WO2013065233A1

WO2013065233A1 - Refrigeration cycle apparatus and air conditioner provided with same

Info

Publication number: WO2013065233A1
Application number: PCT/JP2012/006299
Authority: WO
Inventors: 憲昭山本; 廣和加守田; 富之野間; 正雄犬井
Original assignee: パナソニック株式会社
Priority date: 2011-11-04
Filing date: 2012-10-02
Publication date: 2013-05-10
Also published as: CN103765133B; CN103765133A; JPWO2013065233A1; KR20140092803A

Abstract

A three-way valve (switching device) (42) is provided between an intake tube of a compressor (6) and a four-way valve (8), making possible a switch between a tube (25) draining refrigerant directly from the four-way valve (8) into the intake tube of the compressor (6) and a tube (38) draining refrigerant from the four-way valve (8) into the intake tube of the compressor (6) through an alternate heat exchanger (heat storage tank (32), heat storage exchanger (34), heat storage material (36)) for refrigerant heating; and by controlling the three-way valve (switching device) (42) during defrosting operation, refrigerant flowing to an indoor heat exchanger (first heat exchanger) (16) and an outdoor heat exchanger (second heat exchanger) (14) flows to the alternate heat exchanger (heat storage tank (32), heat storage exchanger (34), heat storage material (36)) via the four-way valve (8), and is guided to the intake tube of the compressor (6).

Description

Refrigeration cycle apparatus and air conditioner equipped with the same

The present invention relates to a refrigeration cycle apparatus having a mechanism for switching between a path for directly flowing a refrigerant in which frost attached to an evaporator is melted to a compressor and a path for flowing the refrigerant to an compressor through an auxiliary heat exchanger for heating the refrigerant, and It relates to air conditioners.

Conventionally, a heat pump air conditioner performs defrosting by switching a four-way valve from a heating cycle to a cooling cycle when the outdoor heat exchanger is frosted during heating operation. 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.

Therefore, a heat storage tank has been proposed that uses a compressor provided in the outdoor unit as a heat source, and defrosts using the waste heat of the compressor stored in the heat storage tank during heating operation. (For example, refer to Patent Documents 1 and 2).

FIG. 6 shows an example of a conventional refrigeration cycle apparatus disclosed in Patent Document 1. The compressor 100, the four-way valve 102, the outdoor heat exchanger 104, the capillary tube 106, and the indoor unit are provided in the outdoor unit. The indoor heat exchanger 108 is connected by a refrigerant pipe, one end is connected to the first bypass circuit 110 that bypasses the capillary tube 106, and the discharge side pipe of the compressor 100, and the other end is connected to the outdoor side from the capillary tube 106. A second bypass circuit 112 connected to the pipe leading to the heat exchanger 104 is provided. 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.

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 four-way. It flows to the valve 102 and the indoor heat exchanger 108. Further, after the refrigerant flowing through the indoor heat exchanger 108 is used for heating, a small amount of refrigerant flows through the capillary tube 106 to the outdoor heat exchanger 104. On the other hand, most of the remaining refrigerant flows into the first bypass circuit 110, flows through the two-way valve 114 to the heat storage heat exchanger 118, takes heat away from the heat storage material 126, and passes through the check valve 116. Thereafter, the refrigerant passes through the capillary tube 106 and flows to the outdoor 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 The defrosting ability is improved by keeping high.

FIG. 7 shows a configuration of a conventional air conditioner in Patent Document 2, and this air conditioner is composed of an outdoor unit 2 and an indoor unit 4 connected to each other by refrigerant piping. Inside the outdoor unit 2, 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 indoor unit 4, an indoor heat exchanger 16 is provided, These are connected to each other via a refrigerant pipe to constitute a refrigeration cycle.

Furthermore, 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 second pipe provided with a strainer 10. 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. The compressor 6 and the third pipe 22 are connected via a fifth pipe 28, and the first solenoid valve 30 is provided in the fifth pipe 28. The fifth pipe 28 and the first electromagnetic valve 30 constitute a discharge gas bypass mechanism.

Furthermore, a heat storage tank 32 is provided around the compressor 6, and a heat storage heat exchanger 34 is provided inside the heat storage tank 32 and is filled with a heat storage material 36 for exchanging heat with the heat storage heat exchanger 34. The heat storage tank 32, the heat storage heat exchanger 34, and the heat storage material 36 constitute a heat storage device that serves as an auxiliary heat exchanger.

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. The pipe 38 is provided with a second electromagnetic valve 31.

An indoor heat exchanger 16 is provided inside the indoor unit 4, and the indoor heat exchanger 16 exchanges indoor heat with indoor air sucked into the indoor unit 4 by a blower fan (not shown). Heat exchange with the refrigerant flowing in the interior of the vessel 16 is performed, and air heated by heat exchange is blown into the room during heating, while air cooled by heat exchange is blown into the room during cooling.

In the conventional air conditioner configured as described above, the mutual connection relationship and function of each component will be described along with the flow of the refrigerant, taking the heating operation as an example.

The refrigerant discharged from the discharge port of the compressor 6 passes from the four-way valve 8 to the indoor heat exchanger 16 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. The heat storage tank 32 that is joined in between and accommodates the heat storage material 36 and the heat storage heat exchanger 34 is arranged so as to be in contact with and surround the compressor 6, and heat generated in the compressor 6 is supplied to the heat storage material 36. Accumulated. And the 6th piping 38 branched from between the indoor heat exchanger 16 and the strainer 10 of the 2nd piping 20 reaches the inlet of the thermal storage heat exchanger 34 through the 2nd electromagnetic valve 31, and the thermal storage heat exchanger 34 The seventh pipe 40 exiting from the outlet of the pipe joins between the four-way valve 8 and the accumulator 26 in the fourth pipe 24.

During the normal heating operation, the first solenoid valve 30 and the second solenoid valve 31 are closed and no refrigerant flows through the refrigerant circuit.

Next, the operation during defrosting and heating and the flow of refrigerant will be described.

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. When a temperature sensor (not shown) for detecting the piping temperature of the outdoor heat exchanger 14 detects that the evaporation temperature has decreased as compared to the time of non-frosting, the control device switches from normal heating operation to defrosting / heating operation. Is output.

When the normal heating operation is shifted to the defrosting / heating operation, the first solenoid valve 30 and the second solenoid valve 31 are controlled to open, and in addition to the refrigerant flow during the normal heating operation described above, the first solenoid valve 30 and the second solenoid valve 31 are discharged from the discharge port of the compressor 6. After a part of the vapor-phase refrigerant passes through the fifth pipe 28 and the first electromagnetic valve 30 and merges with the refrigerant passing through the third pipe 22, the outdoor heat exchanger 14 is heated, condensed, and converted into a liquid phase. Through the fourth pipe 24, the four-way valve 8 and the accumulator 26 are returned to the suction port of the compressor 6.

In addition, 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 31, 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 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 degrees. When melting is finished, the temperature of the outdoor heat exchanger 14 begins to rise again. When this temperature increase in the outdoor heat exchanger 14 is detected by a temperature sensor (not shown), it is determined that the defrosting is completed, and an instruction from the defrosting / heating operation to the normal heating operation is output from the control device. It is configured.

JP-A-3-31666 Japanese Patent No. 4666111

However, in the conventional configuration, when the heat source has a small amount of heat, it is necessary to guide most of the hot gas discharged from the compressor to the outdoor heat exchanger, and accordingly, the pressure of the indoor heat exchanger decreases. As a result, there is a problem that the capacity of the indoor unit is reduced and the comfort is impaired. Further, as in the conventional method, after the refrigerant flows through the indoor heat exchanger, the structure is guided to the outdoor heat exchanger via the heat storage tank, or after the refrigerant flows through the outdoor heat exchanger, the outdoor heat exchanger and When it is configured to be distributed and guided to the heat storage tank, the temperature of the refrigerant flowing through the heat storage tank becomes high, heat absorption from the heat storage tank is not sufficient, and if it is attempted to secure the capacity of the indoor unit, it takes time to defrost. There was a problem of having.

An object of the present invention is to solve the above-described conventional problems, and to provide an air conditioner that can shorten the defrosting time and further includes the refrigeration cycle device to improve comfort during heating operation. And

In order to achieve the above object, the present invention provides:
A compressor,
A first heat exchanger connected to the compressor;
An expansion valve connected to the first heat exchanger;
A second heat exchanger connected to the expansion valve;
A four-way valve to which the second heat exchanger and the compressor are connected;
An auxiliary heat exchanger for heating the refrigerant disposed around the compressor;
Between the suction pipe of the compressor and the four-way valve, a path for flowing the refrigerant directly from the four-way valve to the suction pipe of the compressor, and the refrigerant from the four-way valve to the suction pipe of the compressor through the auxiliary heat exchanger A switching device that enables switching with a flow path;
With
During the defrosting operation for melting frost adhering to the second heat exchanger, the switching device is controlled so that the refrigerant flowing through the first heat exchanger and the second heat exchanger passes through the four-way valve. Then, it flows through the auxiliary heat exchanger and is led to the suction pipe of the compressor.

According to the present invention, the refrigerant after passing through the first heat exchanger and the second heat exchanger passes through the auxiliary heat exchanger during the defrosting operation. It becomes possible to make a heat exchanger into low temperature. Therefore, by quickly absorbing heat from the heat source, it is possible to shorten the defrosting time, to suppress a decrease in the room temperature of the defrosting operation during the heating operation, and to improve the comfort.

The block diagram of the air conditioner provided with the refrigeration cycle apparatus which concerns on Embodiment 1 of this invention. The schematic diagram which shows the flow of the refrigerant | coolant at the time of normal heating in the air conditioner provided with the same refrigeration cycle apparatus The schematic diagram which shows the flow of the refrigerant | coolant at the time of defrost and heating in the air conditioner provided with the same refrigeration cycle apparatus Refrigeration cycle configuration diagram according to Embodiment 2 of the present invention Control time chart according to Embodiment 2 of the present invention Configuration diagram of an air conditioner equipped with a conventional refrigeration cycle apparatus Refrigeration cycle configuration diagram according to a conventional example

The first invention is
A compressor,
A first heat exchanger connected to the compressor;
An expansion valve connected to the first heat exchanger;
A second heat exchanger connected to the expansion valve;
A four-way valve to which the second heat exchanger and the compressor are connected;
An auxiliary heat exchanger for heating the refrigerant disposed around the compressor;
Between the suction pipe of the compressor and the four-way valve, a path for flowing the refrigerant directly from the four-way valve to the suction pipe of the compressor, and the refrigerant from the four-way valve to the suction pipe of the compressor through the auxiliary heat exchanger A switching device that enables switching with a flow path;
With
During the defrosting operation for melting frost adhering to the second heat exchanger, the switching device is controlled so that the refrigerant flowing through the first heat exchanger and the second heat exchanger passes through the four-way valve. The refrigeration cycle apparatus is characterized in that it flows through the auxiliary heat exchanger and is led to the suction pipe of the compressor.
Thereby, since the refrigerant after passing through the first heat exchanger and the second heat exchanger passes through the auxiliary heat exchanger during the defrosting operation, the first heat exchanger is set to a high temperature, and the auxiliary heat exchanger It is possible to reduce the defrosting time by quickly performing the heat absorption from the heat source, and it is possible to improve the comfort by suppressing the decrease in the room temperature of the defrosting operation during the heating operation. .

In the second invention, in particular, in the refrigeration cycle apparatus of the first invention, the switching device is a three-way valve. With this configuration, the apparatus can be stored in a space-saving manner, and the apparatus can be made compact.

In a third aspect of the invention, in particular, in the refrigeration cycle apparatus of the first or second aspect of the invention, a discharge gas bypass mechanism connected between the expansion valve and the second heat exchanger from a discharge pipe of the compressor is provided. It is configured. With this configuration, it is possible to supply the high-temperature refrigerant from the compressor to the second heat exchanger, and the defrosting time can be greatly shortened.

In a fourth aspect of the present invention, in particular, in the refrigeration cycle apparatus according to any one of the first to third aspects, a heat source of the auxiliary heat exchanger for heating the refrigerant is disposed so as to surround the compressor, and the compression It is a heat storage material that stores the heat generated by the machine. By setting it as such a structure, the defrosting of a 2nd heat exchanger can be complete | finished in a short time by the supply of minimum auxiliary power, such as a heater, without auxiliary power. Further, in the case of this configuration, the auxiliary heat exchanger that performs heat exchange with the heat storage material can be set to a low temperature, so that the maximum amount of heat absorbed from the heat storage material can be increased, and the defrosting time can be shortened. The comfort can be improved by suppressing, for example, a decrease in room temperature in the defrosting operation during the heating operation.

In a fifth aspect of the invention, in particular, in the refrigeration cycle apparatus according to any one of the first to fourth aspects, the switching device provided between the four-way valve and the auxiliary heat exchanger and the auxiliary heat exchanger A throttle mechanism for increasing the refrigerant pressure loss is provided between them. By providing this mechanism, the refrigerant flowing through the auxiliary heat exchanger can be further lowered in temperature, and the heat absorption rate from the heat source can be improved.

In a sixth aspect of the invention, in particular, in the refrigeration cycle apparatus according to any one of the first to fifth aspects of the invention, a temperature sensor that detects a pipe temperature of the second heat exchanger, the compressor, the expansion valve, and the switching The apparatus further includes a refrigeration cycle control device electrically connected to the device and the temperature sensor. When the temperature sensor detects that the temperature in the second heat exchanger is lower than that during non-frosting during normal heating operation, the refrigeration cycle control device switches from normal heating operation to defrosting / heating operation. A switching instruction is output. Further, at the time of defrosting / heating operation, the temperature in the second heat exchanger melts frost when the temperature in the second heat exchanger is near zero, and the temperature in the second heat exchanger rises after the frost is melted. When the sensor detects, it is determined that the defrosting is completed, and the refrigeration cycle control device outputs a switching instruction from the defrosting / heating operation to the normal heating operation. Thereby, the start and completion of defrosting / heating operation can be performed efficiently, and efficient defrosting / heating operation can be performed.

According to a seventh aspect of the present invention, in the refrigeration cycle apparatus of the sixth aspect of the invention, the refrigeration cycle control apparatus once decreases the operation speed of the compressor after the determination of the completion of the defrosting operation, and the first After the expansion valve opening of the expansion valve is reduced to such an extent that the liquid refrigerant supercooled by the heat exchanger can be held in the pipe of the first heat exchanger, the switching device for the refrigerant path is moved from the four-way valve to the auxiliary heat. It is configured to switch from a path for flowing the refrigerant to the suction pipe of the compressor through the exchanger to a path for flowing the refrigerant directly from the four-way valve to the suction pipe of the compressor. As a result, when switching from defrosting / heating operation to normal heating operation, the pressure difference at the inlet / outlet of the switching device is kept smaller than the allowable pressure difference of the switching device while suppressing the decline in heating capacity as much as possible, and switching is performed reliably. The device can be switched. In addition, it is possible to provide a rational refrigeration cycle apparatus that can adopt a low-cost apparatus having a relatively small allowable pressure difference as the switching apparatus itself.

The eighth invention is an air conditioner in which the first heat exchanger of the first to seventh inventions is an indoor heat exchanger and the second heat exchanger is an outdoor heat exchanger. When switching from defrosting / heating operation to normal heating operation, the pressure difference at the inlet / outlet of the switching device is kept smaller than the allowable pressure difference of the switching device while suppressing the decline in heating capacity as much as possible. Can be. In addition, it is possible to provide a rational air conditioner in which the switching device itself can adopt a relatively low cost with a small allowable pressure difference.

Hereinafter, embodiments of the refrigeration cycle apparatus of the present invention will be described with reference to the drawings as examples mounted on an air conditioner. 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.

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 (second heat exchanger) 14 are provided inside the outdoor unit 2. An indoor heat exchanger (first heat exchanger) 16 is provided inside the indoor unit 4. These are connected to each other via a refrigerant pipe to constitute a refrigeration cycle.

More specifically, the compressor 6 and the indoor heat exchanger 16 are connected via a pipe 18 provided with a four-way valve 8, and the indoor heat exchanger 16 and the expansion valve 12 are connected to a pipe 20 provided with a strainer 10. Connected through. The expansion valve 12 and the outdoor heat exchanger 14 are connected via a pipe 22, and the outdoor heat exchanger 14 and the compressor 6 are connected via a pipe 24 and a pipe 25. A four-way valve 8 is disposed between the pipe 24 and the pipe 25 connecting the outdoor heat exchanger 14 and the compressor 6. A three-way valve (switching device) 42 is connected between the four-way valve 8 and the compressor 6 via a pipe 25. Further, the three-way valve 42 and the pipe 25 on the compressor refrigerant suction side are provided with an accumulator 26 for separating the liquid-phase refrigerant and the gas-phase refrigerant. The piping 22 connecting the outdoor heat exchanger 14 and the indoor heat exchanger 16 is connected to the compressor 6 via the piping 28, and the piping 28 is provided with an electromagnetic valve 30. The pipe 28 and the electromagnetic valve 30 constitute a discharge gas bypass mechanism.

Furthermore, a heat storage tank 32 is provided around the compressor 6. The heat storage tank 32 is provided with a heat storage heat exchanger 34 and filled with a heat storage material (for example, ethylene glycol aqueous solution) 36 for exchanging heat with the heat storage heat exchanger 34. Thus, the heat storage tank 32, the heat storage heat exchanger 34, and the heat storage material 36 constitute a heat storage device that serves as an auxiliary heat exchanger.

The three-way valve 42 and the heat storage heat exchanger 34 are connected via a pipe 38 including a capillary tube (throttle mechanism) 43, and the pipe 25 connecting the three-way valve 42 and the compressor 6 is connected to the heat storage heat via the pipe 40. It is connected to the exchanger 34.

In addition to the indoor heat exchanger 16, a blower fan (not shown), upper and lower blades (not shown), and left and right blades (not shown) are provided inside the indoor unit 4. The indoor heat exchanger 16 exchanges heat between the indoor air sucked into the indoor unit 4 by the blower fan and the refrigerant flowing inside the indoor heat exchanger 16, and the air heated by the heat exchange during heating is used. While air is blown out, air cooled by heat exchange is blown out into the room during cooling. The upper and lower blades change the direction of the air blown from the indoor unit 4 up and down as necessary. The left and right blades change the direction of the air blown from the indoor unit 4 to the left and right as necessary.

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 valve 30, the three-way valve 42, and the like are electrically connected to a control device (not shown, for example, a microcomputer) for control. It is controlled and operated by the device.

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 through the pipe 18 from the four-way valve 8. Refrigerant condensed by exchanging heat with indoor air in the indoor heat exchanger 16 exits the indoor heat exchanger 16, passes through the piping 20, passes through the strainer 10 that prevents foreign matter from entering the expansion valve 12, and then expands the expansion valve 12. To. The refrigerant decompressed by the expansion valve 12 reaches the outdoor heat exchanger 14 through the pipe 22. The refrigerant evaporated by exchanging heat with the outdoor air in the outdoor heat exchanger 14 passes through the pipe 24, the four-way valve 8, the three-way valve 42, the pipe 25, and the accumulator 26 through the suction port of the compressor 6. Return to 6.

Further, the pipe 28 branched from the discharge port of the compressor 6 of the pipe 18 and the four-way valve 8 is joined between the expansion valve 12 of the pipe 22 and the outdoor heat exchanger 14 via the electromagnetic valve 30.

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 surrounded by the compressor 6, and the heat generated in the compressor 6 is accumulated in the heat storage material 36.

One side of the three-way valve 42 is connected to the suction pipe of the four-way valve 8, the other side is connected to the three-way valve 42 and the pipe 25 connecting the suction port of the compressor 6, and the other side is connected to the three-way valve 42 and heat storage heat. A pipe 38 connected to the exchanger 34 is connected. A path for guiding the refrigerant from the four-way valve 8 to the suction port of the compressor 6 through the pipe 25 and a path for guiding the refrigerant from the four-way valve 8 to the suction port of the compressor 6 through the heat storage heat exchanger 34 through the pipe 38 by the control device. And can be switched.

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

During the normal heating operation, the solenoid valve 30 is controlled to be closed, and 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 pipe 18 as described above. The refrigerant condensed by exchanging heat with the indoor air in the indoor heat exchanger 16 exits the indoor heat exchanger 16 and passes through the pipe 20 to the expansion valve 12. The refrigerant decompressed by the expansion valve 12 reaches the outdoor heat exchanger 14 through the pipe 22. The refrigerant evaporated by exchanging heat with the outdoor air in the outdoor heat exchanger 14 reaches the four-way valve 8 through the pipe 24. During normal heating operation, the three-way valve 42 is controlled so that the refrigerant leads from the outdoor heat exchanger 14 to the suction port of the compressor 6, that is, the pipe 24 and the pipe 25 communicate with each other. The refrigerant passes through the three-way valve 42 and returns to the suction port of the compressor 6.

Further, the heat generated in the compressor 6 is stored in the heat storage material 36 housed in the heat storage tank 32 from the outer wall of the compressor 6 through the inner 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 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 51 that detects the piping temperature of the outdoor heat exchanger 14. When the temperature sensor 51 detects that the evaporating temperature has decreased as compared to non-frosting, an instruction to switch from the normal heating operation to the defrosting / heating operation is output from the control device.

When switching from the normal heating operation to the defrosting / heating operation, the solenoid valve 30 is 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 passes through the pipe 28 and the electromagnetic valve 30 and merges with the refrigerant passing through the pipe 22 to be outdoors. The heat exchanger 14 is heated and condensed to form a liquid phase, and then the four-way valve 8 is reached.

During the defrosting / heating operation, the three-way valve 42 is controlled so that the path leading the refrigerant from the outdoor heat exchanger 14 to the heat storage heat exchanger 34, that is, the pipe 24 and the pipe 38 communicate with each other. The refrigerant that has passed through the four-way valve 8 is depressurized by the capillary tube 43 and becomes a low temperature, absorbs the heat of the heat storage material 36 by the heat storage heat exchanger 34, reaches the accumulator 26 in the gas phase or in a high quality state, and reaches the compressor 6. Return to the inlet.

With such a configuration, the heat storage heat exchanger 34 that exchanges heat with the heat storage material 36 can be cooled. Since the maximum amount of heat absorbed from the heat storage material 36 is proportional to the temperature difference between the temperature of the compressor 6 and the temperature of the heat storage heat exchanger 34, if the temperature of the heat storage heat exchanger 34 can be lowered, the compressor 6 The temperature difference between the temperature and the temperature of the heat storage heat exchanger 34 can be increased, the maximum amount of heat absorbed from the heat storage material 36 can be increased, the defrosting time can be shortened, and the room temperature by the defrosting operation during the heating operation can be increased. The comfort can be improved by suppressing the decrease.

Furthermore, since the evaporation of the liquid refrigerant in the heat storage heat exchanger 34 is promoted, the liquid refrigerant does not return to the compressor 6 and the reliability of the compressor 6 can be improved.

Further, when the refrigerant passing through the heat storage heat exchanger 118 is used as a bypass path as shown in FIG. 6 of the prior art in Patent Document 1, the circulation amount of the refrigerant passing through the heat storage heat exchanger 118 is reduced. When the temperature of the heat storage material 126 is high, the degree of superheat increases in the second half of the heat storage heat exchanger 118, so that the amount of heat exchange decreases, and the defrosting ability may not be sufficiently exhibited. However, in this structure, since it is set as the structure which flows a refrigerant | coolant to the thermal storage heat exchanger 34 by one path | route, the fall of the amount of heat exchange by taking too much superheat degree can be prevented, and defrosting capability can fully be exhibited.

The temperature of the outdoor heat exchanger 14 that has become below freezing due to the attachment of frost at the start of defrosting / heating is the liquid phase or the gas-liquid two-phase returning from the gas-phase refrigerant that exits from the discharge port of the compressor 6 and the indoor heat exchanger 16. When the refrigerant is heated by the mixed refrigerant, the frost is melted at around zero degrees, and when the frost is completely melted, it starts rising again. When the temperature sensor 51 detects the temperature rise of the outdoor heat exchanger 14, it is determined that the defrosting is completed, and an instruction to switch from the defrosting / heating operation to the normal heating operation is output from the control device.

In addition, the discharge gas bypass path from the compressor 6 through the piping 28 through the solenoid valve 30 to the outdoor heat exchanger 14 is not necessarily required, and is configured to be eliminated unless a very large defrosting capacity is required. Also good.

In this case, the gas phase refrigerant flows from the discharge port of the compressor 6 through the pipe 18, the indoor heat exchanger 16, the pipe 20, and the pipe 22 to the outdoor heat exchanger 14, thereby defrosting the outdoor heat exchanger 14. Although it becomes a structure and a defrosting capability falls a little, a low cost and compact structure is attained.

In this configuration, the capillary tube 43 is provided in the pipe 38 extending from the three-way valve 42 to the heat storage heat exchanger 34. However, instead of this configuration, the opening of the three-way valve 42 communicating with the heat storage heat exchanger 34 is provided. It is good also as the specification which narrowed down. In this case, the capillary tube 43 can be removed, and a compact configuration can be achieved at low cost.

(Embodiment 2)
<Background of obtaining one embodiment of the present invention>
The air conditioner of Embodiment 1 shown in FIG. 1 has been proposed as an improved version of the conventional air conditioner shown in FIG. 7, and FIG. 1 shows an example of a refrigeration cycle apparatus with an improved defrosting system. Yes.

In the air conditioner of Embodiment 1 of the present invention, a three-way valve 42 serving as a switching device is connected between the four-way valve 8 and the compressor 6 via a pipe 25, and further, the three-way valve 42 and the compressor refrigerant suction. The pipe 25 on the side is provided with an accumulator 26 for separating the liquid phase refrigerant and the gas phase refrigerant. The three-way valve 42 and the heat storage heat exchanger 34 are connected via a pipe 38 including a capillary tube 43 serving as a throttle mechanism, and the pipe 25 connecting the heat storage heat exchanger 34, the three-way valve 42 and the compressor 6 is It is connected via a pipe 40.

One side of the three-way valve 42 is connected to the suction pipe of the four-way valve 8, the other side is connected to the three-way valve 42 and the pipe 25 connecting the suction port of the compressor 6, and the other side is connected to the three-way valve 42 and heat storage heat. Connected to a pipe 38 connected to the exchanger 34, a path for introducing the refrigerant from the four-way valve 8 through the pipe 25 to the suction port of the compressor 6, and a compressor through the heat storage heat exchanger 34 through the pipe 38 from the four-way valve 8. It is possible to switch the path for guiding the refrigerant to the six suction ports.

During normal heating operation, the refrigerant discharged from the discharge port of the compressor 6 passes through the pipe 18 and reaches the indoor heat exchanger 16 from the four-way valve 8. The refrigerant condensed by exchanging heat with the indoor air in the indoor heat exchanger 16 exits the indoor heat exchanger 16, reaches the expansion valve 12 through the pipe 20, and the refrigerant decompressed by the expansion valve 12 passes through the pipe 22. It passes through to the outdoor heat exchanger 14. The refrigerant evaporated by exchanging heat with the outdoor air in the outdoor heat exchanger 14 reaches the four-way valve 8 through the pipe 24. The three-way valve 42 is controlled so that the passage of the refrigerant from the outdoor heat exchanger 14 to the suction port of the compressor 6, that is, the pipe 24 and the pipe 25 communicate with each other, and the refrigerant passing through the four-way valve 8 is the three-way valve 42. And return to the suction port of the compressor 6.

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.

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. A temperature sensor (not shown) for detecting the piping temperature of the outdoor heat exchanger 14 is provided. When the temperature sensor detects that the evaporating temperature has decreased as compared with the time of non-frosting, the control device performs normal heating operation. Outputs an instruction for defrosting / heating operation.

During the defrosting / heating operation, the three-way valve 42 is controlled so that the refrigerant leads from the outdoor heat exchanger 14 to the heat storage heat exchanger 34, that is, the pipe 24 and the pipe 38 communicate with each other. The pressure is reduced by the capillary tube 43 to a low temperature, the heat storage heat exchanger 34 absorbs the heat of the heat storage material 36, reaches the accumulator 26 in the gas phase or in a high dryness state, and returns to the suction port of the compressor 6.

The temperature of the outdoor heat exchanger 14 that has become below freezing due to the attachment of frost at the start of defrosting / heating is the liquid phase or the gas-liquid two-phase returning from the gas-phase refrigerant that exits from the discharge port of the compressor 6 and the indoor heat exchanger 16. When the refrigerant is heated by the mixed refrigerant and frost is melted at around zero degrees, and the frost is completely melted, the temperature of the outdoor heat exchanger 14 begins to rise again. When the temperature increase of the outdoor heat exchanger 14 is detected by the temperature sensor, it is determined that the defrosting is completed, and an instruction from the defrosting / heating operation to the normal heating operation is output from the control device. .

In the case of using the three-way valve 42, during the defrosting operation, the refrigerant that has flowed through the indoor heat exchanger 16 and the outdoor heat exchanger 14 flows through the heat storage heat exchanger 34 via the four-way valve 8, and is sucked into the compressor 6. As the structure led to the pipe, the indoor heat exchanger 16 is operated at a high temperature and the heat storage heat exchanger 34 is maintained at a low temperature, and the heat absorption from the heat source is quickly performed, thereby reducing the defrosting time and heating operation. It is possible to improve comfort by suppressing a decrease in room temperature during defrosting operation.

In the configuration of the first embodiment of the present invention described above, when refrigerant flows from the inlet of the three-way valve 42 to the inlet of the compressor 6 during the defrosting / heating operation, the pressure difference between the inlet and outlet of the three-way valve 42 is large. Therefore, there is a case where it is larger than the allowable pressure difference of the three-way valve 42 and cannot be switched to the normal heating operation. In order to avoid this, it is expensive to use a three-way valve having a large allowable pressure difference. There was a problem.

Therefore, in order to solve the above-mentioned problems, the present inventors set the pressure difference at the inlet / outlet of the three-way valve while suppressing the decrease in the heating capacity as much as possible when switching from the defrosting / heating operation to the normal heating operation. Finding the configuration of a refrigeration cycle system that can be used with a low-cost one with a relatively small allowable pressure difference, while keeping the three-way valve to be surely switched while keeping it smaller than the allowable pressure difference of the three-way valve. It came to the air conditioner provided with the refrigerating cycle device concerning form 2.

FIG. 4 is a refrigeration cycle configuration diagram showing the configuration of the air conditioner including the refrigeration cycle apparatus according to Embodiment 2 of the present invention, and the same components as in Embodiment 1 of the present invention shown in FIG. The same number is attached and detailed explanation is omitted.

4, in addition to the configuration of the first embodiment, the air conditioner further includes a refrigeration cycle control device 50 that controls the operation thereof. The refrigeration cycle control device 50 is electrically connected to the temperature sensor 51 and detects the temperature of the outdoor heat exchanger (first heat exchanger) 14. The refrigeration cycle control device 50 is also electrically connected to the compressor 6, the expansion valve 12, and the three-way valve 42 serving as a switching device, so that the operating speed of the compressor 6, the throttle amount of the expansion valve 12, and the refrigerant of the three-way valve 42. Determine path switching and drive control.

During normal heating operation, the solenoid valve 30 is controlled to be closed, and the refrigerant discharged from the discharge port of the compressor 6 passes through the pipe 18 and reaches the indoor heat exchanger 16 from the four-way valve 8. The refrigerant condensed by exchanging heat with the indoor air in the indoor heat exchanger 16 exits the indoor heat exchanger 16 and passes through the pipe 20 to the expansion valve 12. In addition, the refrigerant decompressed by the expansion valve 12 passes through the pipe 22 and reaches the outdoor heat exchanger 14. The refrigerant evaporated by exchanging heat with the outdoor air in the outdoor heat exchanger 14 reaches the four-way valve 8 through the pipe 24. The three-way valve 42 is controlled so that the passage of the refrigerant from the outdoor heat exchanger 14 to the suction port of the compressor 6, that is, the pipe 24 and the pipe 25 communicate with each other, and the refrigerant passing through the four-way valve 8 is the three-way valve 42. And return to the suction port of the compressor 6.

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

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. When the temperature sensor 51 detects that the evaporation temperature has decreased as compared with the time of non-frosting, the refrigeration cycle control device 50 outputs a switching instruction from the normal heating operation to the defrosting / heating operation.

When switching from the normal heating operation to the defrosting / heating operation, the solenoid valve 30 is 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 passes through the pipe 28 and the electromagnetic valve 30 serving as a discharge gas bypass mechanism, and passes through the pipe 22. , The outdoor heat exchanger 14 is heated, condensed and converted into a liquid phase, and then the four-way valve 8 is reached.

During the defrosting / heating operation, the three-way valve 42 is controlled so that the path leading the refrigerant from the outdoor heat exchanger 14 to the heat storage heat exchanger 34, that is, the pipe 24 and the pipe 38 communicate with each other. The refrigerant that has passed through the four-way valve 8 is depressurized by the capillary tube 43 serving as a throttling mechanism and becomes a low temperature, absorbs the heat of the heat storage material 36 by the heat storage heat exchanger 34, and enters the accumulator 26 in the gas phase or high dryness state. Finally, it returns to the suction port of the compressor 6.

The temperature of the outdoor heat exchanger 14 that has become below freezing due to the attachment of frost at the start of defrosting / heating is the liquid phase or the gas-liquid two-phase returning from the gas-phase refrigerant that exits from the discharge port of the compressor 6 and the indoor heat exchanger 16. When the refrigerant is heated by the mixed refrigerant, the frost is melted at around zero degrees, and when the frost is completely melted, it starts rising again. When the temperature sensor 51 detects the temperature rise of the outdoor heat exchanger 14, it is determined that the defrosting has been completed, and the refrigeration cycle control device 50 outputs a switching instruction from the defrosting / heating operation to the normal heating operation.

FIGS. 5 (a) to 5 (f) show control time charts according to Embodiment 2 of the present invention, particularly at the timing of shifting to normal heating from the time when it is determined that the above-described defrosting is completed. Changes in compressor speed, expansion valve opening, three-way valve path state, refrigerant pressure (high and low pressure), and heating capacity are shown with time. In FIG. 5, (a) is defrosting determination, (b) is the compressor rotation speed, (c) is the expansion valve opening degree, (d) is the three-way valve path state, and (e) is the refrigerant pressure (high and low pressure). ) And (f) show changes in heating capacity.

First, a control time chart when the expansion valve opening degree of the expansion valve 12 is not throttled when switching from the defrosting / heating operation to the normal heating will be described.
As shown to Fig.5 (a), it determines with defrosting having been completed at the timing of time T1 and transfering to normal heating operation. Here, the time T1 indicates a time when the temperature of the outdoor heat exchanger 14 is equal to or higher than a predetermined temperature. The predetermined temperature is a temperature at which the frost attached to the outdoor heat exchanger 14 is melted and the temperature in the outdoor heat exchanger 14 starts to rise. Further, the temperature of the outdoor heat exchanger 14 is detected by the temperature sensor 51. At time T1, as shown in FIG. 5 (b), the refrigeration cycle control device 50 issues an instruction to reduce the rotational speed of the compressor 6, and the rotational speed that is the set value at the end of the defrosting / heating operation. Control is performed so as to gradually decrease from F1 and reach the rotational speed F2 by time T2. Here, the time T2 indicates a time point after a predetermined time has elapsed from the time T1. As shown in FIG. 5D, the refrigeration cycle control device 50 issues an instruction to switch the three-way valve 42 from the defrosting side to the heating side at the time T2. Specifically, the three-way valve 42 is switched from a path through which refrigerant flows from the four-way valve 8 through the heat storage heat exchanger 34 to the suction pipe of the compressor 6 to a path through which refrigerant flows directly from the four-way valve 8 to the suction pipe of the compressor 6. When the control is performed as described above, as shown in FIG. 5E, the rotation speed of the compressor 6 is lowered, the pressure on the high pressure side of the refrigerant pressure is lowered, and the pressure on the low pressure side is raised. At this time, the high-low pressure difference ΔP between the high-pressure side and the low-pressure side of the refrigerant pressure at time T2 is smaller than the high-low pressure difference at time T1. That is, since the inlet / outlet pressure of the three-way valve 42 can be smaller than the allowable pressure difference of the three-way valve 42 at time T2, the three-way valve 42 can be switched reliably. However, as shown in FIG. 5 (f), there is a problem that the temperature of the indoor heat exchanger 16 is lowered and the heating capacity is lowered due to a decrease in the pressure on the high pressure side of the refrigerant pressure (indicated by a broken line in the figure). .

In the second embodiment of the present invention, the above problem is solved by controlling the expansion valve opening of the expansion valve 12 to be reduced. A control time chart when the expansion valve opening degree of the expansion valve 12 is throttled when switching from the defrosting / heating operation to the normal heating will be described.

In Embodiment 2 of the present invention, as shown in FIG. 5 (a), it is determined that the defrosting is completed at the timing of time T1 and the routine is shifted to the normal heating operation. As shown in FIG. 5B, the refrigeration cycle control device 50 issues an instruction so as to decrease from the rotational speed F <b> 1 of the compressor 6. At the same time, the refrigeration cycle control device 50 issues an instruction to make the expansion valve opening degree of the expansion valve 12 narrow. In particular, as shown in FIG. 5 (c), the expansion valve 12 is gradually throttled from the expansion valve opening P1 that is a set value at the end of the defrosting / heating operation, and is excessively passed by the indoor heat exchanger 16 by time T2. An instruction is given to throttle the cooled liquid refrigerant to an expansion valve opening P2 that can hold the cooled liquid refrigerant in the pipe of the indoor heat exchanger 16. As a result, as shown in FIG. 5 (e) and FIG. 5 (f), as the expansion valve opening degree of the expansion valve 12 is reduced, the pressure drop on the high pressure side of the refrigerant pressure is reduced, and the heating capacity is reduced accordingly. Is reduced (indicated by the solid line in the figure). Further, the high / low pressure difference ΔP between the high pressure side and the low pressure side of the refrigerant pressure at time T2 is smaller than the high / low pressure difference at time T1. As shown in FIG. 5 (d), the refrigeration cycle control device 50 issues an instruction to switch the three-way valve 42 from the defrosting side to the heating side at the timing of time T2. That is, the three-way valve 42 is switched from a path through which refrigerant flows from the four-way valve 8 through the heat storage heat exchanger 34 to the suction pipe of the compressor 6 to a path through which refrigerant flows directly from the four-way valve 8 to the suction pipe of the compressor 6. In Embodiment 2 of the present invention, the high / low pressure difference ΔP between the high pressure side and the low pressure side of the refrigerant pressure is larger than when the expansion valve opening degree of the expansion valve 12 is not throttled, but the switching of the three-way valve 42 is If the high / low pressure difference ΔP is smaller than the allowable pressure difference of the three-way valve 42, the operation can be performed without any problem.

After the time T2, in order to operate as a normal heating operation, the rotation speed of the compressor 6 and the expansion valve opening of the expansion valve 12 are as shown in FIGS. 5 (b) and 5 (c) at time T3. Usually, control is performed so as to be an initial set value when heating is started. Here, the time T3 indicates a point in time when the rotation speed of the compressor 6 and the expansion valve opening of the expansion valve 12 become the initial set values at the time of normal heating activation. Further, after the time T3, the rotation speed of the compressor 6 and the expansion valve opening of the expansion valve 12 are controlled so as to be constant at the initial set values at the time of normal heating activation, but depending on the capacity control after a predetermined time has elapsed. The set value may be changed.

Further, as shown in FIGS. 5E and 5F, in the refrigerant pressure (high and low pressure) and the heating capacity, the time T3 is higher on the high pressure side of the refrigerant pressure than the time T1, and the heating capacity is increased. ing. This is because after the time T2, in order to increase the heating capacity more quickly, the number of rotations of the compressor 6 is increased and the throttle of the expansion valve 12 is adjusted to increase the difference between the high and low pressures of the refrigerant pressure. is there. On the other hand, before the time T1, since it is in the defrost cycle, the heat release side (the part that melts the frost with the high-temperature and high-pressure gas) is cooled by frost, so the high-pressure side of the refrigerant pressure decreases and the heating capacity also decreases. ing.

By operating as described above, when switching from the defrosting / heating operation to the normal heating operation, the pressure difference at the inlet / outlet of the three-way valve 42 is set to the allowable pressure difference of the three-way valve 42 while suppressing a decrease in the heating capacity as much as possible. The three-way valve itself can be used at a lower cost with a relatively small allowable pressure difference while keeping the three-way valve 42 to be switched reliably.

The discharge gas bypass path from the compressor 6 through the piping 28 through the electromagnetic valve 30 to the outdoor heat exchanger (first heat exchanger) is not necessarily required, and a very large defrosting capacity is required. It is good also as a structure which eliminates except the case.

In the second embodiment, the heat storage heat exchanger 34 provided so as to surround the compressor 6 as an auxiliary heat exchanger has been described as an example. However, the present invention is not limited to this, and other configurations may be used. It ’s good.

In the second embodiment, the refrigeration cycle applied to the air conditioner has been described. However, the same effect can be obtained even with other devices such as a heat pump type hot water heater.

The refrigeration cycle apparatus according to the present invention not only improves the heat absorption capability from the heat source and improves the defrosting capability, but also reduces the return of the liquid refrigerant to the compressor as much as possible and improves the reliability of the compressor. Can do. Moreover, since a low-cost refrigerant path switching device can be adopted while reducing the decrease in heating capacity during defrosting as much as possible, it is useful for air conditioners, refrigerators, heat pump water heaters, and the like.

2 Outdoor unit 4 Indoor unit 6 Compressor 8 Four-way valve 10 Strainer 12 Expansion valve 14 Outdoor heat exchanger (second heat exchanger)
16 Indoor heat exchanger (first heat exchanger)
18, 20, 22, 24, 25 Piping 26 Accumulator 28 Piping (Discharge gas bypass mechanism)
30 Solenoid valve (Discharge gas bypass mechanism)
31 Solenoid valve 32 Heat storage tank (auxiliary heat exchanger)
34 Heat storage heat exchanger (auxiliary heat exchanger)
36 Heat storage material (auxiliary heat exchanger)
38, 40 Piping 42 Three-way valve (switching device)
43 Capillary tube (throttle mechanism)
50 Refrigeration cycle control device 51 Temperature sensor

Claims

A compressor,
A first heat exchanger connected to the compressor;
An expansion valve connected to the first heat exchanger;
A second heat exchanger connected to the expansion valve;
A four-way valve to which the second heat exchanger and the compressor are connected;
An auxiliary heat exchanger for heating the refrigerant disposed around the compressor;
Between the suction pipe of the compressor and the four-way valve, a path for flowing the refrigerant directly from the four-way valve to the suction pipe of the compressor, and the refrigerant from the four-way valve to the suction pipe of the compressor through the auxiliary heat exchanger A switching device that enables switching with a flow path;
With
During the defrosting operation for melting frost adhering to the second heat exchanger, the switching device is controlled so that the refrigerant flowing through the first heat exchanger and the second heat exchanger passes through the four-way valve. The refrigeration cycle apparatus is characterized in that it flows through the auxiliary heat exchanger and is led to the suction pipe of the compressor.
The refrigeration cycle apparatus according to claim 1, wherein a three-way valve is used for the switching device.
The refrigeration cycle apparatus according to claim 1 or 2, further comprising a discharge gas bypass mechanism connected between the expansion valve and the second heat exchanger from a discharge pipe of the compressor.
4. The heat source of the auxiliary heat exchanger is a heat storage material that is disposed so as to surround the compressor and stores heat generated by the compressor. 5. Refrigeration cycle equipment.
The throttle mechanism for increasing refrigerant pressure loss is provided between the switching device provided between the four-way valve and the auxiliary heat exchanger and the auxiliary heat exchanger. The refrigeration cycle apparatus according to any one of the above.
A temperature sensor for detecting a pipe temperature of the second heat exchanger;
A refrigeration cycle control device electrically connected to the compressor, the expansion valve, the switching device, and the temperature sensor;
Further comprising
When the temperature sensor detects that the temperature in the second heat exchanger is lower than that during non-frosting during normal heating operation, the refrigeration cycle control device switches from normal heating operation to defrosting / heating operation. Output a switching instruction,
During the defrosting / heating operation, the temperature sensor indicates that the temperature in the second heat exchanger has melted when the temperature in the second heat exchanger is near zero, the frost has been melted, and the temperature in the second heat exchanger has increased. If it detects, it will judge that defrosting was completed and the said refrigeration cycle control apparatus will output the switching instruction | indication from defrost / heating operation to normal heating operation, The refrigeration cycle as described in any one of Claims 1 thru | or 5 apparatus.
The refrigeration cycle control device, after determining the completion of the defrosting operation, temporarily reduces the operating speed of the compressor and supplies the liquid refrigerant supercooled by the first heat exchanger in the pipe of the first heat exchanger. After the expansion valve opening degree of the expansion valve is reduced to such an extent that the expansion valve can be held, the four-way valve from the path through which the refrigerant is switched from the four-way valve to the suction pipe of the compressor through the auxiliary heat exchanger The refrigeration cycle apparatus according to claim 6, wherein the refrigeration cycle apparatus is switched to a path through which a refrigerant flows directly from a suction pipe to a suction pipe of the compressor.
The air conditioner according to any one of claims 1 to 7, wherein the first heat exchanger is an indoor heat exchanger, and the second heat exchanger is an outdoor heat exchanger.