valve 34 are closed, the refrigerant flowing in from the recovery inlet flows into the drying filter 15 through the second recovery outlet, and sequentially flows through the distillation tank 16, the compressor 17, and the first heat exchanger 18, and then flows into the liquid storage tank 13.

[0045] In the embodiment of the present invention, when the refrigerant recovery device operates in the recovery mode, referring to Figure 4 As shown, the first recovery valve 33 and the second recovery valve 34 can be controlled to be opened first, and the third purification valve 35 and the fourth purification valve 36 can be controlled to be closed. Thus, under the action of the cooling assembly 14, a negative pressure is formed in the recovery pipeline 12, so that the refrigerant in the device 8 to be recovered can be sucked into the liquid storage tank 13 by relying on the negative pressure, and the liquid storage capacity of the liquid storage tank 13 can be increased through gas-liquid conversion. The preliminary recovery of the refrigerant is completed under the condition of pressure balance.

[0046] When the refrigerant recovery device operates in the recovery mode and the pressure balance is reached and the recovery cannot continue, the valve assembly 3 can be controlled to act. For example, referring to Figure 5As shown, when the first recovery valve 33, the second purification valve 32, the third purification valve 35, and the fourth purification valve 36 are controlled to open, and at the same time the first purification valve 31 and the second recovery valve 34 are controlled to close, the recovery pipeline 12 is communicated with the purification pipeline 11. And the refrigerant flowing in from the recovery inlet sequentially flows to the drying filter 15, the distillation tank 16, the compressor 17, and the first heat exchanger 18. Through the operation of the compressor 17, a pressure difference is provided, and the low-temperature and low-pressure gaseous refrigerant is compressed into a high-temperature and high-pressure gaseous refrigerant. The first heat exchanger 18 condenses the high-temperature and high-pressure gaseous refrigerant to obtain a liquid refrigerant, and under the pressure of the compressor 17, the liquid refrigerant flowing out of the first heat exchanger 18 is sent into the liquid storage tank 13.

[0047] In an optional embodiment of the invention, with reference to Figures 2-6 As shown, the recovery unit 1 further includes a refrigerant detection device 4, and the refrigerant detection device 4 is arranged in the recovery pipeline 12 for detecting the purity of the refrigerant. The valve assembly 3 further includes a fifth purification valve 37, and the fifth purification valve 37 is located in the purification pipeline 11 communicating the recovery inlet and the purification pump 24. When the fifth purification valve 37 is open and the fourth purification valve 36 is closed, the refrigerant flowing out of the purification pump 24 is subjected to purity detection by the refrigerant detection device 4.

[0048] In the embodiment of the present invention, the refrigerant detection device 4 can be understood as related devices for detecting the purity (or cleanliness) of the refrigerant. For example, the refrigerant detection device 4 may include at least one of the following: a moisture sensor, an acidity sensor, and a non-condensable gas sensor. Correspondingly, the purity data for evaluating the refrigerant may include at least one of the following types: water content, acidity value, and non-condensable gas concentration (or non-condensable gas volume fraction).

[0049] With reference to Figure 3As shown, when the fifth purification valve 37 is opened and the fourth purification valve 36 is closed, the refrigerant flowing out of the purification pump 24 is subjected to purity detection by the refrigerant detection device 4. Thus, when the refrigerant recovery device is operating in the purification mode, the purified refrigerant can flow through the refrigerant detection device 4, so that based on the purity data detected by the refrigerant detection device 4, it can be determined whether the refrigerant flowing through the refrigerant detection device 4 needs to undergo the next purification cycle. If no purification cycle is required, the valve assembly 3 can be controlled to act, and the refrigerant flowing through the refrigerant detection device 4 can be directly introduced into the liquid storage tank 13. When the next purification cycle is required, the valve assembly 3 can be controlled to act, and the refrigerant in the refrigerant detection device 4 can be introduced into the drying filter 15, and then sequentially pass through the distillation tank 16, the low-temperature container 21, the purification pump 24 and then flow into the refrigerant detection device 4 for repeated detection. Until no purification cycle is required, the refrigerant flowing through the refrigerant detection device 4 is introduced into the liquid storage tank 13.

[0050] In an alternative embodiment of the invention, with reference to Figures 1-6 As shown, the refrigerant recovery device may further include a distillation heat exchange device 5. The distillation heat exchange device 5 may include a heat exchange pipeline 51, a second heat exchanger 52, a circulation pump 53 and a third heat exchanger 54. The second heat exchanger 52 is in contact with the hot end of the refrigeration unit 23 and is embedded in the heat exchange pipeline 51. The circulation pump 53 is embedded in the heat exchange pipeline 51 to provide heat exchange power. The third heat exchanger 54 is embedded in the heat exchange pipeline 51 and is in contact with the distillation tank 16 to transfer the heat of the refrigeration unit 23 to the distillation tank 16 for distillation heating of the refrigerant.

[0051] In the embodiment of the present invention, the heat output from the hot end (heat output end) of the refrigeration unit 23 can be heat-exchanged through the second heat exchanger 52 in contact therewith. For example, a heat-conducting medium (such as one of water, ethylene glycol and heat-conducting oil) is provided in the heat exchange pipeline 51, and the heat-conducting medium heated in the second heater is sent into the third heat exchanger 54 under the action of the circulation pump 53. The third heat exchanger 54 and the distillation tank 16 can maintain surface contact, so that the internal space of the distillation tank 16 can be heated by the heated heat-conducting medium in the third heat exchanger 54. Thus, when the refrigerant recovery device is operating in the purification mode, when the refrigeration unit 23 and the circulation pump 53 work simultaneously, the distillation heating of the refrigerant can be realized in the distillation tank 16 to remove the lubricating oil in the refrigerant. And at the same time, the deep purification of the lubricating oil and moisture in the refrigerant can be realized in the low-temperature container 21.

[0052] In one or more embodiments, with reference to Figure 7 As shown, the refrigerant recovery device may further include a controller 7, and the controller 7 is electrically connected to the recovery unit 1, the refrigerant purification device, the valve assembly 3, the refrigerant detection device 4, and the distillation heat exchange device 5 respectively. Specifically, the controller 7 may be electrically connected to the refrigerant detection device 4, the cooling assembly 14, the refrigeration unit 23, the purification pump 24, the compressor 17, the first heat exchanger 18, the circulation pump 53, and the valve assembly 3, so that the working states of the recovery unit 1, the refrigerant purification device, the valve assembly 3, and the distillation heat exchange device 5 can be controlled according to the purity data of the refrigerant detected by the refrigerant detection device 4. For example, the working states of the cooling assembly 14, the refrigeration unit 23, the purification pump 24, the compressor 17, the first heat exchanger 18, the circulation pump 53, and each valve in the valve assembly 3 can be controlled.

[0053] In the embodiments of the present invention, those skilled in the art can adaptively increase or decrease the number of valves in the valve assembly 3 according to actual design requirements, and adaptively modify the installation positions of the valves in the valve assembly 3, which will not be elaborated here. For example, a drain valve can be provided at the bottom of the distillation tank 16, so that the liquid lubricating oil in the distillation tank 16 can be discharged by controlling the closing of the drain valve.

[0054] In some embodiments, with reference to Figures 1-6 As shown, the refrigerant recovery device may further include a flow regulating valve 19. For example, the flow regulating valve 19 may be located between the distillation tank 16 and the low-temperature container 21, so that the refrigerant flow rate entering the low-temperature container 21 can be adjusted by the flow regulating valve 19.

[0055] With reference to Figures 1-6 As shown, the refrigerant recovery device may further include a sight glass 6. The sight glass 6 is a transparent device used to observe the fluid state in fluid pipelines such as refrigeration systems and hydraulic systems, usually made of glass or high-strength plastic, and installed at a visible position of the pipeline. For example, the sight glass 6 may be installed in the purification pipeline 11 between the low-temperature container 21 and the purification pump 24. Thus, it is convenient for users to observe the liquid level height of the liquid refrigerant flowing through the purification pipeline 11, and it is also convenient for users to switch between the purification method by the purification pump 24 and the purification method by the compressor 17.

[0056] In summary, the embodiment of the present invention discloses a refrigerant recovery device, which may include a recovery unit 1 and a refrigeration purification device 2. The recovery unit 1 includes a purification pipeline 11, and the refrigeration purification device 2 is embedded in the purification pipeline 11. The refrigeration purification device 2 includes a low-temperature container 21, a filtration component 22, a refrigeration unit 23, and a purification pump 24. The filtration component 22 is disposed in the low-temperature container 21, and the cold end of the refrigeration unit 23 cooperates with the filtration component 22 to cool the filtration component 22, so as to condense the gaseous refrigerant flowing into the filtration component 22 into a liquid refrigerant, and the impurities in the liquid refrigerant solidify in the filtration component 22. The purification pump 24 communicates with the space below the filtration component 22 in the low-temperature container 21 and communicates with the recovery unit 1 to recover the purified liquid refrigerant. Thus, by utilizing the characteristic that the freezing points of water and lubricating oil are higher than that of the refrigerant, a low-temperature environment can be created in the filtration component 22 by the refrigeration unit 23, and the solidified water and lubricating oil can be captured in the filtration component 22 for deep water and oil removal. Thereby, the purity of the recovered refrigerant is greatly improved, and the refrigeration efficiency of the subsequent reusable refrigerant is also improved.

[0057] Referring to Figure 8 As shown, the embodiment of the present invention discloses a control method for a refrigerant recovery device. The refrigerant recovery device may include the refrigerant recovery device described in any one of the above-mentioned invention embodiments. The control method may include: S801. Obtain the purity data of the refrigerant.

[0058] In the embodiment of the present invention, the purity data of the refrigerant may be detected by a refrigerant purity detection device disposed in the recovery pipeline 12. The types of data used to evaluate the purity of the refrigerant may include at least one of the following: water content, acidity value, and concentration of non-condensable gas (or volume fraction of non-condensable gas).

[0059] S802. When it is determined that the preset purification conditions are met according to the purity data, control the refrigerant recovery device to execute the purification mode. Executing the purification mode includes: controlling the refrigeration unit 23 to operate to cool the filtration component 22, so as to condense the gaseous refrigerant flowing into the filtration component 22 into a liquid refrigerant, and enabling the impurities in the liquid refrigerant to solidify in the filtration component 22; controlling the purification pump 24 to operate to provide pressure to send the liquid refrigerant purified by the filtration component 22 into the recovery unit 1 for recovery.

[0060] In the embodiments of the present invention, the preset purification conditions can be understood as the relevant conditions for determining whether the recovered refrigerant meets the refrigerant purity requirements for reusable. For example, the preset purification conditions may include the evaluation thresholds preset for each data type of the above purity data, wherein the evaluation thresholds can be preset according to various standards. For example, when the type of the purity data includes water content, the corresponding preset purification conditions may include: the water content is greater than the preset water content threshold. When the type of the purity data includes water content and acidity value, the corresponding preset purification conditions may include: the water content is greater than the preset water content threshold, or the acidity value is greater than the preset acidity threshold. Those skilled in the art can determine the preset purification conditions according to the impurities contained in the actual refrigerant. No further limitation is made here.

[0061] If it is determined that the purity data meets the preset purification conditions, it is determined that the purity of the refrigerant recovered from the device 8 to be recovered does not meet the refrigerant purity requirements for reusable, and purification is required. At this time, the refrigerant recovery device can be controlled to execute the purification mode. In one or more embodiments, executing the purification mode may include the following steps: controlling the refrigeration unit 23 to work to cool the filter assembly 22. Thus, the gaseous refrigerant flowing into the filter assembly 22 condenses in a low-temperature environment to form a liquid refrigerant, which is stored in the low-temperature container 21. The impurities (such as water and lubricating oil) in the liquid refrigerant solidify in the filter assembly 22 and adhere to the filter assembly 22. Or the filter assembly 22 can capture the solidified impurities, thereby separating the impurities in the refrigerant from the refrigerant, so that the refrigerant is deeply purified. The purified refrigerant flows to the recovery unit 1 for recovery under the pressure difference generated by the operation of the purification pump 24. Thereby, the purity of the recovered refrigerant is greatly improved, and the refrigeration efficiency of the subsequent reusable refrigerant is improved.

[0062] Refer to Figure 9 As shown, the embodiments of the present invention disclose another control method for a refrigerant recovery device, and the control method may include: S901. Obtain the purity data of the refrigerant.

[0063] In the embodiments of the present invention, the description content of S901 refers to the description content of S801 above.

[0064] S902. Determine whether the purity data meets the preset purification conditions.

[0065] In the embodiments of the present invention, the preset purification conditions can be understood as the relevant conditions for determining whether the recycled refrigerant meets the purity requirements of the reusable refrigerant. For example, the preset purification conditions may include the evaluation thresholds preset for each data type of the above purity data, where the evaluation thresholds can be preset according to various standards. For example, when the type of the purity data includes the water content, the corresponding preset purification conditions may include: the water content is greater than the preset water content threshold. When the type of the purity data includes the water content and the acidity value, the corresponding preset purification conditions may include: the water content is greater than the preset water content threshold, or the acidity value is greater than the preset acidity threshold. Those skilled in the art can determine the preset purification conditions according to the impurities contained in the actual refrigerant. No further limitation is made here.

[0066] If it is determined according to the purity data that the preset purification conditions are met, it is determined that the purity of the refrigerant recovered from the equipment 8 to be recovered does not meet the purity requirements of the reusable refrigerant and needs to be purified. Thus, the following step S903 can be executed.

[0067] If it is determined according to the purity data that the preset purification conditions are not met, it is determined that the purity of the refrigerant recovered from the equipment 8 to be recovered meets the purity requirements of the reusable refrigerant and does not need to be purified. Thus, the following step S904 can be executed.

[0068] S903. Control the refrigerant recovery equipment to execute the purification mode. Executing the purification mode includes: controlling the refrigeration unit 23 to operate to cool the filter assembly 22 so that the gaseous refrigerant flowing into the filter assembly 22 condenses into a liquid refrigerant, so that the impurities in the liquid refrigerant solidify in the filter assembly 22. And control the purification pump 24 to operate to provide pressure to send the liquid refrigerant purified by the filter assembly 22 into the liquid storage tank 13 for recovery.

[0069] In the embodiments of the present invention, the description content of S903 refers to the description content of S803 above.

[0070] In one or more embodiments, when controlling the operation of the refrigeration unit 23, the refrigeration unit 23 can be controlled to cool the filter assembly 22, so as to keep the temperature of the filter assembly 22 between -40 °C and -90 °C. For example, the temperature in the low-temperature container 21 can be -40 °C, -50 °C, -70 °C, -80 °C, -90 °C, etc., which is not limited here too much. Considering that the freezing point of the lubricating oil of the compressor 17 is generally higher than -40 °C, sufficient solidification of the lubricating oil can be ensured within this temperature range. And the water content in the refrigerant is inversely proportional to the temperature, that is, the lower the temperature, the less the water content in the refrigerant. For example, within the above temperature range, the water content in the refrigerant can be controlled to be less than or equal to 0.0079 . Even the water content in the refrigerant can be controlled to be less than or equal to 0.001 . Thus, the recovery purity of the refrigerant can be greatly improved. Among them, the temperature detection of the filter assembly 22 can be obtained by a temperature detection element embedded in the filter assembly 22 or installed on the inner wall of the low-temperature container 21.

[0071] In one or more embodiments, during the execution of the purification mode, after the condensation in the low-temperature container 21, there may also be a very small amount of gaseous refrigerant in the gaseous refrigerant flowing out of the low-temperature container 21. Therefore, when it is detected that the purification switching condition is met, the purification pump 24 is stopped from working, and the valve assembly 3 is controlled to make the gaseous refrigerant flowing out of the low-temperature container 21 flow into the compressor 17. The compressor 17 and the first heat exchanger 18 are controlled to condense the gaseous refrigerant into a liquid refrigerant. Among them, the purification switching condition can be understood as the relevant condition for determining whether to recover the gaseous refrigerant after purification. For example, a liquid level gauge can be arranged at the inner bottom of the low-temperature container 21, so that it can be determined whether to recover the refrigerant after purification by the liquid level height of the liquid refrigerant in the low-temperature container 21. For example, when the liquid level height is lower than or equal to the liquid level height threshold, it is determined that the refrigerant in the device 8 to be recovered is basically purified. The recovery of the gaseous refrigerant is required, and at this time, it is determined that the purification switching condition is met. For another example, the purification switching condition can also be: the running duration of the purification pump 24 reaches the preset running duration. When the preset running duration is reached, it can be determined that the refrigerant in the device 8 to be recovered is basically purified. The recovery of the gaseous refrigerant is required, and at this time, it is determined that the purification switching condition is met. Those skilled in the art can determine the specific purification switching condition according to the actual design requirements, which is not limited here too much.

[0072] Thereby controlling the operation of the valve assembly 3, for example, controlling the opening of the first recovery valve 33, the second purification valve 32, the third purification valve 35, and the fourth purification valve 36, while controlling the closing of the first purification valve 31 and the second recovery valve 34. Thus, under the pressure difference generated by the operation of the compressor 17, the recovery pipeline 12 is communicated with the purification pipeline 11. And the gaseous refrigerant flowing out of the cryogenic container 21 flows towards the compressor 17. The compressor 17 compresses the low-temperature and low-pressure gaseous refrigerant into a high-temperature and high-pressure gaseous refrigerant. The first heat exchanger 18 condenses the high-temperature and high-pressure gaseous refrigerant to obtain a liquid refrigerant, and under the pressure of the compressor 17, the liquid refrigerant flowing out of the first heat exchanger 18 is sent into the liquid storage tank 13 for further recovery.

[0073] In one or more embodiments, during the purification process of the refrigerant, a refrigerant detection step may also be performed. The refrigerant detection step includes: controlling the operation of the valve assembly 3 so that the liquid refrigerant flowing out of the first heat exchanger 18 or the purification pump 24 flows through the refrigerant detection device 4, so that the refrigerant detection device 4 detects the purity data of the refrigerant. Then obtain the purity data of the refrigerant. If it is determined that the preset purification conditions are met based on the purity data, the refrigerant detection step is repeated. If it is determined that the preset purification conditions are not met based on the purity data, control the operation of the valve assembly 3 so that the liquid refrigerant flowing out of the first heat exchanger 18 or the purification pump 24 flows into the liquid storage tank 13.

[0074] In the embodiment of the present invention, controlling the operation of the valve assembly 3 may be: controlling the opening of the fifth purification valve 37 and controlling the closing of the fourth purification valve 36. And the liquid refrigerant flowing out of the first heat exchanger 18 or the purification pump 24 is directed to the refrigerant detection device 4. Re-obtain the purity data of the refrigerant. And determine whether the purity data meets the preset purification conditions. If it is determined that the preset purification conditions are met based on the purity data, it is determined that the purity of the refrigerant recovered from the equipment to be recovered 8 does not meet the purity requirements of the reusable refrigerant and needs to be purified.

[0075] If the purity data does not meet the preset purification conditions, it is determined that the purity of the refrigerant recovered from the device 8 to be recovered meets the requirements for the purity of the reusable refrigerant and does not require purification. At this time, the control of the valve assembly 3 can be: controlling the first recovery valve 33, the second purification valve 32, the third purification valve 35, and the fourth purification valve 36 to open, and at the same time controlling the first purification valve 31, the second recovery valve 34, and the fifth purification valve 37 to close. Or, the control of the valve assembly 3 can be: controlling the first recovery valve 33, the first purification valve 31, the third purification valve 35, and the fourth purification valve 36 to open, and at the same time controlling the second purification valve 32, the second recovery valve 34, and the fifth purification valve 37 to close. Thus, under the pressure difference generated by the operation of the compressor 17 or the purification pump 24, the recovery pipeline 12 and the purification pipeline 11 are connected. And, the refrigerant flowing in from the recovery inlet flows sequentially through the drying filter 15, the distillation tank 16, the compressor 17, and the first heat exchanger 18, and then enters the liquid storage tank 13 for storage. Or the refrigerant flows sequentially through the drying filter 15, the distillation tank 16, and the purification pump 24, and then enters the liquid storage tank 13 for storage.

[0076] In one or more embodiments, the circulation pump 53 can also be started to operate when the refrigeration unit 23 is operating. To transfer the heat of the refrigeration unit 23 to the distillation tank 16 for distillation heating of the refrigerant. The heat output from the hot end (the heat output end) of the refrigeration unit 23 can be heat-exchanged through the second heat exchanger 52 in contact with it. For example, a heat-conducting medium (such as one of water, ethylene glycol, and heat-conducting oil) is provided in the heat-exchange pipeline 51, and the heat-conducting medium heated in the second heater is sent into the third heat exchanger 54 under the action of the circulation pump 53. The third heat exchanger 54 and the distillation tank 16 can be in surface contact, so that the internal space of the distillation tank 16 can be heated by the heated heat-conducting medium in the third heat exchanger 54. Thus, when the refrigeration unit 23 and the circulation pump 53 work simultaneously when the refrigerant recovery device is operating in the purification mode, the distillation heating of the refrigerant can be realized in the distillation tank 16 to remove the lubricating oil in the refrigerant. And at the same time, the deep purification of the lubricating oil and moisture in the refrigerant can be realized in the low-temperature container 21.

[0077] In some embodiments, when the non-condensable gas in the refrigerant detected by the refrigerant detection device 4 meets the preset purification conditions, the control method can further include controlling the valve assembly 3 to act. Specifically, it can be controlling the third purification valve 35 and the sixth purification valve 38 to open, and controlling the other valves in the valve assembly 3 to close, and controlling the flow regulating valve 19 to open. Refer to Figure 6As shown, first, the refrigerant in the device 8 to be recycled is recovered into the cryogenic container 21. When the pressure value in the cryogenic container 21 is greater than the set pressure threshold, for example, the set pressure threshold may include values such as 0.1 MPa. Thus, the sixth purification valve 38 provided on the cryogenic container 21 is opened for exhaust. After discharging a certain amount of gas, the sixth purification valve 38 is closed, and then the refrigerant purification of the refrigerant flowing to the purification pump 24 or the compressor 17 is performed until the non-condensable gas is detected not to meet the preset purification conditions, and the recovery mode is executed.

[0078] S904. Control the refrigerant recovery device to execute the recovery mode. Executing the recovery mode includes: controlling the valve assembly 3 to act and the cooling assembly 14 to work, so that the refrigerant flowing in from the recovery inlet flows into the liquid storage tank 13. And when it is detected that the pressure supply switching condition is met, control the valve assembly 3 to work and the compressor 17 to work, so that the compressor 17 provides pressure, and the refrigerant flowing in from the recovery inlet sequentially flows through the drying filter 15, the distillation tank 16, the compressor 17, and the first heat exchanger 18, and then flows into the liquid storage tank 13.

[0079] In the embodiment of the present invention, controlling the valve assembly 3 to act can close the pipeline connection between the recovery pipeline 12 and the purification pipeline 11, and can open the inlet of the liquid storage tank 13. For example, the first recovery valve 33 and the second recovery valve 34 can be controlled to open, and the third purification valve 35 and the fourth purification valve 36 can be controlled to close. Controlling the cooling assembly 14 to work cools the inside of the liquid storage tank 13. Thus, under the action of the cooling assembly 14, a negative pressure is formed in the recovery pipeline 12, so that the refrigerant in the device 8 to be recycled can be directly sucked into the liquid storage tank 13 by relying on this negative pressure, and the refrigerant is recovered. This recovery mode can improve the recovery speed of the refrigerant.

[0080] The pressure supply switching condition can be understood as a condition for determining whether pressure balance is achieved between the recovery pipeline 12 and the liquid storage tank 13. When pressure balance is achieved, there is no pressure difference between the equipment to be recovered 8 and the liquid storage tank 13, so that the liquid storage tank 13 cannot continue to recover the refrigerant. For example, it can be determined by the difference between the pressure values at two different positions in the recovery pipeline 12, or the pressure value in the recovery pipeline 12 and the pressure value in the liquid storage tank 13. When the pressure difference is within the preset difference range or equal to zero, it is determined that pressure balance is achieved between the recovery pipeline 12 and the liquid storage tank 13, and at this time, it is determined that the pressure supply switching condition is met. Among them, the pressure value can be detected by setting a pressure detection element, and no more limitations are made here. Then, the valve assembly 3 and the compressor 17 can be controlled to work. For example, control the first recovery valve 33, the second purification valve 32, the third purification valve 35, and the fourth purification valve 36 to open, and at the same time control the first purification valve 31 and the second recovery valve 34 to close.

[0081] Thus, under the action of the pressure difference generated by the operation of the compressor 17, the recovery pipeline 12 and the purification pipeline 11 are connected. And the refrigerant flowing in from the recovery inlet sequentially flows through the drying filter 15, the distillation tank 16, the compressor 17, and the first heat exchanger 18. The compressor 17 compresses the low-temperature and low-pressure gaseous refrigerant into a high-temperature and high-pressure gaseous refrigerant. The first heat exchanger 18 condenses the high-temperature and high-pressure gaseous refrigerant to obtain a liquid refrigerant, and under the pressure of the compressor 17, the liquid refrigerant flowing out of the first heat exchanger 18 is sent into the liquid storage tank 13 for continued recovery.

[0082] The difference from the purification mode is that when the recovery mode is running, the refrigeration unit 23 does not work, and the distillation heat exchange device 5 does not work.

[0083] In some embodiments, the recovery stop condition can be determined according to the pressure value in the liquid storage tank 13. For example, when it is detected that the pressure value in the liquid storage tank 13 is less than the preset pressure threshold and less than or equal to one atmosphere, it is determined that the refrigerant recovery is completed, and the operation of the recovery mode is stopped, and all the valves included in the valve assembly 3 are adjusted to the closed state. Among them, the preset pressure threshold can be 10 、15 and other values. No more limitations are made here.

[0084] In summary, the embodiments of the present invention disclose a control method for a refrigerant recovery device. The control method may include first obtaining the purity data of the refrigerant, and then controlling the refrigerant recovery device to execute a purification mode when it is determined according to the purity data that the preset purification conditions are met. Executing the purification mode includes: controlling the refrigeration unit 23 to operate to cool the filter assembly 22, so that the gaseous refrigerant flowing into the filter assembly 22 condenses into a liquid refrigerant, so that the impurities in the liquid refrigerant solidify in the filter assembly 22. Controlling the purification pump 24 to operate to provide pressure to send the liquid refrigerant purified by the filter assembly 22 into the recovery unit 1 for recovery. Thereby, the purity of the recovered refrigerant can be greatly improved, and the refrigeration efficiency of the subsequent recyclable refrigerant can be improved.

[0085] Each embodiment in this specification is described in a progressive manner. The key point of each embodiment is to illustrate the differences from other embodiments. The same or similar parts among the embodiments can be referred to each other.

[0086] It is easy for those skilled in the art to think that any combination application of the above-mentioned various embodiments is feasible. Therefore, any combination among the above-mentioned various embodiments is an implementation scheme of the present invention. However, due to space limitations, this specification will not elaborate on them one by one here.

[0087] In the specification provided herein, a large number of specific details are described. However, it can be understood that the embodiments of the present invention can be practiced without these specific details. In some instances, well-known methods, structures, and technologies are not shown in detail so as not to obscure the understanding of this specification.

[0088] Similarly, it should be understood that, in order to streamline the present invention and help understand one or more of the various aspects of the invention, in the above description of the exemplary embodiments of the present invention, the various features of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof.

[0089] In addition, those skilled in the art can understand that, although some of the embodiments described herein include certain features included in other embodiments rather than other features, the combination of the features of different embodiments means that it is within the scope of the present invention and forms different embodiments. For example, in the claims, any one of the claimed embodiments can be used in any combination.

Claims

1. A refrigerant recovery device, characterized in that, The refrigerant recovery equipment includes: A recovery unit, which includes a purification pipeline; A refrigeration purification device, which is embedded in the purification pipeline, and the refrigeration purification device includes: A low-temperature container; A filter component, which is arranged in the low-temperature container; A refrigeration unit, the cold end of which cooperates with the filter component to cool the filter component, so as to condense the gaseous refrigerant flowing into the filter component into a liquid refrigerant, and the impurities in the liquid refrigerant solidify in the filter component; A purification pump, which is communicated with the space below the filter component in the low-temperature container and is communicated with the recovery unit to recover the purified liquid refrigerant.

2. The refrigerant recovery device according to claim 1, characterized in that, The filter component includes a porous structure for generating a capillary effect to lock the liquid refrigerant in the porous structure.

3. The refrigerant recovery device according to claim 2, wherein, When the refrigeration unit works, the temperature in the low-temperature container is controlled between -40 °C and -90 °C to solidify the impurities in the liquid refrigerant located in the porous structure.

4. The refrigerant recovery device according to claim 1, characterized in that, The recovery unit further includes: A recovery pipeline, which is communicated with the purification pipeline, and the recovery pipeline includes a recovery inlet for communicating with the equipment to be recovered; A liquid storage tank, which is communicated with the recovery pipeline for storing refrigerant; A cooling component, which is used to cool the liquid storage tank to make the liquid storage tank generate negative pressure to suck the refrigerant in the equipment to be recovered; The refrigerant recovery equipment further includes a valve assembly, which is arranged in the recovery pipeline and the purification pipeline for switching the pipeline between the recovery pipeline and the purification pipeline.

5. The refrigerant recovery device according to claim 4, characterized in that, The recovery unit further includes a drying filter, a distillation tank, a compressor and a first heat exchanger. The outlet of the drying filter is communicated with the inlet of the distillation tank, the outlet of the distillation tank is communicated with the refrigerant inlet of the low-temperature container, the refrigerant outlet of the low-temperature container is communicated with the compressor, the outlet of the compressor is communicated with the inlet of the first heat exchanger, and the liquid outlet of the first heat exchanger is communicated with the liquid storage tank. Among them, the inlet of the purification pump is communicated with the inlet of the compressor, and the outlet of the purification pump is communicated with the liquid outlet of the first heat exchanger; The valve assembly includes: A first purification valve, which is arranged at the inlet of the purification pump to control the on-off of the liquid path of the purification pump; A second purification valve, which is arranged at the inlet of the compressor to control the on-off of the gas path of the compressor.

6. The refrigerant recovery device according to claim 5, characterized in that, The recovery pipeline includes a first recovery outlet and a second recovery outlet, and the valve assembly further includes: A first recovery valve, which is arranged at the inlet of the liquid storage tank to control the opening and closing of the liquid storage tank; A second recovery valve, which is arranged between the first recovery outlet and the liquid storage tank; A third purification valve, which is arranged in the purification pipeline communicated with the second recovery outlet, and the second recovery outlet is communicated with the drying filter; The fourth purification valve is arranged in the purification pipeline between the liquid storage tank and the first heat exchanger; wherein, When the first recovery valve and the second recovery valve are opened, and the third purification valve and the fourth purification valve are closed, the refrigerant flowing in from the recovery inlet flows into the liquid storage tank through the first recovery outlet; When the first recovery valve, the second purification valve, the third purification valve and the fourth purification valve are opened, and the first purification valve and the second recovery valve are closed, the refrigerant flowing in from the recovery inlet flows into the dry filter through the second recovery outlet, and then sequentially flows through the distillation tank, the compressor and the first heat exchanger, and then flows into the liquid storage tank.

7. The refrigerant recovery device according to claim 6, characterized in that, The recovery unit further includes a refrigerant detection device arranged in the recovery pipeline for detecting the purity of the refrigerant; The valve assembly further includes a fifth purification valve located in the purification pipeline connecting the recovery inlet and the purification pump. When the fifth purification valve is opened and the fourth purification valve is closed, the refrigerant flowing out of the purification pump passes through the refrigerant detection device for purity detection.

8. The refrigerant recovery device according to claim 5, wherein The refrigerant recovery equipment further includes a distillation heat exchange device, and the distillation heat exchange device includes: A heat exchange pipeline; A second heat exchanger in contact with the hot end of the refrigeration unit and embedded in the heat exchange pipeline; A circulation pump embedded in the heat exchange pipeline for providing heat exchange power; A third heat exchanger embedded in the heat exchange pipeline and in contact with the distillation tank to transfer the heat of the refrigeration unit to the distillation tank for distillation heating of the refrigerant.

9. A control method for a refrigerant recovery device, characterized in that, The refrigerant recovery equipment includes the refrigerant recovery equipment according to any one of claims 1-8, and the control method includes: Obtaining the purity data of the refrigerant; When it is determined that the preset purification conditions are met according to the purity data, controlling the refrigerant recovery equipment to execute the purification mode. Executing the purification mode includes: Controlling the refrigeration unit to work to cool down the filter assembly so that the gaseous refrigerant flowing into the filter assembly condenses into liquid refrigerant, so that the impurities in the liquid refrigerant solidify in the filter assembly; Controlling the purification pump to work to provide pressure to send the liquid refrigerant purified by the filter assembly into the recovery unit for recovery.

10. The control method of the refrigerant recovery device according to claim 9, characterized in that, The controlling the refrigeration unit to work to cool down the filter assembly includes: Controlling the refrigeration unit to work to cool down the filter assembly and keeping the temperature of the filter assembly between -40 degrees Celsius and -90 degrees Celsius.

11. The control method of the refrigerant recovery device according to claim 9, characterized in that, Executing the purification mode further includes: When it is detected that the purification switching condition is met, stopping the purification pump from working and controlling the valve assembly to work so that the gaseous refrigerant flowing out of the low-temperature container flows into the compressor; Controlling the compressor and the first heat exchanger to work to condense the gaseous refrigerant into liquid refrigerant.

12. The control method of the refrigerant recovery device according to claim 9, characterized in that, Executing the purification mode further includes: Perform a refrigerant detection step, the refrigerant detection step including: controlling the valve assembly to act so that the liquid refrigerant flowing out of the first heat exchanger or the purification pump flows through the refrigerant detection device, so that the refrigerant detection device detects the purity data of the refrigerant; Obtain the purity data of the refrigerant; If it is determined that the preset purification conditions are met according to the purity data, repeat the refrigerant detection step; If it is determined that the preset purification conditions are not met according to the purity data, control the valve assembly to act so that the liquid refrigerant flowing out of the first heat exchanger or the purification pump flows into the liquid storage tank.

13. The control method of the refrigerant recovery device according to claim 9, characterized in that, Performing the purification mode further includes: Starting the circulation pump to work to transfer the heat of the refrigeration unit to the distillation tank for distillation heating of the refrigerant.

14. The control method of the refrigerant recovery device according to claim 9, characterized in that The control method further includes: In the case where it is determined that the preset purification conditions are not met according to the purity data, controlling the refrigerant recovery device to execute a recovery mode, and performing the recovery mode includes: Controlling the valve assembly to act and the cooling assembly to work so that the refrigerant flowing in from the recovery inlet flows into the liquid storage tank; When it is detected that the pressure supply switching conditions are met, controlling the valve assembly to work and the compressor to work so that the compressor provides pressure, and the refrigerant flowing in from the recovery inlet sequentially flows through the drying filter, the distillation tank, the compressor, and the first heat exchanger, and then flows into the liquid storage tank.

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