JP2012037130A - Refrigeration cycle device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refrigeration cycle device that can further improve the defrost performance during a defrosting operation while minimizing the return of a liquid phase refrigerant to a compressor so that the reliability of the compressor is ensured.SOLUTION: The refrigeration cycle device includes a defrosting bypass circuit and a heat storage bypass circuit. The refrigeration cycle device is configured to open a second electromagnetic valve 42 during a defrosting operation in a predetermined period after the opening of a first electromagnetic valve 30. This configuration can prevent a large amount of refrigerant accumulated in an indoor heat exchanger and an outdoor heat exchanger during the defrosting operation from returning to the compressor at once, and the reliability of the compressor from losing.

Description

  The present invention relates to a refrigeration cycle apparatus in which a compressor, an indoor heat exchanger, an expansion valve, and an outdoor heat exchanger are connected to each other by refrigerant piping, and in particular, defrosting performance during a defrosting operation while ensuring the reliability of the compressor. The present invention relates to a refrigeration cycle apparatus that can improve the efficiency.

  Conventionally, when frost adheres to an outdoor heat exchanger during heating operation by a heat pump air conditioner, defrosting is performed by switching a four-way valve from a heating cycle to a cooling cycle. In this defrosting method, although the indoor fan is stopped, there is a disadvantage that a feeling of heating is lost because cold air is gradually discharged from the indoor unit.

  In view of this, it has been proposed that a compressor installed in the outdoor unit is provided with a heat storage tank that contains a heat storage material, and defrosts using the waste heat of the compressor stored in the heat storage material during heating operation. (For example, refer to Patent Document 1).

  FIG. 7 shows an example of a refrigeration cycle apparatus that employs such a defrosting method. The compressor 100, the four-way valve 102, the outdoor heat exchanger 104, the capillary tube 106, the indoor unit provided in the outdoor unit are shown. Is connected to the indoor heat exchanger 108 provided by the refrigerant pipe, the first bypass circuit 110 for bypassing the capillary tube 106, and the discharge side of the compressor 100 to the indoor heat exchanger 108 via the four-way valve 102. A second bypass circuit 112 is provided in which one end is connected to the connecting pipe and the other end is connected to the pipe extending from the capillary tube 106 to the outdoor heat exchanger 104. The first bypass circuit 110 is provided with a two-way valve 114, a check valve 116, and a heat storage heat exchanger 118, and the second bypass circuit 112 is provided with a two-way valve 120 and a check valve 122. Yes.

  Furthermore, a heat storage tank 124 is provided around the compressor 100, and the heat storage tank 124 is filled with a latent heat storage material 126 for exchanging heat with the heat storage heat exchanger 118.

  In this refrigeration cycle, during the defrosting operation, the two two-way valves 114 and 120 are controlled to open, a part of the refrigerant discharged from the compressor 100 flows to the second bypass circuit 112, and the remaining refrigerant is the four-way valve. 102 and the indoor heat exchanger 108. In addition, after the refrigerant flowing through the indoor heat exchanger 108 is used for heating, a small amount of refrigerant flows to the outdoor heat exchanger 104 through the capillary tube 106, while the remaining most of the refrigerant passes through the first bypass circuit. 110 flows into the heat storage heat exchanger 118 through the two-way valve 114, takes heat from the heat storage material 126, passes through the check valve 116, and then merges with the refrigerant that has passed through the capillary tube 106 to the outdoor. It flows to the heat exchanger 104. After that, it merges with the refrigerant flowing through the second bypass circuit 112 at the inlet of the outdoor heat exchanger 104, performs defrosting using the heat of the refrigerant, passes through the four-way valve 102, and then enters the compressor 100. Inhaled.

  In this refrigeration cycle apparatus, by providing the second bypass circuit 112, the hot gas discharged from the compressor 100 during defrosting is guided to the outdoor heat exchanger 104 and the pressure of the refrigerant flowing into the outdoor heat exchanger 104 Therefore, the defrosting ability can be increased, and the defrosting can be completed in a very short time.

Japanese Patent Laid-Open No. 2-143060

  However, in the conventional configuration, the timing of the opening operation of the two-way valves 114 and 120 is not clear, and the defrosting performance can be further enhanced while effectively using the heat stored in the heat storage material during the defrosting operation. There wasn't. That is, in the refrigeration cycle apparatus provided with the heat storage tank, it can be said that there is room for improvement with respect to the opening operation timing of the valve.

  This invention solves the said conventional subject, and provides the refrigerating-cycle apparatus which can further improve the defrosting performance at the time of a defrosting operation, ensuring the reliability of the compressor 6. FIG.

  In order to solve the conventional problem, the refrigeration cycle apparatus of the present invention includes a heat storage material that stores heat generated by a compressor, and a heat storage heat exchanger that performs heat exchange between heat stored in the heat storage material, Between the expansion valve and the outdoor heat exchanger, between the discharge port of the compressor and the four-way valve via the first solenoid valve, and between the indoor heat exchanger and the expansion valve A heat storage bypass circuit that connects the four-way valve and the compressor inlet via a second electromagnetic valve and a heat storage heat exchanger, and a controller, and during the defrosting operation, The second solenoid valve is opened after a predetermined time of the opening operation.

  As a result, it is possible to prevent a large amount of refrigerant accumulated in the indoor heat exchanger and the outdoor heat exchanger from returning to the compressor at once, and impairing the reliability of the compressor. Or it can prevent that the sound which a refrigerant | coolant flows through the inside of refrigeration piping becomes noise.

  According to the present invention, since the opening operation of the second electromagnetic valve is performed after a certain time after the opening operation of the first electromagnetic valve, the defrosting performance can be improved while ensuring the reliability of the compressor. Moreover, it is possible to prevent the sound of the refrigerant flowing in the refrigeration pipe from becoming noise.

The figure which shows the structure of the air conditioner provided with the refrigeration cycle apparatus which concerns on Embodiment 1 of this invention, and the figure which shows the structure of the conventional refrigeration cycle apparatus The schematic diagram which shows the operation | movement at the time of normal heating of the air conditioner of FIG. 1, and the flow of a refrigerant | coolant. The schematic diagram which shows the operation | movement at the time of defrosting and heating of the air conditioner of FIG. 1, and the flow of a refrigerant | coolant. The figure which shows the operation timing of the open control of the 1st solenoid valve and the 2nd solenoid valve in the air conditioner provided with the refrigerating cycle apparatus which concerns on Embodiment 1. FIG. Another figure which shows the operation timing of the open control of the 1st solenoid valve and the 2nd solenoid valve in the air conditioner provided with the refrigerating cycle device concerning Embodiment 1. The figure which shows the structure of the air conditioner provided with the refrigerating-cycle apparatus which concerns on Embodiment 2 of this invention. A diagram showing a conventional refrigeration cycle apparatus

In the first aspect of the invention, during the heating operation, an indoor heat exchanger, an expansion valve, an outdoor heat exchanger, a four-way valve, a compressor, a refrigeration cycle connected so that refrigerant flows in the order of the four-way valve, and a compressor Between the expansion valve and the outdoor heat exchanger, the heat storage material that is disposed and stores heat generated by the compressor, the heat storage heat exchanger that exchanges heat with the heat stored in the heat storage material, and the discharge of the compressor A defrosting bypass circuit connecting the outlet and the four-way valve via the first solenoid valve, between the indoor heat exchanger and the expansion valve, and between the four-way valve and the suction port of the compressor, 2 A heat storage bypass circuit connected via a solenoid valve and a heat storage heat exchanger, and a control device, and the second solenoid valve is opened after a predetermined time of the opening operation of the first solenoid valve during the defrosting operation. Is.

  With this configuration, the first solenoid valve and the second solenoid valve are opened at the same time, and a large amount of refrigerant accumulated in the indoor heat exchanger and the outdoor heat exchanger returns to the compressor at once, and the reliability of the compressor is impaired. Or the noise of the refrigerant flowing through the refrigeration pipe can be prevented from becoming noise. In addition, after the defrosting operation is started and the first solenoid valve is opened, until the behavior of the refrigeration cycle is stabilized, the opening operation of the second solenoid valve is refrained, so that the heat stored in the heat storage material is reduced. Opening the second solenoid valve after the behavior of the refrigeration cycle is stabilized while preserving it, makes it possible to make the most effective use of the heat quantity of the heat storage material, and as a result, increase the defrosting performance during the defrosting operation. be able to.

  In the second invention, after the opening operation of the first electromagnetic valve, the predetermined time until the opening of the second electromagnetic valve is 1 second or more and 60 seconds or less, and the heat stored in the heat storage material is effectively removed. While being able to utilize for frost, it can prevent that the liquid phase refrigerant | coolant cooled in order to melt frost with an outdoor heat exchanger returns to a compressor in large quantities and impairs the reliability of a compressor.

  According to a third aspect of the present invention, the operating frequency of the compressor is set to a predetermined frequency before the opening operation of the first solenoid valve. When the heating operation is switched to the defrosting operation, the total pressure loss in the refrigeration pipe is reduced. Even if it changes, the refrigeration cycle can function stably.

  According to a fourth aspect of the present invention, the opening degree of the expansion valve is set to a predetermined opening degree before the opening control of the first electromagnetic valve. When the heating operation is switched to the defrosting operation, the total pressure loss in the refrigeration pipe is reduced. Even if the temperature changes, the refrigeration cycle can function stably.

  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 shows a configuration of an air conditioner including a refrigeration cycle apparatus according to Embodiment 1 of the present invention. The air conditioner includes an outdoor unit 2 and an indoor unit 4 that are connected to each other through refrigerant piping. It is configured. 4 and 5 are diagrams illustrating operation timings of the opening control of the first solenoid valve and the second solenoid valve in the air conditioner including the refrigeration cycle apparatus according to Embodiment 1. FIG.

  As shown in FIG. 1, a compressor 6, a four-way valve 8, a strainer 10, an expansion valve 12, and an outdoor heat exchanger 14 are provided inside the outdoor unit 2. And the indoor heat exchanger 16 is provided in the interior of the indoor unit 4, and these are mutually connected via refrigerant | coolant piping, and comprise the refrigerating cycle.

  More specifically, the compressor 6 and the indoor heat exchanger 16 are connected via a first pipe 18 provided with a four-way valve 8, and the indoor heat exchanger 16 and the expansion valve 12 are provided with a strainer 10. The second pipe 20 is connected. The expansion valve 12 and the outdoor heat exchanger 14 are connected via a third pipe 22, and the outdoor heat exchanger 14 and the compressor 6 are connected via a fourth pipe 24.

  A four-way valve 8 is disposed in the middle of the fourth pipe 24, and an accumulator 26 for separating the liquid-phase refrigerant and the gas-phase refrigerant is provided in the fourth pipe 24 on the refrigerant suction side of the compressor 6. ing. Moreover, the compressor 6 and the 3rd piping 22 are connected through the 5th piping 28, and comprise the defrost bypass circuit. The fifth pipe 28 is provided with a first electromagnetic valve 30.

Further, a heat storage tank 32 is provided around the compressor 6 so as to surround the compressor 6, and a heat storage heat exchanger 34 is provided inside the heat storage tank 32, and the heat storage heat exchanger 34 and the heat are also provided. A latent heat storage material (for example, ethylene glycol aqueous solution) 36 for replacement is filled, and the heat storage tank 32, the heat storage heat exchanger 34, and the heat storage material 36 constitute a heat storage device.

  The second pipe 20 and the heat storage heat exchanger 34 are connected via a sixth pipe 38, and the heat storage heat exchanger 34 and the fourth pipe 24 are connected via a seventh pipe 40, and a heat storage bypass circuit is provided. It is composed. The sixth pipe 38 is provided with a second electromagnetic valve 42.

  In addition to the indoor heat exchanger 16, an air blower fan (not shown), upper and lower blades (not shown), and left and right blades (not shown) are provided inside the indoor unit 4, and indoor heat exchange is performed. The unit 16 exchanges heat between the indoor air sucked into the interior of the indoor unit 4 by the blower fan and the refrigerant flowing through the interior of the indoor heat exchanger 16, and blows out the air warmed by heat exchange into the room during heating. On the other hand, air cooled by heat exchange is blown into the room during cooling. The upper and lower blades change the direction of air blown from the indoor unit 4 up and down as necessary, and the left and right blades change the direction of air blown from the indoor unit 4 to right and left as needed.

  The compressor 6, the blower fan, the upper and lower blades, the left and right blades, the four-way valve 8, the expansion valve 12, the electromagnetic valves 30 and 42, etc. are electrically connected to a control device (not shown, for example, a microcomputer). Be controlled.

  In the refrigeration cycle apparatus according to the present invention having the above-described configuration, the mutual connection relationship and function of each component will be described together with the flow of the refrigerant taking the heating operation as an example.

  The refrigerant discharged from the discharge port of the compressor 6 reaches the indoor heat exchanger 16 from the four-way valve 8 through the first pipe 18. The refrigerant condensed by exchanging heat with the indoor air in the indoor heat exchanger 16 passes through the second pipe 20 through the indoor heat exchanger 16, expands through the strainer 10 that prevents foreign matter from entering the expansion valve 12. To valve 12. The refrigerant decompressed by the expansion valve 12 reaches the outdoor heat exchanger 14 through the third pipe 22, and the refrigerant evaporated by exchanging heat with the outdoor air in the outdoor heat exchanger 14 is the fourth pipe 24 and the four-way valve 8. And returns to the suction port of the compressor 6 through the accumulator 26.

  The fifth pipe 28 branched from the compressor 6 discharge port of the first pipe 18 and the four-way valve 8 is connected to the expansion valve 12 of the third pipe 22 and the outdoor heat exchanger 14 via the first electromagnetic valve 30. I am joining in between.

  Furthermore, the heat storage tank 32 in which the heat storage material 36 and the heat storage heat exchanger 34 are housed is disposed so as to be in contact with and surround the compressor 6, and the heat generated in the compressor 6 is accumulated in the heat storage material 36, and the second The sixth pipe 38 branched from the pipe 20 between the indoor heat exchanger 16 and the strainer 10 reaches the inlet of the heat storage heat exchanger 34 via the second electromagnetic valve 42 and exits from the outlet of the heat storage heat exchanger 34. The seventh pipe 40 joins between the four-way valve 8 and the accumulator 26 in the fourth pipe 24.

  In FIG. 1, the strainer 10 is disposed between the diversion portion of the second pipe 20 and the sixth pipe 38 and the expansion valve 12, but the indoor heat exchanger 16 and the sixth pipe 38 in the second pipe 20 Even if it arrange | positions between these flow-dividing parts, the function of preventing the foreign material penetration | invasion to the expansion valve 12 can be hold | maintained.

However, there is a pressure loss in the strainer 10, and the former arrangement makes it easier for the refrigerant to flow to the sixth pipe 38 side in the part where the second pipe 20 is separated from the sixth pipe 38, and the sixth pipe 38. , The circulation amount of the bypass piping system that reaches the seventh piping 40 through the heat storage heat exchanger 34 increases. As a result, even when the temperature of the heat storage material 36 is high and the heat exchange capacity of the heat storage heat exchanger 34 is very large, the circulation amount of the heat storage heat exchanger 34 is large. As a result, it becomes difficult to cause a phenomenon that heat exchange becomes impossible, and there is an advantage that the heat exchange amount of the heat storage heat exchanger 34 is sufficiently exhibited and the defrosting capability is sufficiently exhibited.

  Next, the operation during normal heating will be described with reference to FIG. 2 schematically showing the operation during normal heating and the flow of the refrigerant of the air conditioner shown in FIG.

  During the normal heating operation, the first electromagnetic valve 30 and the second electromagnetic valve 42 are controlled to be closed, and the refrigerant discharged from the discharge port of the compressor 6 as described above passes through the first pipe 18 and the four-way valve 8. To the indoor heat exchanger 16. The refrigerant condensed by exchanging heat with the indoor air in the indoor heat exchanger 16 exits the indoor heat exchanger 16, passes through the second pipe 20, reaches the expansion valve 12, and the refrigerant decompressed by the expansion valve 12 is the third refrigerant. It reaches the outdoor heat exchanger 14 through the pipe 22. The refrigerant evaporated by exchanging heat with outdoor air in the outdoor heat exchanger 14 returns from the four-way valve 8 to the suction port of the compressor 6 through the fourth pipe 24.

  Further, the heat generated in the compressor 6 is accumulated in the heat storage material 36 housed in the heat storage tank 32 from the outer wall of the compressor 6 through the outer wall of the heat storage tank 32.

  Next, the operation during defrosting / heating will be described with reference to FIG. 3 schematically showing the operation of the air conditioner shown in FIG. 1 during defrosting / heating and the flow of refrigerant. In the figure, the solid line arrows indicate the flow of the refrigerant used for heating, and the broken line arrows indicate the flow of the refrigerant used for defrosting.

  When the outdoor heat exchanger 14 is frosted during the above-described normal heating operation and the frosted frost grows, the ventilation resistance of the outdoor heat exchanger 14 increases and the air flow decreases, and the evaporation in the outdoor heat exchanger 14 increases. The temperature drops. As shown in FIG. 3, the air conditioner according to the present invention is provided with a temperature sensor 44 that detects the piping temperature of the outdoor heat exchanger 14, and the evaporation temperature is lower than that during non-frosting. When this is detected by the temperature sensor 44, an instruction from the normal heating operation to the defrosting / heating operation is output from the control device.

  When the normal heating operation is shifted to the defrosting / heating operation, the frequency of the compressor 6 is set to a predetermined frequency, and the first solenoid valve 30 is controlled to open after the expansion valve opening is also set to the predetermined opening. Further, the second electromagnetic valve 42 is controlled to open after a certain time. When the first solenoid valve 30 and the second solenoid valve 42 are controlled to open, in addition to the refrigerant flow during the normal heating operation described above, a part of the gas-phase refrigerant exiting from the discharge port of the compressor 6 is the fifth pipe. 28 and the first electromagnetic valve 30, merged with the refrigerant passing through the third pipe 22, heats the outdoor heat exchanger 14, condenses into a liquid phase, and then passes through the fourth pipe 24 to the four-way valve 8. And return to the suction port of the compressor 6 through the accumulator 26.

  Further, a part of the liquid-phase refrigerant that is divided between the indoor heat exchanger 16 and the strainer 10 in the second pipe 20 passes through the sixth pipe 38 and the second electromagnetic valve 42, and then is stored in the heat storage material 36 in the heat storage heat exchanger 34. From the accumulator 26 and returns to the suction port of the compressor 6 through the seventh pipe 40 and the refrigerant that passes through the fourth pipe 24.

  The refrigerant returning to the accumulator 26 includes the liquid phase refrigerant returning from the outdoor heat exchanger 14. By mixing this with the high-temperature gas phase refrigerant returning from the heat storage heat exchanger 34, The evaporation of the phase refrigerant is promoted, and the liquid phase refrigerant does not return to the compressor 6 through the accumulator 26, so that the reliability of the compressor 6 can be improved. Even if the accumulator 26 is provided in the compressor 6, the refrigerant returned to the accumulator 26 contains more gas phase refrigerant than liquid phase refrigerant, so that the reliability of the compressor 6 can be further improved. It is possible and desirable.

The temperature of the outdoor heat exchanger 14 that has become below freezing due to the attachment of frost at the start of defrosting and heating is heated by the gas-phase refrigerant discharged from the discharge port of the compressor 6, and the frost is melted near zero, When melting is finished, the temperature of the outdoor heat exchanger 14 begins to rise again. When the temperature sensor 44 detects the temperature rise of the outdoor heat exchanger 14, it is determined that the defrosting has been completed, and the control device outputs an instruction from the defrosting / heating operation to the normal heating operation.

  Here, when the first electromagnetic valve 30 and the second electromagnetic valve 42 are simultaneously controlled to open during the defrosting / heating operation, the line pressure loss in the refrigeration pipe is greatly reduced. For this reason, the refrigerant discharge amount from the compressor 6 increases abruptly, and the refrigerant that reaches the outdoor heat exchanger 14 through the fifth pipe 28 is cooled in the outdoor heat exchanger 14, is converted into a liquid phase, and returns to the accumulator 26. . At the same time, a large amount of the liquid refrigerant condensed in the indoor heat exchanger 16 that is in a higher pressure than the compressor 6 during normal heating operation is heated in the heat storage heat exchanger 34, but the liquid phase is changed. In order to return to the accumulator 26 through the 6th piping 38 and the 7th piping 40, without fully canceling, a large amount of liquid phase refrigerant will be returned to the accumulator 26 at a stretch.

  In addition, when the first solenoid valve 30 and the second solenoid valve 42 are simultaneously controlled to open, the pipe pressure loss in the refrigeration pipe is greatly reduced, and the refrigerant discharge amount from the compressor 6 is rapidly increased. At this time, the flow rate of the refrigerant flowing in the refrigeration pipe increases rapidly, so that the friction between the refrigerant and the pipe increases, or due to the friction in the portion of the pipe where the flow path pressure loss is high. The sound flowing through becomes louder.

  Therefore, when shifting to the defrosting / heating operation as shown in the time chart of FIG. 4, first, the opening control of the first electromagnetic valve 30 is performed. Thereafter, until the behavior of the refrigeration cycle is stabilized, in particular, until the difference in pressure between the indoor heat exchanger 16 and the suction portion of the compressor 6 is settled to a certain level, and is discharged from the compressor 6. Until the refrigerant that has been liquefied through the pipe 28, the outdoor heat exchanger 14, and the fourth pipe 24 returns to the compressor 6 again, the opening control of the second electromagnetic valve 42 is refrained. By preserving the heat stored in the heat storage material, the second solenoid valve is opened after the behavior of the refrigeration cycle is stabilized, and the heat quantity of the heat storage material can be used to the maximum extent possible. Become. As a result, the defrosting performance during the defrosting operation can be enhanced. In addition, when only the first solenoid valve 30 is controlled to open, the pressure loss in the pipe is not significantly reduced compared to the case where the first solenoid valve 30 and the second solenoid valve 42 are simultaneously controlled to open, and the refrigerant passes through the pipe. You can also eliminate the sound of flowing.

  The time from when the first solenoid valve 30 is opened until the behavior of the refrigeration cycle is stabilized varies greatly depending on the outdoor air temperature, the indoor air temperature, the compressor 6 frequency, and the expansion valve 12 opening. This time takes at least 1 second. Further, the time until the refrigerant discharged from the compressor 6 returns to the compressor 6 again through the fifth pipe 28, the outdoor heat exchanger 14, and the fourth pipe 24 is similarly the indoor / outdoor air temperature or the compressor 6. The maximum time is 60 seconds, depending on the frequency of the valve and the opening of the expansion valve 12. Therefore, as shown in FIG. 5, it is preferable that the fixed time from opening the first electromagnetic valve 30 to opening the second electromagnetic valve 42 is 1 second or more and 60 seconds or less.

  Moreover, when shifting to the defrosting / heating operation, the total pressure loss in the refrigeration pipe is reduced by performing the opening control of the first electromagnetic valve 30 and the second electromagnetic valve 42. For this reason, the frequency of the compressor 6 and the opening degree of the expansion valve 12 are set to a predetermined opening degree during operation switching so that the refrigeration cycle does not exhibit an unexpected behavior. Here, for example, at the end of the normal heating operation, the first electromagnetic valve 30 is controlled to open from the state where the frequency of the compressor 6 is high and the opening degree of the expansion valve 12 is reduced to the defrosting / heating operation. Then, as described above, the circulation amount of the refrigerant is excessively increased, leading to damage to each element part in the refrigeration cycle including the compressor 6. For this reason, the first solenoid valve 30 is changed after the frequency 6 of the cold compressor or the opening of the expansion valve 12 is changed to a predetermined opening at the time of operation switching so that the refrigeration cycle does not exhibit an unexpected behavior. The opening operation is performed.

  When the first solenoid valve 30 and the second solenoid valve 42 are controlled to be closed at the end of the defrosting / heating operation, either one of the solenoid valves may be closed first or simultaneously.

(Embodiment 2)
FIG. 6 shows a refrigeration cycle in which the joining portion of the seventh pipe 40 and the fourth pipe 24 is still another form. Only parts different from the first embodiment will be described.

  The joining portion of the seventh pipe 40 and the fourth pipe 24 shown in FIG. 3 is between the four-way valve 8 and the accumulator 26, whereas in the present embodiment, as shown in FIG. A joining portion of the pipe 40 and the fourth pipe 24 is located between the accumulator 26 and the compressor 6.

  In the configuration of FIG. 3, the refrigerant that has evaporated and vaporized by absorbing heat from the heat storage material 36 in the heat storage heat exchanger 34 passes through the seventh pipe 40 and the fourth pipe 24 between the four-way valve 8 and the accumulator 26. The refrigerant merges with the refrigerant and returns from the accumulator 26 to the suction port of the compressor 6.

  However, the accumulator 26 whose temperature has decreased before the defrosting has a large heat capacity, and the high-temperature gas-phase refrigerant returned from the heat storage heat exchanger 34 during the defrosting is cooled by the accumulator 26, so that the defrosting is performed. Heat cannot be used sufficiently and the defrosting time may be extended.

  On the other hand, in the present embodiment, the refrigerant from the outdoor heat exchanger 14 is returned to the compressor 6 without going through the accumulator 26, so that the heat of the high-temperature gas-phase refrigerant can be used for defrosting without waste. This can shorten the defrosting time.

  This configuration is not limited to the present embodiment, but can be applied to the above-described first embodiment.

  Since the refrigeration cycle apparatus according to the present invention can improve the reliability of the compressor by reducing the return of the liquid phase refrigerant to the compressor as much as possible, the air conditioner, the refrigerator, the water heater, and the heat pump washing machine Etc. are useful.

2 outdoor units, 4 indoor units, 6 compressors, 8 four-way valves, 10 strainers, 12
Expansion valve, 14 outdoor heat exchanger, 16 indoor heat exchanger, 18 first piping, 20 second piping, 22 3rd piping, 24 4th piping, 26 accumulator, 28 5th piping, 30 1st solenoid valve, 32 Heat storage tank, 34 heat storage heat exchanger, 36 heat storage material, 38 sixth pipe, 40 seventh pipe, 42 second solenoid valve, 44 temperature sensor

Claims (4)

During the heating operation, an indoor heat exchanger, an expansion valve, an outdoor heat exchanger, a four-way valve, a compressor, a refrigeration cycle connected so that refrigerant flows in the order of the four-way valve,
A heat storage material that is arranged around the compressor and stores heat generated by the compressor; and
A heat storage heat exchanger for exchanging heat with the heat stored in the heat storage material;
A defrost bypass circuit that connects the expansion valve and the outdoor heat exchanger, a discharge port of the compressor, and the four-way valve via a first electromagnetic valve;
A heat storage bypass circuit that connects between the indoor heat exchanger and the expansion valve, between the four-way valve and the suction port of the compressor via a second electromagnetic valve and the heat storage heat exchanger;
A control device,
During the defrosting operation, the second electromagnetic valve is opened after a predetermined time of the opening operation of the first electromagnetic valve. The refrigeration cycle apparatus according to claim 1, wherein the predetermined time is 1 second or more and 60 seconds or less. The refrigeration cycle apparatus according to claim 1 or 2, wherein an operating frequency of the compressor is set to a predetermined value before the opening operation of the first electromagnetic valve. The refrigeration cycle apparatus according to any one of claims 1 to 3, wherein the opening degree of the expansion valve is set to a predetermined opening degree before the opening operation of the first electromagnetic valve.

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