JPS62280548A - Separate type air conditioner - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention (Field of Industrial Application) This invention relates to a heat pump type separate air conditioner. This relates to an air conditioner equipped with a refrigerant recovery circuit that recovers refrigerant to the outdoor unit.

(Prior art) Generally, when inspecting or repairing a separate air conditioner, a pump-down operation is performed to collect the refrigerant charged in the refrigerant circulation circuit to the outdoor unit in advance to prevent loss of refrigerant. At the same time, work safety is ensured.

Such pump down is achieved by operating the refrigerant circulation cycle of the air conditioner or air conditioner in the cooling cycle, and by closing the refrigerant piping between the outdoor heat exchanger and the indoor heat exchanger with a liquid shutoff valve. It is possible to make the outdoor heat exchanger act as a condenser, store the refrigerant charged in the refrigerant circulation circuit in the outdoor heat exchanger, recover it, and pump it down (for example, Utility Model Publication No. 58-54609). (See Japanese Utility Model Publication No. 57-160072', etc.). On the other hand, since an air conditioner dedicated to heating does not have a cooling cycle, it has been difficult to recover the refrigerant to an outdoor heat exchanger or the like using the refrigerant circulation circuit as it is. Therefore, the applicant has previously proposed an improved refrigerant circuit that can easily recover refrigerant in air conditioners used exclusively for heating (
(Japanese Patent Application No. 60-240245). The refrigerant piping system diagram is shown in Figure 3. In the figure, 30 is an outdoor unit;
is an indoor unit, and the outdoor unit 3o is a compressor 5.
1, an outdoor heat exchanger 52 that acts as an evaporator, a pressure reducing mechanism 53 made of a capillary tube, and an accumulator 54, while the indoor unit 40 has an indoor heat exchanger 55 that acts as a condenser. are doing. The discharge port of the compressor 51 and the indoor heat exchanger 55 are connected to the first gas pipe 5
6 and a second gas pipe 57, and a gas shutoff valve 58 consisting of a three-way valve is interposed between the first gas pipe 56 and the second gas pipe 57. Further, the indoor heat exchanger 55 and the outdoor heat exchanger 52 are connected by a first liquid pipe 59 and a 2'/fL pipe 60 in which the pressure reduction mechanism 53 is interposed, and this first liquid pipe 59 and second liquid pipe 60
A liquid shutoff valve 61 consisting of a three-way valve is interposed between the two. Furthermore, the outdoor heat exchanger 52 is connected to the accumulator 54 by a third gas pipe 62, and this accumulator 5
4 is connected to the suction port of the compressor 51 through a suction pipe 63 to form a refrigerant circulation circuit.

On the other hand, the first gas pipe 56 connecting the compressor 51 and the gas shutoff valve 58 is connected to the second liquid pipe 60 through a first bypass pipe 65 in which a solenoid valve 64 is interposed.

Further, in this device, in order to enable pump down, the surplus boat of the gas shutoff valve 58, which is a three-way valve, is connected to the third gas pipe 62 by a second bypass pipe 67 in which a check valve 66 is interposed. are doing.

In the device configured as described above, during pump down operation, the liquid shutoff valve 61 is first switched so that the first liquid pipe 59 and the second liquid pipe 60 are cut off, and the first gas pipe 56 and the second gas pipe 60 are switched off. The gas shutoff valve 58 is switched so that the pipe 57 is cut off and the second gas pipe 57 communicates with the second bypass pipe 67. Further, the solenoid valve 64 in the first bypass pipe 65 is opened to operate the outdoor calm fan (not shown) attached to the compressor 51 and the outdoor heat exchanger 52.

At this time, the refrigerant discharged from the compressor 51 is sent directly to the outdoor heat exchanger 52 through the first bypass pipe 65, where it is cooled, liquefied, and stored in the accumulator 54 through the third gas pipe 62. . On the other hand, the refrigerant in the second gas pipe 57, the indoor heat exchanger 55, and the first liquid pipe 59 passes through the gas shutoff valve 58 and the second bypass pipe 67,
The liquid refrigerant is sucked into the third gas pipe 62 by the action of the low pressure on the suction side of the compressor 51 and sent to the accumulator 54 where it is stored, while the gas refrigerant is returned to the compressor 51. Ru. Thereafter, it is sent to the outdoor heat exchanger 52 through the first bypass pipe 65 in the same way as described above, where it is cooled and liquefied, and then collected in the accumulator 54.

(Problems to be Solved by the Invention) However, the above-described conventional apparatus has a drawback in that it takes a long time to pump down.

In the bypass circulation path consisting of the compressor 51, the first bypass pipe 65, the outdoor heat exchanger 52, the third gas pipe 62, the accumulator 54, and the suction pipe 63, there are no components that have such a large fluid resistance against the refrigerant flow. Therefore, while the gas refrigerant circulating through this bypass circulation path exists, the indoor unit 40 is
This is because the pressure acting as the refrigerant suction force on the side is not so low. Therefore, in the early stage of pump down, the high pressure gas refrigerant and the high pressure liquid refrigerant are blocked on the indoor unit 30 side, so a refrigerant flow occurs from the indoor unit 30 side through the second bypass pipe 67 in accordance with the pressure difference. However, after the pressures on the indoor unit 30 side and the suction pipe 63 become approximately equal, the circulating gas refrigerant is cooled and liquefied in the outdoor heat exchanger 52 and stored in the accumulator. As a result, the amount of refrigerant recovered depends on the degree of pressure drop on the suction side of the compressor 51, which changes as a result. However, condensation in the outdoor heat exchanger 52 becomes less likely to occur as the pressure of the gas refrigerant decreases. Therefore, the lower the pressure on the suction side of the compressor 51, the slower the rate of condensation. It took a long time to retrieve it.

This invention was made to eliminate the above-mentioned conventional drawbacks, and its purpose is to provide a separate air conditioner that can recover refrigerant in an indoor unit to an outdoor unit in a short time. be.

(Means for solving the problem) Therefore, the separate air conditioner of the present invention has three compressors.
An outdoor unit 1 having an outdoor heat exchanger 4 and an accumulator 16, and an indoor unit 2 having an indoor heat exchanger 5 form a refrigerant circulation circuit, and the compressor 3 and the indoor heat exchanger 5 are connected to a first gas The pipe 6 and the second gas pipe 7 are connected, and a gas shutoff valve 8 is connected between both gas pipes 6 and 7, and the indoor heat exchanger 5 and the outdoor heat exchanger 4 are connected to the first liquid pipe 9 and the A liquid closing valve 11 is connected between the two liquid pipes 9 and 10, and a third gas pipe 13 and the accumulator 16 are connected to the outdoor heat exchanger 4 and the suction port of the compressor 3. A cutoff valve 15 is interposed between the third gas pipe 13 and the suction pipe 14, while connecting the first gas pipe 6 and the second liquid pipe 10. A first bypass pipe 17 having a first opening/closing means 18 is connected to the second gas pipe 7 or the first liquid pipe 9 and the suction pipe 1.
4 through a second bypass pipe 19 having a second opening/closing means 15. In FIG. 1, the three-way valve 15 has two functions, that is, a cutoff valve and a second on-off valve, but the two functions may be provided separately.

(Function) In the above-mentioned separate air conditioner, the pump down operation is performed by the gas shutoff valve 8, the liquid shutoff valve 11, and the cutoff valve 15.
This is done with the first opening/closing means 18 and the second opening/closing means 15 open. At this time, the outdoor heat exchanger 4 is passed from the compressor 3 to the first bypass pipe 17.
The third gas pipe 13 connects the cutoff valve 1 with the refrigerant gas directly supplied to the
5, the gas is accumulated in this third gas pipe 13 and the outdoor heat exchanger 4, while the indoor heat exchanger 5 side is connected to the suction pipe 14 through the second bypass pipe 19, A third gas pipe 13 that communicated with this suction pipe 14
is shut off by the shutoff valve 15, so the suction side of the compressor 3 functions exclusively for suctioning refrigerant from the indoor unit 2 side, and as the amount of refrigerant on the indoor unit 2 side decreases, the pressure in the suction pipe 14 suddenly increases. As a result, the suction force further increases, making it possible to recover the refrigerant on the outlet side in a short time.

(Embodiments) Next, specific embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a refrigerant piping system in an embodiment of the separate air conditioner of the present invention. In the figure, 1 is an outdoor unit, 2 is an indoor unit, and 7. It has a compressor 3 and an outdoor heat exchanger S4 that acts as an evaporator, while the indoor unit 2 has an indoor heat exchanger 5 that acts as a condenser. The compressor 3 and the indoor heat exchanger 5 are the first gas pipe 6 and the second gas pipe 7.
A gas shutoff valve 8 consisting of a three-way valve is interposed between the first gas pipe 6 and the second gas pipe 7. The indoor heat exchanger 5 and the outdoor heat exchanger 4 are connected by a first liquid pipe 9 and a second liquid pipe 10, and there is a gap between the first liquid pipe 9 and the second liquid pipe 10. A liquid closing valve 11 consisting of a three-way valve is interposed, and a pressure reducing mechanism 12 consisting of a capillary tube is interposed in the second liquid pipe 10. Furthermore, the outdoor heat exchanger 4 is connected to the suction boat of the compressor 3 by a third gas pipe 13 and a suction pipe 14, and a cutoff valve 15 is provided between the third gas pipe 13 and the suction pipe 14. An accumulator 16 is also interposed in the suction pipe 14 .

On the other hand, the first gas pipe 6 connecting the compressor 3 and the gas shutoff valve 8 is connected to the second liquid pipe 10 by a first bypass pipe 17.
A normally closed electromagnetic valve 18, which serves as a first opening/closing means for opening and closing the channel of the first bypass pipe 17, is interposed in the middle of the first bypass pipe 17. This solenoid valve 18 is opened, and the gas shut-off valve 8 and liquid shut-off valve 11 are opened.
The compressor 3 is operated with the communication passage between the first gas pipe 6 and the second gas pipe 7 and the communication passage between the first liquid pipe 9 and the second liquid pipe 10 closed by operating the As a result, a bypass circulation circuit is formed in which the refrigerant discharged from the compressor 3 circulates only within the outdoor unit 1, as shown by the broken line arrow in the figure. This bypass circulation circuit makes it possible to defrost the outdoor heat exchanger 4, and operates the compressor 3 while the outdoor fan (not shown) attached to the outdoor heat exchanger 4 is stopped. When activated, the hot gas discharged from the compressor 3 passes through the first bypass pipe 17 and is directly sent to the outdoor heat exchanger 4, thereby transferring the heat of the gas refrigerant to the outdoor heat exchanger 4. The outdoor heat exchanger 4 is then removed.

Additionally, this device allows for pump-down,
The surplus boat of the liquid shutoff valve 11, which is a three-way valve, and the surplus boat of the cutoff valve 15, which is also a three-way valve, are
They are connected by a bypass pipe 19. Therefore, the cutoff valve 15 constituted by the three-way valve has the function of cutting off the third gas pipe 13, and also serves as a second opening/closing means for opening and closing the pipeline of the second bypass pipe 19. 2
A schematic diagram of the operating state of the cutoff valve 15 is shown in the figure.

The shutoff valve 15 is a three-way pole valve type valve,
In the state shown in FIG. 2(A), the third gas pipe 13 and the suction pipes 1.1 are in communication with each other, and the second bypass pipe 19 is cut off. In the state shown in FIG. 3B, which is rotated clockwise, the second bypass pipe 19 and the suction pipe 14 are communicated with each other, and the third gas pipe 13 is cut off.

Next, the operating state of the separate air conditioner will be explained. During heating operation, the first gas pipe 6 and the second gas pipe 7, the first liquid pipe 9 and the second liquid pipe 10, and the third gas pipe 1
A gas shutoff valve 8, a liquid shutoff valve 11, and a cutoff valve 15 are set at positions where the valve 3 and the suction pipe 14 communicate with each other. At this time, the second bypass pipe 19 is blocked at both ends by the liquid shutoff valve 11 and the cutoff valve 15, respectively. Also, the solenoid valve 18
The compressor 3 is operated in the closed state. The high-pressure gas refrigerant discharged from the compressor 3 is sent to the indoor heat exchanger 5 through the first gas pipe 6 and the second gas pipe 7, as shown by the solid line arrow in Figure 1, where it radiates heat to the outside air. It becomes a high-pressure liquid refrigerant. This high-pressure liquid refrigerant is sent through the first liquid pipe 9 and the second liquid pipe 10, and at this time, a pressure reducing mechanism 12, which is interposed in the second liquid pipe 10,
becomes a low-pressure liquid refrigerant. This low-pressure liquid refrigerant further absorbs heat from the outside air in the outdoor heat exchanger 4, becomes a low-pressure gas refrigerant, and is returned to the compressor 3 through the third gas pipe 13 and the suction pipe 14.

By continuing the above circulation cycle, the amount of heat absorbed by the refrigerant from the outside air in the outdoor heat exchanger 4 is transferred to the indoor heat exchanger 5.
It is then released into the indoor atmosphere to heat the room.

Next, the pump down operation will be explained. First, from the heating operation state as described above, the solenoid valve 18 provided in the first bypass pipe 17 is opened. Next, the gas shutoff valve 8 is operated to shut off the first gas pipe 6 and the second gas pipe 7. Furthermore, by operating the cutoff valve 15, the third gas pipe 13 is cut off from the suction pipe 14, and the second bypass pipe 19 is connected to the suction pipe 14.
communicate. Also, by operating the liquid shutoff valve 11, the first liquid pipe 9
and the second liquid pipe 10, and the first liquid pipe 9 and the second liquid pipe 10 are cut off.
It communicates with the bypass pipe 19. By performing the above operations, the piping system on the discharge side of the compressor 3 is all closed by the gas shutoff valve 8, liquid shutoff valve 11, and cutoff valve 15 in the outdoor unit 1, and therefore the compressor The refrigerant discharged from 3 will be sealed in this outdoor unit 1, and this sealed refrigerant will be cooled and liquefied in the outdoor heat exchanger 4, and will mainly flow between the 3rd gas pipe and the outdoor heat exchanger 4. It will be stored inside.

On the other hand, a third gas pipe 1 is provided in the piping system on the suction side of the compressor 3.
A second bypass pipe 19 is connected to the suction pipe 14 cut off from 3.
Through this, the first liquid pipe 9, indoor heat exchanger 5, and second gas pipe 7 are brought into communication. At this time, since there is no refrigerant inflow path from other pipes on the suction side of the compressor 3, the suction side of the compressor 3 functions exclusively for refrigerant suction from the indoor unit 2, and the indoor unit 2 side The refrigerant in the pipe is sucked into the suction side of the compressor 3 in a short time, is discharged from the compressor 3 in the same way as described above, and is stored in the pipe between the outdoor heat exchanger 4 and the third gas pipe 13. This means that it is being done. In this way, the pump-down ends when all the refrigerant on the indoor unit side is recovered.

As explained above, the pipes necessary for pumping down are a pipe that sends the refrigerant from the compressor 3 to the outdoor heat exchanger 4 through the first bypass pipe 17, and a pipe that sends the refrigerant from the indoor unit 2 to the second bypass pipe. The refrigerant is collected through the refrigerant pipe 19 to the outdoor unit 1 side, and the compressor 3 acts exclusively on the pipe inside the indoor unit 2 for suction, making it possible to recover the refrigerant in a short time. Further, since the parts additionally installed for pump-down purposes are simple, the device can be constructed at low cost. Furthermore, since the circuit configuration is relatively simple, the refrigerant can flow smoothly and pump down can be performed reliably and easily.

Moreover, since the gas shutoff valve 8, liquid shutoff valve 11, solenoid valve 18, and first bypass pipe 17 are already installed for defrosting operation, only the second bypass pipe 19 and the cutoff valve 15 need be added. , the device can be constructed at a lower cost. In addition, in the above embodiment, since the cutoff valve 15 is constituted by a ball valve type three-way valve, the communication state between the third gas pipe 13, the second bypass pipe 19, and the suction pipe 14 during heating operation and pump-down operation Switching can be performed with an extremely simple operation.

In the above embodiment, the second bypass pipe 19 is connected to the liquid shutoff valve 11.
Although the configuration is such that it is connected to the gas shutoff valve 8, it may also be configured to be connected to the gas shutoff valve 8. Further, the closing valve 8 or 11 on the side to which the second bypass pipe 19 is not connected may be configured not as a three-way valve but as a two-way open/close valve. Furthermore, in the above embodiment, the switching valve 8.15 consisting of a three-way valve was installed at the location where the second bypass pipe 19 is connected, but each valve 8.15 is configured as a two-way opening/closing valve, and the second bypass pipe 19 It is also possible to connect the suction pipe 14 and the second liquid pipe 10 to the second bypass pipe 19, and to provide an on-off valve in the middle of the second bypass pipe 19.

(Effects of the Invention) As explained above, in the separate air conditioner of the present invention, during pump down operation, the refrigerant piping in the indoor unit that is isolated from the outdoor unit by the gas shutoff valve and the liquid shutoff valve is connected to the outdoor unit. The third gas pipe connected to the heat exchanger is communicated with the suction pipe of the compressor which is shut off by the second opening/closing means through the second bypass pipe, so that the suction force on the suction side of the compressor is transferred to the indoor heat exchanger side. As the amount of suction refrigerant on the indoor unit side decreases, the pressure in the suction pipe decreases rapidly.
As a result, the suction force is further increased (this makes it possible to recover the refrigerant from the indoor unit in a short time).

[Brief explanation of drawings]

Figure 1 is a refrigerant piping system diagram showing one embodiment of the present invention, and Figures 2 (A') and (B) are diagrams explaining the operation of the shutoff valve installed at the location marked with ■ in Figure 1. 3 is a refrigerant piping system diagram in a conventional device. 1...Outdoor knee'-soto, 2...Indoor unit, 3
...Compressor, 4...Outdoor heat exchanger, 5...Indoor heat exchanger, 6...First gas pipe, 7...Second gas pipe, 9
...First liquid pipe, 10...Second liquid pipe, 11...Liquid closing valve, 13...Third gas pipe, 14...Suction pipe, 1
5... Shutoff valve (second opening/closing means), 17... First bypass pipe, 18... Solenoid valve (first opening/closing means), 19...
・Second bypass pipe. Patent applicant: Daikin Industries, Ltd. Figure 3

Claims (1)

[Claims] 1. A refrigerant circulation circuit was formed by an outdoor unit (1) having a compressor (3), an outdoor heat exchanger (4), and an accumulator (16), and an indoor unit (2) having an indoor heat exchanger (5). A separate air conditioner, in which the compressor (3) and the indoor heat exchanger (5) are connected to a first gas pipe (6).
and the second gas pipe (7), and both gas pipes (6)
(7), and the indoor heat exchanger (5) and outdoor heat exchanger (4) are connected between the first liquid pipe (9) and the second liquid pipe (10). Connect both liquid pipes (9) (10
), and a third gas pipe (13) between the outdoor heat exchanger (4) and the inlet of the compressor (3).
and a suction pipe (14) in which the accumulator (16) is interposed, and a cutoff valve (15) is interposed between the third gas pipe (13) and the suction pipe (14), respectively, On the other hand, a first bypass pipe (17) having a first opening/closing means (18) connects the first gas pipe (6) and the second liquid pipe (10).
), and the second gas pipe (7) or the first
The liquid pipe (9) and the suction pipe (14) are connected by a second opening/closing means (
15) connected by a second bypass pipe (19).