Refrigerant recovery equipment and control method thereof

Abstract

The present invention discloses a refrigerant recovery device and a control method thereof, and relates to the field of refrigerant recovery technology. The present invention includes a recovery unit and a refrigeration purification device. The recovery unit includes a purification pipeline. The refrigeration purification device is embedded in the purification pipeline. The refrigeration purification device includes 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 cooperates with the filter assembly to cool the filter assembly to condense the gaseous refrigerant flowing into the filter assembly into liquid refrigerant. Impurities in the liquid refrigerant solidify in the filter assembly. The purification pump is connected to the space below the filter assembly in the low-temperature container and is connected to the recovery unit to recover the purified liquid refrigerant. The characteristic that the freezing point of water and lubricating oil is higher than that of refrigerant can be utilized to capture the solidified water and lubricating oil in the filter assembly, thereby greatly improving the purity of the recovered refrigerant.

Description

Technical Field

[0001] The present invention relates to the technical field of refrigerant recovery, and in particular to refrigerant recovery equipment and a control method thereof. Background Art

[0002] Refrigerant is a greenhouse gas, and its recovery aligns with the development of renewable resources. With growing environmental awareness, the demand for refrigerant recycling is also increasing. Refrigerant recovery systems typically use filters to remove impurities and moisture, and oil separators to remove oil. However, these recovery methods result in a lower purity of the refrigerant, reducing its subsequent cooling efficiency for reuse. Summary of the Invention

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

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

[0005] In an optional aspect of the invention, the filter assembly includes a porous structure for generating a capillary effect to lock the liquid refrigerant in the porous structure.

[0006] An optional invention content is that when the refrigeration unit is in operation, the temperature in the low-temperature container is controlled to be between -40 degrees Celsius and -90 degrees Celsius to solidify impurities in the liquid refrigerant located in the porous structure.

[0007] An optional invention content, the recovery unit also includes: a recovery pipeline, the recovery pipeline is connected to the purification pipeline, and the recovery pipeline includes a recovery inlet, the recovery inlet is used to connect with the equipment to be recovered; a liquid storage tank, the liquid storage tank is connected to the recovery pipeline, and is used to store refrigerant; a cooling component, the cooling component is used to cool the liquid storage tank so that the liquid storage tank generates negative pressure to absorb the refrigerant in the equipment to be recovered; the refrigerant recovery equipment also includes a valve component, the valve component is arranged in the recovery pipeline and the purification pipeline, and is used to switch the pipeline between the recovery pipeline and the purification pipeline.

[0008] An optional invention content, the recovery unit also includes a drying filter, a distillation tank, a compressor and a first heat exchanger, the air outlet of the drying filter is connected to the air inlet of the distillation tank, the air outlet of the distillation tank is connected to the refrigerant inlet of the low-temperature container, the refrigerant outlet of the low-temperature container is connected to the compressor, the air outlet of the compressor is connected to the air inlet of the first heat exchanger, and the liquid outlet of the first heat exchanger is connected to the liquid storage tank, wherein the liquid inlet of the purification pump is connected to the air inlet of the compressor, and the liquid outlet of the purification pump is connected to the liquid outlet of the first heat exchanger; the valve assembly includes: a first purification valve, the first purification valve is arranged at the liquid inlet of the purification pump to control the liquid circuit of the purification pump; the second purification valve, the second purification valve is arranged at the air inlet of the compressor to control the gas circuit of the compressor.

[0009] An optional invention, the recovery pipeline includes a first recovery outlet and a second recovery outlet, and the valve assembly further includes: a first recovery valve, the first recovery valve 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, the second recovery valve is arranged between the first recovery outlet and the liquid storage tank; a third purge valve, the third purge valve is arranged in the purge pipeline connected to the second recovery outlet, the second recovery outlet is connected to the drying filter; a fourth purge valve, the fourth purge valve is arranged in the purge 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 purge valve and the fourth purge 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 purge valve, the third purge valve and the fourth purge valve are opened, and the first purge 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 flows through the distillation tank, the compressor and the first heat exchanger in sequence, and then flows into the liquid storage tank.

[0010] An optional invention content, the recovery unit also includes a refrigerant detection device, which is arranged in the recovery pipeline to detect the purity of the refrigerant; the valve assembly also includes a fifth purification valve, and 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 equipment also includes a distillation heat exchange device, and 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 circulating pump, the circulating pump is embedded in the heat exchange pipeline to provide heat exchange power; a third heat exchanger, the third heat exchanger is 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.

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

[0013] An optional invention content, wherein controlling the refrigeration unit to cool the filter assembly includes: controlling the refrigeration unit to cool the filter assembly, maintaining the temperature of the filter assembly between -40 degrees Celsius and -90 degrees Celsius.

[0014] An optional invention content, executing the purification mode also includes: when it is detected that the purification switching conditions are met, stopping the purification pump from working, and controlling the valve assembly to operate 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 operate to condense the gaseous refrigerant into liquid refrigerant.

[0015] An optional invention content, executing the purification mode also includes: executing a refrigerant detection step, the refrigerant detection step including: controlling the action of the valve assembly 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 based on the purity data that the preset purification conditions are met, repeating the refrigerant detection step; if it is determined based on the purity data that the preset purification conditions are not met, controlling the action of the valve assembly 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 is that executing the purification mode also includes starting a circulation pump to transfer the heat of the refrigeration unit to a distillation tank for distillation heating of the refrigerant.

[0017] An optional invention content, the control method also includes: when it is determined based on the purity data that the preset purification conditions are not met, controlling the refrigerant recovery equipment to execute the recovery mode, executing the recovery mode includes: controlling the valve assembly and the cooling assembly to operate 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 and the compressor to operate so that the compressor provides pressure, and the refrigerant flowing in from the recovery inlet flows through the drying filter, the distillation tank, the compressor and the first heat exchanger in sequence, and then flows into the liquid storage tank.

[0018] Compared to 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 cryogenic container, a filter assembly, a refrigeration unit, and a purification pump. The filter assembly is disposed in the cryogenic container, and the cold end of the refrigeration unit cooperates with the filter assembly to cool the filter assembly, thereby condensing the gaseous refrigerant flowing into the filter assembly into liquid refrigerant. Impurities in the liquid refrigerant solidify in the filter assembly. The purification pump communicates with the space below the filter assembly in the cryogenic container and with the recovery unit to recover the purified liquid refrigerant. Thus, by utilizing the fact that the freezing points of water and lubricating oil are higher than those of refrigerant, the refrigeration unit creates a low-temperature environment in the filter assembly, trapping the solidified water and lubricating oil in the filter assembly for deep dehydration and deoiling. This significantly improves the purity of the recovered refrigerant and enhances the refrigeration efficiency of the subsequent refrigerant reuse.

[0019] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are specifically listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be construed as limiting the present invention. The same reference numerals are used throughout the accompanying drawings to denote the same components.

[0021] In the attached figure:

[0022] Figure 1 This is a structural diagram of a refrigerant recovery device provided by an embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of the first refrigerant flow direction of another refrigerant recovery device operating in a purification mode provided by an embodiment of the present invention;

[0024] Figure 3 This is a schematic diagram of the second refrigerant flow direction of another refrigerant recovery device operating in a purification mode provided by an embodiment of the present invention;

[0025] Figure 4 1 is a schematic diagram of a third refrigerant flow direction of another refrigerant recovery device operating in a purification mode according to an embodiment of the present invention;

[0026] Figure 5 This is a schematic diagram of the first refrigerant flow direction of another refrigerant recovery device provided by an embodiment of the present invention in a recovery mode;

[0027] Figure 6 2. It is a schematic diagram of the second refrigerant flow direction of another refrigerant recovery device provided by an embodiment of the present invention in a recovery mode;

[0028] Figure 7 This is a block diagram of the electrical connection structure of a refrigerant recovery device provided by an embodiment of the present invention;

[0029] Figure 8 This 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;

[0030] Figure 9 This is a schematic flow chart of steps of another control method for refrigerant recovery equipment provided by an embodiment of the present invention;

[0031] Figure numerals: 1. Recovery unit; 11. Purification pipeline; 12. Recovery pipeline; 13. Liquid storage tank; 14. Cooling component; 15. Dry filter; 16. Distillation tank; 17. Compressor; 18. First heat exchanger; 19. Flow regulating valve; 2. Refrigeration purification device; 21. Low-temperature container; 22. Filter component; 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 DESCRIPTION

[0032] Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the accompanying 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. Rather, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0033] Refrigerant is a greenhouse gas, and its recovery is consistent with the development of renewable resources. With growing environmental awareness, the demand for refrigerant recycling is also increasing. Refrigerant recovery systems typically use filters to remove impurities and moisture, and use oil separators to remove oil. However, these recovery methods result in a lower purity of the refrigerant, reducing the refrigerant's subsequent cooling efficiency.

[0034] Based on the above technical problems, an embodiment of the present invention is proposed. The embodiment of the present invention may include a recovery unit 1 and a refrigeration purification device 2. The recovery unit 1 includes a purification pipeline 11. The refrigeration purification device 2 is embedded in the purification pipeline 11. The refrigeration purification device 2 includes a low-temperature container 21, a filter assembly 22, a refrigeration unit 23 and a purification pump 24. The filter assembly 22 is arranged in the low-temperature container 21, and the cold end of the refrigeration unit 23 cooperates with the filter assembly 22 to cool the filter assembly 22, so as to condense the gaseous refrigerant flowing into the filter assembly 22 into liquid refrigerant, and impurities in the liquid refrigerant solidify in the filter assembly 22. The purification pump 24 is connected to the space below the filter assembly 22 in the low-temperature container 21 and is connected to the recovery unit 1 to recover the purified liquid refrigerant. By utilizing the fact that the freezing points of water and lubricating oil are higher than those of refrigerant, the refrigeration unit 23 can create a low-temperature environment in the filter assembly 22, trapping the solidified water and lubricating oil in the filter assembly 22 for deep water and oil removal. This significantly improves the purity of the recovered refrigerant and enhances the refrigeration efficiency of the subsequent refrigerant reuse.

[0035] Reference Figure 1-7 As shown, an embodiment of the present invention provides 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 filter assembly 22, a refrigeration unit 23, and a purification pump 24. The filter assembly 22 is disposed in the low-temperature container 21, and the cold end of the refrigeration unit 23 cooperates with the filter assembly 22 to cool the filter assembly 22, thereby condensing the gaseous refrigerant flowing into the filter assembly 22 into liquid refrigerant. Impurities in the liquid refrigerant solidify in the filter assembly 22. The purification pump 24 is connected to the space below the filter assembly 22 in the low-temperature container 21 and is connected to the recovery unit 1 to recover the purified liquid refrigerant.

[0036] In this embodiment of the present invention, the recovery unit 1 can be understood as a collection of components including the devices and pipelines required for refrigerant recovery. It is used to connect to the equipment to be recovered 8 to recover the refrigerant. The equipment to be recovered 8 can be understood as any electrical device that consumes refrigerant. For example, the equipment to be recovered 8 may include, but is not limited to, refrigerators, freezers, air conditioners, refrigeration units, cold drink dispensers, ice makers, and other equipment with refrigeration requirements.

[0037] The purification pipeline 11 can be understood as a related pipeline that constitutes a purification channel in the process of recovering refrigerant. It can be composed of at least two connecting pipes. The refrigeration purification device 2 is embedded in the purification pipeline 11, that is, the refrigerant flowing from 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 may include a low-temperature container 21, a filter 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. The filter component 22 is arranged in the low-temperature container 21, and is provided with small pores for the refrigerant to pass through. The cold end of the refrigeration unit 23 cooperates with the filter assembly 22. For example, the cold end of the refrigeration unit 23 forms surface contact with the filter assembly 22, so that the refrigerant passing through the filter assembly 22 can be quickly cooled, so that the gaseous refrigerant condenses to form liquid refrigerant with a lower temperature.

[0038] In the low-temperature environment provided by the refrigerant unit, impurities in the refrigerant typically include water and the lubricating oil from the compressor 17. Since the freezing points of water and the lubricating oil from the compressor 17 are higher than those of the refrigerant, when the refrigeration unit 23 operates to lower the temperature in the cryogenic container 21 to below the freezing points of the water and the lubricating oil from the compressor 17, but higher than the freezing point of the refrigerant, the impurities in the liquid refrigerant (water and the lubricating oil from the compressor 17) solidify in the filter assembly 22. The deeply purified liquid refrigerant then passes through the filter assembly 22 and flows to the bottom of the cryogenic container 21 for storage. The purification pump 24 pumps the purified liquid refrigerant out of the cryogenic container 21 and directs it to the recovery unit 1, where it can be recovered. By leveraging the physical property of the refrigerant's impurities having a higher freezing point than the refrigerant, the refrigerant is deeply purified, significantly improving the purity of the recovered refrigerant and enhancing the refrigeration efficiency for subsequent refrigerant reuse.

[0039] In an embodiment of the present invention, the filter assembly 22 can be detachably connected to the low-temperature container 21, so that the filter assembly 22 can be taken out of the low-temperature container 21, and after flushing impurities and drying the filter assembly 22, the filter assembly 22 can be reused.

[0040] In an optional embodiment of the invention, the filter assembly 22 includes a porous structure to generate a capillary effect to lock the liquid refrigerant in the porous structure.

[0041] In this embodiment of the present invention, the capillary effect can be understood as the spontaneous rise of liquid refrigerant within the tiny pores of the porous structure in the absence of external pressure. Consequently, when impurities in the liquid refrigerant solidify within the porous structure, they are trapped within it due to the capillary effect and prevented from falling downward. This results in a deeply purified liquid refrigerant in the space below the cryogenic container 21.

[0042] In an optional embodiment of the invention, the refrigeration unit 23 controls the temperature in the low-temperature container 21 to between -40 degrees Celsius and -90 degrees Celsius when in operation, so as to solidify impurities in the liquid refrigerant in the porous structure.

[0043] In the embodiment of the present invention, when the refrigeration unit 23 is working, the temperature in the low-temperature container 21 can be controlled between -40 degrees Celsius and -90 degrees Celsius. For example, the temperature in the low-temperature container 21 can be -40 degrees Celsius, -50 degrees Celsius, -70 degrees Celsius, -80 degrees Celsius and -90 degrees Celsius, etc., which are not limited here. Considering that the freezing point of the lubricating oil of the compressor 17 is generally higher than -40 degrees Celsius, the lubricating oil can be fully solidified 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 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 It is even possible to control the water content in the refrigerant to less than or equal to 0.001 , which can greatly improve the purity of refrigerant recovery.

[0044] In some embodiments, the refrigeration unit 23 may include a Stirling refrigerator, which is a thermodynamic cycle refrigerator that operates based on the reverse Stirling cycle principle, utilizing the expansion and compression of gas at different temperatures to achieve a cooling effect. For example, the cold finger (cold output end) of the refrigeration unit 23 may form surface contact with the porous structure, thereby rapidly reducing the temperature of the gaseous refrigerant passing through the pores of the porous structure, causing it to liquefy quickly and causing impurities in the liquid refrigerant to solidify quickly.

[0045] In an optional embodiment of the invention, referring to Figure 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 in communication with the purification pipeline 11, and the recovery pipeline 12 includes a recovery inlet, which is used to communicate with the equipment to be recovered 8. The liquid storage tank 13 is in communication 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 absorb the refrigerant in the equipment to be recovered 8. The refrigerant recovery equipment also includes a valve assembly 3, which is arranged in the recovery pipeline 12 and the purification pipeline 11 for switching the pipeline between the recovery pipeline 12 and the purification pipeline 11.

[0046] In this embodiment of the present invention, the recovery line 12 can be understood as the associated pipeline that forms the recovery channel during the refrigerant recovery process and can be composed of at least two connected pipes. The difference between the recovery line 12 and the purification line 11 is that the recovery line 12 is not equipped with any related devices for purifying the refrigerant. The recovery line 12 is connected to the purification line 11, so that the purified refrigerant flows through the recovery line 12 and then to the liquid storage tank 13 for storage.

[0047] The recovery line 12 includes at least a recovery inlet, which is used to communicate with the device to be recovered 8. The liquid storage tank 13 is connected to the recovery line 12 and is used to store the recovered refrigerant. The cooling component 14 is in surface contact with the liquid storage tank 13 and is used to cool the refrigerant in the liquid storage tank 13. Figure 4 As shown, the cooling assembly 14 can be located at the bottom or side of the liquid storage tank 13, thereby condensing the gaseous refrigerant entering the liquid storage tank 13 to obtain liquid refrigerant. This can also form a negative pressure in the recovery line 12, thereby drawing the refrigerant from the device to be recovered 8 into the liquid storage tank 13 due to this negative pressure. Furthermore, the liquid storage capacity of the liquid storage tank 13 can be increased through gas-liquid conversion. When pressure balance is achieved, the initial recovery of the refrigerant is completed.

[0048] The valve assembly 3 includes at least one valve, and the valve assembly 3 is arranged in the recovery line 12 and the purification line 11, so that the valve assembly 3 can be operated to switch the connection channel between the recovery line 12 and the purification line 11. For example, referring to Figure 5As shown, when the refrigerant recovery equipment is operating in the recovery mode, when the pressure balance is reached and recovery cannot continue, the valve assembly 3 can be controlled to operate so that the recovery pipeline 12 is connected to the purification pipeline 11, so that the relevant components in the recovery unit 1 located in the purification pipeline 11 are operated, thereby generating a pressure difference, so that the refrigerant flowing into the recovery inlet flows into the purification pipeline 11, and then flows into the liquid storage tank 13 through the purification pipeline 11.

[0049] In an optional embodiment of the invention, referring to Figure 2-6 As shown, the recovery unit 1 further includes a filter dryer 15, a distillation tank 16, a compressor 17, and a first heat exchanger 18. The air outlet of the filter dryer 15 is in communication with the air inlet of the distillation tank 16, the air outlet of the distillation tank 16 is in communication with the refrigerant inlet of the low-temperature container 21, the refrigerant outlet of the low-temperature container 21 is in communication with the compressor 17, the air outlet of the compressor 17 is in communication with the air inlet of the first heat exchanger 18, and the liquid outlet of the first heat exchanger 18 is in communication with the liquid storage tank 13. The liquid inlet of the purge pump 24 is in communication with the air inlet of the compressor 17, and the liquid outlet of the purge pump 24 is in communication with the liquid outlet of the first heat exchanger 18. The valve assembly 3 may include a first purge valve 31 and a second purge valve 32. The first purge valve 31 is provided at the liquid inlet of the purge pump 24 to control the liquid flow of the purge pump 24. The second purge valve 32 is provided at the air inlet of the compressor 17 to control the on-off of the air path of the compressor 17 .

[0050] In this embodiment of the present invention, the filter dryer 15 not only absorbs moisture from the refrigerant, but also filters out impurities in the refrigerant, such as oil, dust, and acidic substances. The distillation tank 16 can remove lubricating oil from the compressor 17 based on the different boiling points of the refrigerant and lubricating oil. Given 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 to be above the boiling point of the refrigerant but below that of the lubricating oil, thereby retaining the liquid lubricating oil at the bottom of the distillation tank 16. The gaseous refrigerant enters the cryogenic container 21 through its air inlet. The refrigerant outlet of the cryogenic container 21 is connected to the compressor 17. In other words, the refrigerant outlet of the cryogenic container 21 is connected to the purification pump 24 and the compressor 17, respectively.

[0051] The first purge valve 31 is provided at the liquid inlet of the purge pump 24 (which can also be understood as the connection point between the refrigerant outlet of the cryogenic container 21 and the purge pump 24), so that the liquid circuit of the purge pump 24 can be controlled by adjusting the first purge valve 31. The second purge valve 32 is provided at the air inlet of the compressor 17 (which can also be understood as the connection point between the refrigerant outlet of the cryogenic container 21 and the compressor 17), so that the air circuit of the compressor 17 can be controlled by adjusting the second purge valve 32.

[0052] In one example, refer to Figure 2 and Figure 3 As shown, when the first purge valve 31 is opened and the second purge valve 32 is closed, the refrigerant flowing out of the low-temperature container 21 flows to the purge pump 24 .

[0053] In another example, refer to Figure 5 As shown, when the first purge valve 31 is closed and the second purge valve 32 is open, the refrigerant flowing out of the cryogenic container 21 flows to the compressor 17. When the refrigerant recovery equipment is operating in recovery mode and pressure equilibrium is reached and recovery cannot continue, the valve assembly 3 can be controlled to operate, connecting the recovery line 12 with the purge line 11. The refrigerant flowing in from the recovery inlet flows sequentially to the filter drier 15, the distillation tank 16, the compressor 17, and the first heat exchanger 18. The operation of the compressor 17 creates a pressure differential and compresses the low-temperature, low-pressure gaseous refrigerant into a high-temperature, high-pressure gaseous refrigerant. The first heat exchanger 18 condenses the high-temperature, high-pressure gaseous refrigerant to produce liquid refrigerant. Under the pressure of the compressor 17, the liquid refrigerant flowing out of the first heat exchanger 18 is then delivered to the liquid storage tank 13. The first heat exchanger 18 can be an air-cooled heat exchanger or other device.

[0054] In an optional embodiment of the invention, referring to Figure 4 and Figure 5As shown, the recovery line 12 includes a first recovery outlet and a second recovery outlet. The valve assembly 3 also includes a first recovery valve 33, a second recovery valve 34, a third purge valve 35, and a fourth purge valve 36. The first recovery valve 33 is disposed 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 disposed between the first recovery outlet and the liquid storage tank 13. The third purge valve 35 is disposed in the purge line 11, which is connected to the second recovery outlet, which is connected to the filter drier 15. The fourth purge valve 36 is disposed in the purge line 11 between the liquid storage tank 13 and the first heat exchanger 18. When the first recovery valve 33 and the second recovery valve 34 are open, and the third purge valve 35 and the fourth purge valve 36 are closed, refrigerant flowing from the recovery inlet flows into the liquid storage tank 13 through the first recovery outlet. If 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 flows through the distillation tank 16, the compressor 17 and the first heat exchanger 18 in sequence, and then flows into the liquid storage tank 13.

[0055] In the embodiment of the present invention, when the refrigerant recovery device operates in the recovery mode, reference is made to Figure 4 As shown, the first recovery valve 33 and the second recovery valve 34 can be controlled to open, and the third purge valve 35 and the fourth purge valve 36 can be controlled to close. As a result, a negative pressure is formed in the recovery pipeline 12 under the action of the cooling assembly 14, so that the refrigerant in the device to be recovered 8 can be sucked into the liquid storage tank 13 by relying on this negative pressure. The liquid storage capacity of the liquid storage tank 13 can also be increased through gas-liquid conversion. The initial recovery of the refrigerant is completed when pressure balance is achieved.

[0056] When the refrigerant recovery equipment is in recovery mode and pressure balance is reached and recovery is no longer possible, the valve assembly 3 can be controlled to operate. Figure 5As shown, when the first recovery valve 33, second purge valve 32, third purge valve 35, and fourth purge valve 36 are controlled to open, and the first purge valve 31 and second recovery valve 34 are controlled to close, the recovery line 12 is connected to the purge line 11. Furthermore, the refrigerant flowing in from the recovery inlet flows sequentially to the filter drier 15, distillation tank 16, compressor 17, and first heat exchanger 18. The operation of compressor 17 creates a pressure differential, compressing the low-temperature, low-pressure gaseous refrigerant into a high-temperature, high-pressure gaseous refrigerant. The first heat exchanger 18 condenses the high-temperature, high-pressure gaseous refrigerant to produce liquid refrigerant. Under the pressure of compressor 17, the liquid refrigerant flowing out of the first heat exchanger 18 is delivered to the liquid storage tank 13.

[0057] In an optional embodiment of the invention, referring to Figure 2-6 As shown, the recovery unit 1 further includes a refrigerant detection device 4, which is disposed in the recovery line 12 and is used to detect the purity of the refrigerant. The valve assembly 3 further includes a fifth purge valve 37, which is located in the purge line 11 connecting the recovery inlet and the purge pump 24. When the fifth purge valve 37 is open and the fourth purge valve 36 is closed, the refrigerant flowing out of the purge pump 24 passes through the refrigerant detection device 4 for purity detection.

[0058] In this embodiment of the present invention, the refrigerant detection device 4 can be understood as a device used to detect the purity (or degree of purity) of the refrigerant. For example, the refrigerant detection device 4 can include at least one of the following: a moisture sensor, an acidity sensor, and a non-condensable gas sensor. Correspondingly, the data used to assess the refrigerant's purity can include at least one of the following types: moisture content, acidity, and non-condensable gas concentration (or non-condensable gas volume fraction).

[0059] Reference Figure 3As shown, when the fifth purge valve 37 is open and the fourth purge valve 36 is closed, the refrigerant flowing out of the purge pump 24 passes through the refrigerant detection device 4 for purity testing. Thus, when the refrigerant recovery equipment is operating in purification mode, the purified refrigerant can flow through the refrigerant detection device 4. Based on the purity data obtained by the refrigerant detection device 4, it can be determined whether the refrigerant flowing through the refrigerant detection device 4 requires the next purification cycle. If a purification cycle is not required, the valve assembly 3 can be controlled to operate, directing the refrigerant flowing through the refrigerant detection device 4 directly into the liquid storage tank 13. When the next purification cycle is required, the valve assembly 3 can be controlled to operate, directing the refrigerant in the refrigerant detection device 4 into the filter drier 15. The refrigerant then passes through the distillation tank 16, the cryogenic container 21, and the purge pump 24, then flows into the refrigerant detection device 4 for repeated testing until the purification cycle is no longer required, at which point the refrigerant flowing through the refrigerant detection device 4 is directed into the liquid storage tank 13.

[0060] In an optional embodiment of the invention, referring to Figure 1-6 As shown, the refrigerant recovery equipment may further include a distillation heat exchange device 5, which 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 contacts 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 contacts the distillation tank 16 to transfer heat from the refrigeration unit 23 to the distillation tank 16 for distillation and heating of the refrigerant.

[0061] In this embodiment of the present invention, the heat output from the hot end (heat output end) of the refrigeration unit 23 can be exchanged with the second heat exchanger 52 in contact therewith. For example, a heat transfer medium (e.g., water, ethylene glycol, or thermal oil) is provided in the heat exchange line 51. After being heated in the second heater, the heat transfer medium is delivered to the third heat exchanger 54 by the circulation pump 53. The third heat exchanger 54 can maintain surface contact with the distillation tank 16, allowing the heated heat transfer medium to heat the interior of the distillation tank 16 in the third heat exchanger 54. Therefore, when the refrigerant recovery equipment is operating in purification mode, the simultaneous operation of the refrigeration unit 23 and the circulation pump 53 can achieve distillation and heating of the refrigerant in the distillation tank 16, removing lubricating oil from the refrigerant. This also allows for deep purification of the lubricating oil and water content in the refrigerant within the cryogenic container 21.

[0062] In one or more embodiments, referring to Figure 7 As shown, the refrigerant recovery device may further include a controller 7, which 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. Specifically, the controller 7 can 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 operating state of the recovery unit 1, the refrigerant purification device, the valve assembly 3, and the distillation heat exchange device 5 can be controlled by the refrigerant purity data detected by the refrigerant detection device 4. For example, the operating state 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.

[0063] In the embodiments of the present invention, those skilled in the art may adaptably increase or decrease the number of valves in the valve assembly 3 and adapt the installation positions of the valves in the valve assembly 3 according to actual design requirements, without further limitation herein. For example, a drain valve may be provided at the bottom of the distillation tank 16 so that the liquid lubricating oil in the distillation tank 16 can be drained by controlling the closure of the drain valve.

[0064] In some embodiments, reference Figure 1-6 As shown, the refrigerant recovery equipment 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 cryogenic container 21 , so that the flow of refrigerant entering the cryogenic container 21 may be regulated by the flow regulating valve 19 .

[0065] Reference Figure 1-6 As shown, the refrigerant recovery equipment may also include a sight glass 6, which is a transparent device used to observe the state of fluid in fluid pipelines such as refrigeration systems and hydraulic systems. It is usually made of glass or high-strength plastic and is installed in a visible position in the pipeline. For example, the sight glass 6 can be installed in the purification pipeline 11 located between the low-temperature container 21 and the purification pump 24. This makes it convenient for the user to observe the liquid level of the liquid refrigerant flowing through the purification pipeline 11. It can also facilitate the user to switch between the purification method using the purification pump 24 and the purification method using the compressor 17.

[0066] In summary, an 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 filter assembly 22, a refrigeration unit 23, and a purification pump 24. The filter assembly 22 is disposed in the low-temperature container 21, and the cold end of the refrigeration unit 23 cooperates with the filter assembly 22 to cool the filter assembly 22, thereby condensing the gaseous refrigerant flowing into the filter assembly 22 into liquid refrigerant. Impurities in the liquid refrigerant solidify in the filter assembly 22. The purification pump 24 is connected to the space below the filter assembly 22 in the low-temperature container 21 and is connected to the recovery unit 1 to recover the purified liquid refrigerant. By utilizing the fact that the freezing points of water and lubricating oil are higher than those of refrigerant, the refrigeration unit 23 can create a low-temperature environment in the filter assembly 22, trapping the solidified water and lubricating oil in the filter assembly 22 for deep water and oil removal. This significantly improves the purity of the recovered refrigerant and enhances the refrigeration efficiency of the subsequent refrigerant reuse.

[0067] Reference Figure 8 As shown, an embodiment of the present invention discloses a control method for a refrigerant recovery device, wherein the refrigerant recovery device may include the refrigerant recovery device as described in any one of the above-mentioned embodiments of the invention, and the control method may include:

[0068] S801. Obtain refrigerant purity data.

[0069] In an embodiment of the present invention, the purity data of the refrigerant can be obtained based on detection by a refrigerant purity detection device arranged in the recovery pipeline 12. The purity data used to evaluate the refrigerant can include at least one of the following types: water content, acidity value and non-condensable gas concentration (or non-condensable gas volume fraction).

[0070] S802. When it is determined based on the purity data that the preset purification conditions are met, the refrigerant recovery equipment is controlled to execute a purification mode. Execution of the purification mode includes: controlling the refrigeration unit 23 to cool the filter assembly 22 so that the gaseous refrigerant flowing into the filter assembly 22 is condensed into liquid refrigerant, so that impurities in the liquid refrigerant are solidified 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.

[0071] In an embodiment of the present invention, the preset purification conditions can be understood as relevant conditions for determining whether the recovered refrigerant meets the refrigerant purity requirements for reusable refrigerants. For example, the preset purification conditions may include evaluation thresholds preset for each data type of the above-mentioned purity data, wherein the evaluation thresholds may 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. The types of the purity data include water content and acidity, and the corresponding preset purification conditions may include: the water content is greater than the preset water content threshold, or the acidity is greater than the preset acidity threshold. Those skilled in the art may determine the preset purification conditions based on the impurities contained in the actual refrigerant. No further restrictions are made here.

[0072] If the purity data meets the preset purification conditions, it is determined that the refrigerant recovered from the recovery device 8 does not meet the refrigerant purity requirements for reusability and requires purification. At this point, the refrigerant recovery device can be controlled to execute a purification mode. In one or more embodiments, executing the purification mode may include the following steps: controlling the refrigeration unit 23 to operate and cool the filter assembly 22. This causes the gaseous refrigerant flowing into the filter assembly 22 to condense in the low-temperature environment, forming liquid refrigerant, which is then stored in the low-temperature container 21. Impurities (such as water and lubricating oil) in the liquid refrigerant solidify in the filter assembly 22 and adhere to it. Alternatively, the filter assembly 22 can capture the solidified impurities, separating the impurities from the refrigerant, thereby deeply purifying the refrigerant. The purified refrigerant, under the pressure differential generated by the purification pump 24, flows to the recovery unit 1 for recovery. This significantly improves the purity of the recovered refrigerant and enhances the refrigeration efficiency for subsequent refrigerant reuse.

[0073] Reference Figure 9 As shown, an embodiment of the present invention discloses another control method for refrigerant recovery equipment, which may include:

[0074] S901. Obtain refrigerant purity data.

[0075] In the embodiment of the present invention, the description of S901 refers to the description of S801 above.

[0076] S902: Determine whether the purity data meets the preset purification conditions.

[0077] In an embodiment of the present invention, the preset purification conditions can be understood as relevant conditions for determining whether the recovered refrigerant meets the refrigerant purity requirements for reusable refrigerants. For example, the preset purification conditions may include evaluation thresholds preset for each data type of the above-mentioned purity data, wherein the evaluation thresholds may 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. The types of the purity data include water content and acidity, and the corresponding preset purification conditions may include: the water content is greater than the preset water content threshold, or the acidity is greater than the preset acidity threshold. Those skilled in the art may determine the preset purification conditions based on the impurities contained in the actual refrigerant. No further restrictions are made here.

[0078] If the purity data meets the preset purification conditions, it is determined that the purity of the refrigerant recovered from the to-be-recovered device 8 does not meet the reusable refrigerant purity requirements and needs to be purified.

[0079] If the purity data does not meet the preset purification conditions, it is determined that the purity of the refrigerant recovered from the to-be-recovered device 8 meets the purity requirements for reusable refrigerant and does not need to be purified.

[0080] S903: Control the refrigerant recovery device to execute a 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 is condensed into liquid refrigerant, so that impurities in the liquid refrigerant solidify in the filter assembly 22. Furthermore, controlling the purification pump 24 to operate to provide pressure to deliver the liquid refrigerant purified by the filter assembly 22 into the liquid storage tank 13 for recovery.

[0081] In the embodiment of the present invention, the description of S903 refers to the description of S803 above.

[0082] In one or more embodiments, when the refrigeration unit 23 is controlled to work, the filter assembly 22 of the refrigeration unit 23 can be controlled to cool down and maintain the temperature of the filter assembly 22 between -40 degrees Celsius and -90 degrees Celsius. For example, the temperature in the low-temperature container 21 can be -40 degrees Celsius, -50 degrees Celsius, -70 degrees Celsius, -80 degrees Celsius and -90 degrees Celsius, etc., which are not limited here. Considering that the freezing point of the lubricating oil of the compressor 17 is generally higher than -40 degrees Celsius, the lubricating oil can be fully solidified 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 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 It is even possible to control the water content in the refrigerant to less than or equal to 0.001 The purity of the recovered refrigerant can thereby be greatly improved. The temperature detection of the filter assembly 22 can be achieved by a temperature detection element embedded in the filter assembly 22 or installed on the inner wall of the low-temperature container 21 .

[0083] In one or more embodiments, during the purification mode, a small amount of gaseous refrigerant may remain in the gaseous refrigerant flowing out of the cryogenic container 21 after condensation in the cryogenic container 21. Therefore, upon detecting that the purification switching condition is met, the purification pump 24 is stopped, and the valve assembly 3 is controlled to allow the gaseous refrigerant flowing out of the cryogenic container 21 to flow into the compressor 17. The compressor 17 and the first heat exchanger 18 are controlled to condense the gaseous refrigerant into liquid refrigerant. The purification switching condition can be understood as a condition used to determine whether to recover the purified gaseous refrigerant. For example, a liquid level gauge can be provided at the inner bottom of the cryogenic container 21, so that the liquid level of the liquid refrigerant in the cryogenic container 21 can be used to determine whether to recover the purified refrigerant. For example, if the liquid level is less than or equal to a liquid level threshold, it is determined that the refrigerant in the recovery device 8 has been substantially purified. Recovery of the gaseous refrigerant is required, and the purification switching condition is determined to be met. For another example, the purification switching condition may be that the operating time of the purification pump 24 reaches a preset operating time. When the preset operating time is reached, it can be determined that the refrigerant in the recovery device 8 is substantially purified. Recovery of the gaseous refrigerant is required, and the purification switching condition is determined to be met. Those skilled in the art can determine the specific purification switching condition based on actual design requirements, and no further limitations are imposed here.

[0084] Thereby, the operation of the valve assembly 3 is controlled, for example, the first recovery valve 33, the second purification valve 32, the third purification valve 35 and the fourth purification valve 36 are controlled to be opened, and the first purification valve 31 and the second recovery valve 34 are controlled to be closed. Thus, under the pressure difference generated by the operation of the compressor 17, the recovery pipeline 12 is connected to the purification pipeline 11. In addition, the gaseous refrigerant flowing out of the low-temperature container 21 flows to 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 liquid refrigerant, and under the pressure of the compressor 17, the liquid refrigerant flowing out of the first heat exchanger 18 is sent to the liquid storage tank 13 for further recovery.

[0085] In one or more embodiments, during the refrigerant purification process, a refrigerant detection step may also be performed. The refrigerant detection step includes: controlling the valve assembly 3 to operate 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. The purity data of the refrigerant is then obtained. If it is determined based on the purity data that the preset purification conditions are met, the refrigerant detection step is repeated. If it is determined based on the purity data that the preset purification conditions are not met, the valve assembly 3 is controlled to operate 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.

[0086] In an embodiment of the present invention, the control valve assembly 3 may operate to: control the fifth purge valve 37 to open, and control the fourth purge valve 36 to close. Furthermore, the liquid refrigerant flowing out of the first heat exchanger 18 or the purge pump 24 is directed to the refrigerant detection device 4. Refrigerant purity data is reacquired. A determination is made as to whether the purity data meets preset purification conditions. If the purity data determines that the preset purification conditions are met, it is determined that the refrigerant recovered from the to-be-recovered device 8 does not meet the refrigerant purity requirements for reusability and requires purification.

[0087] If the purity data does not meet the preset purification conditions, it is determined that the refrigerant recovered from the recovery device 8 meets the refrigerant purity requirements for reusability and does not require purification. In this case, the valve assembly 3 can be controlled to open the first recovery valve 33, the second purification valve 32, the third purification valve 35, and the fourth purification valve 36, while simultaneously closing the first purification valve 31, the second recovery valve 34, and the fifth purification valve 37. Alternatively, the valve assembly 3 can be controlled to open the first recovery valve 33, the first purification valve 31, the third purification valve 35, and the fourth purification valve 36, while simultaneously closing the second purification valve 32, the second recovery valve 34, and the fifth purification valve 37. Thus, under the pressure differential generated by the operation of the compressor 17 or the purification pump 24, the recovery line 12 is connected to the purification line 11. Furthermore, the refrigerant flowing from the recovery inlet flows sequentially to the filter drier 15, the distillation tank 16, the compressor 17, and the first heat exchanger 18, and then enters the liquid storage tank 13 for storage. Alternatively, the refrigerant flows to the drying filter 15, the distillation tank 16 and the purification pump 24 in sequence, and then enters the liquid storage tank 13 for storage.

[0088] In one or more embodiments, the circulating pump 53 can be activated while the refrigeration unit 23 is operating. This transfers heat from the refrigeration unit 23 to the distillation tank 16 for distillation and heating of the refrigerant. The heat output from the hot end (heat output end) of the refrigeration unit 23 can be exchanged via the second heat exchanger 52 in contact therewith. For example, a heat transfer medium (e.g., water, ethylene glycol, or thermal oil) is provided in the heat exchange line 51. After being heated in the second heater, the heat transfer medium is delivered to the third heat exchanger 54 by the circulating pump 53. The third heat exchanger 54 can maintain surface contact with the distillation tank 16, allowing the heated heat transfer medium to heat the interior of the distillation tank 16 in the third heat exchanger 54. Therefore, when the refrigerant recovery equipment is operating in purification mode, the simultaneous operation of the refrigeration unit 23 and the circulating pump 53 allows the refrigerant to be distilled and heated in the distillation tank 16, removing lubricating oil from the refrigerant. At the same time, deep purification of the lubricating oil and water in the refrigerant in the low-temperature container 21 is achieved.

[0089] In some embodiments, if the non-condensable gas in the refrigerant detected by the refrigerant detection device 4 meets the preset purification conditions, the control method may further include controlling the valve assembly 3 to operate, specifically, controlling the third purification valve 35 and the sixth purification valve 38 to open, controlling the other valves in the valve assembly 3 to close, and controlling the flow control valve 19 to open. Figure 6As shown, the refrigerant in the device to be recovered 8 is first recovered into the cryogenic container 21. When the pressure value in the cryogenic container 21 exceeds a set pressure threshold, for example, the set pressure threshold may include a value such as 0.1 MPa, the sixth purge valve 38 provided on the cryogenic container 21 is opened to exhaust gas. After a certain amount of gas is exhausted, the sixth purge valve 38 is closed, and the refrigerant is then purified by flowing to the purification pump 24 or compressor 17. The recovery mode is then executed until the non-condensable gas is detected to not meet the preset purification conditions.

[0090] S904: Control the refrigerant recovery device to execute a recovery mode. Executing the recovery mode includes: controlling the valve assembly 3 and the cooling assembly 14 to operate so that the refrigerant flowing in from the recovery inlet flows into the liquid storage tank 13. Furthermore, if a pressure supply switching condition is detected, controlling the valve assembly 3 and the compressor 17 to operate so that the compressor 17 operates to provide pressure, and the refrigerant flowing in from the recovery inlet sequentially flows through the filter drier 15, the distillation tank 16, the compressor 17, and the first heat exchanger 18 before flowing into the liquid storage tank 13.

[0091] In an embodiment of the present invention, controlling the operation of the valve assembly 3 can close the pipeline connection between the recovery line 12 and the purification line 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. The cooling assembly 14 is controlled to operate to cool the liquid storage tank 13. As a result, a negative pressure is formed in the recovery line 12 under the action of the cooling assembly 14, so that the refrigerant in the device to be recovered 8 can be directly sucked into the liquid storage tank 13 by relying on this negative pressure to recover the refrigerant. This recovery mode can increase the recovery speed of the refrigerant.

[0092] The supply pressure switching condition can be understood as a condition for determining whether pressure equilibrium has been achieved between the recovery line 12 and the liquid storage tank 13. When pressure equilibrium is achieved, there is no pressure differential between the recovery device 8 and the liquid storage tank 13, thus preventing the liquid storage tank 13 from continuing to recover refrigerant. For example, this can be determined by the difference between the pressure values ​​at two different locations in the recovery line 12, or the pressure value in the recovery line 12 and the pressure value in the liquid storage tank 13. If the pressure difference is within a preset range or equal to zero, it is determined that pressure equilibrium has been achieved between the recovery line 12 and the liquid storage tank 13, and the supply pressure switching condition is met. The pressure value can be detected by a pressure detection element, which is not specifically defined herein. The valve assembly 3 and the compressor 17 can then be controlled to operate. For example, the first recovery valve 33, the second purge valve 32, the third purge valve 35, and the fourth purge valve 36 can be controlled to open, while the first purge valve 31 and the second recovery valve 34 can be controlled to close.

[0093] As a result, the pressure differential generated by the operation of the compressor 17 establishes communication between the recovery line 12 and the purification line 11. Furthermore, the refrigerant flowing in from the recovery inlet flows sequentially to the filter drier 15, the distillation tank 16, the compressor 17, and the first heat exchanger 18. The compressor 17 compresses the low-temperature, low-pressure gaseous refrigerant into a high-temperature, high-pressure gaseous refrigerant. The first heat exchanger 18 condenses the high-temperature, high-pressure gaseous refrigerant to produce liquid refrigerant. Under the pressure of the compressor 17, the liquid refrigerant flowing out of the first heat exchanger 18 is then fed into the liquid storage tank 13 for further recovery.

[0094] 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.

[0095] In some embodiments, the recovery stop condition can be determined based on the pressure value in the liquid storage tank 13. For example, when the pressure value in the liquid storage tank 13 is less than a preset pressure threshold and less than or equal to one atmosphere, the refrigerant recovery is determined to be complete, the recovery mode is stopped, and all valves included in the valve assembly 3 are adjusted to a closed state. The preset pressure threshold can be 10% of the initial pressure value of the liquid storage tank 13. , 15 There are no further restrictions here.

[0096] In summary, an embodiment of the present invention discloses a control method for refrigerant recovery equipment. The control method may include first obtaining refrigerant purity data, and then, if it is determined based on the purity data that the refrigerant meets preset purification conditions, controlling the refrigerant recovery equipment to execute a 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 is condensed into liquid refrigerant, so that impurities in the liquid refrigerant solidify in the filter assembly 22. Controlling the purge pump 24 to operate to provide pressure to deliver the liquid refrigerant purified by the filter assembly 22 to the recovery unit 1 for recovery. This significantly improves the purity of the recovered refrigerant and enhances the refrigeration efficiency of the subsequent refrigerant reuse.

[0097] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0098] It is easy for those skilled in the art to think that any combination of the above embodiments is feasible, so any combination of the above embodiments is an implementation scheme of the present invention. However, due to space limitations, this specification will not describe them in detail here.

[0099] In the description provided herein, numerous specific details are described. However, it is understood that embodiments of the present invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques are not shown in detail so as not to obscure the understanding of this description.

[0100] Similarly, it should be understood that in order to streamline the invention and aid in understanding one or more of the various inventive aspects, in the above description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together into a single embodiment, figure, or description thereof.

[0101] Furthermore, those skilled in the art will appreciate that although some embodiments described herein include certain features included in other embodiments but not other features, combinations of features from different embodiments are intended to be within the scope of the present invention and to form different embodiments. For example, in the claims, any of the claimed embodiments may be used in any combination.

Claims

1. A refrigerant recovery device, characterized in that: The refrigerant recovery equipment comprises: a recovery unit, the recovery unit comprising a purification pipeline, a recovery pipeline, a liquid storage tank, a drying filter, a distillation tank, a compressor, and a first heat exchanger, the recovery pipeline being in communication with the purification pipeline, the liquid storage tank being in communication with the recovery pipeline for storing refrigerant, the air outlet of the drying filter being in communication with the air inlet of the distillation tank, the air outlet of the compressor being in communication with the air inlet of the first heat exchanger, and the liquid outlet of the first heat exchanger being in communication with the liquid storage tank; A refrigeration purification device, which is embedded in the purification pipeline and includes: A cryogenic container, wherein the gas outlet of the distillation tank is connected to the refrigerant inlet of the cryogenic container, and the refrigerant outlet of the cryogenic container is connected to the compressor; A filter assembly, the filter assembly being disposed in the cryogenic container; a refrigeration unit, wherein a cold end of the refrigeration unit cooperates with the filter assembly to cool the filter assembly, thereby condensing the gaseous refrigerant flowing into the filter assembly into liquid refrigerant, and impurities in the liquid refrigerant solidify in the filter assembly; A purification pump is connected to the space below the filter assembly in the low-temperature container, the liquid inlet of the purification pump is connected to the air inlet of the compressor, and the liquid outlet of the purification pump is connected to the liquid outlet of the first heat exchanger to recover the purified liquid refrigerant.

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

3. The refrigerant recovery equipment according to claim 2, characterized in that: When the refrigeration unit is in operation, the temperature in the low-temperature container is controlled to be between -40 degrees Celsius and -90 degrees Celsius, so as to solidify impurities in the liquid refrigerant in the porous structure.

4. The refrigerant recovery equipment according to claim 1, characterized in that: The recovery pipeline includes a recovery inlet, and the recovery inlet is used to communicate with the equipment to be recovered; The recovery unit also includes: A cooling component, the cooling component is used to cool the liquid storage tank so that the liquid storage tank generates negative pressure to absorb 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 and is used for pipeline switching between the recovery pipeline and the purification pipeline.

5. The refrigerant recovery equipment according to claim 4, characterized in that: The valve assembly comprises: a first purge valve, which is provided at the liquid inlet of the purge pump to control the on-off of the liquid path of the purge pump; The second purge valve is provided at the air inlet of the compressor to control the on-off of the air path of the compressor.

6. The refrigerant recovery equipment 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, the first recovery valve being arranged at the inlet of the liquid storage tank and being used to control the opening and closing of the liquid storage tank; a second recovery valve, the second recovery valve being disposed between the first recovery outlet and the liquid storage tank; a third purge valve, the third purge valve being disposed in a purge line connected to the second recovery outlet, the second recovery outlet being connected to the filter drier; A fourth purge valve is provided in the purge line between the liquid storage tank and the first heat exchanger; wherein, If the first recovery valve and the second recovery valve are open, and the third purge valve and the fourth purge 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 purge valve, the third purge valve, and the fourth purge valve are opened, and the first purge 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 flows through the distillation tank, the compressor, and the first heat exchanger in sequence before flowing into the liquid storage tank.

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

8. The refrigerant recovery equipment according to claim 5, characterized in that: The refrigerant recovery equipment further includes a distillation heat exchange device, which includes: Heat exchange pipelines; a second heat exchanger, the second heat exchanger being in contact with a hot end of the refrigeration unit and being embedded in the heat exchange pipeline; A circulating pump, embedded in the heat exchange pipeline, for providing heat exchange power; A third heat exchanger is embedded in the heat exchange pipeline and contacts the distillation tank to transfer heat from the refrigeration unit to the distillation tank for distillation and heating of the refrigerant.

9. A control method for a refrigerant recovery device, characterized in that: The refrigerant recovery device includes the refrigerant recovery device according to any one of claims 1 to 8, and the control method includes: Obtain refrigerant purity data; When it is determined according to the purity data that the preset purification conditions are met, controlling the refrigerant recovery device to execute a purification mode, wherein executing the purification mode includes: Controlling the refrigeration unit to cool the filter assembly so that the gaseous refrigerant flowing into the filter assembly is condensed into liquid refrigerant, so that impurities in the liquid refrigerant are solidified in the filter assembly; The purification pump is controlled to operate 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 equipment according to claim 9, characterized in that: The controlling the refrigeration unit to cool the filter assembly includes: The refrigeration unit is controlled to cool the filter assembly and maintain the temperature of the filter assembly between -40 degrees Celsius and -90 degrees Celsius.

11. The control method of the refrigerant recovery equipment according to claim 9, characterized in that: The refrigerant recovery device further includes a valve assembly, which is disposed in the recovery pipeline and the purification pipeline for switching between the recovery pipeline and the purification pipeline. Executing the purification mode further includes: When it is detected that the purification switching condition is met, the purification pump is stopped and the valve assembly is controlled to operate so that the gaseous refrigerant flowing out of the low-temperature container flows into the compressor; The compressor and the first heat exchanger are controlled to operate so as to condense the gaseous refrigerant into liquid refrigerant.

12. The control method of the refrigerant recovery equipment according to claim 9, characterized in that: The recovery unit further includes a refrigerant detection device and a valve assembly. The refrigerant detection device is disposed in the recovery pipeline. The valve assembly is disposed in the recovery pipeline and the purification pipeline for switching between the recovery pipeline and the purification pipeline. Executing the purification mode further includes: Executing a refrigerant detection step, the refrigerant detection step comprising: controlling the valve assembly to allow the liquid refrigerant flowing out of the first heat exchanger or the purification pump to flow through the refrigerant detection device, so that the refrigerant detection device detects refrigerant purity data; Obtain refrigerant purity data; If it is determined according to the purity data that the preset purification conditions are met, repeating the refrigerant detection step; If it is determined based on the purity data that the preset purification condition is not met, the valve assembly is controlled to operate 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 equipment according to claim 9, characterized in that: The refrigerant recovery equipment further includes a distillation heat exchange device, the distillation heat exchange device includes a heat exchange pipeline and a circulation pump, and the circulation pump is embedded in the heat exchange pipeline. Executing the purification mode further includes: The circulating pump is started to transfer the heat of the refrigeration unit to the distillation tank for distillation and heating of the refrigerant.

14. The control method of the refrigerant recovery equipment according to claim 9, characterized in that: The refrigerant recovery equipment further includes a valve assembly, which is disposed in the recovery pipeline and the purification pipeline for switching between the recovery pipeline and the purification pipeline. The recovery unit further includes a cooling assembly, which is used to cool the liquid storage tank. The control method further includes: When it is determined according to the purity data that the preset purification condition is not met, controlling the refrigerant recovery device to execute a recovery mode, wherein executing the recovery mode includes: Control the action of the valve assembly and the operation of the cooling assembly to allow the refrigerant flowing from the recovery inlet to flow into the liquid storage tank; When it is detected that the pressure supply switching conditions are met, the valve assembly and the compressor are controlled to operate so that the compressor operates to provide pressure, and the refrigerant flowing in from the recovery inlet flows through the drying filter, the distillation tank, the compressor and the first heat exchanger in sequence, and then flows into the liquid storage tank.

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