Refrigerant recovery system and refrigerant recovery method

Abstract

To provide a refrigerant collection system and a refrigerant collection method which can reduce non-condensable gas in a collection cylinder while maintaining connection of the collection cylinder, a refrigerant collection device and a refrigeration air-conditioning apparatus.SOLUTION: A first gas separation module 68A includes a separation film 92A for separating a first mixed gas composed of an air-conditioning refrigerant gas component and a non-condensable gas contained in a collection cylinder 16 having collected compression-condensed refrigerant into a first gas component of the air-conditioning refrigerant and a second mixed gas composed of a second gas component of the air-conditioning refrigerant and the non-condensable gas. A second gas separation module 68B includes an adsorption part 315 including an adsorbent for adsorbing the second gas component of the air-conditioning refrigerant out of the second mixed gas separated by the first gas separation module 68A. Resending piping 58A re-sends the first gas component of the air-conditioning refrigerant separated by the first gas separation module device 68A between a refrigerant circuit 30 and a refrigerant collection device 14.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a refrigerant recovery system and method. [Background technology]

[0002] Refrigeration and air conditioning equipment (equipment using refrigerant), such as freezers and air conditioners, are equipped with the following components along the circulation path of the refrigerant that transports thermal energy: an air conditioning compressor that compresses the vaporized gas refrigerant to increase its temperature and pressure; an air conditioning condenser that liquefies the gas refrigerant heated and pressurized by the air conditioning compressor by cooling it with outside air or the like; an expansion valve that expands the refrigerant (liquid refrigerant) liquefied in the air conditioning condenser to gasify it; a refrigerant recovery condenser that liquefies the vaporized refrigerant (gas refrigerant) in the expansion valve; and an accumulator that stores the refrigerant (liquid refrigerant) liquefied in the refrigerant recovery condenser. The refrigerant transports thermal energy, releasing heat to the outside in the air conditioning condenser and receiving heat from outside air or the like after passing through the expansion valve.

[0003] The various refrigerants used in refrigeration and air conditioning equipment have high global warming potential and ozone depletion potential, so their atmospheric emissions are regulated. Therefore, particularly when replacing the refrigerant or disposing of refrigeration and air conditioning equipment, it is mandatory to minimize refrigerant leakage into the atmosphere and to recover the refrigerant contained in the equipment. At the same time, there has been a push to switch to refrigerants with lower environmental impacts, and in recent years, the use of HFCs (hydrofluorocarbons) and other refrigerant substitutes has become mainstream. Examples of HFCs include R134A and R32 as single refrigerants and R410A and R407C as mixed refrigerants.

[0004] A refrigerant recovery system is used to recover refrigerant. In the refrigerant recovery system, the refrigerant in the refrigeration / air-conditioning equipment's accumulator is vaporized, and the gas refrigerant is then sucked in by a compressor inside the refrigerant recovery system and adiabatically compressed. The adiabatically compressed gas refrigerant is liquefied by a condenser inside the refrigerant recovery system and recovered as liquid refrigerant in a recovery cylinder. The amount of recovered refrigerant is measured using a weighing scale.

[0005] Patent Document 1 points out that when a refrigerant in a refrigerant-using device is recovered into a recovery container (recovery cylinder) using a refrigerant recovery device, if non-condensable gases such as air are mixed into the recovery system, the non-condensable gases will also be recovered into the recovery container (see paragraph

[0056] ). Because non-condensable gases do not condense in the recovery container and exist as compressed gases, the pressure and temperature inside the recovery container increase as the amount of liquid refrigerant in the recovery container increases and the volume of the gas phase decreases. Therefore, Patent Document 1 discloses a technique in which, when the temperature inside the recovery container reaches a predetermined value, the recovery container is disconnected from the refrigerant recovery device and the refrigerant-using device, a gas separation device is connected to the recovery container, and the non-condensable gases inside the recovery container are removed using the gas separation device. Specifically, the mixture of gas refrigerant and non-condensable gases in the recovery container is sent to the gas separation device for separation, and the non-condensable gases are discharged into the atmosphere while the gas refrigerant is returned to the recovery container. After the non-condensable gas is removed from the recovery container, the refrigerant recovery device and the refrigerant-using equipment are reconnected to the recovery container, and the operation of recovering the refrigerant into the recovery container is resumed. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-159952 Summary of the Invention [Problem to be solved by the invention]

[0007] As described above, when recovering refrigerant from the refrigeration / air-conditioning equipment refrigerant circuit, the refrigerant recovery device vaporizes the refrigerant, then adiabatically compresses it, and then liquefies it to recover the refrigerant. However, if non-condensable gases, primarily air-based gases such as nitrogen (N2) and oxygen (O2), are mixed into the refrigerant, the non-condensable gases are not condensed in the refrigerant recovery device and are instead filled into the recovery cylinder as a gas. As a result, the internal pressure of the recovery cylinder increases, making it difficult to fill with liquid refrigerant, and the speed at which the refrigerant is recovered into the recovery cylinder decreases. Therefore, it takes a long time to recover all of the refrigerant.

[0008] To address this issue, Patent Document 1 uses a gas separation device to remove non-condensable gases from the recovery container. However, during the refrigerant recovery process, the recovery container (recovery cylinder) must be disconnected from the refrigerant recovery device and the refrigerant-using equipment, and then reconnected to the gas separation device. Furthermore, once the non-condensable gas removal process is complete, the recovery container must be reconnected to the refrigerant recovery device and the refrigerant-using equipment. This requires a lot of work. Furthermore, because the refrigerant is returned (injected) from the gas separation device into the recovery container in gas phase (vapor phase), there is also the problem of a lower refrigerant charge amount in the recovery container compared to when the refrigerant is liquefied and injected.

[0009] What is needed is an improved technique that can reduce non-condensable gases in the recovery cylinder while maintaining connectivity to the recovery cylinder, refrigerant recovery system, and refrigeration and air conditioning equipment.

[0010] Therefore, an object of the present disclosure is to provide a refrigerant recovery system and a refrigerant recovery method that can reduce non-condensable gases in a recovery cylinder when recovering refrigerant from a refrigeration and air conditioning equipment while maintaining the connection between the recovery cylinder, the refrigerant recovery device, and the refrigeration and air conditioning equipment. [Means for solving the problem]

[0011] The refrigerant recovery system disclosed herein recovers air conditioning refrigerant from the refrigerant circuit of a refrigeration and air conditioning equipment and includes: a refrigerant recovery device that produces compressed condensed refrigerant by compressing and condensing the air conditioning refrigerant; a recovery cylinder that recovers the compressed condensed refrigerant produced by the refrigerant recovery device; a first gas separation module including a separation membrane that separates a first mixed gas consisting of a gas component of the air conditioning refrigerant and a non-condensable gas contained inside the recovery cylinder that recovered the compressed condensed refrigerant into the first gas component of the air conditioning refrigerant and a second mixed gas consisting of a second gas component of the air conditioning refrigerant and a non-condensable gas; a second gas separation module including an adsorption section that includes an adsorbent that adsorbs the second gas component of the air conditioning refrigerant from the second mixed gas separated by the first gas separation module; and a re-transmission pipe that re-transmits the first gas component of the air conditioning refrigerant separated by the first gas separation module between the refrigerant circuit and the refrigerant recovery device.

[0012] The refrigerant recovery method of the present disclosure for recovering air-conditioning refrigerant from the refrigeration and air-conditioning equipment refrigerant circuit includes the steps of: a refrigerant recovery device compressing and condensing the air-conditioning refrigerant to produce compressed condensed refrigerant; a recovery cylinder recovering the compressed condensed refrigerant produced by the refrigerant recovery device; a separation membrane of a first gas separation module separating a first mixed gas consisting of a gas component of the air-conditioning refrigerant and a non-condensable gas contained inside the recovery cylinder from which the compressed condensed refrigerant has been recovered, into a first gas component of the air-conditioning refrigerant and a second mixed gas consisting of a second gas component of the air-conditioning refrigerant and a non-condensable gas; a second gas separation module adsorbing the second gas component of the air-conditioning refrigerant from the second mixed gas separated by the separation membrane of the first gas separation module in an adsorption section; and a re-transmission pipe re-transmitting the first gas component of the air-conditioning refrigerant separated by the separation membrane of the first gas separation module between the refrigerant circuit and the refrigerant recovery device. [Effects of the Invention]

[0013] According to the present disclosure, when recovering refrigerant from a refrigeration / air conditioning equipment, non-condensable gases in the recovery cylinder can be reduced while maintaining the connections between the recovery cylinder, refrigerant recovery device, and refrigeration / air conditioning equipment. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a schematic diagram of a refrigerant recovery system 10 according to a first embodiment. [Figure 2] FIG. 10 is a block diagram of a dispatch controller 76. [Figure 3] FIG. 3 is a diagram showing an example of pressure characteristics of each refrigerant. [Figure 4] FIG. 2 is a block diagram of a three-way valve controller 80. [Figure 5] FIG. 10 is a block diagram of a pressure controller 97. [Figure 6] 10 is a diagram for explaining a set pressure PA of the pressure difference between the inside and outside of a separation membrane 92A. FIG. [Figure 7] FIG. 2 is a diagram schematically illustrating the molecular sieving principle of a separation membrane 92A made of an inorganic separation membrane. [Figure 8] 10 is a diagram showing details of a first suction unit 321, a second suction unit 322, and a third suction unit 323. FIG. [Figure 9] 10 is a diagram showing an example of refrigerant adsorption by an adsorbent 350. FIG. [Figure 10] 10 is a diagram showing another example of refrigerant adsorption on an adsorbent 350. FIG. [Figure 11] 3 is a flowchart showing a specific refrigerant recovery method using the refrigerant recovery system 10 in the first embodiment. [Figure 12] 10 is a flowchart showing a first three-way valve control. [Figure 13] 10 is a flowchart showing second three-way valve control. [Figure 14] 10 is a schematic diagram of a refrigerant recovery system 10A according to a second embodiment. FIG. [Figure 15] FIG. 10 is a diagram showing the configuration of a pressure controller 97A according to a second embodiment. [Figure 16] FIG. 10 is a schematic diagram of a refrigerant recovery system 10B according to a third embodiment. [Figure 17] FIG. 2 is a diagram showing an example of the arrangement of filters FL1 and FL2. [Figure 18] FIG. 10 is a schematic diagram of a refrigerant recovery system 10C according to a fourth embodiment. [Figure 19] 10 is a flowchart showing a specific refrigerant recovery method using a refrigerant recovery system 10C in the fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings. The configurations described below are examples for the purpose of explanation and can be modified as appropriate to suit the specifications of systems, devices, etc. Furthermore, when multiple embodiments or variations are included below, it is assumed from the beginning that their characteristic parts will be used in appropriate combination. The same elements will be assigned the same reference numerals in all drawings, and duplicate explanations will be omitted.

[0016] Embodiment 1 FIG. 1 is a schematic diagram of a refrigerant recovery system 10 according to the first embodiment.

[0017] In the figure, thick solid lines indicate pipes through which fluid flows, and dashed dotted lines indicate control lines inputting and outputting to and from each controller. Refrigerant recovery system 10 is a system for recovering air-conditioning refrigerant from refrigeration and air-conditioning equipment and filling recovery cylinder 16. While the following describes an example of recovering air-conditioning refrigerant from air-conditioning device 12 as refrigeration and air-conditioning equipment, refrigerant recovery system 10 can be applied to refrigerant recovery from any equipment that uses refrigerant. Air-conditioning refrigerant transports thermal energy and changes phase between liquid and gas during operation of the refrigeration and air-conditioning equipment, thereby realizing at least one of the cooling and heating functions of the air, etc., in the refrigeration and air-conditioning equipment.

[0018] The refrigerant recovery system 10 includes a refrigerant recovery device 14, a recovery cylinder 16, a gas separation module device 68, a re-transmission pipe 58A, and a three-way valve 40.

[0019] The refrigerant recovery device 14 draws air-conditioning refrigerant from the refrigerant circuit 30 of the air conditioner 12, compresses it adiabatically, and condenses the compressed refrigerant to liquid form, generating compressed condensed refrigerant.

[0020] The recovery cylinder 16 recovers the compressed condensed refrigerant produced by the refrigerant recovery device 14 .

[0021] The gas separation module apparatus 68 separates the mixed gas 22 (first mixed gas) consisting of the gas components of the air-conditioning refrigerant and non-condensable gases contained inside the recovery cylinder 16 that recovered the compressed condensed refrigerant into a plurality of components. The gas separation module apparatus 68 includes a first gas separation module 68A and a second gas separation module 68B.

[0022] The reason why two gas separation modules, first gas separation module 68A and second gas separation module 68B, are used is because the air conditioning refrigerant and non-condensable gases cannot be completely separated by using only one gas separation module.

[0023] The re-transmission pipe 58A re-transmits the gas components separated by the gas separation module device 68 between the refrigerant circuit 30 and the refrigerant recovery device 14. In the vaporization promotion mode, the gas components separated by the gas separation module device 68 are sent to the refrigerant circuit 30. This increases the temperature of the refrigerant in the refrigerant circuit 30, promoting the vaporization of the refrigerant and improving the refrigerant recovery speed when refrigerant recovery is resumed. In the circulation mode, the gas components separated by the gas separation module device 68 are sent to the refrigerant recovery device 14. This allows the recovery process of the gas components of the air-conditioning refrigerant separated by the gas separation module device 68 to be performed again.

[0024] The three-way valve 40 is disposed between the refrigerant circuit 30 and the refrigerant recovery device 14 .

[0025] The air conditioner 12 includes a service port 34 that connects to the refrigerant circuit 30 .

[0026] The refrigerant circuit 30 includes an accumulator 32 that stores liquid refrigerant. The refrigerant recovery device 14 draws, via a service port 34, the gas refrigerant that has been vaporized from the liquid refrigerant in the accumulator 32.

[0027] The refrigerant recovery device 14 includes a compressor and a condenser, and can be realized by a widely available fluorocarbon recovery machine. The refrigerant recovery device 14 includes an inlet 36 (intake port) that takes in the air-conditioning refrigerant from the refrigerant circuit 30, an outlet 38 that discharges the compressed and condensed refrigerant, and a pressure detector 37 that detects the pressure of the air-conditioning refrigerant at the inlet 36.

[0028] The recovery cylinder 16 includes a liquid inlet / outlet 46 through which the compressed and condensed refrigerant from the refrigerant recovery device 14 is introduced into the recovery cylinder 16, and a gas inlet / outlet 48 through which the mixed gas 22 in the recovery cylinder 16 is discharged. The mixed gas 22 accumulates in the head space of the recovery cylinder 16.

[0029] The three-way valve 40 includes a first port 41, a second port 42, and a third port 43. The service port 34 of the air conditioner 12 and the first port 41 of the three-way valve 40 are connected by a connection pipe 50. The second port 42 of the three-way valve 40 and the inlet 36 of the refrigerant recovery device 14 are connected by an upstream pipe 52. The third port 43 of the three-way valve 40 and a re-transmission pipe 58A are connected.

[0030] The outlet 38 of the refrigerant recovery device 14 and the liquid inlet / outlet 46 of the recovery cylinder 16 are connected by a rear pipe 54. When performing general refrigerant recovery, the first port 41 and the second port 42 of the three-way valve 40 are brought into communication (normal mode).

[0031] Due to factors such as air intrusion during valve failure, pipe corrosion, refrigerant decomposition, and refrigerant repair, non-condensable gases primarily composed of air (nitrogen, oxygen, etc.) may become mixed into the air-conditioning refrigerant (hereinafter simply referred to as refrigerant) of the air conditioner 12. When non-condensable gases are drawn into the refrigerant recovery device 14 along with the refrigerant during refrigerant recovery, the non-condensable gases are not condensed in the refrigerant recovery device 14 and are instead charged as gas into the recovery cylinder 16. As a result, the internal pressure of the recovery cylinder 16 increases, making it difficult to charge the liquid refrigerant, and the rate at which the refrigerant is recovered into the recovery cylinder 16 decreases. To address this issue, the refrigerant recovery system 10 includes a separation device 18 for removing non-condensable gases from the recovery cylinder 16. In the recovery cylinder 16, a mixed gas 22 (first mixed gas) is generated, which is a mixture of the gas component of the air-conditioning refrigerant, resulting from the re-evaporation of some of the liquid refrigerant, and the non-condensable gas.

[0032] Separation apparatus 18 includes a gas inlet 60, a delivery line 56, a gas separation module apparatus 68, and a return line 58A.

[0033] The gas inlet 60 is connected to the gas inlet 48 of the recovery cylinder 16. The gas inlet 60 extracts the mixed gas 22 that remains in the head space of the recovery cylinder 16.

[0034] The mixed gas 22 taken in from the gas inlet 60 flows through the delivery pipe 56 .

[0035] The gas separation module device 68 separates the air-conditioning refrigerant as gas components from the inside of the recovery cylinder 16 that has recovered the compressed condensed refrigerant. The mixed gas 22 in the delivery pipe 56 is sent to the gas separation module device 68. The gas separation module device 68 separates the mixed gas 22 into multiple components.

[0036] The re-transmission pipe 58A is connected to the gas separation module device 68. The re-transmission pipe 58A re-transmits the first gas component 23 of the air-conditioning refrigerant separated by the gas separation module device 68 between the refrigerant recovery device 14 and the refrigerant circuit 30.

[0037] The gas separation module device 68 includes a first gas separation module 68A disposed in the front stage and a second gas separation module 68B disposed in the rear stage.

[0038] First gas separation module 68A includes an inlet 90A, a separation membrane 92A, an outlet 94A, and an outlet 96A.

[0039] The inlet 90A receives the gas mixture 22.

[0040] Separation membrane 92A separates mixed gas 22 into a first gas component 23 of the air conditioning refrigerant and a mixed gas 24 (second mixed gas) consisting of a second gas component 25 of the air conditioning refrigerant and a non-condensable gas 26. When a mixed gas containing a large amount of non-condensable gas flows into separation membrane 92A, non-condensable gas 26 flows not only toward discharge port 94A but also toward outlet 96A. As separation is repeated, the amount of non-condensable gas 26 flowing toward discharge port 94A increases, and the amount flowing toward outlet 96A decreases.

[0041] The discharge port 94A discharges the mixed gas 24 that has permeated the separation membrane 92A to the pipe 59. The outlet 96A discharges the first gas component 23 of the air-conditioning refrigerant that has not permeated the separation membrane 92A.

[0042] A first end of the outgoing piping 56 is a gas inlet 60. A second end of the outgoing piping 56 is connected to an inlet 90A of a first gas separation module 68A.

[0043] A first end of the return pipe 58A is connected to the outlet 96A of the first gas separation module 68A. A second end of the return pipe 58A is connected to the third port 43 of the three-way valve 40 as the gas outlet 74.

[0044] The second gas separation module 68B includes an inlet 90B, an outlet 94B, and an adsorber 315.

[0045] The inlet 90B receives the gas mixture 24 .

[0046] The adsorption section 315 adsorbs the second gas component 25 of the air-conditioning refrigerant in the mixed gas 24 onto the adsorbent.

[0047] The discharge port 94 discharges the non-condensable gas 26 that has not been adsorbed by the adsorption section 315 into the atmosphere.

[0048] A first end of piping 59 is connected to outlet 94A of first gas separation module 68A, and a second end of piping 59 is connected to inlet 90B of second gas separation module 68B.

[0049] The separation device 18 further includes a first pressure regulator 98A and a first check valve 99A.

[0050] The first pressure regulator 98A adjusts the differential pressure between the inside and outside of the separation membrane 92A of the first gas separation module 68A. The first pressure regulator 98A is disposed downstream of the first gas separation module 68A and includes a first back pressure valve that adjusts the pressure on the primary side of the first pressure regulator 98A.

[0051] The first check valve 99A is disposed between the first pressure regulator 98A and the gas outlet port 74. The first check valve 99A prevents the gas that has flowed out from the separation membrane 92A from flowing into the separation membrane 92A.

[0052] As will be explained below, detectors, valves, etc. are arranged in the delivery pipe 56 and the return pipe 58A, but the refrigerant recovery system can be configured with some of these omitted. The refrigerant recovery method that forms the basis of the refrigerant recovery system, including such a configuration, comprises the following steps (1) to (4).

[0053] (1) A generation step in which the first port 41 and the second port 42 of the three-way valve 40 are connected (hereinafter referred to as normal mode), the air conditioning refrigerant in the refrigerant circuit 30 is guided to the refrigerant recovery device 14 through the connecting pipe 50 and the front pipe 52, and the air conditioning refrigerant is compressed and condensed using the refrigerant recovery device 14 to generate compressed and condensed refrigerant.

[0054] (2) A recovery step in which the compressed and condensed refrigerant produced by the refrigerant recovery device 14 is recovered in the recovery cylinder 16 through the rear pipe 54.

[0055] (3) A separation step in which the mixed gas 22 contained inside the recovery cylinder 16 is guided to the gas separation module device 68 through the delivery pipe 56, and the mixed gas 22 (first mixed gas) is separated into multiple components using the gas separation module device 68.

[0056] (4) A re-transmission step in which the second port 42 and the third port 43 of the three-way valve 40 are connected (hereinafter referred to as the circulation mode), and the first gas component of the air-conditioning refrigerant that has not permeated the separation membrane 92A is re-transmitted between the refrigerant recovery device 14 and the refrigerant circuit 30 through the re-transmission piping 58A and the front piping 52.

[0057] The separation step (3) above includes the following two steps.

[0058] (3A) A first separation step in which the mixed gas 22 (first mixed gas) is separated into a first gas component 23 of the air conditioning refrigerant and a mixed gas 24 (second mixed gas) consisting of a second gas component 25 of the air conditioning refrigerant and a non-condensable gas 26 using the separation membrane 92A of the first gas separation module 68A.

[0059] (3B) A second separation step in which the second gas separation module 68B adsorbs the second gas component 25 of the air conditioning refrigerant from the mixed gas 24 (second mixed gas) separated by the separation membrane 92A of the first gas separation module 68A into the adsorption section 315, and releases the non-condensable gas 26 from the mixed gas 24 (second mixed gas) that was not adsorbed by the adsorption section 315 into the atmosphere from the discharge port 94B.

[0060] Continuing with the description of the refrigerant recovery system 10 of Figure 1, the separation device 18 further includes a pressure detector 61, a temperature detector 62, a control valve 64, and a pressure reducing valve 66 disposed in the delivery pipe 56.

[0061] A pressure detector 61 and a temperature detector 62 on the delivery pipe 56 are located closer to the recovery cylinder 16 than the control valve 64 and detect the pressure and temperature inside the recovery cylinder 16 .

[0062] The separator 18 further includes a pressure detector 70 and a pressure regulator 72 disposed in the return line 58A.

[0063] A pressure detector 70 on the return pipe 58A detects the pressure inside the return pipe 58A on the upstream side (gas separation module device 68 side) of the pressure regulator 72. The pressure regulator 72 adjusts the pressure inside the return pipe 58A on the downstream side (gas outlet 74 side) of the pressure regulator 72.

[0064] The separation device 18 further includes a dispatch controller 76 , a retransmission controller 78 , a three-way valve controller 80 , and a pressure controller 97 .

[0065] The delivery controller 76, retransmission controller 78, three-way valve controller 80, and pressure controller 97 are controllers, such as a microcomputer equipped with a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), flash memory, input / output ports, etc. These controllers may be implemented by a single common microcomputer. Furthermore, these controllers may include an ASIC (Application Specific Integrated Circuit) or the like instead of or in addition to a microcomputer.

[0066] The dispatch controller 76 determines whether or not it is necessary to remove non-condensable gas from the recovery cylinder 16 based on the detection value DP of the pressure detector 61 and the detection value DT of the temperature detector 62. When the dispatch controller 76 determines that removal is necessary, it opens the control valve 64, and when it determines that removal is not necessary, it closes the control valve 64.

[0067] When the control valve 64 is in the closed state, the three-way valve controller 80 controls the three-way valve 40 to set the first port 41 and the second port 42 in a communication state (normal mode).

[0068] When the control valve 64 is open, the three-way valve controller 80 controls the three-way valve 40 to connect the second port 42 and the third port 43 (circulation mode) or connect the first port 41 and the third port 43 (hereinafter referred to as the vaporization promotion mode). In this way, in the embodiment of Fig. 1, the vaporization promotion mode is added to the basic refrigerant recovery method.

[0069] In the normal mode, refrigerant is recovered from the air conditioner 12 to the recovery cylinder 16. In the circulation mode, a circulation loop is formed using the separation device 18, the refrigerant recovery device 14, and the recovery cylinder 16. The mixed gas 22 in the recovery cylinder 16 is repeatedly sent to the gas separation module 68 to remove non-condensable gases from the recovery cylinder 16. In the vaporization promotion mode, when there is a possibility of low-temperature condensation of the refrigerant in the refrigerant circuit 30 of the air conditioner 12, a portion of the mixed gas 22 in the recovery cylinder 16 is sent from the separation device 18 to the refrigerant circuit 30, raising the temperature of the refrigerant in the refrigerant circuit 30 and promoting vaporization of the refrigerant. The gas refrigerant that passes through the refrigerant recovery device 14 is adiabatically compressed, so its temperature is higher than when it enters the refrigerant circuit 30, i.e., the refrigerant recovery device 14. Therefore, the refrigerant entering the recovery cylinder 16 from the refrigerant recovery device 14 is at a higher temperature.

[0070] The pressure controller 97 controls the first pressure regulator 98A to adjust the differential pressure between the inside and outside of the separation membrane 92A.

[0071] 2 is a block diagram of the dispatch controller 76. The dispatch controller 76 includes a reference pressure acquirer 104, a pressure reducing valve controller 106, and a determiner 108. The separation device 18 includes an input unit 100 such as a keypad or a barcode reader, and a storage unit 102 such as a flash memory. The dispatch controller 76 is electrically connected to the input unit 100 and the storage unit 102. A memory within the dispatch controller 76 may be used as the storage unit 102.

[0072] Before refrigerant recovery, recovered refrigerant information 110 indicating the type of refrigerant to be recovered (hereinafter also referred to as recovered refrigerant) is input from input unit 100 and stored in memory unit 102. For example, a barcode indicating the type of refrigerant used in air conditioner 12, which is attached to the surface of the housing of air conditioner 12, is read by a barcode reader serving as input unit 100, and recovered refrigerant information 110 is stored in memory unit 102. Memory unit 102 also stores in advance the characteristics of saturated vapor pressure versus temperature (hereinafter referred to as pressure characteristics 112) for each of a plurality of types of refrigerant.

[0073] 3 is a diagram showing an example of the pressure characteristics of each refrigerant. In FIG. 3, the pressure characteristics of each refrigerant A, B, C, and D are shown.

[0074] The reference pressure acquirer 104 receives an input of the detected temperature DT (temperature inside the recovery cylinder 16) from the temperature detector 62 on the delivery pipe 56. The reference pressure acquirer 104 reads out the pressure characteristics 112 corresponding to the recovered refrigerant indicated by the recovered refrigerant information 110 from the storage unit 102, and acquires the saturated vapor pressure of the recovered refrigerant (refrigerant A in the example of FIG. 3) at the detected temperature DT (temperature inside the recovery cylinder 16) as the reference pressure RP, as shown in FIG. 3. The reference pressure acquirer 104 then outputs the reference pressure RP to the determiner 108.

[0075] The determiner 108 receives the reference pressure RP and the detected pressure DP (pressure in the recovery cylinder 16) of the pressure detector 61 on the delivery pipe 56. As shown in FIG. 3, if the detected pressure DP is higher than the reference pressure RP (saturated vapor pressure of the recovered refrigerant), this indicates that non-condensable gases are present in the recovery cylinder 16. Therefore, when the detected pressure DP is higher than the reference pressure RP (hereinafter also referred to as a high-pressure state), the determiner 108 controls the control valve 64 to an open state, and sends the mixed gas 22 in the recovery cylinder 16 to the gas separation module device 68. On the other hand, when the high-pressure state is not present, the determiner 108 keeps the control valve 64 closed. The determiner 108 outputs a removal signal indicating whether or not non-condensable gases are being removed. The removal signal is low when the control valve 64 is closed, and high when the control valve 64 is open.

[0076] The pressure reducing valve controller 106 receives the detected pressure DP (pressure inside the recovery cylinder 16) from the pressure detector 61 on the delivery pipe 56. When the control valve 64 is opened and the mixed gas 22 inside the recovery cylinder 16 is sent to the gas separation module device 68, the pressure reducing valve controller 106 controls the pressure reducing valve 66 based on the detected pressure DP so that the separation membrane 92A of the gas separation module device 68 is not damaged by the pressure inside the recovery cylinder 16. By controlling the pressure reducing valve 66, the pressure inside the pipe downstream of the pressure reducing valve 66 (on the gas separation module device 68 side) is adjusted.

[0077] 4 is a block diagram of the three-way valve controller 80. The three-way valve controller 80 includes a determiner 118. The three-way valve controller 80 is electrically connected to an input unit 100 such as a keypad, and a storage unit 102 such as a flash memory. The memory within the three-way valve controller 80 may be used as the storage unit 102.

[0078] Before refrigerant recovery, a pressure threshold 120 as a transition condition to the vaporization enhancement mode and a duration 122 of the vaporization enhancement mode are input from the input unit 100 and stored in the memory unit 102. The determiner 118 receives the removal signal, the detected pressure DPS (pressure at the inlet 36 of the refrigerant recovery device 14) of the pressure detector 37 of the refrigerant recovery device 14, and the pressure threshold 120 and duration 122 stored in the memory unit 102. Here, the detected pressure DPS indicates the pressure in the refrigerant circuit 30 of the air conditioner 12 in the normal mode.

[0079] When the removal signal is Low, the determiner 118 controls the three-way valve 40 so that the first port 41 and the second port 42 of the three-way valve 40 are in a communication state (normal mode).

[0080] When the removal signal changes from low to high, the determiner 118 determines whether to control the three-way valve 40 to the circulation mode or the vaporization promotion mode based on the comparison result between the detected pressure DPS (pressure of the refrigerant circuit 30) and the pressure threshold 120. Specifically, when the detected pressure DPS is higher than the pressure threshold 120, the determiner 118 estimates that the refrigerant in the refrigerant circuit 30 is unlikely to condense at low temperatures, and controls the three-way valve 40 so that the second port 42 and the third port 43 of the three-way valve 40 are in a communication state (circulation mode). On the other hand, when the detected pressure DPS is equal to or lower than the pressure threshold 120, the determiner 118 estimates that the refrigerant in the refrigerant circuit 30 is likely to condense at low temperatures, and controls the three-way valve 40 so that the first port 41 and the third port 43 of the three-way valve 40 are in a communication state (vaporization promotion mode).

[0081] When duration 122 has elapsed since the transition to the vaporization promotion mode, determiner 118 controls three-way valve 40 to switch from the vaporization promotion mode to the circulation mode.

[0082] The determiner 118 outputs a three-way valve signal indicating whether the mode is currently normal mode, circulation mode, or enhanced vaporization mode.

[0083] 1, the retransmission controller 78 receives as input the three-way valve signal, the detected pressure DPR (pressure in the retransmission pipe 58) of the pressure detector 70 on the retransmission pipe 58A, and the detected pressure DPS (pressure at the inlet 36 of the refrigerant recovery device 14) of the pressure detector 37 of the refrigerant recovery device 14. When the three-way valve signal indicates the circulation mode, the retransmission controller 78 controls the pressure regulator 72 based on the detected pressures DPR and DPS so that the pressure in the retransmission pipe 58A on the downstream side of the pressure regulator 72 (on the gas outlet 74 side) is higher than the pressure at the inlet 36 of the refrigerant recovery device 14. This makes it possible to prevent refrigerant from flowing back from the upstream pipe 52 toward the retransmission pipe 58A. When the three-way valve signal indicates the evaporation promotion mode, the retransmission controller 78 controls the pressure regulator 72 so that the pressure in the retransmission pipe 58A downstream of the pressure regulator 72 (on the gas outlet 74 side) becomes a predetermined pressure that allows gas to be sent into the refrigerant circuit 30 of the air conditioner 12.

[0084] 5 is a block diagram of the pressure controller 97. The pressure controller 97 includes a pressure acquirer 211 and a first pressure controller 212. The pressure controller 97 is electrically connected to a storage unit 102 such as a flash memory. The memory within the pressure controller 97 may be used as the storage unit 102.

[0085] The storage unit 102 stores first pressure information 214. The first pressure information 214 represents the pressure difference P1o between the inside and outside of the separation membrane 92A that is set by the first pressure regulator 98A.

[0086] Before recovering the refrigerant, the pressure acquirer 211 acquires first pressure information 214 from the memory unit 102 and sends it to the first pressure controller 212. The first pressure controller 212 controls the first pressure regulator 98A to set the inside-outside pressure differential P1o of the separation membrane 92A to PA.

[0087] Next, the set pressure PA of the pressure difference between the inside and outside of the separation membrane 92A will be described.

[0088] FIG. 6 is a diagram for explaining the set pressure PA of the pressure difference between the inside and outside of the separation membrane 92A.

[0089] When a mixed gas containing non-condensable gas 26 flows through separation membrane 92A at a rate greater than the permeable flow rate, non-condensable gas 26 may flow not only toward outlet 94A but also toward outlet 96A. To prevent this, it is necessary to adjust the amount of mixed gas 22 flowing into separation membrane 92A.

[0090] Even if a large amount of non-condensable gas 26 flows through separation membrane 92A, non-condensable gas 26 passes through outlet 96A and refrigerant recovery device 14, and is returned to recovery cylinder 16. Non-condensable gas 26 then flows into separator 18 again and undergoes the separation process. By repeatedly flowing non-condensable gas 26 into separator 18, the amount of non-condensable gas 26 can be reduced.

[0091] The set pressure PA of the pressure difference between the inside and outside of the separation membrane 92A is set to a value less than the first threshold value TH1, which allows the second gas component 25 of the air-conditioning refrigerant and the non-condensable gas 26 to easily permeate the separation membrane 92A, while making it difficult for the first gas component 23 of the air-conditioning refrigerant to permeate the separation membrane 92A.

[0092] A method for setting the set pressure PA to a more appropriate value that satisfies the above conditions will be described below.

[0093] 1, the differential pressure between the inside and outside of separation membrane 92A is P1o, the pressure inside separation membrane 92A (i.e., the pressure on the input side of separation membrane 92A) is P1i, and the pressure on the permeate side of separation membrane 92A is P1t. If the pressure on the input side of second gas separation module 68B is P2i, the following equation holds:

[0094] P1t = P2i (1) P1t = P1i - P1o (2) In order to prevent gas from flowing back into separation membrane 92A, the following conditions must be met.

[0095] P1i>P1t=P2i (3) By controlling the pressure reducing valve 66 by the delivery controller 76, the pressure P1i can be controlled so as to satisfy the formula (3).

[0096] Pressure controller 97 controls first pressure regulator 98A to control differential pressure P1o across separation membrane 92A of first gas separation module 68A so as to satisfy equation (4).

[0097] P1o=PA <TH1···(4) Next, the first gas separation module 68A will be described.

[0098] The mixed gas 22 flows into the first gas separation module 68A.

[0099] 1, the first gas separation module 68A includes a cylindrical housing 88A and a cylindrical separation membrane 92A disposed in the housing 88A. The housing 88A includes an inlet 90A for taking in the mixed gas 22, an outlet 96A disposed opposite the inlet 90A for discharging the first gas component 23 of the air-conditioning refrigerant (retransmitted gas refrigerant), and a discharge port 94A for discharging the mixed gas 24 consisting of the non-condensable gas 26 and the second gas component 25 (R32) of the air-conditioning refrigerant.

[0100] The second gas component 25 of the air conditioning refrigerant easily permeates the separation membrane 92A. The non-condensable gas 26 easily permeates the separation membrane 92A. The first gas component 23 of the air conditioning refrigerant does not easily permeate the separation membrane 92A.

[0101] A first end of the separation membrane 92A is connected to an inlet 90A of the housing 88A. A second end of the separation membrane 92A is connected to an outlet 96A of the housing 88A. The mixed gas 22 enters the separation membrane 92A from the inlet 90A and proceeds toward the outlet 96A. During this time, most of the non-condensable gas 26 and the second gas component 25 (R32) of the air-conditioning refrigerant permeate the separation membrane 92A and exit the separation membrane 92A, and are eventually released into the pipe 59 from the discharge port 94A of the housing 88A. Furthermore, the first gas component 23 of the air-conditioning refrigerant (retransmitted gas refrigerant) of the mixed gas 22 that did not permeate the separation membrane 92A is discharged from the outlet 96A of the housing 88A into the retransmission pipe 58A.

[0102] The separation membrane 92A can be, for example, a membrane made of an inorganic material (hereinafter referred to as an inorganic separation membrane) or a membrane made of an organic material (hereinafter referred to as an organic separation membrane). Materials that can be used for the inorganic separation membrane include, for example, ceramic and zeolite. The separation membrane 92A is a membrane that can separate gases with small separation diameters, such as non-condensable gases (N2, O2). The molecular diameter of the separation membrane 92A is approximately 3.8 Å. The separation membrane 92A is polar.

[0103] FIG. 7 is a diagram schematically illustrating the molecular sieving principle of a separation membrane 92A made of an inorganic separation membrane. As shown in FIG. 7, an inorganic molecular membrane has minute pores (fine holes) and basically performs gas separation using the molecular sieving principle. Air (non-condensable gas 26), water 28, and R-32 (second gas component 25), which has a small molecular diameter compared to the pore diameter of the inorganic molecular membrane, pass through the pores and exit the separation membrane. Because the molecular diameter of R-32 is close to the pore diameter of the inorganic separation membrane, the permeation amount is smaller than that of air (non-condensable gas 26).

[0104] Next, the second gas separation module 68B will be described.

[0105] The mixed gas 24 (second mixed gas) that has permeated through the separation membrane 92A flows into the second gas separation module 68B.

[0106] The adsorption section 315 includes a switching valve 320, a first adsorption unit 321, a second adsorption unit 322 arranged in parallel with the first adsorption unit 321, a third adsorption unit 323 arranged downstream of the first adsorption unit 321 and the second adsorption unit 322, and a refrigerant detection sensor 324.

[0107] The switching valve 320 switches whether the mixed gas 24 is sent to the first adsorption unit 321 or the second adsorption unit 322. The switching valve 320 is controlled by the adsorption control unit 330.

[0108] The first adsorption unit 321, the second adsorption unit 322, and the third adsorption unit 323 are loaded with a large number of adsorbents. The larger the surface area of ​​the adsorbent, the higher the adsorption performance of the adsorbent. Small adsorbents may flow into the piping. Therefore, the particle size of the adsorbent is preferably about 0.1 to 10 mm. Examples of adsorbents that can be used include zeolite, activated carbon, silica alumina, activated alumina, and synthetic zeolite.

[0109] FIG. 8 is a diagram showing the details of the first suction unit 321, the second suction unit 322, and the third suction unit 323. As shown in FIG.

[0110] Each of the adsorption units 321, 322, and 322 is loaded with an adsorbent 350. The second gas component 25 of the air-conditioning refrigerant can be adsorbed onto the adsorbent 350.

[0111] FIG. 9 is a diagram showing an example of how a refrigerant is adsorbed by the adsorbent 350. In FIG.

[0112] The diameter of the pores (holes) of the adsorbent 350 is approximately equal to the diameter of the second gas component 25 of the air-conditioning refrigerant.

[0113] The second gas component 25 of the air-conditioning refrigerant is easily adsorbed into the pores (holes) of the adsorbent 350 .

[0114] FIG. 10 is a diagram showing another example of how a refrigerant is adsorbed onto an adsorbent 350. In FIG.

[0115] Smaller holes and cracks exist within the larger particles of the adsorbent 350. The second gas component 25 of the air conditioning refrigerant is likely to be adsorbed into such holes and cracks.

[0116] The amount of adsorbent contained in the second adsorption unit 322 is greater than the amount of adsorbent contained in the first adsorption unit 321, and the second adsorption unit 322 can adsorb more refrigerant than the first adsorption unit 321.

[0117] The adsorption control unit 330 receives input of the first threshold pressure TP and the detected pressure DP of the pressure detector 61 on the delivery pipe 56 (the pressure inside the recovery cylinder 16).

[0118] When the detected pressure DP is equal to or lower than the first threshold pressure TP, the adsorption control unit 330 selects the first adsorption unit 321 as the adsorption unit 315 to be used out of the first adsorption unit 321 and the second adsorption unit 322. This is because, if the amount of non-condensable gas 26 mixed in the refrigerant gas is small, the volume of the mixed gas 22 in the recovery cylinder 16 is small, the detected pressure DP is also small, and it can be assumed that the amount of the second gas component 25 of the air-conditioning refrigerant to be adsorbed is also small. The adsorption control unit 330 switches the outflow destination of the switching valve 320 to the first adsorption unit 321.

[0119] When the detected pressure DP exceeds the first threshold pressure TP, the adsorption control unit 330 selects the second adsorption unit 322 as the adsorption unit 315 to be used out of the first adsorption unit 321 and the second adsorption unit 322. This is because, if the amount of non-condensable gas 26 mixed in the refrigerant gas is large, the volume of the mixed gas 22 in the recovery cylinder 16 is large, the detected pressure DP is also large, and it can be assumed that the amount of the second gas component 25 of the air-conditioning refrigerant to be adsorbed is also large. The adsorption control unit 330 switches the outflow destination of the switching valve 320 to the second adsorption unit 322.

[0120] Mixed gas 24 flows into the adsorption section 315 that is being used out of first adsorption unit 321 and second adsorption unit 322. Most of second gas component 25 of the air-conditioning refrigerant contained in mixed gas 24 is adsorbed by the adsorbent of the adsorption section 315 that is being used, and most of non-condensable gas 26 contained in mixed gas 24 flows out from the adsorption section 315 that is being used.

[0121] The third adsorption unit 323 is disposed downstream of the first adsorption unit 321 and the second adsorption unit 322. When the gas flowing out from the adsorption section 315 in use of the first adsorption unit 321 or the second adsorption unit 322 contains a second gas component 25 of the air-conditioning refrigerant, the adsorbent of the third adsorption unit 323 adsorbs the second gas component 25. The non-condensable gas 26 contained in the gas flowing out from the adsorption section 315 in use flows out from the third adsorption unit 323. The non-condensable gas 26 is released into the atmosphere from the outlet 94B.

[0122] The refrigerant detection sensor 324 detects whether or not a refrigerant is contained in the gas that has flowed out from the adsorption section 315 that is being used, of the first adsorption unit 321 or the second adsorption unit 322. The refrigerant detection sensor 324 is configured, for example, by an infrared sensor or the like.

[0123] When the refrigerant detection sensor 324 detects a refrigerant, the adsorption control unit 330 determines that the adsorption unit 315 in use, of the first adsorption unit 321 or the second adsorption unit 322, has broken down (the adsorption unit 315 is unable to adsorb the refrigerant), and switches the unused adsorption unit 315 to the adsorption unit 315 in use. The adsorption control unit 330 switches the outflow destination of the switching valve 320 to the direction of the adsorption unit 315 that is newly being used.

[0124] Next, a specific refrigerant recovery method using refrigerant recovery system 10 will be described. Fig. 11 is a flowchart showing a specific refrigerant recovery method using refrigerant recovery system 10 according to the first embodiment. In Fig. 11, S100 to S104, S126, and S128 are steps performed by an operator, and the other steps are steps performed automatically by refrigerant recovery system 10.

[0125] In S100, an operator prepares the refrigerant recovery device 14, the recovery cylinder 16, and the separation device 18.

[0126] In S101, an operator turns off the power to the air conditioner 12, and then connects the air conditioner 12, the refrigerant recovery device 14, the recovery cylinder 16, and the separation device 18 to one another as shown in FIG.

[0127] In S102, the operator turns on the power of separation device 18. After that, the operator inputs recovered refrigerant information 110 (see FIG. 2) and pressure threshold value 120 and duration 122 (see FIG. 4) related to the vaporization promotion mode through input unit 100. When separation device 18 is turned on, three-way valve controller 80 controls three-way valve 40 to the normal mode in which first port 41 and second port 42 communicate with each other.

[0128] In S103, the operator drives the refrigerant recovery device 14. This starts the recovery of refrigerant from the air conditioner 12.

[0129] S104 to S122 are automatic controls performed by the refrigerant recovery system 10.

[0130] In S104, the reference pressure acquirer 104 of the delivery controller 76 acquires the saturated vapor pressure of the recovered refrigerant at the temperature DT (temperature inside the recovery cylinder 16) detected by the temperature detector 62 as the reference pressure RP based on the pressure characteristics of the recovered refrigerant indicated by the recovered refrigerant information 110 (see FIG. 3). The determiner 108 of the delivery controller 76 checks whether the detected pressure DP (pressure inside the recovery cylinder) of the pressure detector 61 is higher than the reference pressure RP. Note that, as shown in S104, the determiner 108 may check whether the detected pressure DP (pressure inside the recovery cylinder) is higher than the pressure (RP+α, hereinafter referred to as the reference pressure) obtained by adding a predetermined pressure A to the reference pressure RP.

[0131] If the detected pressure DP is equal to or lower than the reference pressure (RP+α) (S104: NO), the decision unit 108 determines that it is not necessary to remove the non-condensable gas from the recovery cylinder 16, and continues the refrigerant recovery (S105).

[0132] On the other hand, if the detected pressure DP is higher than the reference pressure (RP+α) (S104: YES), the determiner 108 determines that removal of the non-condensable gas in the recovery cylinder 16 is necessary, changes the removal signal from Low to High, and proceeds to S106. Note that by making a determination using the reference pressure in this manner, removal of the non-condensable gas can be started after a certain amount of non-condensable gas has accumulated in the recovery cylinder 16.

[0133] In S106, the three-way valve controller 80 executes the first three-way valve control in response to the removal signal changing from Low to High. Figure 12 is a flowchart showing the first three-way valve control.

[0134] In S200, the determiner 118 of the three-way valve controller 80 checks whether the detected pressure DPS (pressure of the refrigerant circuit 30) of the pressure detector 37 of the refrigerant recovery device 14 is equal to or less than the pressure threshold value 120 stored in the memory unit 102. The pressure threshold value 120 is, for example, about 0.1 MPA.

[0135] If S200 is NO, the determiner 118 estimates that the refrigerant in the refrigerant circuit 30 of the air conditioner 12 is unlikely to condense at low temperatures, controls the three-way valve 40 to a circulation mode in which the second port 42 and the third port 43 are connected (S206), turns off the evaporation promotion flag (S208), and ends the first three-way valve control.

[0136] On the other hand, if S200 is YES, the decision unit 118 estimates that there is a high possibility that the refrigerant in the refrigerant circuit 30 of the air conditioner 12 will condense at a low temperature, controls the three-way valve 40 to an evaporation promotion mode in which the first port 41 and the third port 43 are connected (S202), turns on the evaporation promotion flag (S204), and ends the first three-way valve control.

[0137] Referring again to FIG.

[0138] When the detected pressure DP is equal to or lower than the first threshold pressure TP (S107: YES), the adsorption control unit 330 sets the adsorption unit 315 to be used to the first adsorption unit 321, and switches the outflow destination of the switching valve 320 to the direction of the first adsorption unit 321.

[0139] When the detected pressure DP exceeds the first threshold pressure TP (S107: NO), the adsorption control unit 330 sets the adsorption unit 315 to be used to the second adsorption unit 322, and switches the outflow destination of the switching valve 320 to the direction of the second adsorption unit 322.

[0140] In S110, pressure controller 97 starts adjusting the differential pressure P1o across separation membrane 92A of first gas separation module 68A to set pressure PA by controlling first pressure regulator 98A.

[0141] In S111, the determiner 108 of the delivery controller 76 opens the control valve 64 on the delivery pipe 56. The timing of changing the removal signal from Low to High, the execution timing of S106 (first three-way valve control), and the execution timing of S111 (operation of opening the control valve 64) are almost simultaneous. Before opening the control valve 64, the pressure reducing valve 66 is adjusted by the pressure reducing valve controller 106. By opening the control valve 64, the mixed gas 22 in the recovery cylinder 16 is sent to the gas separation module device 68.

[0142] In the circulation mode, a circulation loop is formed consisting of the separation device 18, the refrigerant recovery device 14, and the recovery cylinder 16, and the mixed gas 22 in the recovery cylinder 16 is repeatedly sent to the gas separation module device 68. The non-condensable gas is released to the atmosphere. The returned gas refrigerant is sent to the front pipe 52 in front of the refrigerant recovery device 14, passes through the refrigerant recovery device 14, and returns to the recovery cylinder 16 in a liquefied state. As a result, the non-condensable gas in the recovery cylinder 16 is gradually removed, and the pressure in the recovery cylinder 16 decreases.

[0143] In the evaporation promotion mode, the re-transmitted gas refrigerant, which is part of the mixed gas 22 in the recovery cylinder 16, is sent into the refrigerant circuit 30 of the air conditioner 12, raising the temperature of the refrigerant in the refrigerant circuit 30. This promotes evaporation of the refrigerant, and when refrigerant recovery is resumed, the refrigerant recovery speed can be improved.

[0144] The re-transmission controller 78 controls the pressure regulator 72 in the circulation mode and the vaporization promotion mode to adjust the pressure in the re-transmission pipe 58A on the downstream side of the pressure regulator 72 (on the gas outlet 74 side).

[0145] In S112, the decision unit 108 of the delivery controller 76 checks whether the detected pressure DP (pressure inside the recovery cylinder 16) of the pressure detector 61 has become equal to or lower than the reference pressure RP. If S112 is NO, the removal of non-condensable gases continues (S113), and the process proceeds to S114.

[0146] If the refrigerant detection sensor 324 detects the refrigerant (S114: YES), the adsorption control unit 330 switches the outflow destination of the switching valve 320.

[0147] In S116, the three-way valve controller 80 executes the second three-way valve control. Fig. 13 is a flowchart showing the second three-way valve control.

[0148] In S300, the determiner 118 of the three-way valve controller 80 checks whether the vaporization promotion flag is on. If S300 is NO (in the case of the circulation mode), the second three-way valve control ends. On the other hand, if S300 is YES (in the case of the vaporization promotion mode), the process proceeds to S302.

[0149] In S302, the decision unit 118 checks whether the duration 122 (see FIG. 4) stored in the memory unit 102 has elapsed since the transition to the vaporization promotion mode. If S302 is NO, the decision unit 118 determines that the vaporization promotion mode needs to be continued and terminates the second three-way valve control. On the other hand, if S302 is YES, the decision unit 118 determines that the vaporization promotion mode may be terminated, controls the three-way valve 40 to the circulation mode in which the second port 42 and the third port 43 communicate with each other (S304), sets the vaporization promotion flag to OFF (S306), and terminates the second three-way valve control.

[0150] Referring again to FIG.

[0151] In S112, if the detected pressure DP (pressure inside the recovery cylinder 16) of the pressure detector 61 becomes lower than the reference pressure RP (S112: YES), the decision unit 108 of the dispatch controller 76 determines that the removal of non-condensable gas inside the recovery cylinder 16 has been completed and proceeds to S117.

[0152] In S117, the determiner 108 of the dispatch controller 76 closes the control valve 64 on the dispatch piping 56 and changes the removal signal from High to Low. In response to the change of the removal signal from High to Low, the determiner 118 of the three-way valve controller 80 controls the three-way valve 40 to the normal mode in which the first port 41 and the second port 42 are connected. The pressure reducing valve controller 106 of the dispatch controller 76 ends control of the pressure reducing valve 66, and the retransmission controller 78 ends control of the pressure regulator 72.

[0153] In S118, pressure controller 97 ends the adjustment of the pressure difference P1o across separation membrane 92A of first gas separation module 68A to set pressure PA by controlling first pressure regulator 98A.

[0154] In S119, the refrigerant recovery device 14 checks whether the detected pressure DPS (pressure in the refrigerant circuit 30) of the pressure detector 37 has become negative. If S119 is NO, the refrigerant recovery device 14 continues refrigerant recovery (S120), and if S119 is YES, the refrigerant recovery device 14 notifies the operator that refrigerant recovery has ended by using a lamp, sound, or the like.

[0155] In S121, the operator stops the refrigerant recovery device 14.

[0156] In S122, the operator turns off the power to the separating device 18.

[0157] Next, the effects of the refrigerant recovery system 10 described above will be described.

[0158] According to the refrigerant recovery system 10, the mixed gas 22 inside the recovery cylinder 16 is sent to the gas separation module device 68, whereby non-condensable gases are separated from the mixed gas 22 and discharged into the atmosphere, and the re-transported gas refrigerant, which has reduced non-condensable gases compared to the mixed gas 22, is discharged from the gas separation module device 68 and sent into the piping between the refrigerant circuit 30 of the air conditioner 12 and the refrigerant recovery device 14. The re-transported gas refrigerant passes through the refrigerant recovery device 14 again and returns to the recovery cylinder 16 in a liquefied state.

[0159] In this way, the non-condensable gas in the recovery cylinder 16 can be reduced while maintaining the connections of the recovery cylinder 16, the refrigerant recovery device 14, and the air conditioning device 12. The increase in the internal pressure of the recovery cylinder 16 can be suppressed, the refrigerant recovery speed into the recovery cylinder 16 can be improved, and the refrigerant charge amount of the recovery cylinder 16 can be increased. The re-transported gas refrigerant is liquefied (in a reduced volume) and returned to the recovery cylinder 16, so the refrigerant charge amount of the recovery cylinder 16 can be further increased. The fact that the recovery cylinder 16, gas separation module device 68, and refrigerant recovery device 14 are arranged in this order is important in order to send the mixed gas 22 in the recovery cylinder 16 to the gas separation module device 68.

[0160] Furthermore, most of the air conditioning refrigerant separated by the gas separation module device 68 is re-transmitted between the refrigerant circuit 30 and the refrigerant recovery device 14. The three-way valve 40 can switch whether this separated air conditioning refrigerant is sent to the refrigerant circuit 30 or to the refrigerant recovery device 14. In the evaporation promotion mode, the air conditioning refrigerant separated by the gas separation module device 68 is sent to the refrigerant circuit 30, thereby raising the temperature of the refrigerant in the refrigerant circuit 30. This promotes the evaporation of the refrigerant, and when refrigerant recovery is resumed, the refrigerant recovery speed can be improved. In the circulation mode, the air conditioning refrigerant separated by the gas separation module device 68 is sent to the refrigerant recovery device 14, thereby restarting the recovery process of the air conditioning refrigerant separated by the gas separation module device 68.

[0161] The gas separation module device 68 is attached to the top of the recovery cylinder 16. Therefore, liquid components such as liquid refrigerant and mixed water remain at the bottom of the recovery cylinder 16, preventing the liquid refrigerant and a large amount of water from mixing with the separation membrane 92A and adsorbent 350 of the gas separation module device 68. This prevents a decrease in the gas separation effect of the separation membrane 92A and adsorbent 350. The air-conditioning refrigerant is adiabatically compressed and liquefied in the refrigerant recovery device 14 before being filled into the recovery cylinder 16. Therefore, only an amount of refrigerant equivalent to the saturated vapor pressure is vaporized in the volume of the space within the recovery cylinder 16, and most of the refrigerant is liquefied within the recovery cylinder 16. Because the proportion of vaporized refrigerant (gas refrigerant) is low, the amount of gas refrigerant sent to the gas separation module device 68 can be reduced, thereby reducing the risk of refrigerant leakage from the gas separation module device 68.

[0162] A circulation loop is formed between the separation device 18, the refrigerant recovery device 14, and the recovery cylinder 16, and the gas separation module device 68 repeatedly separates non-condensable gases, thereby effectively removing the non-condensable gases from the recovery cylinder 16.

[0163] Only when non-condensable gas is present in the recovery cylinder 16 is the control valve 64 opened and the non-condensable gas removed by the gas separation module device 68, thereby avoiding unnecessary use of the gas separation module device 68 when there is no or little non-condensable gas in the recovery cylinder 16.

[0164] Since the pressure characteristics 112 of a plurality of types of refrigerants are stored in the memory unit 102 of the separation device 18, a common separation device 18 can be used to recover different types of refrigerants.

[0165] When the gas separation module device 68 is used (when the control valve 64 is open) and the pressure in the refrigerant circuit 30 is higher than a predetermined pressure, the re-sent gas refrigerant can be accurately sent from the re-sent pipe 58A to the refrigerant recovery device 14. Furthermore, when the gas separation module device 68 is used (when the control valve 64 is open) and the pressure in the refrigerant circuit 30 is equal to or lower than a predetermined pressure, the re-sent gas refrigerant (having a higher temperature than the refrigerant in the refrigerant circuit 30) which is part of the gas refrigerant in the recovery cylinder 16 containing refrigerant that has been adiabatically compressed in the refrigerant recovery device 14 and has a higher temperature than when it flowed into the refrigerant recovery device 14, can be sent to the refrigerant circuit 30. This increases the temperature of the refrigerant in the refrigerant circuit 30, promoting gasification of the refrigerant and improving the refrigerant recovery speed when refrigerant recovery is resumed.

[0166] Furthermore, when the air conditioning refrigerant contains R32, one gas separation module cannot separate non-condensable gas 26 from refrigerant gases 23 and 25. In this embodiment, by using two gas separation modules 68A and 68B, only non-condensable gas 26 can be released into the atmosphere.

[0167] In this embodiment, the second gas separation module 68B includes an adsorption section 315 containing an adsorbent 350 that easily adsorbs the second gas component 25 of the air-conditioning refrigerant. By using the adsorbent 350, it is possible to separate the mixed gas 24 that could not be separated by the separation membrane 92A of the first gas separation module 68A. Furthermore, by using an adsorbent as the second gas separation module 68B instead of a separation membrane different from the separation membrane 92A of the first gas separation module 68A, it becomes easier to discard and recover the gas that is not released into the atmosphere.

[0168] This embodiment is equipped with a first adsorption unit 321 and a second adsorption unit 322, each loaded with a different amount of adsorbent, and by using an adsorption unit appropriate for the adsorption amount, it is possible to recover and discard only the adsorbent that has broken through. This is particularly effective because the adsorbent that has adsorbed R-32 is irreversible and must be discarded and replaced.

[0169] Furthermore, according to this embodiment, even if the first adsorption unit 321 or the second adsorption unit 322, which are the main adsorption units, break through adsorption, the existence of the third adsorption unit 323 prevents refrigerant from remaining in the gas released to the atmosphere and leaking into the atmosphere.

[0170] Furthermore, any or all of the first adsorption unit 321 to the third adsorption unit 323 may be detachable. By making the adsorption units detachable, the adsorbent can be quickly collected, discarded, and replaced after the adsorption unit breaks through adsorption.

[0171] By arranging the refrigerant detection sensor 324 downstream of the first adsorption unit 321 and the second adsorption unit 322, even if the adsorption unit in use breaks through adsorption, the refrigerant detection sensor 324 can detect the refrigerant and quickly switch the adsorption unit to be used. Furthermore, because the third adsorption unit 323 is located downstream of the refrigerant detection sensor 324, even if the refrigerant detection sensor 324 detects refrigerant, it is adsorbed by the third adsorption unit 323, and no refrigerant remains in the gas released to the atmosphere.

[0172] Embodiment 2 14 is a schematic diagram of a refrigerant recovery system 10A according to embodiment 2. Refrigerant recovery system 10A according to embodiment 2 differs from refrigerant recovery system 10 according to embodiment 1 in that refrigerant recovery system 10A according to embodiment 2 further includes a second pressure regulator 98B and a pressure controller 97A different from that according to embodiment 1.

[0173] The second pressure regulator 98B included in the second gas separation module 68B adjusts the pressure during adsorption in the adsorption section 315 of the second gas separation module 68B. The second pressure regulator 98B is disposed downstream of the second gas separation module 68B and includes a second back pressure valve that adjusts the pressure on the primary side of the second pressure regulator 98B.

[0174] The pressure controller 97A controls the second pressure regulator 98B to adjust the pressure of the adsorption unit 315 during adsorption.

[0175] FIG. 15 is a diagram showing the configuration of a pressure controller 97A according to the second embodiment.

[0176] Pressure controller 97A of the second embodiment differs from pressure controller 97 of the first embodiment in that it further includes second pressure controller 213 and pressure acquirer 211A different from that of the first embodiment.

[0177] The pressure controller 97A is electrically connected to a storage unit 102A such as a flash memory. A memory within the pressure controller 97A may be used as the storage unit 102A.

[0178] The memory unit 102A stores first pressure information 214 and second pressure information 215. The first pressure information 214 represents the pressure difference PA between the inside and outside of the separation membrane 92A, which is set by the first pressure regulator 98A. The second pressure information 215 represents the pressure PB during adsorption of the adsorption unit 315, which is set by the second pressure regulator 98B.

[0179] Before recovering the refrigerant, the pressure acquirer 211A acquires first pressure information 214 from the memory unit 102A and sends it to the first pressure controller 212. The first pressure controller 212 controls the first pressure regulator 98A to set the inside-outside pressure differential P1o of the separation membrane 92A to PA.

[0180] Before recovering the refrigerant, the pressure acquirer 211A acquires second pressure information 215 from the memory unit 102A and sends it to the second pressure controller 213. The second pressure controller 213 controls the second pressure regulator 98B to set the pressure during adsorption of the adsorption unit 315 to PB.

[0181] When the adsorption pressure PB of the adsorption section 315 is high, the refrigerant is more easily adsorbed by the adsorbent 350, and the amount of refrigerant adsorbed per unit weight of the adsorbent 350 increases. Therefore, the amount of adsorbent 350 used can be reduced.

[0182] Therefore, the adsorption control unit 330 may switch the outflow destination of the switching valve 320 to the first adsorption unit 321 loaded with a small amount of adsorbent 350 when the adsorption pressure PB of the adsorption unit 315 is equal to or greater than a reference value, and may switch the outflow destination of the switching valve 320 to the second adsorption unit 322 loaded with a large amount of adsorbent 350 when the adsorption pressure PB of the adsorption unit 315 is less than the reference value.

[0183] Embodiment 3 16 is a schematic diagram of a refrigerant recovery system 10B according to embodiment 3. Refrigerant recovery system 10B according to embodiment 3 differs from refrigerant recovery system 10A according to embodiment 2 in that second gas separation module 68B of refrigerant recovery system 10B according to embodiment 3 further includes filters FL1 to FL6.

[0184] The first suction unit 321 is connected to the first pipe and the second pipe.

[0185] Filter FL1 is disposed between a first end face of the adsorbent loaded in first adsorption unit 321 and an end face of the first pipe. Filter FL2 is disposed between a second end face of the adsorbent loaded in first adsorption unit 321 and an end face of the second pipe. Filters FL1 and FL2 are disposed to prevent fine particles (such as pieces of adsorbent) generated in first adsorption unit 321 from flowing out into the pipe.

[0186] The second adsorption unit 322 is connected to the third pipe and the fourth pipe.

[0187] Filter FL3 is disposed between a first end face of the adsorbent attached to second adsorption unit 322 and an end face of the third pipe. Filter FL4 is disposed between a second end face of the adsorbent attached to second adsorption unit 322 and an end face of the fourth pipe. Filters FL3 and FL4 are disposed to prevent fine particles (such as pieces of adsorbent) generated in second adsorption unit 322 from flowing out into the pipes.

[0188] The third adsorption unit 323 is connected to the fifth pipe and the sixth pipe.

[0189] Filter FL5 is disposed between a first end face of the adsorbent attached to the third adsorption unit 323 and an end face of the fifth pipe. Filter FL6 is disposed between a second end face of the adsorbent attached to the third adsorption unit 323 and an end face of the sixth pipe. Filters FL5 and FL6 are disposed to prevent fine particles (such as pieces of adsorbent) generated in the third adsorption unit 323 from flowing out into the pipes.

[0190] The filters FL1 to FL6 are made of metal or resin. The filters FL1 to FL6 have a mesh shape with a smaller mesh size than the adsorbent 350. The size of the filters FL1 to FL6 is larger than the diameter of the pipes they come into contact with. Filter FL1 covers the end face of the first pipe. Filter FL2 covers the end face of the second pipe. Filter FL3 covers the end face of the third pipe. Filter FL4 covers the end face of the fourth pipe. Filter FL5 covers the end face of the fifth pipe. Filter FL6 covers the end face of the sixth pipe.

[0191] 17 is a diagram showing an example of the arrangement of filters FL1 and FL2. The same applies to filters FL3 to FL6. The flow path narrows at both ends of the first adsorption unit 321. Filter FL1 is arranged between the end face of pipe P1 and the first end face of the adsorbent of the first adsorption unit 321. Filter FL2 is arranged between the end face of pipe P2 and the second end face of the adsorbent of the first adsorption unit 321.

[0192] Instead of arranging the filters FL1 to FL4, filters may be arranged before the switching valve 320 and before the refrigerant detection sensor 324, respectively.

[0193] Embodiment 4 FIG. 18 is a schematic diagram of a refrigerant recovery system 10C according to the fourth embodiment.

[0194] The refrigerant recovery system 10C of the fourth embodiment differs from the refrigerant recovery system 10 of the first embodiment in that the refrigerant recovery system 10C of the fourth embodiment includes a directional switching valve 251, a bypass pipe 252, a sensor 253, and a bypass controller 254.

[0195] The sensor 253 detects whether the air-conditioning refrigerant contains R32, and outputs a detection signal to the bypass controller 254. The sensor 253 may be disposed in the connection pipe 50.

[0196] The directional switching valve 251 is connected to a pipe 59. The mixed gas 24 flows into the directional switching valve 251 from the pipe 59.

[0197] The directional switching valve 251 can switch the outflow destination of the inflowing mixed gas 24. The first outflow destination is the branch pipe 49. A first end of the branch pipe 49 is connected to the directional switching valve 251. A second end of the branch pipe 49 is connected to the inlet 90B of the second gas separation module 68B.

[0198] The second outflow destination is the bypass pipe 252. A first end of the bypass pipe 252 is connected to the directional switching valve 251. A second end of the bypass pipe 252 is connected to the discharge port 94B.

[0199] The bypass controller 254 switches the outflow destination of the directional switching valve 251 depending on whether the air-conditioning refrigerant contains R32. When the air-conditioning refrigerant contains R32, the bypass controller 254 switches the outflow destination of the directional switching valve 251 to the branch pipe 49, thereby causing the gas 24 that has permeated the separation membrane 92A to flow into the second gas separation module 68B. When the air-conditioning refrigerant does not contain R32, the bypass controller 254 switches the outflow destination of the directional switching valve 251 to the bypass pipe 252, thereby causing the gas 24 that has permeated the separation membrane 92A to be released into the atmosphere without flowing into the second gas separation module 68B.

[0200] FIG. 19 is a flowchart showing a specific refrigerant recovery method using the refrigerant recovery system 10C according to the fourth embodiment.

[0201] The flowchart of the fourth embodiment differs from the flowchart of the first embodiment in that the flowchart of the fourth embodiment includes steps S201 to S203 between S106 and S107.

[0202] In S201, if the sensor 253 detects that the air conditioning refrigerant contains R32, the process proceeds to S202. If the sensor 253 detects that the air conditioning refrigerant does not contain R32, the process proceeds to S203.

[0203] In S202, bypass controller 254 switches the outflow destination of directional switching valve 251 to branch pipe 49. As a result, gas 24 that has permeated separation membrane 92A flows into second gas separation module 68B.

[0204] In S203, bypass controller 254 switches the outflow destination of directional switching valve 251 to bypass pipe 252. As a result, gas 24 that has permeated separation membrane 92A is released to the atmosphere without flowing into second gas separation module 68B.

[0205] Variant. The present disclosure is not limited to the above-described embodiments, and also includes, for example, the following modified examples.

[0206] (1) R32 In the above embodiment, R32 is used as an example of the refrigerant that permeates the separation membrane and is adsorbed by the adsorbent, but the present invention is not limited to this.

[0207] (2) Gas separation module In the above embodiment, a two-stage gas separation module is used, but an N-stage (N≧2) gas separation module may also be used.

[0208] (3) Adsorption units arranged in parallel In the above embodiment, the number of adsorption units arranged in parallel in the upstream stage is two, but it may be three or more. By providing more adsorption units, it is possible to use an adsorption unit that exactly matches the required amount of adsorbent, and therefore the amount of adsorbent used and discarded can be minimized.

[0209] (4) Sensor In the fourth embodiment, sensor 253 detects whether the air-conditioning refrigerant contains R32, but the present invention is not limited to this. Recovered refrigerant information indicating the type of refrigerant contained in the air-conditioning refrigerant may be input from an input unit and stored in a storage unit, and the bypass control unit may determine whether the air-conditioning refrigerant contains R32 based on the recovered refrigerant information.

[0210] (5) Gas separation module device In the above embodiment, the gas separation module apparatus includes the first gas separation module 68A and the second gas separation module 68B. However, the apparatus may include only the second gas separation module 68B. In this case, the mechanism for re-transmitting the gas components of the air-conditioning refrigerant can be omitted. In the second gas separation module 68B, the adsorbent 350 adsorbs all of the gas components of the air-conditioning refrigerant in the mixed gas 22, and the outlet 94B releases the non-condensable gases in the mixed gas 22 to the atmosphere.

[0211] (6) Adsorbed refrigerant The refrigerant adsorbed by the adsorbent 350 may be recovered in the recovery tank 20 by manual or mechanical means.

[0212] [Note] The above-described embodiment is a specific example of the following additional notes.

[0213] (Appendix 1) A refrigerant recovery system that recovers air conditioning refrigerant from a refrigerant circuit of a refrigeration and air conditioning equipment, a refrigerant recovery device that compresses and condenses the air-conditioning refrigerant to generate a compressed and condensed refrigerant; a recovery cylinder for recovering the compressed and condensed refrigerant produced by the refrigerant recovery device; a first gas separation module including a separation membrane that separates a first mixed gas consisting of a gas component of the air-conditioning refrigerant and a non-condensable gas contained inside the recovery cylinder from which the compressed condensed refrigerant has been recovered, into the first gas component of the air-conditioning refrigerant and a second mixed gas consisting of a second gas component of the air-conditioning refrigerant and the non-condensable gas; a second gas separation module including an adsorption section containing an adsorbent that adsorbs the second gas component of the air-conditioning refrigerant in the second mixed gas separated by the first gas separation module; A refrigerant recovery system comprising: a re-transmission pipe for re-transmitting the first gas component of the air-conditioning refrigerant separated by the first gas separation module device between the refrigerant circuit and the refrigerant recovery device.

[0214] (Appendix 2) 2. A refrigerant recovery system as described in Appendix 1, wherein the second gas separation module includes an outlet for releasing the non-condensable gas of the second mixed gas that has not been adsorbed by the adsorption section into the atmosphere.

[0215] (Appendix 3) The adsorption unit is a first adsorption unit loaded with the adsorbent; a second adsorption unit arranged in parallel with the first adsorption unit and loaded with the adsorbent; 3. The refrigerant recovery system according to claim 1, further comprising: a switching valve that switches the destination of the second mixed gas to either the first adsorption unit or the second adsorption unit.

[0216] (Appendix 4) the amount of adsorbent loaded in the first adsorption unit is less than the amount of adsorbent loaded in the second adsorption unit; 4. The refrigerant recovery system of claim 3, further comprising an adsorption control unit that switches the switching valve to direct the second mixed gas to the first adsorption unit when the pressure in the recovery cylinder is equal to or lower than a first threshold pressure, and that switches the switching valve to direct the second mixed gas to the second adsorption unit when the pressure in the recovery cylinder exceeds the first threshold pressure.

[0217] (Appendix 5) the first adsorption unit is connected to a first pipe and a second pipe; a first filter disposed between a first end surface of the adsorbent and an end surface of the first pipe; a second filter disposed between a second end surface of the adsorbent and an end surface of the second pipe; the second adsorption unit is connected to a third pipe and a fourth pipe; a third filter disposed between a first end surface of the adsorbent and an end surface of the third pipe; 5. The refrigerant recovery system of claim 3 or 4, further comprising: a fourth filter disposed between a second end face of the loaded adsorbent and an end face of the fourth piping.

[0218] (Appendix 6) the first filter covers the end surface of the first pipe; the second filter covers the end surface of the second pipe; the third filter covers the end surface of the third pipe; 6. The refrigerant recovery system according to claim 5, wherein the fourth filter covers the end surface of the fourth pipe.

[0219] (Appendix 7) The adsorption unit further comprises: A refrigerant recovery system as described in any one of appendix 3 to 6, including a third adsorption unit arranged downstream of the first adsorption unit and the second adsorption unit and loaded with the adsorbent.

[0220] (Appendix 8) The adsorption unit further comprises: a refrigerant detection sensor disposed downstream of the first adsorption unit and the second adsorption unit, the refrigerant detection sensor detecting the air-conditioning refrigerant; An adsorption control unit that switches the outflow destination of the second mixed gas in the switching valve when the refrigerant detection sensor detects the air-conditioning refrigerant.

[0221] (Appendix 9) the third adsorption unit is connected to a fifth pipe and a sixth pipe; a fifth filter disposed between a first end surface of the adsorbent and an end surface of the fifth pipe; 9. The refrigerant recovery system of claim 7 or 8, further comprising: a sixth filter disposed between a second end face of the loaded adsorbent and an end face of the sixth pipe.

[0222] (Appendix 10) the fifth filter covers the end surface of the fifth pipe, 10. The refrigerant recovery system of claim 9, wherein the sixth filter covers the end surface of the sixth pipe.

[0223] (Appendix 11) The refrigerant recovery system includes: a first pressure regulator for adjusting the pressure difference between the inside and outside of the separation membrane; 11. The refrigerant recovery system according to any one of claims 1 to 10, further comprising: a first pressure controller that controls the first pressure regulator to adjust the pressure difference between inside and outside the separation membrane.

[0224] (Appendix 12) 12. The refrigerant recovery system according to any one of claims 1 to 11, wherein the pressure on the input side of the separation membrane is lower than the pressure on the permeation side of the separation membrane.

[0225] (Appendix 13) The refrigerant recovery system includes: a second pressure regulator for adjusting the pressure of the adsorption unit during adsorption; 13. The refrigerant recovery system according to any one of claims 1 to 12, further comprising: a second pressure controller that controls the second pressure regulator to adjust the pressure of the adsorption section during adsorption.

[0226] (Appendix 14) 14. The refrigerant recovery system according to any one of claims 1 to 13, wherein the second gas component of the air-conditioning refrigerant is R-32.

[0227] (Appendix 15) The refrigerant recovery system includes: a directional switching valve into which the gas that has permeated the separation membrane flows and which can switch the destination of the gas that flows out; A refrigerant recovery system as described in any one of appendixes 1 to 14, further comprising a bypass controller that controls the directional switching valve when the air conditioning refrigerant contains R-32, thereby allowing the gas that has permeated the separation membrane to flow into the second gas separation module, and that controls the directional switching valve when the air conditioning refrigerant does not contain R-32, thereby preventing the gas that has permeated the separation membrane from flowing into the second gas separation module.

[0228] (Appendix 16) a three-way valve disposed between the refrigerant circuit and the refrigerant recovery device; a three-way valve control unit that controls the three-way valve, the three-way valve includes first, second and third ports, the first port of the three-way valve being connected to the refrigerant circuit, the second port of the three-way valve being connected to the refrigerant recovery device, and the third port of the three-way valve being connected to the re-transmission pipe; The refrigerant recovery system according to any one of appendixes 1 to 15, wherein the three-way valve control unit controls the three-way valve in a first mode so that the first port and the third port of the three-way valve are in a communicating state, and controls the three-way valve in a second mode so that the second port and the third port of the three-way valve are in a communicating state.

[0229] (Appendix 17) Further provided is a pressure detector for detecting the pressure in the recovery cylinder, The three-way valve control unit controls the three-way valve so that the first port and the third port of the three-way valve are in a communicating state when the pressure in the recovery cylinder is equal to or lower than a second threshold pressure, and controls the three-way valve so that the second port and the third port of the three-way valve are in a communicating state when the pressure in the recovery cylinder exceeds the second threshold pressure.

[0230] (Appendix 18) A refrigerant recovery system that recovers air conditioning refrigerant from a refrigerant circuit of a refrigeration and air conditioning equipment, a refrigerant recovery device that compresses and condenses the air-conditioning refrigerant to generate a compressed and condensed refrigerant; a recovery cylinder for recovering the compressed and condensed refrigerant produced by the refrigerant recovery device; a gas separation module including an adsorption section containing an adsorbent that adsorbs the gas components of the air-conditioning refrigerant in a mixed gas consisting of gas components of the air-conditioning refrigerant and non-condensable gases contained inside the recovery cylinder from which the compressed condensed refrigerant was recovered.

[0231] (Appendix 19) A refrigerant recovery method for recovering air conditioning refrigerant from a refrigeration / air conditioning equipment refrigerant circuit, comprising: a refrigerant recovery device compressing and condensing the air conditioning refrigerant to generate a compressed and condensed refrigerant; a recovery cylinder recovering the compressed condensed refrigerant produced by the refrigerant recovery device; a step in which a separation membrane of a first gas separation module separates a first mixed gas consisting of a gas component of the air-conditioning refrigerant and a non-condensable gas contained inside the recovery cylinder from which the compressed condensed refrigerant has been recovered, into a first gas component of the air-conditioning refrigerant and a second mixed gas consisting of a second gas component of the air-conditioning refrigerant and the non-condensable gas; a step in which a second gas separation module adsorbs the second gas component of the air-conditioning refrigerant in an adsorption unit of the second mixed gas separated by the separation membrane of the first gas separation module; A refrigerant recovery method comprising a step of retransmitting the first gas component of the air conditioning refrigerant separated by the separation membrane of the first gas separation module between the refrigerant circuit and the refrigerant recovery device using a retransmission pipe.

[0232] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0233] 10, 10A, 10B, 10C refrigerant recovery system, 12 air conditioning unit, 14 refrigerant recovery unit, 16 recovery cylinder, 18 separation unit, 20 recovery tank, 22, 24 mixed gas, 23 first gas component of air conditioning refrigerant, 25 second gas component of air conditioning refrigerant, 26 non-condensable gas, 28 water, 29 other gas components, 30 refrigerant circuit, 32 accumulator, 34 service port, 36, 90A, 90B inlet, 37, 61, 70 pressure detector, 38, 96A outlet, 40 three-way valve, 41 first port, 42 second port, 43 third port, 46 liquid inlet / outlet, 48 gas inlet / outlet, 49 branch pipe, 50 connecting pipe, 52 front pipe, 54 rear pipe, 56 delivery pipe, 58A return pipe, 59, P1, P2 pipe, 60 Gas inlet, 62 temperature detector, 64 control valve, 66 pressure reducing valve, 68 gas separation module device, 68A first gas separation module, 68B second gas separation module, 72 pressure regulator, 74 gas outlet, 76 delivery controller, 78 retransmission controller, 80 three-way valve controller, 88A housing, 92A separation membrane, 94, 94A, 94B discharge port, 97, 97A pressure controller, 98A first pressure regulator, 98B second pressure regulator, 99A first check valve, 100 input unit, 102, 102A memory unit, 104 reference pressure acquirer, 106 pressure reducing valve controller, 108, 118 judger, 110 recovered refrigerant information, 112 pressure characteristics, 120 pressure threshold, 122 duration, 211, 211A pressure acquirer, 212 First pressure controller, 213 Second pressure controller, 214 First pressure information, 215 Second pressure information, 251 Directional switching valve, 252 Bypass piping, 253 Sensor, 254 Bypass controller, 315 Adsorption section, 320 Switching valve, 321 First adsorption unit, 322 Second adsorption unit, 323 Third adsorption unit, 324 Refrigerant detection sensor, 330 Adsorption control section, 350 Adsorbent, FL1, FL2, FL3, FL4, FL5, FL6 Filters.

Claims

1. A refrigerant recovery system that recovers air conditioning refrigerant from a refrigerant circuit of a refrigeration and air conditioning equipment, a refrigerant recovery device that compresses and condenses the air-conditioning refrigerant to generate a compressed and condensed refrigerant; a recovery cylinder for recovering the compressed and condensed refrigerant produced by the refrigerant recovery device; a first gas separation module including a separation membrane that separates a first mixed gas consisting of a gas component of the air-conditioning refrigerant and a non-condensable gas contained inside the recovery cylinder from which the compressed condensed refrigerant has been recovered, into a first gas component of the air-conditioning refrigerant and a second mixed gas consisting of a second gas component of the air-conditioning refrigerant and the non-condensable gas; a second gas separation module including an adsorption section containing an adsorbent that adsorbs the second gas component of the air-conditioning refrigerant in the second mixed gas separated by the first gas separation module; a re-transmission pipe for re-transmitting the first gas component of the air-conditioning refrigerant separated by the first gas separation module between the refrigerant circuit and the refrigerant recovery device, The adsorption unit is a first adsorption unit loaded with the adsorbent; a second adsorption unit arranged in parallel with the first adsorption unit and loaded with the adsorbent; a switching valve that switches the destination of the second mixed gas to the first adsorption unit or the second adsorption unit, the amount of the adsorbent loaded in the first adsorption unit is less than the amount of the adsorbent loaded in the second adsorption unit; The refrigerant recovery system includes: an adsorption control unit that switches the switching valve to direct the second mixed gas to the first adsorption unit when the pressure in the recovery cylinder is equal to or lower than a first threshold pressure, and that switches the switching valve to direct the second mixed gas to the second adsorption unit when the pressure in the recovery cylinder exceeds the first threshold pressure.

2. The refrigerant recovery system according to claim 1 , wherein the second gas separation module includes a discharge port for discharging the non-condensable gas of the second mixed gas that has not been adsorbed by the adsorption section into the atmosphere.

3. the first adsorption unit is connected to a first pipe and a second pipe; a first filter disposed between a first end surface of the adsorbent and an end surface of the first pipe; a second filter disposed between a second end surface of the adsorbent and an end surface of the second pipe; the second adsorption unit is connected to a third pipe and a fourth pipe; a third filter disposed between a first end surface of the adsorbent and an end surface of the third pipe; 2. The refrigerant recovery system of claim 1, further comprising: a fourth filter disposed between a second end face of the loaded adsorbent and an end face of the fourth pipe.

4. the first filter covers the end surface of the first pipe; the second filter covers the end surface of the second pipe; the third filter covers the end surface of the third pipe; The refrigerant recovery system according to claim 3 , wherein the fourth filter covers the end surface of the fourth pipe.

5. The adsorption unit further comprises:

2. The refrigerant recovery system according to claim 1, further comprising a third adsorption unit disposed downstream of said first adsorption unit and said second adsorption unit and loaded with said adsorbent.

6. The adsorption unit further comprises: a refrigerant detection sensor disposed downstream of the first adsorption unit and the second adsorption unit, the refrigerant detection sensor detecting the air-conditioning refrigerant; 2. The refrigerant recovery system according to claim 1, further comprising: an adsorption control unit that switches the outlet of the second mixed gas in the switching valve when the refrigerant detection sensor detects the air-conditioning refrigerant.

7. the third adsorption unit is connected to a fifth pipe and a sixth pipe; a fifth filter disposed between a first end surface of the adsorbent and an end surface of the fifth pipe; 6. The refrigerant recovery system of claim 5, further comprising a sixth filter disposed between the second end of the loaded adsorbent and the end of the sixth pipe.

8. the fifth filter covers the end surface of the fifth pipe, The refrigerant recovery system according to claim 7 , wherein the sixth filter covers the end surface of the sixth pipe.

9. The refrigerant recovery system includes: a first pressure regulator for adjusting the pressure difference between the inside and outside of the separation membrane; The refrigerant recovery system according to claim 1 , further comprising: a first pressure controller that controls the first pressure regulator to adjust the pressure difference between inside and outside the separation membrane.

10. 2. The refrigerant recovery system of claim 1, wherein the pressure on the input side of the separation membrane is greater than the pressure on the permeate side of the separation membrane.

11. The refrigerant recovery system includes: a second pressure regulator for adjusting the pressure of the adsorption unit during adsorption; The refrigerant recovery system according to claim 1 , further comprising: a second pressure controller that controls the second pressure regulator to adjust the pressure of the adsorption section during adsorption.

12. 2. The refrigerant recovery system of claim 1, wherein the second gas component of the air conditioning refrigerant is R-32.

13. The refrigerant recovery system includes: a directional switching valve into which the gas that has permeated the separation membrane flows and which can switch the destination of the gas that flows out; 2. The refrigerant recovery system of claim 1, further comprising a bypass controller that controls the directional switching valve when the air-conditioning refrigerant contains R-32, thereby allowing the gas that has permeated the separation membrane to flow into the second gas separation module, and that controls the directional switching valve when the air-conditioning refrigerant does not contain R-32, thereby preventing the gas that has permeated the separation membrane from flowing into the second gas separation module.

14. a three-way valve disposed between the refrigerant circuit and the refrigerant recovery device; a three-way valve control unit that controls the three-way valve, the three-way valve includes first, second and third ports, the first port of the three-way valve being connected to the refrigerant circuit, the second port of the three-way valve being connected to the refrigerant recovery device, and the third port of the three-way valve being connected to the re-transmission pipe; 2. The refrigerant recovery system according to claim 1, wherein the three-way valve control unit controls the three-way valve in a first mode so that the first port and the third port of the three-way valve are in a communication state, and controls the three-way valve in a second mode so that the second port and the third port of the three-way valve are in a communication state.

15. Further provided is a pressure detector for detecting the pressure in the recovery cylinder, 15. The refrigerant recovery system of claim 14, wherein the three-way valve control unit controls the three-way valve so that the first port and the third port of the three-way valve are in a communicating state when the pressure in the recovery cylinder is equal to or lower than a second threshold pressure, and controls the three-way valve so that the second port and the third port of the three-way valve are in a communicating state when the pressure in the recovery cylinder exceeds the second threshold pressure.

16. A refrigerant recovery system that recovers air conditioning refrigerant from a refrigerant circuit of a refrigeration and air conditioning equipment, a refrigerant recovery device that compresses and condenses the air-conditioning refrigerant to generate a compressed and condensed refrigerant; a recovery cylinder for recovering the compressed and condensed refrigerant produced by the refrigerant recovery device; a gas separation module including an adsorption section containing an adsorbent that adsorbs the gas components of the air-conditioning refrigerant in a mixed gas consisting of gas components of the air-conditioning refrigerant and non-condensable gases contained inside the recovery cylinder from which the compressed condensed refrigerant was recovered.

17. A refrigerant recovery method for recovering air conditioning refrigerant from a refrigeration / air conditioning equipment refrigerant circuit, comprising: a refrigerant recovery device compressing and condensing the air conditioning refrigerant to generate a compressed and condensed refrigerant; a recovery cylinder recovering the compressed condensed refrigerant produced by the refrigerant recovery device; a step in which a separation membrane of a first gas separation module separates a first mixed gas consisting of a gas component of the air-conditioning refrigerant and a non-condensable gas contained inside the recovery cylinder from which the compressed and condensed refrigerant has been recovered, into a first gas component of the air-conditioning refrigerant and a second mixed gas consisting of a second gas component of the air-conditioning refrigerant and the non-condensable gas; a step in which a second gas separation module adsorbs, in an adsorption unit, the second gas component of the air-conditioning refrigerant from the second mixed gas separated by the separation membrane of the first gas separation module; a re-transmission piping for re-transmitting the first gas component of the air-conditioning refrigerant separated by the separation membrane of the first gas separation module between the refrigerant circuit and the refrigerant recovery device.

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