JP4687326B2 - Air conditioner - Google Patents

Description

  The present invention relates to an air conditioner capable of performing a defrosting operation for defrosting frost adhering to an outdoor heat exchanger while heating is continued during a heating operation by a heat pump operation.

  Conventionally, this type of air conditioner switches the four-way valve to flow the refrigerant in the refrigeration cycle in the opposite direction to that during heating, that is, the same refrigerant flow direction as in cooling, and allows high-temperature and high-pressure refrigerant to flow through the outdoor heat exchanger. The defrosting method is used to melt the frost adhering to the heat exchanger. In this defrosting method, since the indoor heat exchanger serves as an evaporator during defrosting, there is a basic problem that the heating stops, the temperature decreases, and a cold wind feeling is felt.

  On the other hand, as a countermeasure against this basic problem, as a defrosting method that performs defrosting operation while continuing heating, a refrigerant heating circuit having a refrigerant heater and a defrosting circuit are provided in the refrigeration cycle, and the refrigerant heated by the refrigerant heater After passing through the compressor, the flow branches through the flow through the indoor heat exchanger and the flow into the outdoor heat exchanger through the defrosting circuit in the opposite direction to that during heating. Some heat exchangers perform defrosting simultaneously (for example, see Patent Document 1).

  FIG. 6 shows a configuration diagram of a refrigeration cycle of a conventional air conditioner described in Patent Document 1, wherein (a) shows a defrosting operation state, and (b) shows other heating and cooling operation states. is there. 6 (a) and 6 (b), a heat pump refrigeration cycle in which a compressor 101, a four-way valve 102, an indoor heat exchanger 110, an expansion mechanism 105, and an outdoor heat exchanger 103 are connected by a refrigerant circuit. A refrigerant heating circuit having a refrigerant heater 104 connected between the expansion mechanism 105 and the outdoor heat exchanger 103 and between the suction side of the compressor 101, the discharge side of the compressor 101, and the outdoor heat exchanger 103 And a circuit for defrosting that connects between the four-way valve 102 and when the outdoor heat exchanger 103 is defrosted, the refrigerant heated by the refrigerant heater 104 passes through the compressor 101, The flow is divided into a flow passing through the heat exchanger 110 and a flow passing through the outdoor heat exchanger 103 via a circuit for defrosting, and the flow of these branched refrigerants merges at the inlet of the refrigerant heating circuit, and again the refrigerant heater 104 Will be heated by It is configured.

  However, this refrigeration cycle is configured such that when the defrosting operation is performed, the two-way valve 109a in the defrosting circuit is opened, and the compressor 101 discharges between the outdoor heat exchanger 103 and the four-way valve 102. Since the refrigerant flows, the two-way valve 106 is necessary so that the hot gas refrigerant to be defrosted does not flow to the compressor 101 suction side, but the two-way valve 106 is connected to the suction side of the compressor 101, In order to reduce the pressure loss during cooling and heating operations, a two-way valve with a large diameter is required, resulting in a very expensive two-way valve.

  Further, when switching from the heating operation to the defrosting operation, the flow of the refrigerant in the outdoor heat exchanger 103 is reversed, so that the refrigerant flowing into the outdoor heat exchanger 103 is stopped before the defrosting operation is performed. A two-way valve 107 is required at the 103 inlet.

  Therefore, this refrigeration cycle requires as many as four two-way valves, which is a complicated and expensive method.

  In addition, since the refrigerant after being defrosted and the refrigerant after being radiated by the indoor heat exchanger 110 merge, if the refrigerant pressure at the junction is higher than the refrigerant pressure after being defrosted, If the refrigerant flows back to the heat exchanger 103 and is low, the refrigerant will flow to the indoor heat exchanger 110 side, and the defrosting operation may not be performed while heating.

  Moreover, since the refrigerant after being defrosted and the refrigerant after radiating heat in the indoor heat exchanger 110 merge, refrigerant noise is likely to be generated, and the pressure balance problem and refrigerant noise problem of the refrigerant merge part are solved. Therefore, there may be a case where a refrigerant merger is required.

  In addition, since the refrigerant circulation amount increases and the pressure loss increases in the refrigerant junction, it is necessary to increase the pipe diameter as a countermeasure, and there is a structural problem that the refrigerant heater 104 becomes large. .

  Furthermore, when the cooling circuit is operated, the inside of the piping of the refrigerant heater 104 is stabilized with the low-pressure refrigerant, and the temperature of the refrigerant heater 104 is decreased. Therefore, when the dew condensation occurs on the refrigerant heater 104 or the two-way valve 108 breaks down, the refrigerant Even when leakage occurs, condensation occurs in the refrigerant heater, and there is a big problem in the reliability and safety of the refrigerant heater.

  As one countermeasure to solve this problem, a first bypass circuit and a second bypass circuit having a refrigerant heater are provided in the refrigeration cycle, and after the refrigerant heated by the refrigerant heater passes through the compressor, the indoor heat There is one that branches into a flow passing through the exchanger and a flow passing directly through the outdoor heat exchanger via the second bypass circuit, and simultaneously performs indoor heating by the indoor heat exchanger and defrosting of the outdoor heat exchanger. Such prior art is described in Japanese Patent Application No. 2004-318985, and has not been disclosed yet, and does not relate to a known invention.

As shown in FIG. 7, the air conditioner of this measure is a heat pump refrigeration cycle in which a compressor 1, a four-way valve 2, an indoor heat exchanger 3, a decompressor 4, and an outdoor heat exchanger 5 are connected by a refrigerant circuit. The first bypass circuit for connecting the indoor heat exchanger 3 and the decompressor 4 and the four-way valve 2 and the outdoor heat exchanger 5 is provided, and the two-way valve 7 and the refrigerant heater 8 are provided in the first bypass circuit. Furthermore, between the four-way valve 2 and the indoor heat exchanger 3, between the pressure reducer 4 and the outdoor heat exchanger 5, or between the compressor 1 and the four-way valve 2, the pressure reducer 4 and the outdoor heat exchanger 5 A second bypass circuit is provided to connect the two, the two-way valve 10 is provided in the second bypass circuit, and the two-way valve 7 of the first bypass circuit is opened when the outdoor heat exchanger 5 is defrosted. The first bypass operation for flowing the refrigerant heated by the refrigerant heater 8 to the suction side of the compressor 1, and the second bypass circuit Opens the way valve 10 characterized in that performing a second bypass operation for passing the refrigerant to the outdoor heat exchanger 5, it is defrosting operation while continuing the heating operation.
JP-A-11-182994

  However, in the conventional configuration, during the heating operation, the refrigerant flows from the two-way valve to the refrigerant heater in the first bypass circuit, and the refrigerant is exchanged between the four-way valve and the indoor heat in the second bypass circuit. Although it flows in the direction from the space between the decompressor and the outdoor heat exchanger, the refrigerant may flow in the first bypass circuit and the second bypass circuit in reverse because the high and low pressures are reversed during cooling. However, since the refrigerant leaks with respect to the reverse pressure and the chatter operation of the two-way valve with respect to the refrigerant pressure balance occurs, it has been required to ensure durability and reliability.

  The present invention solves the above-described conventional problems, and can continue the heating operation in which the refrigeration cycle can be configured with a simple bypass circuit, and refrigerant noise and pressure balance problems do not occur without causing refrigerant leakage against reverse pressure. An object of the present invention is to provide an air conditioner that can perform a defrosting operation.

In order to solve the conventional problems, the air conditioner of the present invention is characterized in that a check valve is provided between the two-way valve of the first bypass circuit and the refrigerant heater. Thereby, the check valve provided in the first bypass circuit can eliminate the chatter sound of the two-way valve during the cooling operation. In addition, a simple bypass circuit can be used to solve the problem that condensation of the refrigerant heater can be eliminated due to leakage of the two-way valve and accumulation of low-pressure refrigerant in the refrigerant heater during cooling. It is possible to provide an air conditioner that can perform a defrosting operation while continuing the operation.

  The air conditioner of the present invention can perform defrosting while continuing the heating operation, improves the reliability and reliability of the two-way valve with respect to the reliability and pressure balance of the refrigeration cycle, and the outside air temperature decreases. Even so, it is possible to provide an air conditioner that can perform heating without causing a feeling of cold air without lowering the temperature of the room.

A first invention is a heat pump type in which a compressor, a four-way valve, an indoor heat exchanger, a decompressor, and an outdoor heat exchanger are connected by a refrigerant circuit, and cooling and heating are performed by reversing the refrigerant flow by switching the four-way valve. and a refrigeration cycle, the first bypass circuit for connecting the between and the outdoor heat exchanger and said four-way valve of the pressure reducer and connected to said indoor heat exchanger in the refrigeration cycle is provided, the first bypass The circuit includes a refrigerant heating two-way valve, a heater heating type refrigerant heater and a check valve, and the check valve is provided between the refrigerant heating two-way valve and the refrigerant heater of the first bypass circuit. The refrigerant is arranged so that the refrigerant flows from the two-way valve toward the refrigerant heater, and further, between the four-way valve and the indoor heat exchanger connected to the refrigeration cycle, and between the pressure reducer and the outdoor heat exchange. Or connected to the refrigeration cycle The second bypass circuit is provided for, arranged defrosting two-way valve in the second bypass circuit for connecting between said between compressor and the four-way valve and the pressure reducer and the outdoor heat exchangers When the defrosting of the outdoor heat exchanger is performed, the refrigerant heated by the refrigerant heater by opening the refrigerant heating two-way valve of the first bypass circuit is compressed through the four-way valve. A first bypass operation that flows to the suction side of the machine, and a second bypass operation that opens the two-way defrost valve of the second bypass circuit and allows the refrigerant to pass through the outdoor heat exchanger. This makes it possible to perform defrosting while continuing the heating operation, and to prevent the two-way valve from being constantly applied with a reverse pressure, and to prevent refrigerant leakage and chatter noise in the pressure fluctuation of the cooling operation and the reverse pressure. Durability and reliability can be improved.

A second invention is a heat pump type in which a compressor, a four-way valve, an indoor heat exchanger, a decompressor, and an outdoor heat exchanger are connected by a refrigerant circuit, and cooling and heating are performed by reversing the refrigerant flow by switching the four-way valve. and a refrigeration cycle, the first bypass circuit for connecting the between and the outdoor heat exchanger and said four-way valve of the pressure reducer and connected to said indoor heat exchanger in the refrigeration cycle is provided, the first bypass The circuit includes a refrigerant heating two-way valve, a heater heating type refrigerant heater and a check valve, and the check valve is provided between the refrigerant heating two-way valve of the first bypass circuit and the refrigerant heater. The refrigerant is arranged so that the refrigerant flows from the two-way valve toward the refrigerant heater , and further, between the four-way valve and the indoor heat exchanger connected to the refrigeration cycle, and between the pressure reducer and the outdoor heat exchange. Or between the refrigeration cycles The second bypass circuit is provided in the second two-way valve for defrosting the bypass circuit and the inverse for connecting the imaging has been the compressor and between the pressure reducer of the four-way valve the outdoor heat exchanger The check valve is provided with a check valve in a direction from between the four-way valve and the indoor heat exchanger to the pressure reducer and the outdoor heat exchanger, or between the compressor and the four-way valve. The refrigerant is arranged so that the refrigerant flows in a direction between the outdoor heat exchanger and the two-way valve for heating the refrigerant of the first bypass circuit is opened when defrosting the outdoor heat exchanger. The first bypass operation for flowing the refrigerant heated by the refrigerant heater to the suction side of the compressor through the four- way valve, and opening the two-way defrosting valve of the second bypass circuit to open the outdoor The heating operation is continued by performing the second bypass operation for allowing the refrigerant to pass through the heat exchanger. It is possible to perform defrosting and prevent reverse pressure from being constantly applied to the two-way valve, as well as prevent refrigerant leakage and chatter noise and improve durability and reliability of the two-way valve due to pressure fluctuations and reverse pressure during cooling operation. Can be made.

According to a third aspect of the present invention , the check valve according to the second aspect of the present invention is disposed between the two-way defrosting valve of the second bypass circuit and connected to the pressure reducer and the outdoor heat exchanger. By adopting a configuration in which the refrigerant flows in a direction in which the outdoor heat exchanger is connected, it is possible to prevent a reverse pressure from being constantly applied during the cooling operation.

A fourth invention is a heat pump type in which a compressor, a four-way valve, an indoor heat exchanger, a decompressor, and an outdoor heat exchanger are connected by a refrigerant circuit, and cooling and heating are performed by reversing the refrigerant flow by switching the four-way valve. A refrigeration cycle, and a first bypass circuit that connects the indoor heat exchanger and the pressure reducer connected to the refrigeration cycle, and the four-way valve and the outdoor heat exchanger. The circuit is provided with a refrigerant heating two-way valve, a refrigerant heater, and a check valve, and the check valve provided in the first bypass circuit is replaced with the refrigerant heating two-way valve and the refrigerant heater of the first bypass circuit. Between the four-way valve connected to the refrigeration cycle and the indoor heat exchanger, the pressure reducer, and the two-way valve for refrigerant heating are provided to flow in the direction of the refrigerant heater. Between the outdoor heat exchanger or the cooling A second bypass circuit for connecting the compressor and the four-way valve connected in a cycle, and between the pressure reducer and the outdoor heat exchanger is provided, and the two-way valve for defrosting is provided in the second bypass circuit And the check valve is connected between the defrosting two-way valve of the second bypass circuit and the decompressor and the outdoor heat exchanger, and between the four-way valve and the indoor heat exchanger. The outdoor heat exchange is configured to flow in a direction between the decompressor and the outdoor heat exchanger, or in a direction from the compressor and the four-way valve to the decompressor and the outdoor heat exchanger. A first bypass operation for opening the refrigerant heating two-way valve of the first bypass circuit and flowing the refrigerant heated by the refrigerant heater to the suction side of the compressor when performing defrosting of the compressor; A second defrosting two-way valve of the second bypass circuit is opened to allow the refrigerant to pass through the outdoor heat exchanger. By performing the bypass operation, defrosting can be carried out while continuing the heating operation, so that the back pressure is not constantly applied to the two-way valve, and the refrigerant leakage of the two-way valve due to the pressure fluctuation of the cooling operation or the back pressure And chatter noise prevention, durability and reliability can be improved.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.
(Embodiment 1)
FIG. 1 is a configuration diagram of an air-conditioning apparatus according to the first embodiment of the present invention. In FIG. 1, an outdoor unit 20 includes a compressor 1, a four-way valve 2, a decompressor 4, an outdoor heat exchanger 5, a first bypass circuit 6, a refrigerant heating two-way valve 7, a refrigerant heater 8, a first Check circuit 30 of the bypass circuit, second bypass circuit 9, two-way valve 10 for defrosting, decompressor 11 of the second bypass circuit, decompressor 12 of the first bypass circuit, refrigerant heater 13, refrigerant The passage pipe part 14, the heat storage part 15, and the outdoor blower 19 are provided. The indoor unit 18 is provided with the indoor heat exchanger 3 and the indoor blower 17. The decompressor 4 here may be an electromagnetic expansion valve.

  Next, FIG. 4 is a control block diagram showing the first embodiment according to the present invention, and FIG. 5 is a time chart showing the behavior when the control is operated. In FIG. 4, the defrosting start determination is made by the defrosting start determining means 50 on the outdoor unit side, and when it is determined that the defrosting is started, the compressor operating means 51, the refrigerant heating two-way valve opening / closing means 52, and the defrosting two-way The valve opening / closing means 53, the expansion valve opening varying means 54, the outdoor fan operating means 55, the four-way valve switching means 56, and the heater heater operation stopping means 57 perform the defrosting operation by performing the operations shown in FIG.

  At this time, the defrosting start signal is received from the outdoor unit 20 by the indoor unit 18 by the defrosting start signal receiving means 58, and the indoor fan 17 is controlled by the indoor fan operating means 59 based on the determination of the defrosting operation.

  As shown in FIG. 5, when the start of defrosting is determined, the heating operation by the heat pump in step 1 is shifted to the heating operation by the refrigerant heating operation in step 2. At this time, the refrigerant heating two-way valve is turned on and controlled in the opening direction. Also, the heater is turned on to perform the refrigerant heating operation. At this time, the expansion valve performs a closed operation or an operation close to the closed state. The outdoor blower stops during defrosting. Since a four-way valve continues heating, it does not switch during defrosting with a heating circuit. Moreover, since an indoor air blower continues heating, it does not stop. Next, in step 3, in order to perform defrosting, the two-way valve for defrosting is turned on and controlled in the opening direction. The compressor is operated at an operating frequency for defrosting.

  Next, in step 4, the operation before defrosting is returned to when the defrosting is completed. Next, after step 5, the normal heat pump heating operation is resumed. In the first embodiment, the operating frequency of the compressor is changed, but the defrosting operation can be performed by continuing heating even with a constant speed compressor.

  A heat pump refrigeration cycle in which a compressor, a four-way valve, an indoor heat exchanger, a decompressor, and an outdoor heat exchanger are connected by a refrigerant circuit; and between the indoor heat exchanger and the decompressor connected to the refrigeration cycle, and A first bypass circuit that connects the four-way valve and the outdoor heat exchanger is provided, a refrigerant heating two-way valve, a refrigerant heater, and a check valve are provided in the first bypass circuit, and the refrigeration cycle is further provided. Between the connected four-way valve and the indoor heat exchanger, between the pressure reducer and the outdoor heat exchanger, or between the compressor and the four-way valve connected to the refrigeration cycle, and the pressure reducer When the defrosting of the outdoor heat exchanger is performed by providing a second bypass circuit connecting between the outdoor heat exchanger and the outdoor heat exchanger, and providing a defrosting two-way valve in the second bypass circuit. The two-way valve for heating the refrigerant of the first bypass circuit The first bypass operation for opening the refrigerant heated by the refrigerant heater to the suction side of the compressor and the two-way defrosting valve for the second bypass circuit are opened to the outdoor heat exchanger. The configuration is characterized in that the second bypass operation for allowing the refrigerant to pass is performed.

Thus, since the defrosting operation is performed while continuing the heating, no refrigerant noise is generated when the four-way valve is switched. Further, since the four-way valve is not switched during defrosting, the pressure fluctuation is small and the oil fluctuation of the compressor is small, so that the compressor can be operated with high reliability. In addition, since the defrosting circuit is performed outdoors even when the length of the connection pipe is long, the compressor oil level does not decrease during the defrosting operation by the pipe length, and the compressor can be operated with high reliability even with long pipe products. . In addition, since a part of the whole refrigerant is used for defrosting, an extremely large amount of refrigerant does not flow in the refrigerant heating unit, so that a compact refrigerant heater can be used. Even when the cooling operation is performed, the high-temperature and high-pressure refrigerant gas does not stay in the refrigerant heater, and the refrigerant heater does not cause dew condensation.

The check valve is disposed between the refrigerant heater and the refrigerant heating two-way valve. The check valve provided in the first bypass circuit reduces the suction pulsation during startup due to pressure balance fluctuations during heating operation, eliminates the noise of the refrigerant heating two-way valve, and switches the four-way valve to perform defrosting operation. When the refrigerant heating two-way valve is leaking, the refrigerant heater will cool and cause condensation, or the refrigerant heating two-way valve leaks or low-pressure refrigerant accumulates in the refrigerant heater. An air conditioner that can be defrosted while continuing the heating operation that can be configured with a simple bypass circuit and no refrigerant noise and pressure balance problems, such as solving the problem of eliminating the occurrence of dew condensation Can provide.
In the present embodiment, one end of the first bypass circuit is connected between the four-way valve and the outdoor heat exchanger, but may be connected between the four-way valve and the suction side of the compressor. (Embodiment 2)
Next, Embodiment 2 will be described with reference to FIG. FIG. 2 is a configuration diagram of an air-conditioning apparatus according to the second embodiment of the present invention. In the figure, an outdoor unit 20 includes a compressor 1, a four-way valve 2, a decompressor 4, an outdoor heat exchanger 5, a first bypass circuit 6, a refrigerant heating two-way valve 7, a refrigerant heater 8, a second bypass circuit 9, defrosting two-way valve 10, pressure reducer 11 of the second bypass circuit, the check valve 31 of the second bypass circuit, decompressor 12 of the first bypass circuit, refrigerant heater heater 13, The refrigerant passage pipe section 14, the heat storage section 15, the check valve 16, and the outdoor blower 19 are provided. The indoor unit 18 is provided with the indoor heat exchanger 3 and the indoor blower 17. The decompressor 4 here may be an electromagnetic expansion valve. A heat pump refrigeration cycle in which a compressor, a four-way valve, an indoor heat exchanger, a decompressor, and an outdoor heat exchanger are connected by a refrigerant circuit; and between the indoor heat exchanger and the decompressor connected to the refrigeration cycle, and A first bypass circuit that connects between the four-way valve and the outdoor heat exchanger is provided, a two-way valve, a refrigerant heater, and a check valve are provided in the first bypass circuit, and further connected to the refrigeration cycle. Between the four-way valve and the indoor heat exchanger, between the pressure reducer and the outdoor heat exchanger, or between the compressor and the four-way valve connected to the refrigeration cycle, and between the pressure reducer and the outdoor A second bypass circuit for connecting between the heat exchangers is provided, and a two-way valve and a check valve are provided in the second bypass circuit to defrost the outdoor heat exchanger. The two-way valve is opened and cooled by the refrigerant heater. And a second bypass operation for opening the two-way valve of the second bypass circuit and allowing the refrigerant to pass through the outdoor heat exchanger. The configuration is as follows.

  Thus, since the defrosting operation is performed while continuing the heating, no refrigerant noise is generated when the four-way valve is switched. Further, since the four-way valve is not switched during defrosting, the pressure fluctuation is small and the oil fluctuation of the compressor is small, so that the compressor can be operated with high reliability. In addition, since the defrosting circuit is performed outdoors even when the length of the connection pipe is long, the compressor oil level does not decrease during the defrosting operation by the pipe length, and the compressor can be operated with high reliability even with long pipe products. . In addition, since a part of the whole refrigerant is used for defrosting, an extremely large amount of refrigerant does not flow in the refrigerant heating unit, so that a compact refrigerant heater can be used. Even when the cooling operation is performed, the high-temperature and high-pressure refrigerant gas does not stay in the refrigerant heater, and the refrigerant heater does not cause dew condensation.

  The check valve is disposed between the two-way valve of the second bypass circuit and connected to the decompressor and the outdoor heat exchanger. Further, the check valve provided in the second bypass circuit is arranged so that the refrigerant flows in a direction in which the decompressor and the outdoor heat exchanger are connected, and at the time of start-up due to pressure balance fluctuation during heating operation Durable against refrigerant pressure balance by reducing the discharge pulsation and eliminating the two-way valve dance noise, and reducing the suction pulsation due to pressure balance fluctuation during cooling operation and eliminating the two-way valve dance noise Stable air-conditioning system that determines the position of the check valve that does not apply back pressure to the two-way valve at all times to protect the two-way valve, which requires ensuring safety and reliability. The structure characterized by being able to provide is taken.

In the present embodiment, one end of the first bypass circuit is connected between the four-way valve and the outdoor heat exchanger, but may be connected between the four-way valve and the suction side of the compressor. (Embodiment 3)
Next, Embodiment 3 will be described with reference to FIG. In FIG. 3, the outdoor unit 20 includes a compressor 1, a four-way valve 2, a decompressor 4, an outdoor heat exchanger 5, a first bypass circuit 6, a refrigerant heating two-way valve 7, a refrigerant heater 8, a first Check valve 30 of the bypass circuit, second bypass circuit 9, two-way valve 10 for defrosting, decompressor 11 of the second bypass circuit, check valve 31 of the second bypass circuit, first bypass circuit The decompressor 12, the refrigerant heater 13, the refrigerant passage pipe section 14, the heat storage section 15, and the outdoor blower 19 are provided. The indoor unit 18 is provided with the indoor heat exchanger 3 and the indoor blower 17. The decompressor 4 here may be an electromagnetic expansion valve.

In FIG. 1, an outdoor unit 20 includes a compressor 1, a four-way valve 2, a decompressor 4, an outdoor heat exchanger 5, a first bypass circuit 6, a refrigerant heating compressor, a four-way valve, an indoor heat exchanger, and a decompressor. A heat pump refrigeration cycle in which an outdoor heat exchanger is connected by a refrigerant circuit, a connection between the indoor heat exchanger and the decompressor connected to the refrigeration cycle, and a connection between the four-way valve and the outdoor heat exchanger. A first bypass circuit, a two-way valve, a refrigerant heater and a check valve provided in the first bypass circuit, and between the four-way valve and the indoor heat exchanger connected to the refrigeration cycle; A second bypass circuit that connects between the decompressor and the outdoor heat exchanger, or between the compressor and the four-way valve connected to the refrigeration cycle, and between the decompressor and the outdoor heat exchanger. Providing a two-way valve to the second bypass circuit. When the outdoor heat exchanger is defrosted by providing a check valve, the two-way valve of the first bypass circuit is opened to allow the refrigerant heated by the refrigerant heater to flow to the suction side of the compressor. And the second bypass operation of opening the two-way valve of the second bypass circuit and allowing the refrigerant to pass through the outdoor heat exchanger.

  Thus, since the defrosting operation is performed while continuing the heating, no refrigerant noise is generated when the four-way valve is switched. Further, since the four-way valve is not switched during defrosting, the pressure fluctuation is small and the oil fluctuation of the compressor is small, so that the compressor can be operated with high reliability. In addition, since the defrosting circuit is performed outdoors even when the length of the connection pipe is long, the compressor oil level does not decrease during the defrosting operation by the pipe length, and the compressor can be operated with high reliability even with long pipe products. . In addition, since a part of the whole refrigerant is used for defrosting, an extremely large amount of refrigerant does not flow in the refrigerant heating unit, so that a compact refrigerant heater can be used. Even when the cooling operation is performed, the high-temperature and high-pressure refrigerant gas does not stay in the refrigerant heater, and the refrigerant heater does not cause dew condensation.

  The check valve is connected to the decompressor and the outdoor heat exchanger between the refrigerant heater of the first bypass circuit and the two-way valve for heating the refrigerant and from the two-way defrost valve of the second bypass circuit. Is placed in between.

  The check valve provided in the first bypass circuit reduces the suction pulsation during startup due to pressure balance fluctuations during heating operation, eliminates the noise of the refrigerant heating two-way valve, and switches the four-way valve to perform defrosting operation. When the refrigerant heating two-way valve is leaking, the refrigerant heater will cool and cause condensation, or the refrigerant heating two-way valve leaks or low-pressure refrigerant accumulates in the refrigerant heater. An air conditioner that can be defrosted while continuing the heating operation that can be configured with a simple bypass circuit and no refrigerant noise and pressure balance problems, such as solving the problem of eliminating the occurrence of dew condensation Can provide.

Further, the check valve provided in the second bypass circuit is arranged so that the refrigerant flows in a direction in which the decompressor and the outdoor heat exchanger are connected, and at the time of start-up due to pressure balance fluctuation during heating operation Durable against refrigerant pressure balance by reducing the discharge pulsation and eliminating the two-way valve dance noise, and reducing the suction pulsation due to pressure balance fluctuation during cooling operation and eliminating the two-way valve dance noise Stable air-conditioning system that determines the position of the check valve that does not apply back pressure to the two-way valve at all times to protect the two-way valve, which requires ensuring safety and reliability. The structure characterized by being able to provide is taken.

  In the present embodiment, one end of the first bypass circuit is connected between the four-way valve and the outdoor heat exchanger, but may be connected between the four-way valve and the suction side of the compressor.

  As described above, the air-conditioning apparatus of the present invention can perform the defrosting operation while performing the heating operation, and thus can be applied to an air-conditioning apparatus in a cold district where the outdoor temperature is very low.

The block diagram of the air conditioning apparatus in Embodiment 1 of this invention The block diagram of the air conditioning apparatus in Embodiment 2 of this invention The block diagram of the air conditioning apparatus in Embodiment 3 of this invention Control block diagram according to Embodiment 1 of the present invention Control time chart in Embodiment 1 of the present invention Configuration diagram of conventional air conditioner Configuration diagram of conventional air conditioner

DESCRIPTION OF SYMBOLS 1 Compressor 2 Four-way valve 3 Indoor heat exchanger 4 Pressure reducer 5 Outdoor heat exchanger 6 First bypass circuit 7 Two-way valve for refrigerant heating 8 Heater 9 Second bypass circuit 10 Two-way valve for defrosting 11 Removal Frost decompressor 12 Refrigerant heating decompressor 13 Heater heater 14 Refrigerant passage tube part 15 Heat storage part 17 Indoor blower 18 Indoor unit 19 Outdoor blower 20 Outdoor unit 30 Check valve 31 of the first bypass circuit 31 Second bypass circuit Check valve

Claims (4)

A heat pump refrigeration cycle in which a compressor, a four-way valve, an indoor heat exchanger, a pressure reducer, and an outdoor heat exchanger are connected by a refrigerant circuit and the refrigerant flow is reversed by cooling and heating by switching the four-way valve, and the refrigeration provided a first bypass circuit for connecting the said indoor heat exchanger coupled to the cycle and during said pressure reducer and said four-way valve the outdoor heat exchanger, refrigerant heated for secondary to the first bypass circuit A non-return valve, a heater heating type refrigerant heater, and a check valve , the check valve being provided between the refrigerant heating two-way valve and the refrigerant heater of the first bypass circuit, while arranged so that the refrigerant flows in the direction of the refrigerant heater, further wherein during connected to the refrigeration cycle a and the four-way valve and between the pressure reducer of the indoor heat exchanger of said outdoor heat exchanger or said, The pressure connected to the refrigeration cycle The second bypass circuit for connecting the machine with and between the pressure reducer of the four-way valve between the outdoor heat exchanger provided with a structure which is disposed a two-way valve for defrosting the second bypass circuit, When performing defrosting of the outdoor heat exchanger, the refrigerant heating two-way valve of the first bypass circuit is opened, and the refrigerant heated by the refrigerant heater is passed through the four-way valve to the suction side of the compressor An air conditioner characterized by performing a first bypass operation to flow through and a second bypass operation to open the two-way defrosting valve of the second bypass circuit and allow the refrigerant to pass through the outdoor heat exchanger apparatus. A heat pump refrigeration cycle in which a compressor, a four-way valve, an indoor heat exchanger, a pressure reducer, and an outdoor heat exchanger are connected by a refrigerant circuit and the refrigerant flow is reversed by cooling and heating by switching the four-way valve, and the refrigeration provided a first bypass circuit for connecting the said indoor heat exchanger coupled to the cycle and during said pressure reducer and said four-way valve the outdoor heat exchanger, refrigerant heated for secondary to the first bypass circuit A non-return valve, a heater heating type refrigerant heater, and a check valve, the check valve being provided between the refrigerant heating two-way valve and the refrigerant heater of the first bypass circuit, The refrigerant is arranged to flow in the direction of the refrigerant heater , and further, between the four-way valve and the indoor heat exchanger connected to the refrigeration cycle, and between the pressure reducer and the outdoor heat exchanger, or Connected to the refrigeration cycle Providing the second bypass circuit for connecting the compressor and between the pressure reducer of the four-way valve between the outdoor heat exchanger, provided the two-way valve and a check valve for defrosting the second bypass circuit The check valve is arranged in a direction from between the four-way valve and the indoor heat exchanger to the pressure reducer and the outdoor heat exchanger, or between the compressor and the four-way valve. The refrigerant is arranged so that the refrigerant flows in the direction between the exchangers, and when the defrosting of the outdoor heat exchanger is performed, the refrigerant heating two-way valve of the first bypass circuit is opened to heat the refrigerant. A first bypass operation in which the refrigerant heated by the cooler flows to the suction side of the compressor through the four-way valve, and the two-way valve for defrosting of the second bypass circuit is opened to the outdoor heat exchanger. An air conditioner that performs a second bypass operation for allowing a refrigerant to pass therethrough. A check valve provided in the second bypass circuit, to Claim 2 characterized in that disposed between coupled to decompressor and an outdoor heat exchanger from defrosting two-way valve in the second bypass circuit The air conditioning apparatus described. While being connected from the two-way defrosting valve of the second bypass circuit to the decompressor and the outdoor heat exchanger, from between the four-way valve and the indoor heat exchanger to between the decompressor and the outdoor heat exchanger. The air according to claim 2 , wherein the check valve is arranged so as to flow in a direction from the compressor or between the compressor and the four-way valve to the pressure reducer and the outdoor heat exchanger. Harmony device.

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