JP4211106B2 - Refrigerant recovery method and refrigerant recovery device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a refrigerant recovery method and a refrigerant recovery apparatus for recovering a refrigerant.
[0002]
[Prior art]
Conventionally, this type of refrigerant recovery apparatus includes one recovery compressor having a fixed capacity, and this recovery compressor recovers the refrigerant from the recovery target machine.
[0003]
[Problems to be solved by the invention]
However, as shown in FIG. 4, an example of a refrigerant recovery apparatus equipped with a large-capacity recovery compressor is capable of recovering 97% of the total refrigerant in the initial four minutes, and has a high recovery speed. Since the clearance of each part of the component parts is large, there is a problem that if the residual gas in the machine to be collected decreases, precise collection cannot be performed. In the example of FIG. 4, the refrigerant recovery rate did not increase from 97% even when the large capacity compressor was continuously operated for 4 minutes or more. However, even with a large capacity compressor, if the machining accuracy is increased, the clearance can be reduced and leakage can be reduced, but in this case, the cost is greatly increased.
[0004]
On the other hand, in a refrigerant recovery apparatus equipped with a small-capacity recovery compressor, since there is relatively little leakage, precise recovery can be performed, but there is a problem that the recovery time becomes longer. As shown in FIG. 4, when the small capacity compressor is operated for 9 minutes, the recovery rate reaches 99%, and the final recovery rate is higher than that of the large capacity compressor. The recovery rate is 84%, and the initial recovery rate is slower than that of a large capacity compressor.
[0005]
SUMMARY OF THE INVENTION An object of the present invention is to provide a refrigerant recovery method and a refrigerant recovery apparatus that can perform high-speed refrigerant recovery, perform precise refrigerant recovery, and improve the final refrigerant recovery rate.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the refrigerant recovery method of the invention of claim 1 operates a large capacity compressor and a small capacity compressor, and the refrigerant from the large capacity compressor and the small capacity compressor. Is a refrigerant recovery method in which the refrigerant is recovered by condensing the refrigerant with one condenser, and the operation of the large capacity compressor is stopped before the small capacity compressor is operated .
[0007]
According to the first aspect of the present invention, the refrigerant can be quickly recovered with a large-capacity compressor, and since the capacity is small, the refrigerant can be collected with a small amount of residue with a compressor having a small clearance (dead space) and little leakage.
[0008]
Further, in the refrigerant recovery method of an embodiment, The first is the refrigerant was recovered by driving a compressor of large capacity, then we recover refrigerant driving a compressor of a small capacity.
[0009]
In this embodiment , first, the large capacity compressor is operated to recover the refrigerant at high speed, and then the small capacity compressor is operated to perform dense refrigerant recovery with little leakage. In addition, precise refrigerant recovery can be performed. Also, if you do not operate the small capacity compressor first, operate only the large capacity compressor, then stop the large capacity compressor and operate only the small capacity compressor, In addition, precise refrigerant recovery without leakage can be performed efficiently.
[0010]
Further, in the inventions of the refrigerant recovery method, before operating the compressor of a small capacity, it stops the operation of the compressor of a large capacity.
[0011]
The inventions of this, before operating the compressor of a small capacity, to stop the operation of the compressor of a large capacity, perform a dense refrigerant recovery in the only compressor of a small capacity from the middle. That is, in the second half of the recovery when the residual gas is reduced, the compressor having a large capacity whose recovery efficiency is greatly reduced can be stopped to improve the operation efficiency of the compressor.
[0012]
Further, the refrigerant recovery device of the invention of claim 2 is a connection port for connecting to the refrigerant circuit,
A large-capacity recovery compressor connected to the connection port;
A small capacity recovery compressor connected to the connection port;
One condenser for condensing the refrigerant from the large and small capacity recovery compressors;
A refrigerant outlet condensed by the condenser;
A refrigerant recovery circuit capable of driving the large and small capacity recovery compressors one by one,
The refrigerant recovery circuit is
A first shut-off valve connected between the one condenser and the large capacity recovery compressor;
And a second closing valve connected between the one condenser and the small-capacity recovery compressor.
[0013]
According to the second aspect of the present invention, it is possible to operate the large-capacity recovery compressor connected to the connection port and recover the refrigerant from the recovery target connected to the connection port at high speed. Moreover, the refrigerant | coolant of the to-be-collected machine connected to the connection port can be collect | recovered densely by operating the small capacity | capacitance recovery compressors connected to the connection port. Then, the refrigerant collected at high speed and densely by the large-capacity recovery compressor and the small-capacity recovery compressor is condensed by the condenser and recovered from the refrigerant discharge port to a predetermined recovery container. .
[0014]
In the invention of claim 2 , the refrigerant of the machine to be recovered connected to the connection port can be recovered at high speed by opening the first closing valve and operating the large capacity recovery compressor. Moreover, the refrigerant | coolant of the to-be-recovered machine connected to the said connection port can be collect | recovered densely by opening the 2nd closing valve and operating the small capacity | capacitance recovery compressor.
[0015]
Further, by opening only the first closing valve, closing the second closing valve, and operating only the large-capacity recovery compressor, high-speed refrigerant recovery can be efficiently performed, and the first closing valve is closed, By opening the shut-off valve and operating only a small-capacity recovery compressor with little leakage, dense refrigerant recovery can be performed efficiently.
[0016]
Moreover, invention of Claim 3 is a refrigerant | coolant collection | recovery apparatus of Claim 2 ,
The large-capacity recovery compressor is a reciprocating compressor, and the small-capacity recovery compressor is a rotary compressor or a swing compressor.
[0017]
In the invention of claim 3 , since the rotary compressor or the swing compressor is a recovery compressor having a small capacity, it is possible to reduce the clearance (dead space) of each part of the component parts compared to the reciprocating compressor. It is easy to configure a small capacity compressor for collecting a precise refrigerant with little leakage. In addition, since the reciprocating compressor is a large-capacity recovery compressor, a large-capacity compressor for high-speed recovery can be configured at a relatively low cost.
[0018]
According to a fourth aspect of the present invention, in the refrigerant recovery apparatus according to any one of the second or third aspects, a pressure sensor for detecting the refrigerant pressure of the refrigerant recovery circuit is provided.
[0019]
The invention of claim 4 is provided with a pressure sensor for detecting the refrigerant pressure of the refrigerant recovery circuit, and the operation of the compressor having a large or small capacity according to the large or small of the refrigerant pressure detected by the pressure sensor. Operation can be selected.
[0020]
The invention of claim 5 provides the refrigerant recovery apparatus according to claim 4 ,
Upon receiving a signal representing the refrigerant pressure detected by the pressure sensor, the large capacity compressor is operated when the refrigerant pressure is equal to or higher than a predetermined pressure, and when the refrigerant pressure is lower than the predetermined pressure, An operation control unit for operating a small-capacity compressor is provided.
[0021]
In the fifth aspect of the present invention, the operation control unit operates at a high speed with a large-capacity compressor when the refrigerant pressure is equal to or higher than the predetermined pressure, that is, when the amount of refrigerant to be recovered is equal to or higher than the predetermined amount. Recover the refrigerant. On the other hand, when the refrigerant pressure is less than a predetermined pressure, that is, when the remaining amount of refrigerant to be recovered is less than a predetermined amount, precise refrigerant recovery can be performed with a small capacity compressor.
[0022]
Further, in the refrigerant recovery apparatus of one reference example, the first connection port to the recovery target circuit,
A second connection port to a large capacity recovery compressor;
A third connection to a small capacity recovery compressor;
A first closing valve connected between the first connection port and the second connection port;
A second closing valve connected between the first connection port and the third connection port;
[0023]
According to the refrigerant recovery apparatus of this reference example, the first connection port is connected to the circuit to be recovered, the second connection port is connected to a large capacity recovery compressor, and the third connection port is used for a small capacity recovery. Connect to the compressor. Thereby, preparation for refrigerant | coolant collection is completed, and a refrigerant | coolant can be collect | recovered from a to-be-collected circuit at high speed by opening a 1st shut-off valve and operating a large capacity compressor next. Next, the refrigerant can be recovered from the circuit to be recovered without leakage by opening the second closing valve and operating the small capacity compressor. Therefore, by using this refrigerant recovery device and opening the first closing valve and the second closing valve in order, it is possible to recover dense refrigerant as a whole with high speed and little residual collection.
[0024]
In this reference example, the refrigerant circuit from the first connection port connected to the circuit to be recovered to the large and small recovery compressors is a single unit, so it can be carried separately from the compressor and handled. It becomes easy. Further, when the refrigerant is recovered, it can be easily connected to large and small recovery compressors using the second connection port and the third connection port.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.
[0026]
Embodiment
FIG. 1 shows a state in which an embodiment of the refrigerant recovery apparatus of the present invention is connected to a refrigerator 100 for refrigerant recovery. The refrigerant recovery apparatus 1 of this embodiment includes a large capacity recovery compressor 2 composed of a reciprocating compressor and a small capacity recovery compressor 3 composed of a rotary compressor. The large capacity compressor 2 and the small capacity compressor 3 are connected in parallel, and the suction side ports 2A, 3A of the compressors 2, 3 are connected to the connection port 5 via the heat exchanger 8. It is connected. Further, the discharge side ports 2B and 3B of the compressors 2 and 3 are connected to the merging pipe 10 via the shut-off valves 6 and 7, respectively. The merging pipe 10 passes through the heat exchanger 8 and It is connected to the discharge port 11.
[0027]
Further, a pressure sensor 13 is attached to the refrigerant pipe 12 connecting the connection port 5 and the heat exchanger 8, and the pressure of the refrigerant in the refrigerant pipe 12 is detected by the pressure sensor 13. The pressure sensor 13 outputs a pressure signal representing the detected refrigerant pressure to the operation control unit 15 including a microcomputer. The operation control unit 15 controls the opening and closing of the closing valves 6 and 7 and the operation and stop of the compressors 2 and 3 based on the pressure signal from the pressure sensor 13.
[0028]
In the refrigerant recovery apparatus 1 of this embodiment, the connection port 5 is connected to the connection port 101A of the refrigerant circuit 101 of the refrigeration machine 100 to be recovered by the connection pipe 21. The refrigerant circuit 101 includes a first heat exchanger 102, an expansion valve 103, a second heat exchanger 104, and a compressor 105 that are sequentially connected in a loop.
[0029]
The operation of the refrigerant recovery apparatus 1 for recovering the refrigerant of the refrigerator 100 will be described with reference to the flowchart of FIG.
[0030]
First, in step S1, the operation control unit 15 operates the compressor 2 having a large capacity, opens the closing valve 6, and simultaneously stops the compressor 3 having a small capacity and closes the closing valve 7. . Thereby, the refrigerant | coolant collection | recovery apparatus 1 can operate | move only the compressor 2 with a big capacity | capacitance, and can collect | recover the refrigerant | coolants of the refrigerator 100 at high speed.
[0031]
Next, as shown in step S2, the operation control unit 15 determines whether or not the refrigerant pressure in the refrigerant pipe 12 represented by the pressure signal from the pressure sensor 13 is equal to or lower than a predetermined value, and the refrigerant pressure is equal to or lower than the predetermined value. When it is determined that the refrigerant pressure is, the process proceeds to step S3, and when it is determined that the refrigerant pressure exceeds the predetermined value, the process returns to step S1.
[0032]
In step S <b> 3, the operation control unit 15 stops the large capacity compressor 2 and closes the closing valve 6, and simultaneously operates the small capacity compressor 3 and opens the closing valve 7. As a result, the refrigerant recovery apparatus 1 can operate only the small capacity compressor 3 and accurately recover the refrigerant remaining in the refrigerant circuit 101 of the refrigerator 100 without leakage.
[0033]
Next, proceeding to step S4, the operation control unit 15 determines whether or not the refrigerant pressure represented by the pressure signal from the pressure sensor 13 has become a specified negative pressure, and when determining that the specified negative pressure has been reached, The compressor 3 having a small capacity is stopped, and the closing valve 7 is closed to complete the refrigerant recovery operation.
[0034]
The refrigerant discharged from the large and small compressors 2 and 3 passes through the junction pipe 10, is condensed by the heat exchanger 8, and is stored in the refrigerant cylinder (not shown) from the discharge port 11.
[0035]
According to this embodiment, first, the large capacity compressor 2 is operated to recover the refrigerant at a high speed, and then the small capacity compressor 3 is operated to perform a precise refrigerant recovery with little leakage. Overall, high-speed and precise refrigerant recovery can be performed. First, only the large capacity compressor 2 is operated without operating the small capacity compressor 3, and then the large capacity compressor 2 is stopped and only the small capacity compressor 3 is operated. As a result, it is possible to efficiently perform high-speed and precise leakage recovery without leakage.
[0036]
In this embodiment, since the rotary compressor is the recovery compressor 3 having a small capacity, it is easier to reduce the clearance (dead space) of each part of the component parts than the reciprocating compressor, and the leakage A small-capacity compressor 3 for recovering a dense refrigerant with a small amount can be easily configured at low cost. In addition, since the reciprocating compressor is the large-capacity recovery compressor 2, the large-capacity compressor 2 for high-speed recovery can be configured at a relatively low cost.
[0037]
[Reference example]
Next, FIG. 2 shows a refrigerant recovery device 80 according to a reference example of the present invention.
[0038]
The refrigerant recovery device 80 includes a first connection port 53 to a circuit to be recovered, a second connection port 63 to a large capacity recovery compressor 51, and a third connection port to a small capacity recovery compressor 52. 68. The first connection port 53 is connected to a first closing valve 65 via a refrigerant pipe 73 and a branch pipe 71, and the first closing valve 65 is connected to the first connection port 53. The first connection port 53 is connected to the second closing valve 70 via the refrigerant pipe 73 and the branch pipe 72, and the second closing valve 70 is connected to the second connection port 68.
[0039]
Further, the refrigerant recovery device 80 includes a pressure sensor 75 attached to the refrigerant pipe 73 connected to the branch pipes 71 and 73 from the first connection port 53. The pressure signal detected by the pressure sensor 75 is input to the operation control unit 77, and the operation control unit 77 controls the opening and closing of the closing valves 65 and 70 based on the pressure signal.
[0040]
The large capacity recovery compressor 51 is a reciprocating compressor. The small-capacity recovery compressor 52 is a rotary compressor. The large capacity compressor 51 and the small capacity compressor 52 are connected to the connection port 53 in parallel. The discharge-side port 51 </ b> A of the large-capacity recovery compressor 51 is connected to the large-capacity discharge port 55 via the large-capacity heat exchanger 60. On the other hand, the discharge-side port 52A of the small-capacity recovery compressor 52 is connected to the small-capacity discharge port 56 via the small-capacity heat exchanger 61.
[0041]
Further, the suction-side port 51B of the large-capacity recovery compressor 51 is connected to the connection port 53 via the large-capacity heat exchanger 60, the connection port 63, and the closing valve 65. On the other hand, the suction-side port 52B of the small-capacity recovery compressor 52 is connected to the connection port 53 via the small-capacity heat exchanger 61, the connection port 68, and the closing valve 70.
[0042]
A pressure sensor 75 is attached to the refrigerant pipe 73 upstream of the pipes 71 and 72 branched from the connection port 53 toward the large capacity compressor 51 and the small capacity compressor 52. The pressure sensor 75 detects the refrigerant pressure in the refrigerant pipe 73. The pressure sensor 75 outputs a pressure signal representing the detected pressure to the operation control unit 77 formed of a microcomputer. The operation control unit 77 controls the opening and closing of the closing valves 65 and 70 and the operation and stop of the compressors 51 and 52 based on the pressure signal from the pressure sensor 75.
[0043]
In the refrigerant recovery apparatus of this reference example, the connection port 53 is connected to the refrigerant circuit of the refrigerator 100 as the refrigerant recovery target as shown in FIG.
[0044]
The operation of the refrigerant recovery apparatus of this reference example for recovering the refrigerant of the refrigerator 100 will be described with reference to the flowchart of FIG.
[0045]
First, in step S1, the operation control unit 77 operates the large-capacity compressor 51 and opens the closing valve 65. At the same time, the operation control unit 77 stops the small-capacity compressor 52 and closes the closing valve 70. . Thereby, only the compressor 51 with a large capacity can be operated, and the refrigerant of the refrigerator 100 can be recovered at high speed.
[0046]
Next, as shown in step S2, the operation control unit 77 determines whether or not the refrigerant pressure in the refrigerant pipe 73 represented by the pressure signal from the pressure sensor 75 is equal to or lower than a predetermined value, and the refrigerant pressure is equal to or lower than the predetermined value. When it is determined that the refrigerant pressure is, the process proceeds to step S3, and when it is determined that the refrigerant pressure exceeds the predetermined value, the process returns to step S1.
[0047]
In step S <b> 3, the operation control unit 77 stops the large capacity compressor 51, closes the closing valve 65, operates the small capacity compressor 52, and opens the closing valve 70. As a result, only the compressor 52 having a small capacity can be operated, and the refrigerant remaining in the refrigerant circuit 101 of the refrigerator 100 can be accurately collected without leakage.
[0048]
Next, proceeding to step S4, the operation control unit 77 determines whether or not the refrigerant pressure represented by the pressure signal from the pressure sensor 75 has reached a specified negative pressure, and determines that the specified negative pressure has been reached. The compressor 52 having a small capacity is stopped, and the closing valve 65 is closed to complete the refrigerant recovery operation.
[0049]
According to the refrigerant recovery device 80 of this reference example, the refrigerant circuit from the first connection port 53 connected to the circuit to be recovered to the large and small recovery compressors 51 and 52 is a single unit. It can be carried separately and is easy to handle. Further, at the time of refrigerant recovery, the second connection port 63 and the third connection port 68 can be used to easily connect to the recovery compressors 51 and 52.
[0050]
According to the refrigerant recovery device 80, as in the above embodiment, the first half can recover the refrigerant at high speed with the large capacity compressor 51, and the second half can perform the precise refrigerant recovery with little leakage with the small capacity compressor 52. it can.
[0051]
In the first half high-speed refrigerant recovery, the refrigerant recovered at high speed by the large-capacity compressor 51 can be efficiently condensed by the large-capacity heat exchanger 60. In the latter half of the low-speed but dense refrigerant recovery, the refrigerant recovered at a relatively low speed by the small-capacity compressor 52 can be efficiently condensed by the small-capacity heat exchanger 61.
[0052]
Further, since the rotary compressor is a small-capacity recovery compressor 52, it is easier to reduce the clearance (dead space) of each part of the component parts than a reciprocating compressor, and a dense refrigerant with less leakage. Recovery can be performed. In addition, since the reciprocating compressor is replaced with a large-capacity recovery compressor 51, the large-capacity compressor 51 for high-speed recovery can be configured at a relatively low cost.
[0053]
In the embodiment and the reference example, the large capacity compressors 2 and 51 are stopped, and then the small capacity compressors 3 and 52 are operated . Moreover, in the said embodiment and the reference example, although the small capacity compressors 3 and 52 were used as the rotary compressor, it is good also as a swing compressor. Moreover, in the said embodiment, although the one heat exchanger 8 was provided as a condenser, when two heat exchangers independent with respect to the compressors 2 and 3 are provided, it becomes a reference example. In the above reference example, the pipes 71 and 72 on the suction side are joined to the pipe 73, but when the recovery target circuit 101 has two connection ports 101A and 101B as in the refrigerator 100 shown in FIG. As shown in FIG. 2B, the joining pipe 73 may be eliminated and the pipes 71 and 72 may be directly connected to the connection ports 101A and 101B.
[0054]
【The invention's effect】
As is clear from the above, the refrigerant recovery method of the invention of claim 1 can recover the refrigerant quickly with a large capacity compressor, and is recovered with a compressor having a small clearance (dead space) and less leakage because of its small capacity. Dense refrigerant can be recovered with little residue.
[0055]
The refrigerant recovery method of one embodiment first operates a large capacity compressor to recover the refrigerant at a high speed, and then operates a small capacity compressor to perform a precise refrigerant recovery with little leakage. Therefore, high-speed and precise refrigerant recovery can be performed as a whole. Also, if you do not operate the small capacity compressor first, operate only the large capacity compressor, then stop the large capacity compressor and operate only the small capacity compressor, In addition, precise refrigerant recovery without leakage can be performed efficiently.
[0056]
The refrigerant recovery method of this inventions, before operating the compressor of a small capacity, stops the operation of the compressor of a large capacity, it performs dense refrigerant recovery only compressor of a small capacity in the middle. That is, in the second half of the recovery when the residual gas is reduced, the compressor having a large capacity whose recovery efficiency is greatly reduced can be stopped to improve the operation efficiency of the compressor.
[0057]
In the refrigerant recovery device of the second aspect of the invention, the refrigerant having a large capacity connected to the connection port can be operated to recover the refrigerant from the recovery target connected to the connection port at a high speed. Moreover, the refrigerant | coolant of the to-be-collected machine connected to the connection port can be collect | recovered densely by operating the small capacity | capacitance recovery compressors connected to the connection port.
[0058]
In the invention of claim 2 , the refrigerant of the machine to be collected connected to the connection port can be collected at a high speed by opening the first closing valve and operating a large capacity collecting compressor. Moreover, the refrigerant | coolant of the to-be-recovered machine connected to the said connection port can be collect | recovered densely by opening the 2nd closing valve and operating the small capacity | capacitance recovery compressor. Further, by opening only the first closing valve, closing the second closing valve, and operating only the large-capacity recovery compressor, high-speed refrigerant recovery can be efficiently performed, and the first closing valve is closed, By opening the shut-off valve and operating only a small-capacity recovery compressor with little leakage, dense refrigerant recovery can be performed efficiently.
[0059]
In the invention of claim 3 , since the rotary compressor or the swing compressor is a small-capacity recovery compressor, the clearance (dead space) of each part of the component parts can be reduced compared to the reciprocating compressor. Therefore, it is possible to easily construct a small-capacity compressor for recovering a dense refrigerant with little leakage. In addition, since the reciprocating compressor is a large-capacity recovery compressor, a large-capacity compressor for high-speed recovery can be configured at a relatively low cost.
[0060]
Further, since the invention of claim 4 is provided with a pressure sensor for detecting the refrigerant pressure of the refrigerant recovery circuit, the operation of the compressor having a large or small capacity according to the large or small refrigerant pressure detected by the pressure sensor. And non-operating can be selected.
[0061]
Further, in the invention of claim 5 , when the operation control unit receives a signal indicating the refrigerant pressure detected by the pressure sensor and the refrigerant pressure is equal to or higher than a predetermined pressure, that is, the remaining refrigerant amount to be recovered is When the amount exceeds a predetermined amount, high-speed refrigerant recovery is performed with a large capacity compressor. On the other hand, when the refrigerant pressure is less than a predetermined pressure, that is, when the remaining amount of refrigerant to be recovered is less than a predetermined amount, precise refrigerant recovery can be performed with a small capacity compressor.
[0062]
In one reference example, the first connection port to the circuit to be recovered, the second connection port to the large-capacity recovery compressor, the third connection port to the small-capacity recovery compressor, A first closing valve connected between the first connection port and the second connection port, and a second closing valve connected between the first connection port and the third connection port.
[0063]
According to the refrigerant recovery apparatus of this reference example, the first connection port is connected to the circuit to be recovered, the second connection port is connected to a large capacity recovery compressor, and the third connection port is recovered to a small capacity. Connect to compressor. Thereby, preparation for refrigerant | coolant collection is completed, and a refrigerant | coolant can be collect | recovered from a to-be-collected circuit at high speed by opening a 1st shut-off valve and operating a large capacity compressor next. Next, the refrigerant can be recovered from the circuit to be recovered without leakage by opening the second closing valve and operating the small capacity compressor. Therefore, by using this refrigerant recovery device and opening the first closing valve and the second closing valve in order, it is possible to recover dense refrigerant as a whole with high speed and little residual collection.
[0064]
In this reference example, the refrigerant circuit from the first connection port connected to the circuit to be recovered to the large and small recovery compressors is a single unit, so it can be carried separately from the compressor and handled. It becomes easy. Further, when the refrigerant is recovered, it can be easily connected to large and small recovery compressors using the second connection port and the third connection port.
[Brief description of the drawings]
FIG. 1 is a refrigerant circuit diagram showing an embodiment of a refrigerant recovery apparatus of the present invention.
FIG. 2 is a refrigerant circuit diagram showing a reference example of the refrigerant recovery apparatus of the present invention.
FIG. 3 is a flowchart illustrating a refrigerant recovery operation of the embodiment and the reference example.
FIG. 4 is a chart showing refrigerant recovery characteristics of a large capacity compressor and a small capacity compressor.
[Explanation of symbols]
1 ... refrigerant recovery device, 2,51 ... high capacity recovery compressor,
2A, 51B ... suction side port, 3, 52 ... small capacity recovery compressor,
3A, 52B ... suction side port, 5, 53 ... connection port,
6, 7, 65, 70 ... shut-off valve, 8, 60, 61 ... heat exchanger, 10 ... merge pipe,
11, 55, 56 ... discharge port, 12, 73 ... refrigerant piping,
13, 75 ... Pressure sensor, 15, 77 ... Operation control unit, 21 ... Connection piping,
100 ... refrigerator, 101 ... refrigerant circuit, 101A ... connection port,
102 ... 1st heat exchanger, 103 ... Expansion valve, 104 ... 2nd heat exchanger,
105: Compressor.

Claims (5)

The large capacity compressor (2) and the small capacity compressor (3) are operated, and the refrigerant from the large capacity compressor and the small capacity compressor is condensed in one condenser to collect the refrigerant. Refrigerant recovery method
A refrigerant recovery method characterized in that the operation of the large capacity compressor ( 2 ) is stopped before the small capacity compressor ( 3 ) is operated . A connection port (5) for connection to the refrigerant circuit (101);
A large capacity recovery compressor (2) connected to the connection port (5);
A small capacity recovery compressor (3) connected to the connection port (5);
One condenser (8) for condensing the refrigerant from the large and small capacity recovery compressors (2, 3);
A refrigerant outlet (11) condensed by the condenser (8);
A refrigerant recovery circuit (10, 12) capable of driving the large and small capacity recovery compressors one by one;
The refrigerant recovery circuit is
A first closing valve (6) connected between the one condenser (8) and the large capacity recovery compressor (2);
A refrigerant recovery apparatus comprising a second closing valve (7) connected between the one condenser (8) and the small capacity recovery compressor (3). The refrigerant recovery apparatus according to claim 2 ,
The large capacity recovery compressor (2) is a reciprocating compressor, and the small capacity recovery compressor (3) is a rotary compressor or a swing compressor. In the refrigerant recovery device according to claim 2 or 3 ,
A refrigerant recovery apparatus comprising a pressure sensor (13) for detecting a refrigerant pressure of the refrigerant recovery circuit. The refrigerant recovery apparatus according to claim 4 , wherein
In response to the signal representing the refrigerant pressure detected by the pressure sensor (13), when the refrigerant pressure is equal to or higher than a predetermined pressure, the large capacity compressor (2) is operated, and the refrigerant pressure is less than the predetermined pressure. A refrigerant recovery apparatus comprising an operation control section (15) for operating the small capacity compressor (3).

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