JP2009228975A - Remote condenser type air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make the refrigerant flow rates uniform among a plurality of outdoor units and to improve reliability and performance of a refrigerating cycle in a remote condenser type air conditioner. <P>SOLUTION: The remote condenser type air conditioner is equipped with: a compressor 1; an indoor heat exchanger 15; an indoor unit 17 having an indoor pressure reducing device 14;, and an outdoor unit 18 connected to the indoor unit 17 by a pipe and having an indoor heat exchanger 6 and an outdoor pressure reducing device 7. The outdoor unit 18 is provided in a plurality of numbers in parallel. A receiver 10 is provided in each outdoor unit 18. The outdoor pressure reducing device 7 is arranged between the receiver 10 and the outdoor heat exchanger 6. The outdoor pressure reducing device 7 is composed of an expansion valve whose opening is adjusted. A bypass circuit for bypassing the outdoor pressure reducing device 7 is provided, and the bypass circuit is equipped with a check valve 9 for allowing only a flow to the receiver 10 side. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a remote condenser type air conditioner having an indoor unit having a compressor, an indoor heat exchanger, and an indoor pressure reducing device, and having an outdoor heat exchanger and an outdoor pressure reducing device connected to the outdoor unit. In particular, the present invention relates to a configuration in which a plurality of outdoor units are connected in parallel in the same refrigeration cycle system.

  In a remote condenser type air conditioner having a compressor in an indoor unit, in order to enable proper cooling and heating even when the pipe connecting the indoor unit and the outdoor unit becomes long, as a conventional technique, for example, Patent Document 1 and There are those described in 2.

JP-A-60-126557 Japanese Patent Laid-Open No. 60-165466

  However, in the structures of Patent Documents 1 and 2, when a plurality of independent outdoor units are provided, refrigerant accumulates in one outdoor heat exchanger, and the amount of refrigerant flowing into each outdoor heat exchanger differs. The pressure loss is not considered enough. If the refrigerant accumulates in the heat exchanger of one outdoor unit when the operation is stopped, and the amount of refrigerant stored in the heat exchanger of the outdoor unit is different at the start of operation, the outdoor unit that has a large amount of refrigerant has a pressure loss. Increases, the refrigerant flow rate decreases, and the outdoor unit that does not hold a large amount of refrigerant has a small pressure loss, so the refrigerant flow rate increases. In this state, the pressure state between the outdoor units becomes uniform. As a result, the pressure loss increases due to the increase in the flow rate of the refrigerant, and the heat exchanger is also blocked by the liquid refrigerant in the other, reducing the passage. This increases the pressure loss. When the pressure between the outdoor units is balanced, the operation is continued, and as a refrigeration cycle, the original heat exchange amount and refrigerant amount may change and the operation state may become unstable.

  An object of the present invention is to make the refrigerant flow rate between a plurality of outdoor units uniform in a remote condenser type air conditioner and to improve the refrigeration cycle reliability and performance. Another object of the present invention is to improve the defrosting performance during defrosting during heating operation.

  In order to achieve the above object, the present invention provides an indoor unit having a compressor, an indoor heat exchanger, and an indoor pressure reducing device, and an indoor heat exchanger and an outdoor pressure reducing device connected to the indoor unit by piping. In the remote condenser type air conditioner provided with an outdoor unit having a plurality of the outdoor units are provided in parallel, and each outdoor unit is provided with a receiver, and between the receiver and the outdoor heat exchanger. The outdoor pressure reducing device is disposed, the outdoor pressure reducing device is configured by an expansion valve whose opening degree can be adjusted, and further, a bypass circuit for bypassing the outdoor pressure reducing device is provided, and only the flow to the receiver side is provided in the bypass circuit. It is characterized by having a check valve to allow.

  In the above configuration, it is desirable to provide an electromagnetic valve in series with the check valve in the bypass circuit.

  In the above configuration, it is desirable that the solenoid valve be opened when the outdoor decompression device is fully open, and closed when the outdoor decompression device is other than fully open.

  According to the present invention, a plurality of outdoor units are provided in parallel, and each outdoor unit is provided with a receiver, and the outdoor pressure reducing device is disposed between the receiver and the outdoor heat exchanger. Since the pressure reducing device is composed of an expansion valve whose opening degree can be adjusted, and further provided with a bypass circuit that bypasses the outdoor pressure reducing device, the bypass circuit includes a check valve that allows only flow to the receiver side. Refrigerant can be prevented from accumulating in the outdoor unit during cooling operation, the effect of increased pressure loss when the refrigerant flow rate increases can be reduced, and the refrigerant flow between the outdoor units can be made uniform and stable cooling operation and performance improvement can be achieved. It becomes possible.

  In addition, since the circuit bypassing the outdoor pressure reducing device is shut off by the check valve during the heating operation, it passes only through the outdoor pressure reducing device, and an appropriate refrigeration cycle state can be maintained by the pressure reducing effect.

  Furthermore, by providing a solenoid valve in series with the check valve, the solenoid valve is configured to be opened if the outdoor decompression device is fully open, and to be closed if the outdoor decompression device is not fully open, It is possible to efficiently perform defrosting of the outdoor unit.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a cycle system diagram of an air conditioner according to an embodiment of the present invention. In the case of cooling operation, the high-temperature and high-pressure gas refrigerant compressed by the plurality of compressors 1a and 1b is discharged from the compressor 1, passes through the four-way valve 2, the gas connection pipe 4, and the outdoor gas branch pipe 5, It flows into the outdoor heat exchangers 6a and 6b, where heat is exchanged to condense into liquid. The condensed and liquefied refrigerant is sent to the indoor unit 17 through the outdoor decompression devices 7a and 7b that are fully open, leaving the surplus refrigerant in the receivers 10a and 10b, the outdoor liquid branch pipe 11, the liquid connection pipe 12, and the like. The sent liquid refrigerant flows into the indoor decompression device 14, where the pressure becomes low, and heat exchange is performed in the indoor heat exchanger 15 to evaporate and gasify. Thereafter, the gas refrigerant returns to the compressor 1 through the four-way valve 2 and the accumulator 16.

  In the case of heating operation, the high-temperature and high-pressure gas refrigerant compressed by the plurality of compressors 1a and 1b is discharged from the compressors 1a and 1b, flows into the indoor heat exchanger 15 through the four-way valve 2, and is heated here. Change to condensate. The condensed and liquefied refrigerant flows into the plurality of receivers 10a and 10b through the indoor decompression device 14, the indoor liquid blocking valve 13, the liquid connection pipe 12, and the outdoor liquid branch pipe 11 that are fully opened, and excess refrigerant is supplied to the receiver 10a. 10b, the pressure is reduced by the outdoor pressure reducing devices 7a and 7b, and heat is exchanged by the outdoor heat exchangers 6a and 6b to evaporate and gasify. The gasified refrigerant passes through the outdoor gas branch pipe 5, the gas connection pipe 4, the indoor gas blocking valve 3, the four-way valve 2, and the accumulator 16, and returns to the plurality of compressors 1a and 1b.

  In the case of defrosting operation, the four-way valve 2 is switched to operate in the cycle during the cooling operation.

  When a large amount of liquid refrigerant accumulates on the outdoor heat exchanger 6a side and almost no liquid refrigerant accumulates on the outdoor heat exchanger 6b side at the start of the cooling operation, the liquid refrigerant on the outdoor heat exchanger 6a side becomes the outdoor decompression device 7a. However, since the outdoor decompression device 7a has a capacity of one compressor, that is, half the total refrigerant flowing out from the two compressors in this embodiment, a large amount of refrigerant is used. A large amount of refrigerant remains in the outdoor heat exchanger 6a.

  Further, since there is almost no accumulation of liquid refrigerant on the outdoor heat exchanger 6b side, gas refrigerant that is larger in volume than liquid refrigerant tends to flow in, but the capacity of the outdoor decompression device 7b is the same as that of the compressor 1 as described above. Since it is the capacity of the liquid refrigerant for the stand, the necessary refrigerant cannot be exhausted.

  Therefore, a bypass circuit that bypasses the outdoor decompression device that is fully opened during the cooling operation is provided, and the bypass valve is provided with an electromagnetic valve 8 and a check valve 9, and the solenoid valve 8 is energized and opened so that the refrigerant is only the outdoor decompression device. Since it also flows from the bypass circuit, it is possible to improve the flow of the refrigerant, and even when the outdoor heat exchangers 6a and 6b before the start of operation have a refrigerant bias, the refrigerant can flow smoothly. The bias of the refrigerant flowing between the plurality of outdoor units is less likely to occur, and the performance and reliability during the cooling operation can be improved.

  In addition, during the heating operation, the flow of liquid refrigerant in the bypass circuit is blocked by the check valve 9, so that it can be controlled only by the outdoor pressure reducing device.

  Further, during the defrosting operation, the plurality of outdoor units are in a cooling cycle. However, the outdoor unit that has been defrosted reduces the refrigerant flow by reducing the outdoor pressure reducing device and closing the electromagnetic valve 8 to defrost. The defrosting can be efficiently performed by increasing the flow of the refrigerant to the outdoor unit 18 that is not finished.

The cycle system diagram which shows the Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Compressor 2 Four-way valve 3 Indoor gas blocking valve 4 Gas connection piping 5 Outdoor gas branch pipe 6 Outdoor heat exchanger 7 Outdoor decompression device 8 Solenoid valve 9 Check valve 10 Receiver 11 Outdoor liquid branch pipe 12 Liquid connection pipe 13 Indoor liquid Stop valve 14 Indoor pressure reducing device 15 Indoor heat exchanger 16 Accumulator 17 Indoor unit 18 Outdoor unit

Claims (3)

Remote condenser type air having an indoor unit having a compressor, an indoor heat exchanger, and an indoor pressure reducing device, and an outdoor unit connected to the indoor unit by a pipe and having an outdoor heat exchanger and an outdoor pressure reducing device In the harmony machine,
A plurality of the outdoor units are provided in parallel, and each outdoor unit is provided with a receiver, and the outdoor pressure reducing device is disposed between the receiver and the outdoor heat exchanger. A remote condenser comprising an adjustable expansion valve, further comprising a bypass circuit that bypasses the outdoor pressure reducing device, and further including a check valve that allows only the flow to the receiver side. Type air conditioner.   The remote condenser type air conditioner according to claim 1, wherein an electromagnetic valve is provided in series with the check valve in the bypass circuit.   3. The remote condenser type air conditioner according to claim 2, wherein the solenoid valve is opened when the outdoor decompression device is fully open, and is closed when the outdoor decompression device is not fully opened.

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