WO2023042269A1

WO2023042269A1 - Refrigerant recovery system and refrigerant recovery method

Info

Publication number: WO2023042269A1
Application number: PCT/JP2021/033774
Authority: WO
Inventors: 善宏堂岸; 勝也谷口; 正樹近藤; 亜加音野村; 幸治太田
Original assignee: 三菱電機ビルソリューションズ株式会社; 三菱電機株式会社
Priority date: 2021-09-14
Filing date: 2021-09-14
Publication date: 2023-03-23
Also published as: CN117545972A; JP7106030B1; JPWO2023042269A1

Abstract

A gas separation module device (68) includes a first gas separation module (68A) and a second gas separation module (68B) that separate an air-conditioning refrigerant as a gas component from the interior of a recovery cylinder (16) that has recovered the compressed and condensed refrigerant. The second gas separation module (68B) is disposed at a later stage than the first gas separation module (68A). The first gas separation module (68A) includes a first separation membrane (92A), the second gas separation module (68B) includes a second separation membrane (92B), and gas that has permeated the first separation membrane (92A) can flow into the second separation membrane (92B).

Description

Refrigerant recovery system and refrigerant recovery method

The present disclosure relates to refrigerant recovery systems and refrigerant recovery methods.

Refrigerating and air-conditioning equipment (refrigerant-using equipment) such as refrigerators and air conditioners has an air-conditioning compressor that compresses gaseous refrigerant, which is vaporized, into a high-temperature and high-pressure state, and an air-conditioning compressor that compresses gaseous refrigerant that conveys thermal energy. An air-conditioning condenser that liquefies the gas refrigerant that has been raised to high temperature and pressure by the air-conditioning compressor by cooling it with outside air, etc., an expansion valve that expands the refrigerant (liquid refrigerant) that has been liquefied in the air-conditioning condenser and gasifies it, and an expansion valve and a refrigerant recovery condenser for liquefying the refrigerant (gas refrigerant) vaporized in the refrigerant recovery condenser, and an accumulator for storing the refrigerant (liquid refrigerant) liquefied by the refrigerant recovery condenser. The refrigerant plays a role of transporting thermal energy, and while releasing heat to the outside in the air conditioning condenser, it receives heat from outside air or the like after passing through the expansion valve.

　Various refrigerants used in refrigeration and air conditioning equipment have high global warming potential and ozone depletion potential, so their emissions into the atmosphere are regulated. Therefore, especially when replacing the refrigerant or disposing of the refrigerating and air-conditioning equipment, it is obligatory to minimize leakage of the refrigerant into the atmosphere and recover the refrigerant filled in the refrigerating and air-conditioning equipment. At the same time, a shift to refrigerants with less environmental load is also being promoted, and in recent years, the use of HFCs (hydrofluorocarbons) and the like as substitutes for chlorofluorocarbons has become mainstream. HFCs include, for example, R134A or R32 as a single refrigerant, and R410A or R407C as a mixed refrigerant.

A refrigerant recovery device is used to recover the refrigerant. In the refrigerant recovery device, after the refrigerant in the accumulator of the refrigerating and air-conditioning equipment is vaporized, the gas refrigerant is sucked by the compressor in the refrigerant recovery device and adiabatically compressed. The adiabatically compressed gas refrigerant is liquefied by the condenser in the refrigerant recovery device and recovered as liquid refrigerant in the recovery cylinder. The amount of refrigerant recovered is measured by a weight scale.

In Patent Document 1, when a non-condensable gas such as air is mixed in the recovery system when the refrigerant in a device using a refrigerant is recovered in a recovery container (recovery cylinder) by a refrigerant recovery device, the non-condensable gas is also discharged into the recovery container. (see paragraph 0056 of the same document). Since the non-condensable gas does not condense in the recovery vessel and exists as a compressed gas, as the amount of liquid refrigerant in the recovery vessel increases and the volume of the gas phase decreases, the pressure and temperature inside the recovery vessel increase. do. Therefore, in the same document, when the temperature in the recovery container reaches a predetermined value, the connection between the recovery container, the refrigerant recovery device, and the refrigerant-using equipment is released, the gas separation device is connected to the recovery container, and the gas is A technique is disclosed for removing non-condensable gas in a collection vessel by means of a separation device. Specifically, the mixed gas of the gas refrigerant and the non-condensable gas in the recovery container is sent to the gas separation device to be separated, the non-condensable gas is discharged into the atmosphere, and the gas refrigerant is returned to the recovery container. ing. After removing the non-condensable gas in the collection container, the refrigerant collection device and the equipment using the refrigerant are connected to the collection container again, and the work of collecting the refrigerant into the collection container is restarted.

JP 2010-159952 A

As described above, in recovering the refrigerant from the refrigerant circuit of the refrigerating and air-conditioning equipment, the refrigerant recovering device vaporizes the refrigerant, adiabatically compresses it, and then liquefies it to recover the refrigerant. Under such circumstances, when non-condensable gas mainly composed of air such as nitrogen (N2) and oxygen (O2) is mixed with the refrigerant, the non-condensable gas is not condensed in the refrigerant recovery device and is recovered as gas. The cylinder will be filled. As a result, the internal pressure of the recovery cylinder rises, making it difficult to fill the liquid refrigerant, and the speed of recovering the refrigerant into the recovery cylinder decreases. Therefore, it takes a long time to recover all the refrigerant.

To address this problem, in Patent Document 1, the non-condensable gas in the recovery container is removed by a gas separation device. It is necessary to disconnect the instrument and connect the collection vessel to the gas separator. Moreover, when the non-condensable gas removal process is completed, it is necessary to reconnect the recovery container, the refrigerant recovery device, and the refrigerant-using equipment. Therefore, it takes a lot of time and effort. In addition, since the refrigerant from the gas separation device is returned (injected) to the recovery container in the state of gas refrigerant (gas phase), the amount of refrigerant charged in the recovery container is reduced compared to the case where the refrigerant is liquefied and injected. There is also the problem of a decline in

There is a need for improved technology that can reduce the non-condensable gas in the recovery cylinder while maintaining the connection of the recovery cylinder, refrigerant recovery equipment, and refrigeration and air conditioning equipment.

Therefore, an object of the present disclosure is to reduce the non-condensable gas in the recovery cylinder while maintaining the connection between the recovery cylinder, the refrigerant recovery device, and the refrigeration and air conditioning equipment when recovering the refrigerant from the refrigeration and air conditioning equipment. An object of the present invention is to provide a refrigerant recovery system and a refrigerant recovery method that can be used.

The refrigerant recovery system of the present disclosure is a refrigerant recovery system that recovers the air conditioning refrigerant from the refrigerant circuit of the refrigeration and air conditioning equipment. The refrigerant recovery system includes a refrigerant recovery device that generates compressed and condensed refrigerant by compressing and condensing the air conditioning refrigerant, a recovery cylinder that recovers the compressed and condensed refrigerant generated by the refrigerant recovery device, and a recovery cylinder that recovers the compressed and condensed refrigerant. a gas separation module device including a first gas separation module and a second gas separation module for separating the air-conditioning refrigerant as a gas component from the inside of the gas separation module device; and a resending pipe for resending to and from the recovery device. The second gas separation module is arranged after the first gas separation module. The first gas separation module includes a first separation membrane. The second gas separation module includes a second separation membrane. Gas that permeates the first separation membrane can flow into the second separation membrane.

The refrigerant recovery method of the present disclosure is a refrigerant recovery method for recovering the air-conditioning refrigerant from the refrigerant circuit of the refrigerating and air-conditioning equipment. The refrigerant recovery method includes the steps of: a refrigerant recovery device compressing and condensing an air-conditioning refrigerant to generate a compressed condensed refrigerant; a recovery cylinder recovering the compressed and condensed refrigerant generated by the refrigerant recovery device; a gas separation module apparatus comprising a separation module and a second gas separation module separating air conditioning refrigerant from gas components contained within a recovery cylinder in which compressed condensed refrigerant is recovered; and retransmitting the gaseous component of the separated air-conditioning refrigerant between the refrigerant circuit and the refrigerant recovery device. The second gas separation module is arranged after the first gas separation module. The first gas separation module includes a first separation membrane. The second gas separation module includes a second separation membrane. Gas that permeates the first separation membrane can flow into the second separation membrane.

According to the present disclosure, when recovering the refrigerant from the refrigerating and air-conditioning equipment, the non-condensable gas in the recovery cylinder can be reduced while maintaining the connection between the recovery cylinder, the refrigerant recovery device, and the refrigerating and air-conditioning equipment. Since the gas components of the air-conditioning refrigerant separated by the gas separation module device are re-sent between the refrigerant circuit and the refrigerant recovery device, the separated gas components of the air-conditioning refrigerant are recovered again or used in the refrigerant circuit. be able to.

1 is a schematic diagram of a refrigerant recovery system 10 according to Embodiment 1. FIG. FIG. 4 is a block diagram of dispatch controller 76; FIG. 4 is a diagram showing an example of pressure characteristics of each refrigerant; 3 is a block diagram of a three-way valve controller 80; FIG. 3 is a block diagram of a pressure controller 97; FIG. FIG. 10 is a diagram for explaining a set pressure PA of an internal-external differential pressure of the first separation membrane 92A; FIG. 10 is a diagram for explaining a set pressure PB of a differential pressure between the inside and outside of a second separation membrane 92B; FIG. 4 is a diagram schematically showing how gas is separated by a first separation membrane 92A made of an inorganic separation membrane. (a) is a diagram schematically showing how gas is separated by a second separation membrane 92B made of an inorganic separation membrane when the transmembrane pressure difference is less than TH2. (b) is a diagram schematically showing how gas is separated by the second separation membrane 92B composed of an inorganic separation membrane when the transmembrane pressure difference is TH2 or higher. 4 is a flow chart showing a specific refrigerant recovery method using the refrigerant recovery system 10 according to Embodiment 1. FIG. 4 is a flowchart showing first three-way valve control; It is a flowchart which shows a 2nd three-way valve control. FIG. 4 is a schematic diagram of a refrigerant recovery system 10A according to Embodiment 2; 10 is a flow chart showing a specific refrigerant recovery method using the refrigerant recovery system 10A in Embodiment 2. FIG.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. The configuration described below is an example for explanation, and can be changed as appropriate according to the specifications of the system, device, and the like. Also, when a plurality of embodiments or modified examples are included below, it is assumed from the beginning that the characteristic parts thereof will be used in combination as appropriate. The same reference numerals are given to the same elements in all the drawings, and redundant explanations are omitted.

Embodiment 1.
FIG. 1 is a schematic diagram of a refrigerant recovery system 10 according to Embodiment 1. FIG.

In the figure, thick solid lines indicate piping through which fluid flows, and dashed-dotted lines indicate control lines for input and output to each controller. The refrigerant recovery system 10 is a system for recovering air-conditioning refrigerant from refrigerating and air-conditioning equipment and filling a recovery cylinder 16 with the refrigerant. An example of recovering air-conditioning refrigerant from an air conditioner 12 as a refrigerating and air-conditioning device will be described below, but the refrigerant recovery system 10 can be applied to refrigerant recovery from all devices that use refrigerant. In addition, the refrigerant for air conditioning means at least one of the cooling function and the heating function of the air etc. It is a refrigerant that realizes

The refrigerant recovery system 10 includes a refrigerant recovery device 14, a recovery cylinder 16, a gas separation module device 68,

retransmission pipes

58A, 58B, 58C, and a three-way valve 40.

The refrigerant recovery device 14 sucks the air conditioning refrigerant from the refrigerant circuit 30 of the air conditioner 12, adiabatically compresses it, condenses the compressed refrigerant and liquefies it to generate compressed condensed refrigerant.

The recovery cylinder 16 recovers the compressed condensed refrigerant generated by the refrigerant recovery device 14 .
The gas separation module device 68 separates the air conditioning refrigerant from the mixed gas component 22 contained inside the recovery cylinder 16 in which the compressed condensed refrigerant is recovered. The gas separation module arrangement 68 comprises a first gas separation module 68A and a second gas separation module 68B.

The reason why two of the first gas separation module 68A and the second gas separation module 68B are used is that when the refrigerant for air conditioning is a mixed refrigerant containing R-32 and other refrigerants, the molecular diameter of R-32 and the This is because it is difficult to separate the air-conditioning refrigerant and the non-condensable gas with one gas separation module because the molecular diameters of the condensable gases are close.

The resending

pipes

58A, 58B, and 58C resend the air-conditioning refrigerant separated by the gas separation module device 68 between the refrigerant circuit 30 and the refrigerant recovery device 14 . In the accelerated vaporization mode, the air-conditioning refrigerant separated by the gas separation module device 68 is sent to the refrigerant circuit 30 . As a result, the temperature of the refrigerant in the refrigerant circuit 30 rises, so that vaporization of the refrigerant is promoted, and when refrigerant recovery is resumed, the refrigerant recovery speed can be improved. In circulation mode, the air conditioning refrigerant separated by the gas separation module device 68 is sent to the refrigerant recovery device 14 . As a result, the process of recovering the air-conditioning refrigerant separated by the gas separation module device 68 is performed again.

A three-way valve 40 is arranged between the refrigerant circuit 30 and the refrigerant recovery device 14 .
Air conditioner 12 includes a service port 34 that connects to refrigerant circuit 30 .

The refrigerant circuit 30 includes an accumulator 32 in which liquid refrigerant is stored. The refrigerant recovery device 14 sucks through the service port 34 the gas refrigerant obtained by vaporizing the liquid refrigerant in the accumulator 32 .

　Refrigerant recovery device 14 includes a compressor and a condenser, and can be realized by a widely commercially available Freon recovery machine. The refrigerant recovery device 14 includes an inlet 36 (take-in 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. including.

The recovery cylinder 16 includes a liquid inlet/outlet 46 for admitting the compressed condensed refrigerant from the refrigerant recovery device 14 into the recovery cylinder 16 and a gas inlet/outlet 48 for exiting the gas component 22 in the recovery cylinder 16 .

The three-way valve 40 includes a second port 41, a second port 42 and a third port 43. A connection pipe 50 connects the service port 34 of the air conditioner 12 and the first port 41 of the three-way valve 40 . A front pipe 52 connects the second port 42 of the three-way valve 40 and the inlet 36 of the refrigerant recovery device 14 . The third port 43 of the three-way valve 40 and the resending pipe 58C are connected.

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).

Air (nitrogen, oxygen etc.) may be mixed in. In refrigerant recovery, when the non-condensable gas is sucked into the refrigerant recovery device 14 together with the refrigerant, the non-condensable gas is not condensed in the refrigerant recovery device 14 and is filled in the recovery cylinder 16 as it is. be. As a result, the internal pressure of the recovery cylinder 16 rises, making it difficult to fill the liquid refrigerant, and the refrigerant recovery speed to the recovery cylinder 16 decreases. To address this, the refrigerant recovery system 10 includes a separation device 18 for removing non-condensable gases within the recovery cylinder 16 . In the recovery cylinder 16, the gaseous refrigerant obtained by partially re-vaporizing the liquid refrigerant 20 and the non-condensable gas are combined to generate a mixed gas 22 (gas component 22).

The separation device 18 includes a gas inlet 60, a delivery line 56, a gas separation module device 68, and

re-transmission lines

58A, 58B, 58C.

The gas inlet 60 is connected to the gas inlet/outlet 48 of the recovery cylinder 16 .
The mixed gas 22 taken in from the gas inlet 60 flows through the delivery pipe 56 .

The gas separation module device 68 separates the air-conditioning refrigerant as a gas component from the inside of the recovery cylinder 16 in which the compressed and condensed refrigerant is recovered. Gas separation module apparatus 68 is fed with gas mixture 22 in delivery line 56 and separates gas refrigerant and non-condensable gases from gas mixture 22 .

The

retransmission pipes

58A, 58B, 58C are connected to the gas separation module device 68. The resending

pipes

58A, 58B, and 58C resend the gas components of the air-conditioning refrigerant separated by the gas separation module device 68 between the refrigerant recovery device 14 and the refrigerant circuit 30 .

The gas separation module device 68 includes a first gas separation module 68A and a second gas separation module 68B. The second gas separation module 68B is arranged after the first gas separation module 68A.

The first gas separation module 68A includes an inlet 90A, a first separation membrane 92A, an outlet 94A, and an outlet 96A.

Inlet 90A takes in mixed gas 22 .
The first separation membrane 92A performs gas separation.

The discharge port 94A discharges the mixed gas 24 composed of the non-condensable gas separated by the first separation membrane 92A and R32 to the pipe 59.

The outlet 96A discharges the retransmitted gas refrigerant (refrigerant for air conditioning), which is a gas component in which the non-condensable gas and R32 are reduced compared to the mixed gas 22 by the first separation membrane 92A.

A first end of the delivery pipe 56 is the gas inlet 60 . A second end of the delivery line 56 is connected to the inlet 90A of the first gas separation module 68A.

A first end of the retransmission pipe 58A is connected to the outlet 96A of the first gas separation module 68A. A second end of the retransmission pipe 58A is connected to the junction ND.

The second gas separation module 68B includes an inlet 90B, a second separation membrane 92B, an outlet 94B, and an outlet 96B.

Inlet 90B takes in mixed gas 24 .
The second separation membrane 92B performs gas separation.

The discharge port 94B discharges the non-condensable gas separated by the second separation membrane 92B to the atmosphere.
The outlet 96B discharges retransmitted gas refrigerant (air-conditioning refrigerant), which is a gas component in which the non-condensable gas is reduced compared to the mixed gas 24 by the second separation membrane 92B.

A first end of the pipe 59 is connected to the outlet 94A of the first gas separation module 68A. A second end of tubing 59 is connected to inlet 90B of second gas separation module 68B.

A first end of the retransmission pipe 58B is connected to the outlet 96B of the second gas separation module 68B. A second end of the retransmission pipe 58B is connected to the junction ND.

A first end of the retransmission pipe 58C is connected to the junction ND. A second end of the resending pipe 58C is connected to the third port 43 of the three-way valve 40 as a gas outlet 74 .

The separation device 18 further comprises a first pressure regulator 98A, a second pressure regulator 98B, a first check valve 99A and a second check valve 99B.

The first pressure regulator 98A adjusts the internal and external pressure difference of the first separation membrane 92A of the first gas separation module 68A. The first pressure regulator 98A is positioned after the first gas separation module 68A and includes a first back pressure valve that regulates the pressure on the primary side of the first pressure regulator 98A.

The second pressure regulator 98B adjusts the internal and external pressure difference of the second separation membrane 92B of the second gas separation module 68B. The second pressure regulator 98B is positioned after the second gas separation module 68B and includes a second back pressure valve that regulates the pressure on the primary side of the second pressure regulator 98B.

The first check valve 99A is arranged between the first pressure regulator 98A and the junction ND. The first check valve 99A prevents the gas that has flowed out from the first separation membrane 92A and the gas that has flowed out from the second separation membrane 92B from flowing into the first separation membrane 92A.

The second check valve 99B is arranged between the second pressure regulator 98B and the junction ND. The second check valve 99B prevents the gas that has flowed out from the first separation membrane 92A and the gas that has flowed out from the second separation membrane 92B from flowing into the second separation membrane 92B.

As will be described later, detectors, valves, etc. are arranged in the delivery pipe 56 and the

retransmission pipes

58A, 58B, 58C, but some of them can be omitted to configure the refrigerant recovery system. The refrigerant recovery method, which is the basis of the refrigerant recovery system including such a configuration, comprises the following steps (1) to (4).

(1) The first port 41 and the second port 42 of the three-way valve 40 are brought into communication (hereinafter referred to as normal mode), and the refrigerant for air conditioning in the refrigerant circuit 30 is collected through the connecting pipe 50 and the front pipe 52. A production step of directing to the device 14 and compressing and condensing the air conditioning refrigerant using the refrigerant recovery device 14 to produce a compressed condensed refrigerant.

(2) A recovery step of recovering the compressed condensed refrigerant generated by the refrigerant recovery device 14 to the recovery cylinder 16 through the rear pipe 54 .

(3) The gas component 22 contained inside the recovery cylinder 16 is led to the gas separation module device 68 through the delivery pipe 56, and the gas separation module device 68 is used to separate the mixed gas 22 from the non-condensable gas and the resent gas refrigerant (air conditioning Refrigerant for use) and a separation step.

(4) The second port 42 and the third port 43 of the three-way valve 40 are brought into communication (hereinafter referred to as circulation mode), and the resent gas refrigerant separated by the gas separation module device 68 is transferred to the resending

pipes

58A, 58B, a resending step of resending between the refrigerant recovery device 14 and the refrigerant circuit 30 through 58C and the front pipe 52;

The separation step (3) includes the following two steps.
(3A) A first separation step in which the first gas separation module 68A separates the mixed gas 24 consisting of the non-condensable gas and R32 from the mixed gas 22 and the refrigerant other than R32.

(3B) A second separation step of separating the non-condensable gas and R32 from the mixed gas 24 by the second gas separation module 68B.

The description of the refrigerant recovery system 10 in FIG. 1 continues. The separation device 18 further comprises a pressure detector 61 , a temperature detector 62 , a control valve 64 and a pressure reducing valve 66 arranged in the delivery line 56 .

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

The separation device 18 further comprises a pressure detector 70 and a pressure regulator 72 arranged in the retransmission pipe 58C.

The pressure detector 70 on the resending pipe 58C detects the pressure inside the resending pipe 58C upstream of the pressure regulator 72 (gas separation module device 68 side). The pressure regulator 72 regulates the pressure in the retransmission pipe 58C downstream of the pressure regulator 72 (on the side of the gas outlet 74).

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

The sending controller 76, the resending controller 78, the three-way valve controller 80, and the pressure controller 97 are controllers, for example, CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), flash It is a microcomputer equipped with memory, input/output ports, and the like. These controllers may be realized by one common microcomputer. Also, these controllers may include an ASIC (Application Specific Integrated Circuit) or the like instead of or together with a microcomputer.

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

When the control valve 64 is closed, the three-way valve controller 80 controls the three-way valve 40 to set the first port 41 and the second port 42 to communicate (normal mode).

When the control valve 64 is open, the three-way valve controller 80 controls the three-way valve 40 so that the second port 42 and the third port 43 are in communication (circulation mode), or the first port 41 and the third port 43 are connected to each other (hereinafter referred to as vaporization promotion mode). As described above, in the embodiment of FIG. 1, the vaporization acceleration mode is added to the basic refrigerant recovery method.

The normal mode is a mode in which refrigerant is recovered from the air conditioner 12 to the recovery cylinder 16 . In the circulation mode, a circulation loop is formed by 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, and the inside of the recovery cylinder 16 is This mode removes non-condensable gases. In the vaporization promotion mode, when there is a possibility that the refrigerant in the refrigerant circuit 30 of the air conditioner 12 is condensed at a low temperature, part of the mixed gas 22 in the recovery cylinder 16 is sent from the separator 18 into the refrigerant circuit 30, This is a mode in which the temperature of the refrigerant in the refrigerant circuit 30 is raised to promote vaporization of the refrigerant. Since the gas refrigerant that has passed through the refrigerant recovery device 14 is adiabatically compressed, it has a higher temperature than when it flows into the refrigerant circuit 30 , that is, into the refrigerant recovery device 14 . Therefore, the temperature of the refrigerant entering the recovery cylinder 16 from the refrigerant recovery device 14 is high.

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

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

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 the input unit 100 and stored in the storage unit 102 . For example, by reading a barcode indicating the type of refrigerant used in the air conditioner 12 attached to the surface of the housing of the air conditioner 12 with a barcode reader as the input unit 100, the recovered refrigerant information 110 can be obtained. It is stored in the storage unit 102 . The storage unit 102 further stores in advance the characteristic of saturated vapor pressure with respect to temperature (hereinafter referred to as pressure characteristic 112) for each of a plurality of types of refrigerants.

FIG. 3 is a diagram showing an example of pressure characteristics of each refrigerant. FIG. 3 shows the pressure characteristics of A, B, C, and D refrigerants.

The temperature DT detected by the temperature detector 62 on the shipping pipe 56 (temperature inside the recovery cylinder 16) is input to the reference pressure acquirer 104. The reference pressure acquirer 104 reads the pressure characteristic 112 corresponding to the recovered refrigerant indicated by the recovered refrigerant information 110 from the storage unit 102, and, as shown in FIG. In the example of FIG. 3, the saturated vapor pressure of refrigerant A) is obtained as the reference pressure RP. The reference pressure acquirer 104 then outputs the reference pressure RP to the determiner 108 .

The reference pressure RP and the detected pressure DP of the pressure detector 61 on the shipping pipe 56 (the pressure in the recovery cylinder 16) are input to the determiner 108. Here, when the detected pressure DP is higher than the reference pressure RP (the saturated vapor pressure of the recovered refrigerant) as shown in FIG. 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 open, and the mixed gas 22 in the recovery cylinder 16 is discharged. Send to gas separation module device 68 . On the other hand, the determiner 108 keeps the control valve 64 closed when the high pressure is not present. The determiner 108 outputs a removal signal indicating whether the non-condensable gas is being removed. The removal signal is a signal that becomes Low when the control valve 64 is closed and becomes High when the control valve 64 is open.

The pressure DP detected by the pressure detector 61 on the delivery pipe 56 (the pressure inside the recovery cylinder 16) is input to the pressure reducing valve controller 106. In the pressure reducing valve controller 106, when the control valve 64 is opened and the mixed gas 22 in the recovery cylinder 16 is sent to the gas separation module device 68, the

separation membranes

92A and 92B of the gas separation module device 68 are separated from the recovery cylinder. Based on the detected pressure DP, the pressure reducing valve 66 is controlled so that the pressure in 16 does not damage it. By controlling the pressure reducing valve 66, the pressure in the pipe downstream of the pressure reducing valve 66 (on the side of the gas separation module device 68) is adjusted.

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

Before refrigerant recovery, a pressure threshold value 120 as a transition condition to the vaporization promotion mode and a vaporization promotion mode duration 122 are input from the input unit 100 and stored in the storage unit 102 . The determination device 118 stores the removal signal, the detected pressure DPS of the pressure detector 37 of the refrigerant recovery device 14 (the pressure at the inlet 36 of the refrigerant recovery device 14), and the pressure threshold 120 and duration 122 stored in the storage unit 102. is entered. Here, the detected pressure DPS indicates the pressure in the refrigerant circuit 30 of the air conditioner 12 in the normal mode.

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 communication (normal mode).

When the removal signal changes from Low to High, the determiner 118 selects one of the circulation mode and the vaporization acceleration mode based on the result of comparison between the detected pressure DPS (the pressure in the refrigerant circuit 30) and the pressure threshold 120. It is decided which way the three-way valve 40 will be controlled. 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 a low temperature, and the second port 42 of the three-way valve 40 and The three-way valve 40 is controlled so that it communicates with the third port 43 (circulation mode). On the other hand, when the detected pressure DPS is equal to or less than the pressure threshold 120, the determiner 118 estimates that the refrigerant in the refrigerant circuit 30 may be condensed at a low temperature, and the first port 41 and the third port of the three-way valve 40 43 is in communication (vaporization acceleration mode).

The determiner 118 controls the three-way valve 40 from the vaporization promotion mode to the circulation mode when the duration time 122 has elapsed after the transition to the vaporization promotion mode.

The determiner 118 outputs a three-way valve signal indicating the current state of the normal mode, the circulation mode, or the vaporization promotion mode.

As shown in FIG. 1, the resending controller 78 includes a three-way valve signal, a detected pressure DPR of the pressure detector 70 on the resending pipe 58C (pressure inside the resending pipe 58), and a pressure detector of the refrigerant recovery device 14. 37 detected pressure DPS (the pressure at the inlet 36 of the refrigerant recovery device 14) is input. The resending controller 78 is controlled based on the sensed pressures DPR, DPS when the 3-way valve signal indicates the circulation mode, and the pressure downstream of the pressure regulator 72 (gas outlet 36) relative to the pressure at the inlet 36 of the refrigerant recovery device 14. 74 side), the pressure regulator 72 is controlled so that the pressure in the retransmission pipe 58C increases. Thereby, it is possible to prevent the refrigerant from flowing back from the front pipe 52 toward the resending pipe 58C. When the three-way valve signal indicates the vaporization promotion mode, the resending controller 78 controls the pressure in the resending pipe 58C on the downstream side (gas outflow port 74 side) of the pressure regulator 72 to increase the pressure in the refrigerant circuit 30 of the air conditioner 12. The pressure regulator 72 is controlled to provide a predetermined pressure at which gas can be delivered to the .

FIG. 5 is a block diagram of the pressure controller 97. FIG. The pressure controller 97 comprises a pressure acquirer 211 , a first pressure controller 212 and a second pressure controller 213 . The pressure controller 97 is electrically connected to a storage unit 102 such as a flash memory. A memory within the pressure controller 97 may be used as the storage unit 102 .

The storage unit 102 stores first pressure information 214 and second pressure information 215 . The first pressure information 214 represents the internal and external pressure difference PA of the first separation membrane 92A set by the first pressure regulator 98A. The second pressure information 215 represents the internal and external pressure difference PB of the second separation membrane 92B set by the second pressure regulator 98B.

The pressure acquirer 211 acquires first pressure information 214 from the storage unit 102 and sends it to the first pressure controller 212 before refrigerant recovery. The first pressure controller 212 controls the first pressure regulator 98A to set the internal and external pressure difference P1o of the first separation membrane 92A to PA.

The pressure acquirer 211 acquires the second pressure information 215 from the storage unit 102 and sends it to the second pressure controller 213 before refrigerant recovery. The second pressure controller 213 controls the second pressure regulator 98B to set the internal and external differential pressure P2o of the second separation membrane 92B to PB.

Next, the set pressure PA for the internal and external differential pressure of the first separation membrane 92A and the set pressure PB for the internal and external differential pressure of the second separation membrane 92B will be described.

FIG. 6 is a diagram for explaining the set pressure PA of the internal and external differential pressure of the first separation membrane 92A.
When the pressure difference between the inside and outside of the first separation membrane 92A is less than the first threshold value TH1, the gas component of R32 and the non-condensable gas can permeate the first separation membrane 92A, and the refrigerant gas other than R32 Components cannot permeate the first separation membrane 92A.

The set pressure PA of the internal and external differential pressure of the first separation membrane 92A is set to a value less than the first threshold TH1. As a result, the R32 gas component and the non-condensable gas can permeate the first separation membrane 92A, and the refrigerant gas components other than R32 cannot permeate the first separation membrane 92A.

FIG. 7 is a diagram for explaining the set pressure PB of the internal and external differential pressure of the second separation membrane 92B.
When the pressure difference between the inside and outside of the second separation membrane 92B is less than the second threshold TH2, the non-condensable gas can permeate the second separation membrane 92B, and the gas component of R32 and the refrigerant gas other than R32 Components cannot permeate the second separation membrane 92B.

The set pressure PB of the internal and external differential pressure of the second separation membrane 92B is set to a value less than the second threshold TH2. As a result, the non-condensable gas can permeate the second separation membrane 92B, and the gas component of R32 and the gas components of refrigerants other than R32 cannot permeate the second separation membrane 92B.

A method for satisfying the above conditions and setting the set pressure PA and the set pressure PB to more appropriate values will be explained.

As shown in FIG. 1, the pressure difference between the inside and outside of the first separation membrane 92A is P1o, the pressure inside the first separation membrane 92A (that is, the pressure on the input side of the first separation membrane 92A) is P1i, and the first separation membrane 92A Let P1t be the pressure on the permeation side of . P2o is the pressure difference between the inside and outside of the second separation membrane 92B, P2i is the pressure inside the second separation membrane 92B (that is, the pressure on the input side of the second separation membrane 92B), and P2t is the pressure on the permeation side of the second separation membrane 92B. and The following formula holds.

P1t=P2i (1)
P2t=P2i-P2o (2)
P1t=P1i-P1o (3)
In the second separation membrane 92B, the permeated gas is released to the atmosphere, so the following equation holds.

P2t=0 (4)
From equations (1) to (4), the following equation holds.

P2o=P2i=P1t (5)
Moreover, the following conditions are required to prevent the gas from flowing back to the first separation membrane 92A.

P1t<P1i (6)
P1t<P1o (7)
From equations (5) to (7), the following equation holds.

P1i>P2o (8)
P1o>P2o (9)
Therefore, it is desirable to set the magnitudes of the set pressures PA and PB as follows.

PA>PB (10)
From equations (1), (3), and (5), the following equation holds.

P1i=P1o+P2o (11)
Control of the pressure reducing valve 66 by the dispatch controller 76 allows the pressure P1o to be controlled. Should P1i be significantly greater than P1o, pressure reducing valve 66 vents gas downstream for control of pressure P1o. In other words, a large amount of gas flows out without being separated by the first separation membrane 92A. Therefore, it is desirable that P1i is slightly higher than P2o. Specifically, P1i is desirably higher than P2o by 0 [MPa] or more and 0.1 [MPa] or less by control of the pressure reducing valve 66 by the shipping controller 76 .

In other words, it is desirable that the set pressure PA of the internal and external differential pressure of the first separation membrane 92A be higher than the set pressure PB of the internal and external differential pressure of the second separation membrane 92B.

Next, the first gas separation module 68A and the second gas separation module 68B will be explained.

A mixed gas 22 containing R32, a refrigerant other than R32, and a non-condensable gas flows into the first gas separation module 68A.

As shown in FIG. 1, the first gas separation module 68A includes a tubular housing 88A and a tubular first separation membrane 92A disposed within the housing 88A. Enclosure 88A includes an inlet 90A for taking in mixed gas 22, an outlet 96A positioned opposite inlet 90A for discharging rerouted gas refrigerant, and an outlet 94A for discharging non-condensable gases and R32. The gas component of R32 can permeate the first separation membrane 92A. A non-condensable gas can permeate the first separation membrane 92A. Gas components of refrigerants other than R32 cannot permeate the first separation membrane 92A.

A first end of the first separation membrane 92A is connected to the inlet 90A of the housing 88A. A second end of the first separation membrane 92A is connected to the outlet 96A of the housing 88A. Mixed gas 22 enters the interior of first separation membrane 92A from inlet 90A and proceeds toward outlet 96A, during which air-based non-condensable gas and R32 permeate first separation membrane 92A. Then, it goes out of the first separation membrane 92A, and is eventually released into the pipe 59 from the discharge port 94A of the housing 88A. In addition, the non-condensable gas and the retransmitted gas refrigerant with reduced R32 compared to the mixed gas 22 are discharged from the outlet 96A of the housing 88A into the retransmitted pipe 58A.

As the first separation membrane 92A and the second separation membrane 92B, 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 ) can be used. Ceramics, zeolites, and the like, for example, can be used as materials for the inorganic separation membrane. The first separation membrane 92A and the second separation membrane 92B are membranes capable of separating gases with a small separation diameter, such as non-condensable gases (N2, O2). The molecular diameters of the first separation membrane 92A and the second separation membrane 92B are approximately 3.8 Å. The first separation membrane 92A has polarity, and the second separation membrane 92B does not have polarity.

FIG. 8 is a diagram schematically showing how gas is separated by the first separation membrane 92A composed of an inorganic separation membrane. As shown in FIG. 8, the inorganic separation membrane basically uses the difference in molecular diameter to separate gases. Air (non-condensable gas) 26 with a small molecular diameter and water 28 go out of the first separation membrane 92A through the pores of the first separation membrane 92A. The refrigerant 24 other than R32 having a large molecular diameter remains inside the first separation membrane 92A. The molecular diameter of R32 is slightly larger than that of the inorganic separation membrane. However, since the first separation membrane 92A has polarity, R32 permeates the first separation membrane 92A by being deformed.

Although the molecular diameters of the first separation membrane 92A and the second separation membrane 92B are the same, the first separation membrane 92A has polarity. Since the second separation membrane 92B does not have polarity, R32 may or may not permeate the second separation membrane 92B depending on the transmembrane pressure difference.

A mixed gas 24 containing R32 and non-condensable gas flows into the second gas separation module 68B.

As shown in FIG. 1, the second gas separation module 68B includes a tubular housing 88B and a tubular second separation membrane 92B disposed within the housing 88B. Enclosure 88B includes an inlet 90B for taking in mixed gas 24, an outlet 96B disposed opposite inlet 90B for discharging rerouted gas refrigerant, and an outlet 94B for discharging non-condensable gases. The R32 gas component cannot permeate the second separation membrane 92B. A non-condensable gas can permeate the second separation membrane 92B.

A first end of the second separation membrane 92B is connected to the inlet 90B of the housing 88B. A second end of the second separation membrane 92B is connected to the outlet 96B of the housing 88B. The mixed gas 24 enters the interior of the second separation membrane 92B from the inlet 90B and proceeds toward the outlet 96B, during which the non-condensable gas mainly composed of air permeates the second separation membrane 92B to It goes out of the second separation membrane 92B and is released into the atmosphere from the discharge port 94B of the housing 88B before long. Further, the retransmitted gas refrigerant having a reduced non-condensable gas content compared to the mixed gas 24 is discharged from the outlet 96B of the housing 88B into the retransmitted pipe 58B.

FIG. 9(a) is a diagram schematically showing how gas is separated by the second separation membrane 92B composed of an inorganic separation membrane when the transmembrane pressure difference is less than TH2. FIG. 9(b) is a diagram schematically showing how gas is separated by the second separation membrane 92B composed of an inorganic separation membrane when the transmembrane pressure difference is TH2 or higher.

As shown in FIGS. 9(a) and (b), the inorganic separation membrane basically uses the difference in molecular diameter to separate gases. Air (non-condensable gas) 26 with a small molecular diameter and water 28 go out of the second separation membrane 92B through the pores of the second separation membrane 92B. Since the second separation membrane 92B does not have polarity, R32 (25) remains inside the second separation membrane 92B unless the transmembrane pressure difference becomes equal to or greater than the second threshold TH2.

Next, a specific refrigerant recovery method using the refrigerant recovery system 10 will be described. FIG. 10 is a flow chart showing a specific refrigerant recovery method using the refrigerant recovery system 10 according to the first embodiment. In FIG. 10, S100 to S104, S126 and S128 are steps performed by the operator, and other steps are steps performed automatically by the refrigerant recovery system 10. FIG.

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

In S102, after turning off the air conditioner 12, the operator connects the air conditioner 12, the refrigerant recovery device 14, the recovery cylinder 16, and the separation device 18 to each other as shown in FIG.

In S103, the operator turns on the separation device 18. After that, the operator inputs the collected refrigerant information 110 (see FIG. 2) and the pressure threshold 120 and the duration 122 (see FIG. 4) regarding the accelerated vaporization mode from the input section 100. FIG. When the isolation device 18 is powered on, the three-way valve controller 80 controls the three-way valve 40 to a normal mode in which the first port 41 and the second port 42 are in communication.

At S104, the operator drives the refrigerant recovery device 14. Thereby, refrigerant recovery from the air conditioner 12 is started.

S106 to S122 are automatic controls by the refrigerant recovery system .
In S106, the reference pressure acquirer 104 of the dispatch controller 76 determines the detected temperature DT of the temperature detector 62 (the temperature in the recovery cylinder 16 ) is obtained as the reference pressure RP. A determiner 108 of the delivery controller 76 checks whether or not the detected pressure DP of the pressure detector 61 (the pressure inside the recovery cylinder) is higher than the reference pressure RP. Note that, as shown in S106 in FIG. 7, the determination device 108 determines that the detected pressure DP (inside the recovery cylinder pressure) is high.

If the detected pressure DP is equal to or lower than the reference pressure (RP+α) (S106: NO), the determiner 108 determines that it is not necessary to remove the non-condensable gas in the recovery cylinder 16, and continues to recover the refrigerant (S108 ).

On the other hand, when the detected pressure DP is higher than the reference pressure (RP+α) (S106: YES), the determiner 108 determines that the non-condensable gas in the recovery cylinder 16 needs to be removed, and outputs a removal signal. is changed from Low to High, and the process proceeds to S110. If the determination is made using the reference pressure in this way, removal of the non-condensable gas can be started after a certain amount of non-condensable gas is accumulated in the recovery cylinder 16 .

At S110, the three-way valve controller 80 executes the first three-way valve control in response to the removal signal changing from Low to High. FIG. 11 is a flowchart showing first three-way valve control.

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 120 stored in the storage unit 102. do. Note that the pressure threshold 120 is, for example, about 0.1 MPa.

When 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 a low temperature, and the three-way valve 40 is connected between the second port 42 and the third port 43. (S206), the vaporization acceleration flag is turned off (S208), and the first three-way valve control is terminated.

On the other hand, when S200 is YES, the determiner 118 estimates that the refrigerant in the refrigerant circuit 30 of the air conditioner 12 is highly likely to be condensed at a low temperature, and the three-way valve 40 is connected to the first port 41 and the third port 43. (S202), turns on the vaporization promotion flag (S204), and ends the first three-way valve control.

Refer to FIG. 10 again.
In S111 after S110, the pressure controller 97 adjusts the internal and external differential pressure P1o of the first separation membrane 92A of the first gas separation module 68A to the set pressure PA by controlling the first pressure regulator 98A. Then, by controlling the second pressure regulator 98B, the adjustment of the internal and external differential pressure P1o of the second separation membrane 92B of the second gas separation module 68B to the set pressure PB is started.

At S<b>112 , the determiner 108 of the shipping controller 76 opens the control valve 64 on the shipping pipe 56 . The timing of changing the removal signal from Low to High, the execution timing of S110 (first three-way valve control), and the execution timing of S112 (operation of opening the control valve 64) are substantially the same. Moreover, the pressure reducing valve 66 is adjusted by the pressure reducing valve controller 106 before the control valve 64 is opened. By opening control valve 64 , mixed gas 22 in recovery cylinder 16 is sent to gas separation module device 68 .

In the circulation mode, a circulation loop consisting of the separation device 18, the refrigerant recovery device 14, and the recovery cylinder 16 is formed, and the mixed gas 22 in the recovery cylinder 16 is repeatedly sent to the gas separation module device 68. Non-condensable gases are vented to the atmosphere. The resent 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 inside the recovery cylinder 16 is gradually removed, and the pressure inside the recovery cylinder 16 decreases.

In the accelerated vaporization mode, the resent gas refrigerant that is part of the mixed gas 22 in the recovery cylinder 16 is sent into the refrigerant circuit 30 of the air conditioner 12 to raise the temperature of the refrigerant in the refrigerant circuit 30 . As a result, vaporization of the refrigerant is accelerated, and when refrigerant recovery is restarted, the refrigerant recovery speed can be improved.

The resending controller 78 controls the pressure regulator 72 in the circulation mode and the vaporization promotion mode to adjust the pressure in the resending pipe 58C on the downstream side of the pressure regulator 72 (gas outflow port 74 side).

In S114, the determiner 108 of the shipping controller 76 confirms whether or not the detected pressure DP of the pressure detector 61 (the pressure inside the recovery cylinder 16) has become equal to or less than the reference pressure RP. If S114 is NO, the removal of non-condensable gas is continued (S116), and the process proceeds to S118.

At S118, the three-way valve controller 80 executes second three-way valve control. FIG. 12 is a flow chart showing second three-way valve control.

At S300, the determiner 118 of the three-way valve controller 80 confirms whether or not the vaporization promotion flag is ON. If S300 is NO (in the circulation mode), the second three-way valve control is ended. On the other hand, if S300 is YES (in the case of vaporization promotion mode), the process proceeds to S302.

In S302, the determiner 118 checks whether the duration 122 (see FIG. 4) stored in the storage unit 102 has passed since the transition to the vaporization acceleration mode. If S302 is NO, the determiner 118 determines that it is necessary to continue the vaporization acceleration mode, and ends the second three-way valve control. On the other hand, if S302 is YES, the determiner 118 determines that the vaporization promotion mode may be terminated, and controls the three-way valve 40 to the circulation mode in which the second port 42 and the third port 43 communicate ( S304), the vaporization promotion flag is turned off (S306), and the second three-way valve control ends.

Refer to FIG. 10 again.
In S114, when the pressure DP detected by the pressure detector 61 (the pressure in the recovery cylinder 16) is equal to or lower than the reference pressure RP (S114: YES), the determination device 108 of the dispatch controller 76 determines that the recovery cylinder 16 It is determined that the removal of the non-condensable gas inside has been completed, and the process proceeds to S120.

At S120, the determiner 108 of the shipping controller 76 closes the control valve 64 on the shipping pipe 56 and changes the removal signal from High to Low. The decision device 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 communicate with each other in response to the removal signal changing from High to Low. The pressure reducing valve controller 106 of the dispatch controller 76 terminates control of the pressure reducing valve 66 and the retransmission controller 78 terminates control of the pressure regulator 72 .

In S121, the pressure controller 97 finishes adjusting the internal and external differential pressure P1o of the first separation membrane 92A of the first gas separation module 68A to the set pressure PA by controlling the first pressure regulator 98A. The adjustment of the internal and external differential pressure P1o of the second separation membrane 92B of the second gas separation module 68B to the set pressure PB by controlling the two-pressure regulator 98B is completed.

At S122, the refrigerant recovery device 14 confirms whether or not the pressure DPS detected by the pressure detector 37 (the pressure in the refrigerant circuit 30) has become negative. If S122 is NO, the refrigerant recovery device 14 continues refrigerant recovery (S124), and if S122 is YES, the refrigerant recovery device 14 notifies the completion of refrigerant recovery by means of a lamp, sound, or the like. tell people.

At S<b>126 , the operator stops the refrigerant recovery device 14 .
At S<b>128 , the operator turns off the separation device 18 .

The above is the refrigerant recovery flow.
Next, the effects of the refrigerant recovery system 10 described above will be described.

According to the refrigerant recovery system 10, by sending the mixed gas 22 inside the recovery cylinder 16 to the gas separation module device 68, the non-condensable gas is separated from the mixed gas 22 and discharged to the atmosphere, and the mixed gas The rerouted gaseous refrigerant, which has reduced noncondensable gases compared to 22 , is discharged from the gas separation module arrangement 68 and directed into the piping between the refrigerant circuit 30 of the air conditioner 12 and the refrigerant recovery system 14 . Further, the retransmitted gas refrigerant passes through the refrigerant recovery device 14 again and returns to the recovery cylinder 16 in a liquefied state.

Thus, the non-condensable gas in the recovery cylinder 16 can be reduced while maintaining the connection between the recovery cylinder 16, the refrigerant recovery device 14 and the air conditioner 12. The increase in internal pressure of the recovery cylinder 16 can be suppressed, the speed of refrigerant recovery to the recovery cylinder 16 can be improved, and the amount of refrigerant charged in the recovery cylinder 16 can be increased. Since the resent gas refrigerant is liquefied (with a reduced volume) and returned to the recovery cylinder 16, the amount of refrigerant charged in the recovery cylinder 16 can be further increased. In order to send the mixed gas 22 in the recovery cylinder 16 to the gas separation module device 68, it is important that the recovery cylinder 16, the gas separation module device 68, and the refrigerant recovery device 14 are arranged in this order.

Furthermore, the air-conditioning refrigerant separated by the gas separation module device 68 is resent between the refrigerant circuit 30 and the refrigerant recovery device 14 . The separated air-conditioning refrigerant can be switched by the three-way valve 40 to be sent to the refrigerant circuit 30 or sent to the refrigerant recovery device 14 . In the vaporization promotion mode, the air-conditioning refrigerant separated by the gas separation module device 68 is sent to the refrigerant circuit 30, so that the temperature of the refrigerant in the refrigerant circuit 30 can be raised. As a result, vaporization of the refrigerant is accelerated, 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, so that the recovery process of the air-conditioning refrigerant separated by the gas separation module device 68 is performed again.

The gas separation module device 68 is attached to the top of the recovery cylinder 16. Therefore, liquid components such as the liquid refrigerant and mixed water remain at the bottom of the recovery cylinder 16, and the liquid refrigerant and a large amount of water are mixed in the first separation membrane 92A and the second separation membrane 92B of the gas separation module device 68. Therefore, it is possible to suppress the deterioration of the gas separation effect of the first separation membrane 92A and the second separation membrane 92B. The air-conditioning refrigerant is adiabatically compressed and liquefied by the refrigerant recovery device 14 and filled in the recovery cylinder 16 . Therefore, most of the refrigerant is liquefied in the recovery cylinder 16, with only the saturated vapor pressure of the refrigerant being vaporized in the volume of the space in the recovery cylinder 16. FIG. Since 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, and the risk of refrigerant leakage in the gas separation module device 68 can also be reduced.

A circulation loop of the separation device 18, the refrigerant recovery device 14, and the recovery cylinder 16 is formed, and the separation of the non-condensable gas is repeatedly performed by the gas separation module device 68, effectively removing the non-condensable gas in the recovery cylinder 16. elimination of toxic gases is achieved. That is, the separation efficiency can be increased compared to a configuration in which the mixed gas 22 passes through the gas separation module device 68 only once.

Only when non-condensable gas is mixed in the recovery cylinder 16, the non-condensable gas is removed by the gas separation module device 68 by opening the control valve 64. Unnecessary use of gas separation module devices 68 with no or little gas can be avoided.

Since the storage unit 102 of the separation device 18 stores the pressure characteristics 112 of multiple types of refrigerants, the common separation device 18 can be used to recover different types of refrigerants.

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 resent gas refrigerant is discharged from the resending pipe 58C. It can be accurately sent to the collection device 14 . 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 refrigerant is adiabatically compressed in the refrigerant recovery device 14. , the resent gas refrigerant (higher in temperature than in the refrigerant circuit 30), which is a part of the gas refrigerant in the recovery cylinder 16 containing the refrigerant whose temperature is higher than when it flowed into the refrigerant recovery device 14, is used as the refrigerant It can be fed into circuit 30 . As a result, the temperature of the refrigerant in the refrigerant circuit 30 can be raised, gasification of the refrigerant can be promoted, and the refrigerant recovery speed can be improved when refrigerant recovery is restarted.

Furthermore, when the air-conditioning refrigerant contains R32, the non-condensable gas and the refrigerant gas cannot be separated by one gas separation module. In this embodiment, two gas separation modules are used, and the non-condensable gas and the refrigerant gas can be separated by setting the differential pressure between the inside and outside of the separation membrane of each module to an appropriate value.

Embodiment 2.
FIG. 13 is a schematic diagram of a refrigerant recovery system 10A according to Embodiment 2. FIG.

The refrigerant recovery system 10A of the second embodiment differs from the refrigerant recovery system 10 of the first embodiment in that the refrigerant recovery system 10A of the second embodiment includes a directional switching valve 251, a bypass pipe 252, a sensor 253, and A bypass controller 254 is provided.

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 arranged on the connecting pipe 50 .

The direction switching valve 251 connects with the pipe 59 . The mixed gas 24 flows into the direction switching valve 251 from the pipe 59 .

The direction switching valve 251 can switch the outflow destination of the mixed gas 24 that has flowed in. A first outflow destination is the branch pipe 49 . A first end of the branch pipe 49 is connected to the direction switching valve 251 . A second end of the branch pipe 49 connects with the inlet 90B of the second gas separation module 68B.

The second outflow destination is the bypass pipe 252 . A first end of the bypass pipe 252 is connected to the direction switching valve 251 . A second end of the bypass pipe 252 connects with the outlet 94B.

The bypass controller 254 switches the outflow destination of the direction 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 direction switching valve 251 to the branch pipe 49 so that the gas 24 that has permeated the first separation membrane 92A is transferred to the second separation membrane 92A. flow into 92B. Bypass controller 254 switches the outflow destination of direction switching valve 251 to bypass pipe 252 when the air-conditioning refrigerant does not contain R32. Do not let it flow into 92B.

FIG. 14 is a flow chart showing a specific refrigerant recovery method using the refrigerant recovery system 10A according to Embodiment 2. FIG. In FIG. 14, S100 to S104, S126 and S128 are steps performed by the operator, and other steps are steps automatically performed by the refrigerant recovery system 10A.

The flowchart of the second embodiment differs from the flowchart of the first embodiment in that the flowchart of the second embodiment includes S201 to S205 instead of S111, and S206 to S208 instead of S121. It is a point to be prepared.

In S201, when the sensor 253 detects that the air-conditioning refrigerant contains R32, the process proceeds to S202. When the sensor 253 detects that the air-conditioning refrigerant does not contain R32, the process proceeds to S204.

In S202, the bypass controller 254 switches the outflow destination of the direction switching valve 251 to the branch pipe 49.

In S203, the pressure controller 97 starts adjusting the internal and external differential pressure P1o of the first separation membrane 92A of the first gas separation module 68A to the set pressure PA by controlling the first pressure regulator 98A. The adjustment of the internal and external differential pressure P1o of the second separation membrane 92B of the second gas separation module 68B to the set pressure PB is started by controlling the two-pressure regulator 98B. After that, the process proceeds to S112.

In S204, the bypass controller 254 switches the outflow destination of the direction switching valve 251 to the bypass pipe 252.

In S205, the pressure controller 97 starts adjusting the internal and external differential pressure P1o of the first separation membrane 92A of the first gas separation module 68A to the set pressure PA by controlling the first pressure regulator 98A.

In S206, when the sensor 253 detects that the air-conditioning refrigerant contains R32, the process proceeds to S207. When the sensor 253 detects that the air-conditioning refrigerant does not contain R32, the process proceeds to S208.

In S207, the pressure controller 97 finishes adjusting the internal and external differential pressure P1o of the first separation membrane 92A of the first gas separation module 68A to the set pressure PA by controlling the first pressure regulator 98A. The adjustment of the internal and external differential pressure P1o of the second separation membrane 92B of the second gas separation module 68B to the set pressure PB by controlling the pressure regulator 98B is completed.

In S208, the pressure controller 97 finishes adjusting the internal and external differential pressure P1o of the first separation membrane 92A of the first gas separation module 68A to the set pressure PA by controlling the first pressure regulator 98A.

Modification.
The present disclosure is not limited to the above embodiments, and includes, for example, the following modifications.

(1) R32
In the above embodiment, R32 is used as an example of the refrigerant that permeates the first separation membrane but does not permeate the second separation membrane, but the refrigerant is not limited to this. Other refrigerants may be used as the refrigerant that permeates the first separation membrane but does not permeate the second separation membrane. Refrigerants having such properties can generally be referred to as first refrigerants for purposes of explanation.

(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 be used.

(3) Sensor In the second embodiment, the sensor 253 detects whether or not the air-conditioning refrigerant contains R32, but the present invention is not limited to this. Collected refrigerant information indicating the type of refrigerant contained in the air-conditioning refrigerant is input from the input unit and stored in the storage unit, and the bypass control unit determines whether the air-conditioning refrigerant contains R32 based on the collected refrigerant information. It may be determined.

The embodiments disclosed this time should be considered illustrative in all respects and not restrictive. The scope of the present disclosure is indicated by the scope of claims rather than the above description, and is intended to include all changes within the meaning and scope of equivalence to the scope of claims.

10, 10A refrigerant recovery system, 12 air conditioner, 14 refrigerant recovery device, 16 recovery cylinder, 18 separation device, 22, 24 gas, 28 water, 30 refrigerant circuit, 32 accumulator, 34 service port, 36, 90A, 90B inlet, 37, 61, 70 pressure detectors. 38, 96A, 96B outlet, 40 three-way valve, 41 1st port, 42 2nd port, 43 3rd port, 46 liquid inlet/outlet, 48 gas inlet/outlet, 49 branch pipe, 50 connection pipe, 52 front pipe, 54 rear pipe, 56 Shipping piping, 58A, 58B, 58C Retransmitting piping, 59 Piping, 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 dispatch controller, 78 retransmission controller, 80 three-way valve controller, 88A, 88B housing, 92A first separation membrane, 92B second separation membrane, 94A, 94B Discharge port, 97 pressure controller, 98A first pressure regulator, 98B second pressure regulator, 99A first check valve, 99B second check valve, 100 input section, 102 storage section, 104 reference pressure acquisition device, 106 pressure reducing valve controller, 108, 118 determiner, 110 recovered refrigerant information, 112 pressure characteristics, 120 pressure threshold, 122 duration, 211 pressure acquirer, 212 first pressure controller, 213 second pressure controller, 214 second 1 pressure information, 215 second pressure information, 251 directional switching valve, 252 bypass pipe, 253 sensor, 254 bypass controller, ND junction, PA, PB set pressure, RP reference pressure, TH1 first threshold, TH2 second threshold.

Claims

A refrigerant recovery system for recovering an air-conditioning refrigerant from a refrigerant circuit of a refrigerating and air-conditioning equipment,
a refrigerant recovery device for generating a compressed condensed refrigerant by compressing and condensing the air conditioning refrigerant;
a recovery cylinder for recovering the compressed and condensed refrigerant generated by the refrigerant recovery device;
a gas separation module device including a first gas separation module and a second gas separation module for separating the air-conditioning refrigerant as a gas component from the inside of the recovery cylinder in which the compressed condensed refrigerant is recovered;
a retransmission pipe for retransmitting the gas component of the air-conditioning refrigerant separated by the gas separation module device between the refrigerant circuit and the refrigerant recovery device,
The second gas separation module is arranged after the first gas separation module, the first gas separation module includes a first separation membrane, the second gas separation module includes a second separation membrane, A refrigerant recovery system, wherein the gas that permeates the first separation membrane can flow into the second separation membrane.
The air conditioning refrigerant can contain a first refrigerant,
A gas component of the first refrigerant is permeable through the first separation membrane and impermeable through the second separation membrane,
Non-condensable gas is permeable through the first separation membrane and the second separation membrane,
2. The refrigerant recovery system according to claim 1, wherein gas components of refrigerants other than said first refrigerant contained in said air-conditioning refrigerant cannot permeate said first separation membrane and said second separation membrane.
The refrigerant recovery system includes
a first pressure regulator for adjusting the differential pressure between the inside and outside of the first separation membrane;
a second pressure regulator for adjusting the differential pressure between the inside and outside of the second separation membrane;
A pressure controller that controls the first pressure regulator to adjust the differential pressure across the first separation membrane, and controls the second pressure regulator to adjust the differential pressure across the second separation membrane. 3. The refrigerant recovery system of claim 2, further comprising:
When the pressure difference between the inside and outside of the first separation membrane is less than a first threshold value, the gas component of the first refrigerant and the non-condensable gas can permeate the first separation membrane, and the other refrigerant of the gas component cannot permeate the first separation membrane,
When the differential pressure between the inside and outside of the second separation membrane is less than a second threshold value, the non-condensable gas can permeate the second separation membrane, and the gas component of the first refrigerant and the other refrigerant of the gas component cannot permeate the second separation membrane,
The pressure controller controls the internal and external pressure difference of the first separation membrane to a value less than the first threshold, and controls the internal and external pressure difference of the second separation membrane to a value less than the second threshold. 4. The refrigerant recovery system of claim 3.
5. The refrigerant recovery system according to claim 4, wherein the pressure controller controls the differential pressure between the inside and outside of the first separation membrane to be greater than the differential pressure between the inside and outside of the second separation membrane.
The first pressure regulator includes a first back pressure valve arranged downstream of the first gas separation module and regulating the pressure on the primary side of the first pressure regulator;
6. The second pressure regulator according to any one of claims 3 to 5, wherein the second pressure regulator includes a second back pressure valve that is arranged after the second gas separation module and regulates the pressure on the primary side of the second pressure regulator. 2. A refrigerant recovery system according to claim 1.
The molecular diameter of the second separation membrane and the molecular diameter of the first separation membrane are the same, the first separation membrane has polarity, and the second separation membrane does not have polarity. 7. The refrigerant recovery system according to any one of 1 to 6.
The refrigerant recovery system according to claim 7, wherein said first refrigerant is R-32.
The refrigerant recovery system includes
a directional switching valve into which the gas that has permeated the first separation membrane flows and that can switch the outflow destination of the gas;
When the air-conditioning refrigerant contains the first refrigerant, by controlling the direction switching valve, the gas that has permeated the first separation membrane flows into the second separation membrane, and the air-conditioning refrigerant does not contain the first refrigerant, a bypass controller that controls the direction switching valve to prevent the gas that has permeated the first separation membrane from flowing into the second separation membrane. The refrigerant recovery system according to any one of claims 1-8.
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, two and three ports, the first port of the three-way valve being connected to the refrigerant circuit and the second port of the three-way valve being connected to the refrigerant recovery device. and the third port of the three-way valve is connected to the resending pipe,
The three-way valve control section controls the three-way valve so that the first port and the third port of the three-way valve are in communication in a first mode, and controls the three-way valve in a second mode. 10. The refrigerant recovery system according to any one of claims 1 to 9, wherein said three-way valve is controlled so that said second port and said third port are in communication.
Further comprising a pressure detector that detects 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 communication when the pressure in the recovery cylinder is equal to or less than the pressure threshold, and 11. The refrigerant recovery system according to claim 10, wherein the three-way valve is controlled such that the second port and the third port of the three-way valve are in communication when the pressure in the recovery cylinder exceeds the pressure threshold. .
A refrigerant recovery method for recovering an air-conditioning refrigerant from a refrigerant circuit of a refrigeration and air-conditioning equipment,
a refrigerant recovery device compressing and condensing the air conditioning refrigerant to produce a compressed condensed refrigerant;
a recovery cylinder recovering the compressed condensed refrigerant produced by the refrigerant recovery device;
a gas separation module apparatus comprising a first gas separation module and a second gas separation module separating the air conditioning refrigerant from gas components contained within the recovery cylinder in which the compressed condensed refrigerant is recovered;
a retransmission pipe retransmitting gas components of the air-conditioning refrigerant separated by the gas separation module device between the refrigerant circuit and the refrigerant recovery device;
The second gas separation module is arranged after the first gas separation module, the first gas separation module includes a first separation membrane, the second gas separation module includes a second separation membrane, A refrigerant recovery method, wherein the gas that has permeated the first separation membrane can flow into the second separation membrane.