CN106032955B - Refrigerant recovery unit and outdoor unit connected to the same - Google Patents

Refrigerant recovery unit and outdoor unit connected to the same Download PDF

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Publication number
CN106032955B
CN106032955B CN201510102367.9A CN201510102367A CN106032955B CN 106032955 B CN106032955 B CN 106032955B CN 201510102367 A CN201510102367 A CN 201510102367A CN 106032955 B CN106032955 B CN 106032955B
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refrigerant
port
unit
storage container
recovery
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CN106032955A (en
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冈本敦
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Daikin Industries Ltd
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Daikin Industries Ltd
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Abstract

The present invention has been made in an effort to provide an additionally provided refrigerant recovery unit capable of recovering only refrigerant in an indoor unit and a communication pipe when the indoor unit is moved. In the refrigerant recovery unit (50), after a normal port (371) of the liquid side stop valve (37) is closed and a refrigerant inflow port (51) is connected to a maintenance port (372) of the liquid side stop valve (37) via a pipe (511), the refrigerant is circulated in a heating operation cycle and gas refrigerant is pushed in from the gas side stop valve (38), whereby the liquid refrigerant in the indoor heat exchanger (21), the liquid side communication pipe (14), and the gas side communication pipe (16) can be pushed out from the maintenance port (372) of the liquid side stop valve (37), and the liquid refrigerant can be stored in the refrigerant storage container (55).

Description

Refrigerant recovery unit and outdoor unit connected to the same
Technical Field
The present invention relates to a refrigerant recovery unit, and more particularly to a refrigerant recovery unit additionally installed in an outdoor unit or the like.
Background
When an existing indoor unit of an air conditioner is moved, added, or changed, it is necessary to draw out refrigerant. Conventionally, for example, in a refrigeration apparatus described in patent document 1 (japanese patent laid-open No. 2000-249385), a method of storing refrigerant in an outdoor heat exchanger, an accumulator, and the like of an outdoor unit by refrigerant recovery is employed.
Documents of the prior art
Patent document
Patent document 1: japanese patent laid-open No. 2000-249385
However, the above method is difficult to recover the entire amount in a machine type having a large amount of refrigerant. In addition, the refrigerant can be recovered by the refrigerant recovery device, but it is difficult to recover only the refrigerant in the indoor unit, and as a result, it is necessary to recover the entire amount, and the recovery time is long. In addition, the refrigerant recovered by the refrigerant recovery device needs to be regenerated, and is difficult to use.
Disclosure of Invention
The present invention has been made in an effort to provide an additionally provided refrigerant recovery unit capable of recovering only refrigerant in an indoor unit and a communication pipe when the indoor unit is moved.
A refrigerant recovery unit according to a first aspect of the present invention is a refrigerant recovery unit that is temporarily attached to a refrigeration apparatus that forms a refrigerant circuit including a refrigerant inflow port, a refrigerant outflow port, a refrigerant storage container, and a pressure reducing mechanism, by an indoor unit, an outdoor unit, and a communication pipe connecting the indoor unit and the outdoor unit, and performs refrigerant recovery and refrigerant return. The refrigerant inflow port is connected to a high-pressure line of the refrigerant circuit at the time of refrigerant recovery. The refrigerant outflow port is connected to a low-pressure line of the refrigerant circuit when the refrigerant returns. The refrigerant storage container stores the refrigerant flowing into the refrigerant inflow port. The pressure reducing mechanism is connected between the refrigerant storage container and the refrigerant outflow port.
In general, two shut valves are provided in an outdoor unit of an air conditioner, and a communication pipe connected to an indoor unit is connected to each connection port of the shut valves. In addition to the connection port, each shut-off valve also has a service port communicating with the connection port.
Therefore, in this refrigerant recovery unit, when the refrigerant is circulated in a cycle of a heating operation, for example, the liquid refrigerant can be stored in the refrigerant storage container by closing a stop valve (liquid-side stop valve) communicating with the refrigerant outlet side of the indoor unit, connecting the refrigerant inflow port to a maintenance port of the stop valve, and then pressing the gas refrigerant from the stop valve (gas-side stop valve) communicating with the refrigerant inlet side of the indoor unit, thereby pressing the liquid refrigerant in the indoor unit and the communication pipe out of the maintenance port.
A refrigerant recovery unit according to a second aspect of the present invention is the refrigerant recovery unit according to the first aspect, further comprising a temperature sensor that directly or indirectly detects a temperature of the refrigerant flowing from the refrigerant inflow port to the refrigerant storage container.
In this refrigerant recovery unit, the refrigerant is recovered from the indoor unit and the communication pipe, and when the amount of refrigerant in the pipe decreases, the refrigerant evaporates to become a gas refrigerant, and therefore, the temperature of the refrigerant flowing into the refrigerant inflow port decreases. By detecting the temperature and determining whether the detected value is equal to or less than a predetermined value, the end of refrigerant recovery can be determined.
A refrigerant recovery unit according to a third aspect of the present invention is the refrigerant recovery unit according to the first aspect, further comprising an electromagnetic valve connected between the pressure reducing mechanism and the refrigerant outflow port.
In this refrigerant recovery unit, the refrigerant can be prevented from flowing out from the refrigerant storage container via the pressure reducing mechanism except when the refrigerant is returned.
A refrigerant recovery unit according to a fourth aspect of the present invention is the refrigerant recovery unit according to the first aspect, further comprising a safety valve that opens when the pressure in the refrigerant storage container is equal to or higher than a predetermined pressure.
In this refrigerant recovery unit, an abnormal pressure rise in the refrigerant storage container at the time of refrigerant recovery can be prevented.
A refrigerant recovery unit according to a fifth aspect of the present invention is the refrigerant recovery unit according to any of the first through fourth aspects, wherein the outdoor unit includes a compressor, a first stop valve, a second stop valve, and a switching valve. The first shutoff valve has a first port connected to a first communication pipe connected to the indoor unit and through which a liquid refrigerant flows, and a first service port communicated with the first communication pipe. The second shutoff valve has a second port connected to a second communication pipe that is connected to the indoor unit and through which the gas refrigerant flows. The switching valve flows high-pressure refrigerant from the compressor to the first port of the first stop valve or the second port of the second stop valve. The refrigerant inflow port is connected to the first maintenance port, and performs an operation of flowing the high-pressure refrigerant to the second port in a state where the first port is closed and the second port is open.
In this refrigerant recovery unit, since the high-pressure refrigerant flows to the second port, the refrigerant in the indoor unit and each communication pipe is pushed by the high-pressure refrigerant and pushed out from the first maintenance port, and is stored in the refrigerant storage container via the refrigerant inflow port. As a result, the refrigerant in the indoor unit and the communication pipes is collected in the refrigerant storage container.
A refrigerant recovery unit according to a sixth aspect of the present invention is the refrigerant recovery unit according to any of the first through fourth aspects, wherein the outdoor unit includes a compressor, a first stop valve, a second stop valve, a third stop valve, and a switching valve. The first shutoff valve has a first port connected to a first communication pipe connected to the indoor unit and through which a liquid refrigerant flows. The second shutoff valve has a second port connected to a second communication pipe that is connected to the indoor unit and through which the gas refrigerant flows. The third cut-off valve has a third port that branches off the refrigerant flowing to the first port of the first cut-off valve. The switching valve flows high-pressure refrigerant from the compressor to the first port of the first stop valve or the second port of the second stop valve. The refrigerant inflow port is connected to the third port, and the operation of flowing the high-pressure refrigerant to the first port is performed in a state where the first port is closed and the second port and the third port are open.
In this refrigerant recovery unit, the high-pressure refrigerant flows to the first port and is branched to flow toward the third port, a part of the refrigerant in the outdoor unit is stored in the refrigerant storage container, and the refrigerant in the indoor unit and the communication pipes is recovered to the outdoor unit.
A refrigerant recovery unit according to a seventh aspect of the present invention is the refrigerant recovery unit according to any of the first through fourth aspects, further comprising a refrigerant recovery compressor having a suction side connected to the top surface of the refrigerant storage container and a discharge side connected to the refrigerant outflow port side. The outdoor unit has a first cut-off valve and a second cut-off valve. The first shutoff valve has a first port connected to a first communication pipe connected to the indoor unit and through which a liquid refrigerant flows, and a first service port communicated with the first communication pipe. The second shutoff valve has a second port connected to a second communication pipe that is connected to the indoor unit and through which the gas refrigerant flows, and a second service port that communicates with the second communication pipe. The refrigerant inflow port is connected to the first maintenance port, the refrigerant outflow port is connected to the second maintenance port, and the refrigerant recovery compressor is operated in a state where the first port and the second port are closed.
In this refrigerant recovery unit, the high-pressure gas refrigerant is pushed from the refrigerant outflow port to the second communication pipe through the second maintenance port of the second shutoff valve by the operation of the refrigerant recovery compressor, and therefore the liquid refrigerant in the second communication pipe, the indoor unit, and the first communication pipe is pushed out to the refrigerant inflow port through the first maintenance port of the first shutoff valve. As a result, the refrigerant in the indoor unit and the communication pipes is collected in the refrigerant storage container.
A refrigerant recovery unit according to an eighth aspect of the present invention is the refrigerant recovery unit according to any one of the first to fourth aspects, further comprising: a heat exchanger having an outlet pipe connected to a top surface of the refrigerant storage container; a blower that blows air toward the heat exchanger; and a refrigerant recovery compressor having a suction side connected to the refrigerant outflow port side and a discharge side connected to an inlet pipe of the heat exchanger. The outdoor unit has a first cut-off valve and a second cut-off valve. The first shutoff valve has a first port connected to a first communication pipe connected to the indoor unit and through which a liquid refrigerant flows, and a first service port communicated with the first communication pipe. The second shutoff valve has a second port connected to a second communication pipe that is connected to the indoor unit and through which the gas refrigerant flows, and a second service port that communicates with the second communication pipe. The refrigerant inflow port is connected to the first maintenance port, the refrigerant outflow port is connected to the second maintenance port, and the refrigerant recovery compressor is operated in a state where the first port and the second port are closed.
In this refrigerant recovery unit, the refrigerant in the second communication pipe, the indoor unit, and the first communication pipe is sucked into the compressor from the second relief port of the second shutoff valve through the refrigerant outflow port by the operation of the refrigerant recovery compressor. The compressed refrigerant is sent to the heat exchanger, condensed, and stored in the refrigerant storage container. The refrigerant inflow port is connected to the first maintenance port, and the refrigerant inflow port is connected to the refrigerant-storage container, and therefore, the first maintenance port becomes high pressure. Therefore, the residual refrigerant in the first communication pipe, the indoor unit, and the second communication pipe is pushed out so as to flow toward the second repaired port side. As a result, the refrigerant in the indoor unit and the communication pipes is collected in the refrigerant storage container.
An outdoor unit according to a ninth aspect of the present invention is an outdoor unit connected to the refrigerant recovery unit according to the second aspect, and includes a control unit that executes a refrigerant recovery operation mode in which refrigerant is recovered in the refrigerant storage container. The control unit has a connection unit connected to the temperature sensor, and executes the refrigerant recovery operation mode on condition that it is determined that the temperature sensor is connected to the connection unit.
In this outdoor unit, the refrigerant recovery operation can be performed even when the refrigerant recovery unit is not provided with the control unit.
An outdoor unit according to a tenth aspect of the present invention is an outdoor unit connected to the refrigerant recovery unit according to the third aspect, and includes a control unit that executes a refrigerant return operation mode in which the refrigerant is returned from the refrigerant storage container to the refrigerant circuit. The control unit has a connection unit connected to the solenoid valve, and executes the refrigerant return operation mode on condition that it is determined that the solenoid valve is connected to the connection unit.
In this outdoor unit, the refrigerant return operation can be performed without providing a control unit in the refrigerant recovery unit.
An outdoor unit according to an eleventh aspect of the present invention is the outdoor unit according to any of the first through tenth aspects, wherein the refrigerant to be recovered and returned in the refrigerant circuit is R32. In the outdoor unit, by using a single refrigerant, the refrigerant can be easily reused.
In the refrigerant recovery unit according to the first aspect of the present invention, for example, when the refrigerant is circulated in a cycle of a heating operation, the stop valve (liquid-side stop valve) communicating with the refrigerant outlet side of the indoor unit is closed, the refrigerant inflow port is connected to the maintenance port of the stop valve, and then the gas refrigerant is pushed in from the stop valve (gas-side stop valve) communicating with the refrigerant inlet side of the indoor unit, whereby the liquid refrigerant in the indoor unit and the communication pipe can be pushed out from the maintenance port, and the liquid refrigerant can be stored in the refrigerant storage container.
In the refrigerant recovery unit according to the second aspect of the present invention, the refrigerant is recovered from the indoor unit and the communication pipe, and when the amount of refrigerant in the pipe decreases, the refrigerant evaporates and becomes a gas refrigerant, and therefore, the temperature of the refrigerant flowing into the refrigerant inflow port decreases. By detecting the temperature and determining whether the detected value is equal to or less than a predetermined value, the end of refrigerant recovery can be determined.
In the refrigerant recovery unit according to the third aspect of the present invention, the refrigerant can be prevented from flowing out from the refrigerant storage container via the pressure reducing mechanism except when the refrigerant is returned.
In the refrigerant recovery unit according to the fourth aspect of the present invention, an abnormal pressure rise in the refrigerant storage container at the time of refrigerant recovery can be prevented.
In the refrigerant recovery unit according to the fifth aspect of the present invention, since the high-pressure refrigerant flows to the second port, the refrigerant in the indoor unit and each communication pipe is pushed by the high-pressure refrigerant and is pushed out from the first maintenance port, and is stored in the refrigerant storage container via the refrigerant inflow port. As a result, the refrigerant in the indoor unit and the communication pipes is collected in the refrigerant storage container.
In the refrigerant recovery unit according to the sixth aspect of the present invention, since the high-pressure refrigerant flows to the first port and is branched to flow toward the third port, a part of the refrigerant in the outdoor unit is stored in the refrigerant storage container, and the refrigerant in the indoor unit and the refrigerant in each communication pipe are recovered to the outdoor unit, the refrigerant recovery unit is substantially the same as the refrigerant in the indoor unit and the refrigerant in each communication pipe are stored in the refrigerant storage container.
In the refrigerant recovery unit according to the seventh aspect of the present invention, since the high-pressure gas refrigerant is pushed from the refrigerant outflow port to the second communication pipe through the second maintenance port of the second shutoff valve by the operation of the refrigerant recovery compressor, the liquid refrigerant in the second communication pipe, the indoor unit, and the first communication pipe is pushed out to the refrigerant inflow port through the first maintenance port of the first shutoff valve. As a result, the refrigerant in the indoor unit and the communication pipes is collected in the refrigerant storage container.
In the refrigerant recovery unit according to the eighth aspect of the present invention, the refrigerant in the second communication pipe, the indoor unit, and the first communication pipe is sucked into the refrigerant recovery compressor from the second relief port of the second shutoff valve through the refrigerant outflow port by the operation of the refrigerant recovery compressor. The compressed refrigerant is sent to the heat exchanger, condensed, and stored in the refrigerant storage container. The refrigerant inflow port is connected to the first maintenance port, and the refrigerant inflow port is connected to the refrigerant-storage container, and therefore, the first maintenance port becomes high pressure. Therefore, the residual refrigerant in the first communication pipe, the indoor unit, and the second communication pipe is pushed out so as to flow toward the second repaired port side. As a result, the refrigerant in the indoor unit and the communication pipes is collected in the refrigerant storage container.
In the outdoor unit according to the ninth aspect of the present invention, the refrigerant recovery operation can be performed even when the refrigerant recovery unit is not provided with the control unit.
In the outdoor unit according to the tenth aspect of the present invention, the refrigerant recovery operation can be performed without providing a control unit in the refrigerant recovery unit.
In the outdoor unit according to the eleventh aspect of the present invention, the refrigerant can be easily reused by using a single refrigerant.
Drawings
Fig. 1 is a refrigerant circuit diagram of a refrigeration apparatus connected to a refrigerant recovery unit according to a first embodiment of the present invention.
Fig. 2 is a block diagram of the control section.
Fig. 3 is a control flowchart of the refrigerant recovery operation according to the first embodiment.
Fig. 4 is a control flowchart of the refrigerant returning operation according to the first embodiment.
Fig. 5 is a refrigerant circuit diagram of a refrigeration apparatus connected to a refrigerant recovery unit according to a second embodiment of the present invention.
Fig. 6 is a control flowchart of the refrigerant recovery operation according to the second embodiment.
Fig. 7 is a circuit diagram of a refrigeration apparatus connected to the refrigerant recovery unit of the third embodiment.
Fig. 8 is a control block diagram of the third embodiment.
Fig. 9 is a control flowchart of the refrigerant recovery operation according to the third embodiment.
Fig. 10 is a circuit diagram of a refrigeration apparatus connected to the refrigerant recovery unit of the fourth embodiment.
Fig. 11 is a control block diagram of the fourth embodiment.
Fig. 12 is a control flowchart of the refrigerant recovery operation according to the fourth embodiment.
Description of the symbols
14 liquid side communication piping (first communication piping)
16 gas side communication pipe (second communication pipe)
20 indoor unit
30 outdoor unit
31 compressor
32 four-way switching valve (switching valve)
37 liquid side stop valve (first stop valve)
371 common Port (first Port)
372 service port (first service port)
38 gas side stop valve (second stop valve)
381 common Port (second port)
382 service port (second service port)
40 third stop valve
401 Normal port (third port)
50 refrigerant recovery unit
51 refrigerant inflow port
52 refrigerant outflow port
55 refrigerant storage container
56 pressure reducing mechanism
59 solenoid valve
61 compressor for recovering refrigerant
63 Heat exchanger
65 fan (blower)
80 control part
81 temperature sensor
83 safety valve
Detailed Description
Embodiments of the present invention will be described below with reference to the drawings. The following embodiments are specific examples of the present invention, and do not limit the technical scope of the present invention.
< first embodiment >
(1) Structure of refrigerating apparatus 1
Fig. 1 is a circuit diagram of a refrigeration apparatus 1 connected to a refrigerant recovery unit 50 according to a first embodiment of the present invention. The refrigeration apparatus 1 is constituted by an indoor unit 20 and an outdoor unit 30. The refrigeration apparatus 1 performs refrigeration and heating in a building by performing a vapor compression refrigeration cycle operation.
In the refrigeration apparatus 1, the refrigerant circuit 10 is configured by connecting together the compressor 31, the four-way switching valve 32, the outdoor heat exchanger 33, the outdoor expansion valve 34, the indoor heat exchanger 21, the accumulator 36, and the like by the liquid-side communication pipe 14 and the gas-side communication pipe 16.
During the cooling operation, the four-way switching valve 32 is in a state shown by the solid line in fig. 1, that is, in a state in which the discharge side of the compressor 31 is connected to the gas side of the outdoor heat exchanger 33 and the suction side of the compressor 31 is connected to the gas side of the indoor heat exchanger 21 via the accumulator 36. In the cooling operation, the refrigeration apparatus 1 causes the outdoor heat exchanger 33 to function as a radiator and causes the indoor heat exchanger 21 to function as an evaporator.
During the heating operation, the four-way switching valve 32 is in a state shown by the solid line in fig. 1, that is, in a state in which the discharge side of the compressor 31 is connected to the gas side of the indoor heat exchanger 21 and the suction side of the compressor 31 is connected to the gas side of the outdoor heat exchanger 33 via the accumulator 36. In the heating operation, the refrigeration apparatus 1 causes the indoor heat exchanger 21 to function as a radiator and causes the outdoor heat exchanger 33 to function as an evaporator.
(1-1) indoor Unit 20
The indoor unit 20 is installed on an indoor wall surface by being hung on a wall surface or the like, or installed on an indoor ceiling of a building or the like by being buried or hung. The indoor unit 20 includes an indoor heat exchanger 21, an indoor expansion valve 22, and an indoor fan 71.
(1-1-1) indoor Heat exchanger 21
The indoor heat exchanger 21 is a cross-fin type fin-and-tube heat exchanger including a heat transfer tube and a plurality of fins. A heat exchanger temperature sensor 211 is installed at an appropriate position of the indoor heat exchanger 21.
In the present embodiment, the indoor heat exchanger 21 is a cross-fin type fin-and-tube heat exchanger, but is not limited thereto, and another type of heat exchanger may be employed.
(1-1-2) indoor expansion valve 22
The indoor expansion valve 22 is an electric expansion valve. The indoor expansion valve 22 is connected to the liquid side of the indoor heat exchanger 21 in order to adjust the flow rate of the refrigerant flowing through the indoor side of the refrigerant circuit 10. The indoor expansion valve 22 can also shut off the flow of the refrigerant.
(1-1-3) indoor Fan 71
The indoor unit 20 has an indoor fan 71. The indoor fan 71 sucks indoor air into the indoor unit 20, causes the indoor air to exchange heat with the refrigerant in the indoor heat exchanger 21, and then supplies the air to the room as supply air. The indoor fan 71 can change the air volume of the air supplied to the indoor heat exchanger 21 within a predetermined air volume range.
(1-2) outdoor Unit 30
The outdoor unit 30 internally houses a compressor 31, a four-way switching valve 32, an outdoor heat exchanger 33, an outdoor expansion valve 34, an accumulator 36, a supercooling heat exchanger 45, an outdoor fan 73, and the like. The outdoor unit 30 also houses a branch circuit 19 that passes through the supercooling heat exchanger 45.
(1-2-1) compressor 31
The compressor 31 is a variable displacement compressor, and the rotational speed of the motor is controlled by an inverter. In the present embodiment, there is only one compressor 31, but the present invention is not limited to this, and two or more compressors may be connected in parallel depending on the number of connected air-conditioning indoor units.
(1-2-2) four-way switching valve 32
The four-way switching valve 32 is a valve that switches the flow direction of the refrigerant. During the cooling operation, the four-way switching valve 32 connects the discharge side of the compressor 31 to the gas side of the outdoor heat exchanger 33, and connects the suction side of the compressor 31 (specifically, the accumulator 36) to the gas-side communication pipe 16 (cooling operation state: see the solid line of the four-way switching valve 32 in fig. 1).
As a result, the outdoor heat exchanger 33 functions as a condenser of the refrigerant, and the indoor heat exchanger 21 functions as an evaporator of the refrigerant.
During the heating operation, the four-way switching valve 32 connects the discharge side of the compressor 31 to the gas side communication pipe 16, and connects the suction side of the compressor 31 to the gas side of the outdoor heat exchanger 33 (heating operation state: see the broken line of the four-way switching valve 32 in fig. 1).
As a result, the indoor heat exchanger 21 functions as a condenser of the refrigerant, and the outdoor heat exchanger 33 functions as an evaporator of the refrigerant.
(1-2-3) outdoor Heat exchanger 33
The outdoor heat exchanger 33 is a cross-fin type finned tube heat exchanger. However, the present invention is not limited to this, and other types of heat exchangers may be used. The gas side of the outdoor heat exchanger 33 is connected to the four-way switching valve 32, and the liquid side of the outdoor heat exchanger 33 is connected to the outdoor expansion valve 34.
(1-2-4) outdoor expansion valve 34
The outdoor expansion valve 34 is an electrically driven expansion valve that adjusts the pressure, flow rate, and the like of the refrigerant flowing outside the outdoor side of the refrigerant circuit 10. The outdoor expansion valve 34 is disposed downstream of the outdoor heat exchanger 33 in the refrigerant flow direction in the refrigerant circuit 10 during the cooling operation.
During the cooling operation, the opening degree of the outdoor expansion valve 34 is fully opened. On the other hand, during the heating operation, the opening degree of the outdoor expansion valve 34 is adjusted so as to reduce the pressure of the refrigerant flowing into the outdoor heat exchanger 33 to a pressure at which the refrigerant can be evaporated in the outdoor heat exchanger 33 (i.e., an evaporation pressure).
(1-2-5) storage tank 36
The accumulator 36 separates liquid refrigerant from gaseous refrigerant. The receiver 36 is connected to a suction return pipe 361, and the suction return pipe 361 allows the refrigerant to be drawn out from the receiver 36 and returned to the suction side of the compressor 31. The intake return pipe 361 is provided with an intake return opening/closing valve 362. The adsorption return on-off valve 362 is an electromagnetic valve.
(1-2-6) supercooling heat exchanger 45
The supercooling heat exchanger 45 is a heat exchanger that exchanges heat between the refrigerant cooled in the outdoor heat exchanger 33 or the indoor heat exchanger 21 and the refrigerant flowing through the branch circuit 19, and has a flow path through which two paths of refrigerants flow in an opposing manner. A branch-side expansion valve 47 is provided at a position upstream of the branch circuit 19, which is the supercooling heat exchanger 45.
(1-2-7) outdoor fan 73
The outdoor fan 73 sends the sucked outdoor air to the outdoor heat exchanger 33 and causes the air to exchange heat with the refrigerant. The outdoor fan 73 can change the air volume when supplied to the outdoor heat exchanger 33. The outdoor fan 73 is a propeller or the like, and is driven by a motor configured by a dc fan motor or the like.
(1-2-8) liquid side shutoff valve 37
The liquid-side shutoff valve 37 is disposed on the downstream side of the outdoor expansion valve 34 and on the upstream side of the liquid-side communication pipe 14 in the refrigerant circuit 10 in the flow direction of the refrigerant during the cooling operation.
The liquid-side shutoff valve 37 includes: typically ports 371; a service port 372; and a valve 373 for opening and closing the normal port 371. The liquid side communication pipe 14 through which the liquid refrigerant flows is connected to the normal port 371.
When the valve 373 closes the normal port 371, the maintenance port 372 also communicates with the normal port 371, and therefore, as a result, the maintenance port 372 communicates with the liquid-side communication pipe 14 without being restricted by the opening and closing of the valve 373.
(1-2-9) gas side shutoff valve 38
The gas-side shutoff valve 38 is connected to the four-way switching valve 32. The gas-side shutoff valve 38 includes: a normal port 381; a service port 382; and a valve 383 for opening and closing the normal port 381. The gas-side communication pipe 16 through which the gas refrigerant flows is connected to the normal port 381. Since the maintenance port 382 communicates with the normal port 381 even if the valve 383 closes the normal port 381, the maintenance port 382 communicates with the gas-side communication pipe 16 without being restricted by the opening and closing of the valve 383.
(1-2-10) gas side preliminary stop valve 39
The gas-side backup shutoff valve 39 is connected to the low-pressure-side pipe between the four-way switching valve 32 and the accumulator 36. The gas-side preliminary shutoff valve 39 includes: a general port 391; and a check valve 393 that enables the refrigerant to flow only to the low-pressure side pipe from the normal port 391. The auxiliary port 53 of the refrigerant recovery unit 50 is connected to the normal port 391 via a pipe 531.
(1-2-11) third stop valve 40
The third stop valve 40 has: a normal port 401 connected to a branch pipe branched from a midway portion of the pipe from the outdoor heat exchanger 33 to the normal port 371 of the liquid-side shutoff valve 37; and a valve 403, the valve 403 being used to open and close the normal port 401.
(1-2-12) control section 80
Fig. 2 is a block diagram of the control unit 80. In fig. 2, the controller 80 includes an outdoor controller 801 and an indoor controller 803.
The outdoor side controller 801 is disposed in the outdoor unit 30, and controls the operation of each device. The indoor-side control unit 803 is disposed in the indoor unit 20 and controls the indoor expansion valve 22 and the like. The outdoor control unit 801 and the indoor control unit 803 each have a microcomputer, a memory, and the like, and can exchange control signals and the like with each other.
The outdoor side controller 801 is provided with a terminal connection portion 801a to which the wire harness from the refrigerant recovery unit 50 is connected.
(1-3) refrigerant recovery Unit 50
When the refrigerant in the indoor unit 20, the liquid-side communication pipe 14, and the gas-side communication pipe 16 is recovered when the indoor unit 20 is transferred, or when the refrigerant is returned to the refrigerant circuit 10 after the transfer of the indoor unit 20 is completed, the refrigerant recovery unit 50 is connected to the outdoor unit 30 via the liquid-side shutoff valve 37 and the gas-side shutoff valve 38.
The refrigerant recovery unit 50 includes a refrigerant inflow port 51, a refrigerant outflow port 52, a refrigerant storage container 55, and a decompression mechanism 56.
(1-3-1) refrigerant inflow port 51
The refrigerant inflow port 51 is connected to the inside of the refrigerant storage container 55 via a connection pipe 501. Further, the refrigerant inflow port 51 is connected to a maintenance port 372 of the liquid-side shutoff valve 37 via a pipe 511 at the time of refrigerant recovery. In addition, the refrigerant inflow port 51 itself also includes a shutoff valve.
(1-3-2) refrigerant outflow port 52
The refrigerant outflow port 52 is connected to the container inner bottom portion of the refrigerant storage container 55 via a connection pipe 502. The refrigerant outflow port 52 is connected to the service port 382 of the gas-side shutoff valve 38 via the pipe 521 when the refrigerant returns. In addition, the refrigerant outflow port 52 itself also includes a shutoff valve.
(1-3-3) refrigerant-storing vessel 55
The refrigerant storage container 55 stores the refrigerant flowing into the refrigerant inflow port 51. The refrigerant storage tank 55 is connected to a connection pipe 501 connected to the refrigerant inlet port 51, a connection pipe 502 connected to the refrigerant outlet port 52, and a connection pipe 503 connected to the auxiliary port 53.
(1-3-4) pressure reducing mechanism 56
The pressure reducing mechanism 56 is a capillary tube connected to a middle portion of a connection pipe 502, and the connection pipe 502 connects the refrigerant storage tank 55 and the refrigerant outflow port 52. The pressure reducing mechanism 56 reduces the pressure of the refrigerant in the refrigerant storage container 55 when the refrigerant returns.
(1-3-5) check valve 58
The check valve 58 is connected to a middle portion of the connection pipe 502 and between the decompression mechanism 56 and the solenoid valve 59, and allows the refrigerant to flow from the refrigerant storage tank 55 to the refrigerant outflow port 52. That is, the refrigerant is prevented from flowing backward from the refrigerant outflow port 52.
(1-3-6) solenoid valve 59
The solenoid valve 59 is connected to a middle portion of the connection pipe 502 and is connected between the pressure reducing mechanism 56 and the refrigerant outflow port 52. The solenoid valve 59 can prevent the refrigerant from flowing out of the refrigerant-storage container 55 via the pressure-reducing mechanism 56 at times other than when the refrigerant returns.
(1-3-7) temperature sensor 81
The temperature sensor 81 directly or indirectly detects the temperature of the refrigerant flowing from the refrigerant inflow port 51 to the refrigerant-storage container 55. In the present embodiment, the temperature sensor 81 is disposed in the connection pipe 501.
(1-3-8) safety valve 83
The relief valve 83 performs an opening operation when the pressure in the refrigerant storage container 55 is equal to or higher than a predetermined pressure, so as to prevent an abnormal pressure increase in the refrigerant storage container 55.
(1-3-9) preparation Port 53
The auxiliary port 53 is connected to an upper portion of the refrigerant storage container 55 in the container via a pipe. The auxiliary port 53 is connected to a normal port 391 of the gas-side auxiliary shutoff valve 39 via a pipe 531 during the refrigerant recovery operation. In addition, the reserve port 53 itself also includes a shutoff valve.
(2) Operation of the refrigeration apparatus 1
(2-1) Cooling operation
During the cooling operation, the four-way switching valve 32 is in the state shown by the solid line in fig. 1. In this refrigerant circuit, when the compressor 31, the outdoor fan 73, and the indoor fan 71 are operated, the low-pressure gas refrigerant is compressed by the compressor 31 to become a high-pressure gas refrigerant.
The high-pressure gas refrigerant is sent to the outdoor heat exchanger 33 via the oil separator 311, the check valve 313, and the four-way switching valve 32. Then, the high-pressure gas refrigerant exchanges heat with the outdoor air supplied by the outdoor fan 73 in the outdoor heat exchanger 33 to dissipate heat.
The high-pressure refrigerant cooled and condensed in the outdoor heat exchanger 33 flows through the outdoor expansion valve 34 in the fully open state to the supercooling heat exchanger 45. A part of the refrigerant flowing through the supercooling heat exchanger 45 flows into the branch circuit 19, is decompressed by the branch-side expansion valve 47, and then enters the supercooling heat exchanger 45. Therefore, the refrigerant cooled in the outdoor heat exchanger 33 is further cooled by heat exchange with the refrigerant flowing through the branch circuit 19 in the supercooling heat exchanger 45.
The refrigerant flowing out of the supercooling heat exchanger 45 is sent to the indoor expansion valve 22 through the liquid-side shutoff valve 37 and the liquid-side communication pipe 14, and is decompressed by the indoor expansion valve 22 to become a low-pressure refrigerant in a gas-liquid two-phase state. The low-pressure gas-liquid two-phase refrigerant is sent to the indoor heat exchanger 21, exchanges heat with the indoor air supplied by the indoor fan 71 in the indoor heat exchanger 21, evaporates, and becomes a low-pressure gas refrigerant.
The low-pressure gas refrigerant enters the accumulator 36 through the gas-side communication pipe 16, the gas-side shutoff valve 38, and the four-way switching valve 32. In addition, the refrigerant from the branch circuit 19 also enters the accumulator 36.
The low-pressure refrigerant flowing out of the accumulator 36 and the oil separated by the oil separator 311 and depressurized in the capillary tube 312 join together in the middle of flowing to the suction side of the compressor 31, and are sucked into the compressor 31. Thus, the cooling operation is performed.
(2-2) heating operation
During the heating operation, the four-way switching valve 32 is in a state shown by a broken line in fig. 1. In this refrigerant circuit, when the compressor 31, the outdoor fan 73, and the indoor fan 71 are operated, the low-pressure gas refrigerant is compressed by the compressor 31 to become a high-pressure gas refrigerant.
The high-pressure gas refrigerant is sent to the indoor heat exchanger 21 through the oil separator 311, the check valve 313, and the four-way switching valve 32. Then, the high-pressure gas refrigerant exchanges heat with the indoor air supplied by the indoor fan 71 in the indoor heat exchanger 21 to dissipate the heat.
The high-pressure refrigerant cooled and condensed in the indoor heat exchanger 21 flows from the indoor heat exchanger 21 to the supercooling heat exchanger 45 through the fully opened indoor expansion valve 22, the liquid-side communication pipe 14, and the liquid-side shutoff valve 37.
Among the refrigerants that have entered the supercooling heat exchanger 45, a portion of the refrigerant that has first passed through the supercooling heat exchanger 45 flows into the branch circuit 19, is reduced in pressure in the branch-side expansion valve 47, and then enters the supercooling heat exchanger 45 again, so that the refrigerant that has been cooled in the indoor heat exchanger 21 exchanges heat with the refrigerant that has passed through the branch circuit 19 in the supercooling heat exchanger 45, and is further cooled.
The refrigerant flowing out of the supercooling heat exchanger 45 is sent to the outdoor expansion valve 34, and is decompressed by the outdoor expansion valve 34 to become a low-pressure refrigerant in a gas-liquid two-phase state. The low-pressure gas-liquid two-phase refrigerant is sent to the outdoor heat exchanger 33, exchanges heat with outdoor air supplied by the outdoor fan 73 in the outdoor heat exchanger 33, evaporates, and becomes a low-pressure gas refrigerant.
The low-pressure gas refrigerant enters the accumulator 36 through the four-way switching valve 32. In addition, the refrigerant from the branch circuit 19 also enters the accumulator 36.
The low-pressure refrigerant flowing out of the accumulator 36 and the oil separated by the oil separator 311 and depressurized in the capillary tube 312 join together in the middle of flowing to the suction side of the compressor 31, and are sucked into the compressor 31. Thus, the heating operation is performed.
(2-3) refrigerant recovery operation
The refrigerant recovery unit 50 is not connected to the refrigerant circuit 10 in fig. 1 during the cooling operation and the heating operation. However, during the refrigerant recovery operation, the refrigerant inflow port 51 is connected to the service port 372 of the liquid-side shutoff valve 37, and normally the port 371 is closed by the valve 373. In addition, in a state where the normal port 381 of the gas side shutoff valve 38 is opened, the operation of flowing the high-pressure refrigerant to the normal port 381 of the gas side shutoff valve 38 is performed by the heating cycle. Hereinafter, the operation in the refrigerant recovery operation will be described with reference to the control flow.
Fig. 3 is a control flowchart of the refrigerant recovery operation. In fig. 3, in step S1, the control unit 80 determines whether or not there is a temperature sensor connection signal. When the refrigerant recovery unit 50 is connected to the outdoor unit 30 and the harness from the refrigerant recovery unit 50 is connected to the terminal connection portion 801a of the outdoor side control unit 801, the inter-terminal resistance of the terminal connected to the temperature sensor 81 in the refrigerant recovery unit 50 changes, and therefore the change becomes a signal indicating the connection of the temperature sensor 81, and the control unit 80 determines that the refrigerant recovery unit 50 is connected by the outdoor side control unit 801.
Next, the control unit 80 determines whether or not there is a refrigerant recovery operation determination signal in step S2. Even if the refrigerant recovery unit 50 is connected to the outdoor unit 30 and the temperature sensor connection signal is input, since it is necessary for the serviceman to determine whether or not the refrigerant recovery operation is actually performed, the serviceman finally inputs the determination signal through a predetermined input unit of the outdoor side controller 801 of the outdoor unit 30 or a remote controller.
Next, the control unit 80 starts the refrigerant recovery operation in step S3. The refrigerant recovery operation is performed in the heating operation cycle with the indoor expansion valve 22 fully opened. At this time, the refrigerant inflow port 51 is connected to the maintenance port 372 of the liquid-side shutoff valve 37, and the valve 373 of the liquid-side shutoff valve 37 is closed and the normal port 381 of the gas-side shutoff valve 38 is open.
In this state, since the high-pressure refrigerant flows to the normal port 381, the refrigerant in the liquid-side communication pipe 14, the indoor heat exchanger 21, and the gas-side communication pipe 16 is pushed by the high-pressure refrigerant and is pushed out from the maintenance port 372.
The refrigerant pushed out from the maintenance port 372 is stored in the refrigerant storage container 55 through the refrigerant inflow port 51. As a result, the refrigerant in the liquid-side communication pipe 14, the indoor heat exchanger 21, and the gas-side communication pipe 16 is recovered to the refrigerant storage container 55.
The gas component in the refrigerant subjected to gas-liquid separation in the refrigerant storage container 55 is sucked into the compressor 31 through the auxiliary port 53, the normal port 391 of the gas-side auxiliary stop valve 39, and the accumulator 36.
Even if the internal pressure of the refrigerant storage container 55 abnormally increases, the safety valve 83 opens when the pressure in the refrigerant storage container 55 is equal to or higher than a predetermined pressure, and therefore, the inside of the refrigerant storage container 55 is maintained at a safe pressure.
Next, in step S4, the control unit 80 determines whether or not the detection value T of the temperature sensor 81 is equal to or less than a predetermined value Tp, and if T is equal to or less than Tp, the process proceeds to step S5, and if T is not equal to or less than Tp, the determination is continued.
When the amount of refrigerant in the pipe decreases due to the refrigerant recovery, the refrigerant evaporates to become a gas refrigerant, and therefore the temperature of the refrigerant flowing into the refrigerant inflow port 51 decreases. Since the temperature sensor 81 detects the temperature of the refrigerant flowing from the refrigerant inflow port 51 to the refrigerant storage tank 55, it is possible to determine the completion of refrigerant recovery by determining whether or not the detected value is equal to or less than the predetermined value Tp.
Therefore, when T is equal to or less than Tp, the control unit 80 stops the compressor and ends the refrigerant recovery operation in step S5.
(2-4) refrigerant Return operation
When the refrigerant recovery operation is completed, the shutoff valve of the refrigerant inflow port 51 and the shutoff valve of the auxiliary port 53 of the refrigerant recovery unit 50 are both closed, and the liquid-side shutoff valve 37 and the gas-side shutoff valve 38 of the outdoor unit 30 are both closed.
When the transfer of the indoor unit 20 is completed, the indoor unit 20, the liquid-side communication pipe 14, and the gas-side communication pipe 16 are vacuum-dried and evacuated. After the completion of the evacuation, the operation of returning the refrigerant in the refrigerant storage container 55 to the refrigerant circuit 10 is performed this time.
First, the refrigerant outflow port 52 of the refrigerant recovery unit 50 is connected to the maintenance port 382 of the gas side shutoff valve 38 of the outdoor unit 30 via the pipe 521. At this time, the shutoff valve of the refrigerant outflow port 52 itself is still closed. The refrigerant return operation will be described below with reference to the control flow.
Fig. 4 is a control flowchart of the refrigerant return operation. In fig. 4, in step S11, the control unit 80 determines whether or not there is a solenoid connection signal. When the wire harness of the refrigerant recovery unit 50 is connected to the terminal connection portion 801a of the outdoor side control unit 801, the inter-terminal resistance of the terminal connected to the solenoid valve 29 in the refrigerant recovery unit 50 changes, and therefore the change becomes a signal indicating the connection of the solenoid valve 59, and the control unit 80 can determine that the refrigerant recovery unit 50 is connected by the outdoor side control unit 801 (at this time, the inter-terminal resistance of the terminal connected to the temperature sensor 81 also changes, and therefore the change becomes a signal indicating the connection of the temperature sensor 81, and the control unit 80 can determine that the refrigerant recovery unit 50 is connected by the temperature sensor connection signal).
Next, the control unit 80 determines whether or not there is a refrigerant return operation determination signal in step S12. Even if the refrigerant recovery unit 50 is connected to the outdoor unit 30 and the electromagnetic valve connection signal is input, since it is necessary for the serviceman to determine whether or not the refrigerant return operation is actually performed, the serviceman finally inputs the refrigerant return determination signal through a remote controller or a predetermined input unit of the outdoor side controller 801 of the outdoor unit 30.
Next, the control unit 80 starts the refrigerant returning operation in step S13. Upon receiving the refrigerant return determination signal, the control unit 30 operates the solenoid valve 59 in the opening direction. Then, the maintenance worker opens the shutoff valve of the refrigerant outflow port 52 itself, and returns the refrigerant in the refrigerant storage container 55 to the liquid-side communication pipe 14, the indoor heat exchanger 21, and the gas-side communication pipe 16 immediately after the evacuation.
Next, the control unit 80 determines in step S14 whether or not the detection value T of the temperature sensor 81 is equal to or less than a predetermined value Ts, and if T is equal to or less than Ts, the process proceeds to step S15, and if T is not equal to or less than Ts, the determination is continued.
When the refrigerant is returned and the amount of refrigerant in the refrigerant storage container 55 is reduced, the refrigerant evaporates to become a gas refrigerant, and therefore the detection value T of the temperature sensor 81 attached to the connection pipe 501 connecting the refrigerant inflow port 51 and the refrigerant storage container 55 is reduced. By determining whether or not the detection value T is equal to or less than a predetermined value Ts, it is possible to determine the end of the refrigerant return operation.
Therefore, when T ≦ Ts, the control portion 80 closes the solenoid valve 59 and ends the refrigerant returning operation in step S15.
(3) Features of the first embodiment
(3－1)
In the refrigerant recovery unit 50, after the valve 373 of the liquid side stop valve 37 is closed and the refrigerant inflow port 51 is connected to the maintenance port 372 of the liquid side stop valve 37, the refrigerant is circulated in the heating operation to press the gas refrigerant from the gas side stop valve 38 into the indoor heat exchanger 21, whereby the liquid refrigerant in the indoor heat exchanger 21, the liquid side communication pipe 14, and the gas side communication pipe 16 is pushed out from the maintenance port 372 of the liquid side stop valve 37, and the liquid refrigerant is stored in the refrigerant storage container 55.
(3－2)
In the refrigerant recovery unit 50, refrigerant recovery is performed, and when the amount of refrigerant in the indoor heat exchanger 21, the liquid-side communication pipe 14, and the gas-side communication pipe 16 decreases, the refrigerant evaporates and becomes a gas refrigerant, and therefore, the temperature of the refrigerant flowing into the refrigerant inflow port 51 decreases. The temperature sensor 81 detects the temperature, and the control unit 80 can determine the end of refrigerant recovery by determining whether the detection value T is equal to or less than a predetermined value Tp.
(3－3)
The outdoor side control unit 801 has a terminal connection unit 801a connected to the temperature sensor 81, and executes the refrigerant recovery operation mode when it is determined that the temperature sensor 81 is connected to the terminal connection unit 801 a. Therefore, the refrigerant recovery operation can be performed even if the control unit is not provided in the refrigerant recovery unit 50.
(3－4)
When it is determined that the solenoid valve 59 is connected to the terminal connection portion 801a, the outdoor side control portion 801 executes the refrigerant return operation mode. Therefore, the refrigerant returning operation can be performed even if the control unit is not provided in the refrigerant recovery unit 50.
< second embodiment >
In the first embodiment described above, the refrigerant is circulated through the heating operation cycle to recover the refrigerant in the indoor heat exchanger 21, the liquid-side communication pipe 14, and the gas-side communication pipe 16, but here, an embodiment in which the refrigerant is circulated through the cooling operation cycle to recover the refrigerant in the indoor heat exchanger 21, the liquid-side communication pipe 14, and the gas-side communication pipe 16 will be described.
(1) Structure of refrigeration device 101
Fig. 5 is a circuit diagram of the refrigeration apparatus 101 connected to the refrigerant recovery unit 50 according to the second embodiment of the present invention. In fig. 5, the refrigerant inflow port 51 of the refrigerant recovery unit 50 is connected to the normal port 401 of the third cut-off valve 40 via a pipe 511. The refrigerant outflow port 52 of the refrigerant recovery unit 50 is connected to the maintenance port 382 of the gas-side shutoff valve 38 via the pipe 521. Further, the backup port 53 of the refrigerant recovery unit 50 is connected to the maintenance port 372 of the liquid-side shutoff valve 37 via a pipe 531. Further, no pipe is connected to the gas side auxiliary shutoff valve 39 of the outdoor unit 30. The structure other than the above is the same as that of the first embodiment.
(2) Operation of the refrigeration apparatus 101
The operations of the cooling operation, the heating operation, and the refrigerant returning operation of the cooling device 101 are the same as those of the first embodiment, and therefore, the refrigerant recovering operation will be described here.
Fig. 6 is a control flowchart of the refrigerant recovery operation according to the second embodiment. In fig. 6, in step S21, the control unit 80 determines whether or not there is a temperature sensor connection signal. When the refrigerant recovery unit 50 is connected to the outdoor unit 30 and the harness from the refrigerant recovery unit 50 is connected to the terminal connection portion 801a of the outdoor side control unit 801, the inter-terminal resistance of the terminal connected to the temperature sensor 81 in the refrigerant recovery unit 50 changes, and therefore the change becomes a signal indicating the connection of the temperature sensor 81, and the control unit 80 determines that the refrigerant recovery unit 50 is connected by the outdoor side control unit 801.
Next, the control unit 80 determines whether or not there is a refrigerant recovery operation determination signal in step S22. Even if the refrigerant recovery unit 50 is connected to the outdoor unit 30 and the temperature sensor connection signal is input, since it is necessary for the serviceman to determine whether or not the refrigerant recovery operation is actually performed, the serviceman finally inputs the determination signal through a predetermined input unit of the outdoor side controller 801 of the outdoor unit 30 or a remote controller.
Next, the control unit 80 starts the refrigerant recovery operation in step S23. The refrigerant recovery operation is performed by the cooling operation cycle in a state in which the opening degree of the indoor expansion valve 22 is appropriately adjusted. At this time, the valve 403 of the third stop valve 40 is in an open state, the valve 373 of the liquid-side stop valve 37 is in a closed state, and the valve 383 of the gas-side stop valve 38 is in an open state.
Since the refrigerant inflow port 51 of the refrigerant recovery unit 50 is connected to the normal port 401 of the third cut-off valve 40 via the pipe 511, when the cooling operation is performed in this state, the high-pressure refrigerant cannot flow to the normal port 371 of the closed liquid side cut-off valve 37 but flows to the normal port 401 of the open third cut-off valve 40. As a result, the refrigerant in the outdoor unit 30 flows into the refrigerant inflow port 51 and is stored in the refrigerant storage tank 55.
The inside of the refrigerant storage container 55 is at a high pressure, and the gas component of the refrigerant after gas-liquid separation enters the liquid-side communication pipe 14 through the connection pipe 503 connecting the upper portion of the refrigerant storage container 55 and the auxiliary port 53, the pipe 531, and the maintenance port 372 of the liquid-side shutoff valve 37. As a result, the refrigerant remaining in the liquid-side communication pipe 14 is quickly sent to the indoor expansion valve 22 side.
Further, the refrigerant in the liquid-side communication pipe 14, the indoor heat exchanger 21, and the gas-side communication pipe 16 is sucked into the low-pressure side of the compressor 31 from the normal port 381 of the opened gas-side shutoff valve 38, and therefore the amount of the refrigerant transferred from the outdoor unit 30 to the refrigerant storage container 55 is replenished to the outdoor unit 30 side. That is, the same result as when the refrigerant in the liquid side communication pipe 14, the indoor heat exchanger 21, and the gas side communication pipe 16 is collected in the refrigerant storage container 55 can be obtained.
Next, the control unit 80 determines in step S24 whether or not the detection value Th of the heat exchanger temperature sensor 211 of the indoor heat exchanger 21 is equal to or less than the first predetermined value Th1, and proceeds to step S25 when Th is equal to or less than Th1, and continues the determination when Th is not equal to or less than Th 1.
Since the temperature of the indoor heat exchanger 21 decreases while the refrigerant is depressurized in the indoor expansion valve 22 and evaporated in the indoor heat exchanger 21, the detection value of the heat exchanger temperature sensor 211 becomes equal to or less than the first predetermined value Th1 while the refrigerant is present in the liquid side communication pipe 14, the indoor heat exchanger 21, and the gas side communication pipe 16, and the control unit 80 can confirm that the refrigerant is being recovered.
Next, in step S25, the control unit 80 waits for a predetermined time while performing the refrigerant recovery operation.
Next, the control unit 80 determines in step S26 whether or not the detection value Th of the heat exchanger temperature sensor 211 of the indoor heat exchanger 21 is equal to or greater than the second predetermined value Th2, and proceeds to step S27 when Th is equal to or greater than Th2, and continues the determination when Th is not equal to or greater than Th 2.
While the refrigerant is depressurized in the indoor expansion valve 22 and evaporated in the indoor heat exchanger 21, the temperature of the indoor heat exchanger 21 decreases, but when the refrigerant is no longer present in the liquid-side communication pipe 14, the indoor heat exchanger 21, and the gas-side communication pipe 16, the temperature of the indoor heat exchanger 21 increases to near room temperature, and therefore the detection value Th of the heat exchanger temperature sensor 211 becomes equal to or greater than the second predetermined value Th2, and the control unit 80 can determine that the refrigerant recovery is complete.
Therefore, when Th ≧ Th2, controller 80 stops the compressor in step S27, and ends the refrigerant recovery operation.
(3) Features of the second embodiment
In the refrigerant recovery unit 50, the high-pressure refrigerant flowing to the normal port 371 of the closed liquid-side stop valve 37 branches and flows to the normal port 401 of the open third stop valve 40, and a part of the refrigerant in the outdoor unit 30 is stored in the refrigerant storage container 55. On the other hand, the refrigerant in the liquid-side communication pipe 14, the indoor heat exchanger 21, and the gas-side communication pipe 16 is recovered to the outdoor unit 30.
Therefore, the refrigerant is stored in the refrigerant storage container 55 in the same manner as the refrigerant in the liquid side communication pipe 14, the indoor heat exchanger 21, and the gas side communication pipe 16.
< third embodiment >
In the first and second embodiments, the refrigerant recovery unit 50 itself is not provided with a compressor, but adopts the following configuration: the refrigerant in the liquid side communication pipe 14, the indoor heat exchanger 21, and the gas side communication pipe 16 is recovered to the refrigerant storage container 55 by the compressor 31 in the outdoor unit 30. In the third embodiment, the refrigerant recovery unit 150 provided with a compressor will be described.
(1) Structure of refrigerating device 201
Fig. 7 is a circuit diagram of a refrigeration apparatus 201 connected to a refrigerant recovery unit 150 according to a third embodiment of the present invention.
In fig. 7, the refrigerant recovery unit 150 is provided with a connection pipe 504 instead of the connection pipe 503 of the refrigerant recovery unit 50 in the first and second embodiments. The connection pipe 504 is a pipe that connects the upper portion of the refrigerant storage container 55 to the refrigerant outflow port 52.
The refrigerant recovery compressor 61 is connected to the connection pipe 504. The refrigerant recovery compressor 61 has a suction side connected to an upper portion of the refrigerant storage container 55 and a discharge side connected to the refrigerant outflow port 52. Fig. 8 is a control block diagram of the third embodiment, and the refrigerant recovery unit 150 does not have a controller itself, but the electromagnetic valve 59, the refrigerant recovery compressor 61, and the like are managed by the outdoor controller 801 by connecting the wire harness of the refrigerant recovery unit 150 to the terminal connection section 801a of the outdoor controller 801.
The refrigerant inflow port 51 of the refrigerant recovery unit 50 is connected to the service port 372 of the liquid side stop valve 37 via a pipe 511. The valve 373 of the liquid-side shutoff valve 37 is closed.
The refrigerant outflow port 52 of the refrigerant recovery unit 50 is connected to the maintenance port 382 of the gas-side shutoff valve 38 via the pipe 521. The valve 383 of the gas side shutoff valve 38 is closed. In addition, during the refrigerant recovery operation, the refrigerant outflow port 52 is closed.
No pipe is connected to the gas side preliminary stop valve 39 and the third stop valve 40. The other structures are the same as those of embodiment 1, and therefore, the description thereof is omitted.
(2) Operation of the refrigeration apparatus 201
The operations of the cooling operation, the heating operation, and the refrigerant returning operation of the cooling device 201 are the same as those of the first embodiment, and therefore, the refrigerant recovering operation will be described here.
Fig. 9 is a control flowchart of the refrigerant recovery operation according to the third embodiment. In fig. 9, in step S41, the control unit 80 determines whether or not there is a temperature sensor connection signal. When the refrigerant recovery unit 150 is connected to the outdoor unit 30 and the harness from the refrigerant recovery unit 150 is connected to the terminal connection portion 801a of the outdoor side control unit 801, the inter-terminal resistance of the terminal connected to the temperature sensor 81 in the refrigerant recovery unit 150 changes, and therefore the change becomes a signal indicating the connection of the temperature sensor 81, and the control unit 80 determines that the refrigerant recovery unit 150 is connected by the outdoor side control unit 801.
Next, the control unit 80 determines whether or not there is a refrigerant recovery operation determination signal in step S42. Even if the refrigerant recovery unit 150 is connected to the outdoor unit 30 and the temperature sensor connection signal is input, since it is necessary for the serviceman to determine whether or not the refrigerant recovery operation is actually performed, the serviceman finally inputs the determination signal through a predetermined input unit of the outdoor side controller 801 of the outdoor unit 30 or a remote controller.
Next, the control unit 80 starts the refrigerant recovery operation in step S43. The refrigerant recovery operation operates the refrigerant recovery compressor 61 with the indoor expansion valve 22 fully opened. At this time, the refrigerant inflow port 51 is connected to the maintenance port 372 of the liquid side stop valve 37, and the refrigerant outflow port 52 is connected to the maintenance port 382 of the gas side stop valve 38. The valve 373 of the liquid-side shutoff valve 37 and the valve 383 of the gas-side shutoff valve 38 are both closed.
In this state, since the refrigerant recovery compressor 61 is operated, the high pressure is applied to the maintenance port 382 side of the gas side shutoff valve 38, and the low pressure is applied to the maintenance port 372 side of the liquid side shutoff valve 37, so that the refrigerant in the liquid side communication pipe 14, the indoor heat exchanger 21, and the gas side communication pipe 16 is pressed by the high pressure and is pushed out from the maintenance port 372 toward the refrigerant inflow port 51.
The refrigerant pushed out from the maintenance port 372 is stored in the refrigerant storage container 55 through the refrigerant inflow port 51. As a result, the refrigerant in the liquid-side communication pipe 14, the indoor heat exchanger 21, and the gas-side communication pipe 16 is recovered to the refrigerant storage container 55.
Since the safety valve 83 is provided, and the safety valve 83 is opened when the pressure in the refrigerant storage container 55 is equal to or higher than a predetermined pressure, the pressure in the refrigerant storage container 55 is maintained at a safe pressure even if the internal pressure of the refrigerant storage container 55 abnormally increases.
Next, in step S44, the control unit 80 determines whether or not the detection value T of the temperature sensor 81 is equal to or less than a predetermined value Tp, and if T is equal to or less than Tp, the process proceeds to step S5, and if T is not equal to or less than Tp, the determination is continued.
When the amount of refrigerant in the pipe decreases due to the refrigerant recovery, the refrigerant evaporates to become a gas refrigerant, and therefore the temperature of the refrigerant flowing into the refrigerant inflow port 51 decreases. Since the temperature sensor 81 detects the temperature of the refrigerant flowing from the refrigerant inflow port 51 to the refrigerant storage tank 55, it is possible to determine the end of refrigerant recovery by determining whether or not the detected value is equal to or less than the predetermined value Tp.
Therefore, when T is equal to or less than Tp, the control unit 80 stops the compressor and ends the refrigerant recovery operation in step S45.
(3) Features of the third embodiment
In the refrigerant recovery unit 150, since the high-pressure gas refrigerant is pushed into the gas-side communication pipe 16 from the refrigerant outflow port 52 through the maintenance port 382 of the gas-side shutoff valve 38 by the operation of the refrigerant recovery compressor 61, the liquid refrigerant in the liquid-side communication pipe 14, the indoor heat exchanger 21, and the gas-side communication pipe 16 is pushed out to the refrigerant inflow port 51 through the maintenance port 372 of the liquid-side shutoff valve 37. As a result, the liquid refrigerant in the liquid-side communication pipe 14, the indoor heat exchanger 21, and the gas-side communication pipe 16 is recovered to the refrigerant storage container 55.
< fourth embodiment >
In the third embodiment, the refrigerant recovery unit 150 is provided with the refrigerant recovery compressor 61 itself, but the indoor unit 20 is used for the condensation of the refrigerant. In the fourth embodiment, a refrigerant recovery unit 250 equipped with a condenser will be described.
(1) Structure of refrigeration device 301
Fig. 10 is a circuit diagram of a refrigeration apparatus 301 connected to a refrigerant recovery unit 250 according to a fourth embodiment of the present invention.
In fig. 10, in the refrigerant recovery unit 250, the refrigerant recovery compressor 61 and the heat exchanger 63 are connected to a connection pipe 504. An outlet pipe of the heat exchanger 63 is connected to the top surface of the refrigerant storage container 55. The suction side of the refrigerant recovery compressor 61 is connected to the refrigerant outflow port 52 side, and the discharge side is connected to an inlet pipe of the heat exchanger 63. Further, a fan 65 that blows air toward the heat exchanger 63 is disposed so as to face the heat exchanger 63.
Fig. 11 is a control block diagram of the fourth embodiment, and the refrigerant recovery unit 250 does not have a controller itself, and the solenoid valve 59, the refrigerant recovery compressor 61, and the fan 65 are managed by the outdoor controller 801 by connecting the wire harness of the refrigerant recovery unit 250 to the terminal connection section 801a of the outdoor controller 801.
The refrigerant inflow port 51 of the refrigerant recovery unit 250 is connected to the service port 372 of the liquid side stop valve 37 via a pipe 511. The valve 373 of the liquid-side shutoff valve 37 is closed.
The refrigerant outflow port 52 of the refrigerant recovery unit 250 is connected to the maintenance port 382 of the gas-side shutoff valve 38 via the pipe 521. The valve 383 of the gas side shutoff valve 38 is closed. In addition, during the refrigerant recovery operation, the refrigerant outflow port 52 is closed.
No pipe is connected to the gas side preliminary stop valve 39 and the third stop valve. The other structures are the same as those of embodiment 1, and therefore, the description thereof is omitted.
(2) Operation of the refrigeration device 301
The operations of the cooling operation, the heating operation, and the refrigerant returning operation of the cooling device 301 are the same as those of the first embodiment, and therefore, the refrigerant recovering operation will be described here.
Fig. 12 is a control flowchart of the refrigerant recovery operation according to the fourth embodiment. In fig. 12, in step S61, the control unit 80 determines whether or not there is a temperature sensor connection signal. When the refrigerant recovery unit 250 is connected to the outdoor unit 30 and the harness from the refrigerant recovery unit 250 is connected to the terminal connection portion 801a of the outdoor side control unit 801, the inter-terminal resistance of the terminal connected to the temperature sensor 81 in the refrigerant recovery unit 250 changes, and therefore the change becomes a signal indicating the connection of the temperature sensor 81, and the control unit 80 determines that the refrigerant recovery unit 250 is connected by the outdoor side control unit 801.
Next, the control unit 80 determines whether or not there is a refrigerant recovery operation determination signal in step S62. Even if the refrigerant recovery unit 250 is connected to the outdoor unit 30 and the temperature sensor connection signal is input, since it is necessary for the serviceman to determine whether or not the refrigerant recovery operation is actually performed, the serviceman finally inputs the determination signal through a predetermined input unit of the outdoor side controller 801 of the outdoor unit 30 or a remote controller.
Next, the control unit 80 starts the refrigerant recovery operation in step S63. In the refrigerant recovery operation, the refrigerant recovery compressor 61 is operated in a state where the opening degree of the indoor expansion valve 22 is appropriately adjusted. At this time, the refrigerant inflow port 51 is connected to the maintenance port 372 of the liquid side stop valve 37, and the refrigerant outflow port 52 is connected to the maintenance port 382 of the gas side stop valve 38. The valve 373 of the liquid-side shutoff valve 37 and the valve 383 of the gas-side shutoff valve 38 are both closed.
In this state, since the refrigerant recovery compressor 61 is operated, the refrigerant outflow port 52 is at a low pressure, and the refrigerant inflow port is at a high pressure. As a result, the maintenance port 382 side of the gas side shutoff valve 38 is at a low pressure, and the maintenance port 372 side of the liquid side shutoff valve 37 is at a high pressure, so that the refrigerant in the liquid side communication pipe 14, the indoor heat exchanger 21, and the gas side communication pipe 16 is pushed at a high pressure, and is pushed out from the maintenance port 382 of the gas side shutoff valve 38 toward the refrigerant outflow port 52.
The refrigerant in the liquid-side communication pipe 14 is depressurized when flowing through the indoor expansion valve 22, and evaporates in the indoor heat exchanger 21, and is therefore in a gas refrigerant state. The refrigerant liquefied in the indoor heat exchanger 21 and the gas-side communication pipe 16 before the refrigerant recovery operation does not flow through the indoor expansion valve 22, but evaporates while flowing into the refrigerant recovery compressor 61.
The refrigerant entering the service port 382 of the gas side shutoff valve 38 flows through the refrigerant outflow port 52, is sucked into the refrigerant recovery compressor 61, and is compressed. The refrigerant discharged from the refrigerant recovery compressor 61 is condensed by heat exchange with an air flow generated by the fan 65 in the heat exchanger 63. The condensed refrigerant is sent to the refrigerant storage container 55 and stored therein. As a result, the refrigerant in the liquid-side communication pipe 14, the indoor heat exchanger 21, and the gas-side communication pipe 16 is recovered to the refrigerant storage container 55.
Since the safety valve 83 is provided, and the safety valve 83 is opened when the pressure in the refrigerant storage container 55 is equal to or higher than a predetermined pressure, the pressure in the refrigerant storage container 55 is maintained at a safe pressure even if the internal pressure of the refrigerant storage container 55 abnormally increases.
Next, the control unit 80 determines in step S64 whether or not the detection value Th of the heat exchanger temperature sensor 211 of the indoor heat exchanger 21 is equal to or less than the first predetermined value Th1, and proceeds to step S65 when Th is equal to or less than Th1, and continues the determination when Th is not equal to or less than Th 1.
Since the temperature of the indoor heat exchanger 21 decreases while the refrigerant is depressurized in the indoor expansion valve 22 and evaporated in the indoor heat exchanger 21, the detection value of the heat exchanger temperature sensor 211 becomes equal to or less than the first predetermined value Th1 while the refrigerant is present in the liquid side communication pipe 14, the indoor heat exchanger 21, and the gas side communication pipe 16, and the control unit 80 can confirm that the refrigerant is being recovered.
Next, in step S65, the control unit 80 waits for a predetermined time while performing the refrigerant recovery operation.
Next, the control unit 80 determines in step S66 whether or not the detection value Th of the heat exchanger temperature sensor 211 of the indoor heat exchanger 21 is equal to or greater than the second predetermined value Th2, and proceeds to step S67 when Th is equal to or greater than Th2, and continues the determination when Th is not equal to or greater than Th 2.
While the refrigerant is depressurized in the indoor expansion valve 22 and evaporated in the indoor heat exchanger 21, the temperature of the indoor heat exchanger 21 decreases, but when the refrigerant is no longer present in the liquid-side communication pipe 14, the indoor heat exchanger 21, and the gas-side communication pipe 16, the temperature of the indoor heat exchanger 21 increases to near room temperature, and therefore the detection value Th of the heat exchanger temperature sensor 211 becomes equal to or greater than the second predetermined value Th2, and the control unit 80 can determine that the refrigerant recovery is complete.
Therefore, when Th ≧ Th2, controller 80 stops the compressor in step S67, and ends the refrigerant recovery operation.
(3) Features of the fourth embodiment
In the refrigerant recovery unit 250, the refrigerant in the gas-side communication pipe 16, the indoor heat exchanger 21, and the liquid-side communication pipe 14 is drawn into the refrigerant recovery compressor 61 from the maintenance port 382 of the gas-side shutoff valve 38 through the refrigerant outflow port 52 by the operation of the refrigerant recovery compressor 61. The refrigerant compressed by the refrigerant recovery compressor 61 is sent to the heat exchanger 63, condensed, and stored in the refrigerant storage tank 55.
Since the refrigerant inflow port 51 is connected to the maintenance port 372 of the liquid side shutoff valve 37 and the refrigerant inflow port 51 is connected to the refrigerant storage tank 55, the maintenance port 372 of the liquid side shutoff valve 37 is at a high pressure. Therefore, the residual refrigerant in the liquid side communication pipe 14, the indoor heat exchanger 21, and the gas side communication pipe 16 is pushed out so as to flow toward the maintenance port 382 of the gas side shutoff valve 38. As a result, the refrigerant in the gas-side communication pipe 16, the indoor heat exchanger 21, and the liquid-side communication pipe 14 is quickly recovered to the refrigerant storage container 55.
< Others >
As the refrigerant to be charged into the refrigerant circuit 10, a mixed refrigerant such as R401 and R407C may be used, but a single refrigerant such as R32 and R22 may be used.
When a single refrigerant such as R32 or R22 is used, the effect of easy reuse can be exhibited.
Industrial applicability of the invention
According to the present invention, the refrigerant in the indoor unit and the communication pipe can be recovered only by additionally installing the refrigerant recovery unit to the outdoor unit, and therefore, the present invention can be widely applied to air conditioners.

Claims (12)

1. A refrigerant recovery unit (50) which is temporarily attached to a refrigeration apparatus and which performs refrigerant recovery and refrigerant return, wherein the refrigeration apparatus forms a refrigerant circuit by an indoor unit (20), an outdoor unit (30), and communication pipes (14, 16) connecting the indoor unit (20) and the outdoor unit (30),
the refrigerant recovery unit (50) is characterized by comprising:
a refrigerant inflow port (51), the refrigerant inflow port (51) being connected to a high-pressure line of the refrigerant circuit during refrigerant recovery;
a refrigerant outflow port (52), the refrigerant outflow port (52) being connected to a low-pressure line of the refrigerant circuit when the refrigerant returns;
a refrigerant storage container (55), wherein the refrigerant storage container (55) stores the refrigerant flowing into the refrigerant inflow port (51);
a pressure reducing mechanism (56), the pressure reducing mechanism (56) being connected between the refrigerant storage container (55) and the refrigerant outflow port (52); and
a temperature sensor (81), the temperature sensor (81) directly or indirectly detecting the temperature of the refrigerant flowing from the refrigerant inflow port (51) to the refrigerant storage container (55),
the decompression mechanism (56) decompresses the refrigerant in the refrigerant storage container (55) when the refrigerant returns.
2. A refrigerant recovery unit (50) which is temporarily attached to a refrigeration apparatus and which performs refrigerant recovery and refrigerant return, wherein the refrigeration apparatus forms a refrigerant circuit by an indoor unit (20), an outdoor unit (30), and communication pipes (14, 16) connecting the indoor unit (20) and the outdoor unit (30),
the refrigerant recovery unit (50) is characterized by comprising:
a refrigerant inflow port (51), the refrigerant inflow port (51) being connected to a high-pressure line of the refrigerant circuit during refrigerant recovery;
a refrigerant outflow port (52), the refrigerant outflow port (52) being connected to a low-pressure line of the refrigerant circuit when the refrigerant returns;
a refrigerant storage container (55), wherein the refrigerant storage container (55) stores the refrigerant flowing into the refrigerant inflow port (51);
a pressure reducing mechanism (56), the pressure reducing mechanism (56) being connected between the refrigerant storage container (55) and the refrigerant outflow port (52); and
a solenoid valve (59), the solenoid valve (59) being connected between the pressure reducing mechanism (56) and the refrigerant outflow port (52),
the decompression mechanism (56) decompresses the refrigerant in the refrigerant storage container (55) when the refrigerant returns.
3. Refrigerant recovery unit (50) according to claim 1 or 2,
the refrigerant recovery unit (50) further comprises a safety valve (83), and the safety valve (83) performs an opening operation when the pressure in the refrigerant storage container (55) is equal to or higher than a predetermined pressure.
4. A refrigerant recovery unit (50) which is temporarily attached to a refrigeration apparatus and which performs refrigerant recovery and refrigerant return, wherein the refrigeration apparatus forms a refrigerant circuit by an indoor unit (20), an outdoor unit (30), and communication pipes (14, 16) connecting the indoor unit (20) and the outdoor unit (30),
the refrigerant recovery unit (50) is characterized by comprising:
a refrigerant inflow port (51), the refrigerant inflow port (51) being connected to a high-pressure line of the refrigerant circuit during refrigerant recovery;
a refrigerant outflow port (52), the refrigerant outflow port (52) being connected to a low-pressure line of the refrigerant circuit when the refrigerant returns;
a refrigerant storage container (55), wherein the refrigerant storage container (55) stores the refrigerant flowing into the refrigerant inflow port (51); and
a pressure reducing mechanism (56), the pressure reducing mechanism (56) being connected between the refrigerant storage container (55) and the refrigerant outflow port (52),
the outdoor unit (30) includes:
a compressor (31);
a first shutoff valve (37) having a first port (371) connected to a first communication pipe (14) and a first maintenance port (372) communicating with the first communication pipe (14), the first communication pipe (14) being connected to the indoor unit (20) and through which a liquid refrigerant flows;
a second shutoff valve (38), the second shutoff valve (38) having a second port (381) connected to a second communication pipe (16), wherein the second communication pipe (16) is connected to the indoor unit (20) and through which a gas refrigerant flows; and
a switching valve (32), the switching valve (32) flowing high-pressure refrigerant from the compressor to the first port (371) of the first stop valve (37) or the second port (381) of the second stop valve (38),
the refrigerant inflow port (51) is connected to the first service port (372), and the operation of flowing the high-pressure refrigerant to the second port (381) is performed in a state where the first port (371) is closed and the second port (381) is open.
5. A refrigerant recovery unit (50) which is temporarily attached to a refrigeration apparatus and which performs refrigerant recovery and refrigerant return, wherein the refrigeration apparatus forms a refrigerant circuit by an indoor unit (20), an outdoor unit (30), and communication pipes (14, 16) connecting the indoor unit (20) and the outdoor unit (30),
the refrigerant recovery unit (50) is characterized by comprising:
a refrigerant inflow port (51), the refrigerant inflow port (51) being connected to a high-pressure line of the refrigerant circuit during refrigerant recovery;
a refrigerant outflow port (52), the refrigerant outflow port (52) being connected to a low-pressure line of the refrigerant circuit when the refrigerant returns;
a refrigerant storage container (55), wherein the refrigerant storage container (55) stores the refrigerant flowing into the refrigerant inflow port (51); and
a pressure reducing mechanism (56), the pressure reducing mechanism (56) being connected between the refrigerant storage container (55) and the refrigerant outflow port (52),
the outdoor unit (30) includes:
a compressor (31);
a first shutoff valve (37), the first shutoff valve (37) having a first port (371) connected to a first communication pipe (14), the first communication pipe (14) being connected to the indoor unit (20) and allowing a liquid refrigerant to flow therethrough;
a second shutoff valve (38), the second shutoff valve (38) having a second port (381) connected to a second communication pipe (16), wherein the second communication pipe (16) is connected to the indoor unit (20) and through which a gas refrigerant flows;
a third shutoff valve (40), the third shutoff valve (40) having a third port (401), the third port (401) branching off refrigerant flowing to the first port (371) of the first shutoff valve (37); and
a switching valve (32), the switching valve (32) causing the high-pressure refrigerant from the compressor (31) to flow to the first port (371) of the first stop valve (37) or the second port (381) of the second stop valve (38),
the refrigerant inflow port (51) is connected to the third port (401), and the operation of flowing the high-pressure refrigerant to the first port (371) is performed in a state where the first port (371) is closed and the second port (381) and the third port (401) are open.
6. A refrigerant recovery unit (50) which is temporarily attached to a refrigeration apparatus and which performs refrigerant recovery and refrigerant return, wherein the refrigeration apparatus forms a refrigerant circuit by an indoor unit (20), an outdoor unit (30), and communication pipes (14, 16) connecting the indoor unit (20) and the outdoor unit (30),
the refrigerant recovery unit (50) is characterized by comprising:
a refrigerant inflow port (51), the refrigerant inflow port (51) being connected to a high-pressure line of the refrigerant circuit during refrigerant recovery;
a refrigerant outflow port (52), the refrigerant outflow port (52) being connected to a low-pressure line of the refrigerant circuit when the refrigerant returns;
a refrigerant storage container (55), wherein the refrigerant storage container (55) stores the refrigerant flowing into the refrigerant inflow port (51);
a pressure reducing mechanism (56), the pressure reducing mechanism (56) being connected between the refrigerant storage container (55) and the refrigerant outflow port (52); and
a refrigerant recovery compressor (61) having a suction side connected to the top surface of the refrigerant storage container (55) and a discharge side connected to the refrigerant outflow port (52),
the outdoor unit (30) has:
a first shutoff valve (37) having a first port (371) connected to a first communication pipe (14) and a first maintenance port (372) communicating with the first communication pipe (14), the first communication pipe (14) being connected to the indoor unit (20) and through which a liquid refrigerant flows; and
a second shut-off valve (38) having a second port (381) connected to a second communication pipe (16) and a second service port (382) communicated with the second communication pipe (16), wherein the second communication pipe (16) is connected to the indoor unit (20) and is used for gas refrigerant to flow through,
the refrigerant inflow port (51) is connected to the first maintenance port (372), the refrigerant outflow port (52) is connected to the second maintenance port (382), and the refrigerant recovery compressor (61) is operated in a state where the first port (371) and the second port (381) are closed.
7. A refrigerant recovery unit (50) which is temporarily attached to a refrigeration apparatus and which performs refrigerant recovery and refrigerant return, wherein the refrigeration apparatus forms a refrigerant circuit by an indoor unit (20), an outdoor unit (30), and communication pipes (14, 16) connecting the indoor unit (20) and the outdoor unit (30),
the refrigerant recovery unit (50) is characterized by comprising:
a refrigerant inflow port (51), the refrigerant inflow port (51) being connected to a high-pressure line of the refrigerant circuit during refrigerant recovery;
a refrigerant outflow port (52), the refrigerant outflow port (52) being connected to a low-pressure line of the refrigerant circuit when the refrigerant returns;
a refrigerant storage container (55), wherein the refrigerant storage container (55) stores the refrigerant flowing into the refrigerant inflow port (51);
a pressure reducing mechanism (56), the pressure reducing mechanism (56) being connected between the refrigerant storage container (55) and the refrigerant outflow port (52);
a heat exchanger (63) having an outlet pipe connected to the top surface of the refrigerant storage container (55);
a blower (65), wherein the blower (65) blows air to the heat exchanger (63); and
a refrigerant recovery compressor (61) having a suction side connected to the refrigerant outflow port (52) side and a discharge side connected to an inlet pipe of the heat exchanger (63),
the outdoor unit (30) has:
a first shutoff valve (37) having a first port (371) connected to a first communication pipe (14) and a first maintenance port (372) communicating with the first communication pipe (14), the first communication pipe (14) being connected to the indoor unit (20) and through which a liquid refrigerant flows; and
a second shut-off valve (38) having a second port connected to a second communication pipe (16) and a second service port communicating with the second communication pipe (16), wherein the second communication pipe (16) is connected to the indoor unit (20) and allows gas refrigerant to flow therethrough,
the refrigerant inflow port (51) is connected to the first maintenance port (372), the refrigerant outflow port (52) is connected to the second maintenance port (382), and the refrigerant recovery compressor (61) is operated in a state where the first port (371) and the second port (381) are closed.
8. An outdoor unit (30) connected to the refrigerant recovery unit (50) of claim 1, characterized in that,
the outdoor unit (30) includes a control unit (80), the control unit (80) executing a refrigerant recovery operation mode in which refrigerant is recovered to the refrigerant storage container (55),
the control unit (80) has a connection unit connected to the temperature sensor (81), and executes the refrigerant recovery operation mode when it is determined that the temperature sensor (81) is connected to the connection unit.
9. Outdoor unit (30) according to claim 8,
the refrigerant of the refrigerant circuit to be subjected to the refrigerant recovery and the refrigerant return is R32.
10. An outdoor unit (30) connected to the refrigerant recovery unit (50) of claim 2,
the outdoor unit (30) includes a control unit (80), the control unit (80) executing a refrigerant return operation mode in which the refrigerant is returned from the refrigerant storage container (55) to the refrigerant circuit,
the control unit (80) has a connection unit connected to the solenoid valve (59), and executes the refrigerant return operation mode when it is determined that the solenoid valve (59) is connected to the connection unit.
11. Outdoor unit (30) according to claim 10,
the refrigerant of the refrigerant circuit to be subjected to the refrigerant recovery and the refrigerant return is R32.
12. An outdoor unit (30), being the outdoor unit (30) connected to the refrigerant recovery unit (50) of any one of claims 1 to 7,
the refrigerant of the refrigerant circuit to be subjected to the refrigerant recovery and the refrigerant return is R32.
CN201510102367.9A 2015-03-09 2015-03-09 Refrigerant recovery unit and outdoor unit connected to the same Active CN106032955B (en)

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EP3730593A4 (en) * 2017-12-18 2021-10-27 Daikin Industries, Ltd. Refrigeration machine oil for refrigerant or refrigerant composition, method for using refrigeration machine oil, and use of refrigeration machine oil
CN111473568A (en) * 2019-01-23 2020-07-31 青岛海尔电冰箱有限公司 Refrigerator with a door
CN111397082B (en) * 2020-04-01 2021-10-26 宁波奥克斯电气股份有限公司 Refrigerant recovery system and control method

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CN202835963U (en) * 2012-07-31 2013-03-27 宝钢发展有限公司 Air-conditioning refrigerant recycling and adding device

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CN201724485U (en) * 2010-03-12 2011-01-26 神旺工业有限公司 Electronic instrument of refrigerant recovery machine
CN202835963U (en) * 2012-07-31 2013-03-27 宝钢发展有限公司 Air-conditioning refrigerant recycling and adding device

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