JP2009281659A - Refrigerating cycle device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a refrigerating cycle device capable of operating with high energy efficiency even under frost formation conditions, and capable of preventing the contact of a ventilation fan and ice. <P>SOLUTION: The refrigerating cycle circulating a refrigerant is formed by annularly connecting a compressor (not shown in the figure), a radiator (not shown in the figure), a pressure reducing mechanism (not shown in the figure), and an evaporator 4 in this order, the evaporator 4 is composed of a heat transfer tube 31 substantially perpendicularly inserted into multiple fins 32 at predetermined pitches and carrying the refrigerant, the fin 32 disposed in the most downwind side has a length in a vertical direction shorter than the fin 32 disposed in an upwind side, and an upper end of the fin 32 in a downwind side is positioned in a vertical direction lower side than an upper end of the fin 32 in an upwind side. The development of ice to a lower end of the fin 32 of a downwind side under the frost formation conditions is suppressed, the deterioration of heat radiation performance and the deterioration of an air capacity of the evaporator 4 are suppressed, operation with high energy efficiency can be carried out, and the contact of the ventilation fan (not shown in the figure) with ice is prevented. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a refrigeration cycle apparatus, and more particularly to a refrigeration cycle apparatus that uses a substance that can be supercritical on the high-pressure side as a refrigerant.

  Conventionally, this type of refrigeration cycle apparatus is typically used as a refrigeration cycle apparatus equipped with a heat pump water heater as shown in FIG. Therefore, below, the conventional structure and operation | movement are demonstrated taking the example of the refrigerating-cycle apparatus carrying a heat pump water heater.

  In FIG. 4, a conventional refrigeration cycle apparatus equipped with a heat pump water heater is composed of a heat pump unit 41 and a hot water storage unit 42. The heat pump unit 41 is a compressor 1, a gas cooler 2 serving as a radiator, and a pressure reducing mechanism. The expansion valve 3 and the evaporator 4 have a refrigerant circuit 5 configured in such a manner that they are sequentially connected in an annular shape. Note that the refrigerant circuit 5 is not provided with a device that reverses the circulation direction of the refrigerant, such as a four-way valve. Further, the evaporator 4 is a fin-and-tube heat exchanger composed of heat transfer tubes 31 and fins 32 as shown in FIG. 5, and the heat transfer tubes 31 are arranged in a staggered manner along the air flow direction. It has a structure inserted perpendicularly to the fins 32. The fins 32 that are arranged in two rows on the leeward side and the leeward side are usually arranged with their upper ends aligned.

  On the other hand, the hot water storage unit 42 is connected to the hot water storage tank 51, the stacking pump 52, the three-way valve 53, the hot water mixing valve 54, and the bottom of the hot water storage tank 51 through the stacking pump 52, the gas cooler 2, and the three-way valve 53. A boiling circuit 55 for refluxing to the top of the column is provided.

  Next, about the above refrigeration cycle apparatuses, the operation | movement at the time of the heating (or cooling) operation and the defrosting operation on the conditions that frost adheres to the evaporator 4 is demonstrated.

  In the heating operation, the high-pressure refrigerant discharged from the compressor 1 exchanges heat with water in the gas cooler 2 and dissipates heat, and then is supplied to the expansion valve 3 and decompressed. The refrigerant that has been decompressed at the expansion valve 3 to become low temperature and low pressure is supplied to the evaporator 4, absorbs heat from the atmosphere, and is supplied to the compressor 1 again.

  When the heating operation is performed by operating the refrigerant in this way, the evaporation temperature of the refrigerant flowing through the evaporator 4 is about 7 to 10 ° C. lower than the atmospheric temperature, and the evaporation temperature of the refrigerant is about −1 ° C. to −2 ° C. If it becomes low, the condensed water which condensed the water | moisture content in air | atmosphere will freeze and adhere to the atmospheric | air flow path 33 pinched | interposed between the fin 32 and the fin 32 of the evaporator 4 as frost. When the frost starts to adhere, the air flow path 33 is blocked, and the gas cooler 2 cannot obtain sufficient heating capability, and the refrigeration cycle apparatus cannot be operated with high energy efficiency. Therefore, when the refrigeration cycle apparatus detects adhesion of frost to the evaporator 4, it performs the following defrosting operation to remove the frost.

  In the defrosting operation, the refrigerant is circulated in the refrigerant circuit 5 in the same order as in the heating operation, a relatively high-temperature refrigerant is supplied to the evaporator 4, and the heat energy of the refrigerant is used for the evaporator 4. The frost adhering to the fin 32 is melted and removed. At this time, it is normal to operate the water flow rate or the like so that the refrigerant does not radiate heat as much as possible in the gas cooler 2.

The refrigeration cycle apparatus that performs the defrosting operation as described above requires a longer time for the defrosting operation than the refrigeration cycle apparatus that performs the defrosting operation by reversing the refrigerant circulation direction using a four-way valve or the like. There is a problem that it is easy to cause unmelted after the defrosting operation and to reduce the energy efficiency of the refrigeration cycle apparatus.

As a refrigeration cycle apparatus that solves the above problems, for example, a refrigeration cycle apparatus as described in Patent Document 1 has been proposed. This refrigeration cycle apparatus does not include means for reversing the direction of refrigerant circulation such as a four-way valve, and as shown in FIG. Each of the leeward fins 12 and the leeward fins 12 is formed by the fins 32 and the heat transfer tubes 31 inserted into the fins 32. From the heat transfer tubes 31 of the windward fins 11, the leeward fins 12 are formed. The refrigerant flows in order toward the heat transfer tubes 31, and the heat transfer tubes 31 inserted in the leeward fins 12 are hot in the order from the heat transfer tubes 31 inserted in the windward fins 11 having a large amount of frost adhesion during the defrosting operation. Some have improved the defrosting performance by supplying a refrigerant.
JP 2006-23005 A

  However, according to the configuration of the conventional refrigeration cycle apparatus, as shown in FIG. 6, the leeward fin 12 is shorter in the vertical direction than the leeward fin 11, and the lower end of the leeward fin 12 is the lower end of the upwind fin 11. In the refrigeration cycle apparatus equipped with the evaporator 4 on the upper side in the vertical direction, as in the refrigeration cycle apparatus described in Patent Document 1, the heat transfer tube is configured such that the refrigerant flows in order from the windward side toward the leeward side. When 31 is configured, the frost melted by the defrosting operation becomes water droplets at the lower end of the leeward fin 12 and remains due to surface tension, and the amount of air flowing around the lower end of the leeward fin 12 is large. Water droplets remaining at the time of resuming operation are cooled and re-frozen, the heat dissipation performance of the evaporator 4 is lowered, energy efficiency in the operation of the refrigeration cycle apparatus is lowered, and ice is further reduced. In contact with to hear grow the blower fan (not shown), there is a problem that the refrigeration cycle apparatus can not be operated normally.

  The present invention solves the above-described conventional problems, suppresses the heat dissipation performance of the leeward fin and the airflow, and can operate with high energy efficiency even under frosting conditions. It is an object of the present invention to provide a refrigeration cycle apparatus capable of continuing normal operation without a fan coming into contact with ice.

  In order to achieve the above object, the refrigeration cycle apparatus of the present invention comprises a refrigeration cycle in which at least a compressor, a radiator, a decompression mechanism, and an evaporator are sequentially connected in an annular manner to circulate a refrigerant. The container is stacked in parallel at a constant pitch and a number of plate-like fins through which a gas such as air flows, and is inserted into the fins at a predetermined pitch at a substantially right angle and is closely bonded to the fins. The inside of the heat transfer tube is configured such that a refrigerant flows therein, and the heat transfer tubes are arranged in at least two rows on the windward side and the leeward side, and the fins arranged on the most leeward side are arranged on the windward side. A fin-and-tube heat exchanger with a shorter vertical length than the fins, wherein the main flow direction of the gas, that is, the column direction, is horizontal, and the perpendicular direction, that is, the step direction, is perpendicular to the main flow direction of the gas. The upper end of the fin on the leeward side is positioned vertically lower than the upper end of the fin on the leeward side, and ice is applied to the lower end of the fin on the leeward side of the evaporator under frosting conditions. Suppresses growth, suppresses the heat dissipation performance of the evaporator and the airflow, and can operate the refrigeration cycle device with high energy efficiency even under frosting conditions, and the blower fan comes into contact with ice The operation can be continued normally.

The refrigeration cycle apparatus according to the present invention includes an evaporator in which the leeward fin has a shorter vertical length than the windward fin and the lower end of the leeward fin is vertically higher than the lower end of the windward fin. In the installed refrigeration cycle device, by suppressing the growth of ice on the leeward fin lower end under frosting conditions, it is possible to suppress the decrease in heat dissipation performance and the air volume of the leeward fins, In this case, the refrigeration cycle apparatus can be operated with high energy efficiency, and an effect that the operation can be continued normally without the blower fan coming into contact with ice can be obtained.

  According to a first aspect of the present invention, at least a compressor, a radiator, a pressure reducing mechanism, and an evaporator are sequentially connected in an annular manner to form a refrigeration cycle in which refrigerant circulates, and the evaporators are stacked in parallel at a constant pitch. And a large number of plate-like fins through which a gas such as air flows, and a heat transfer tube inserted into the fins at a predetermined pitch substantially perpendicular to the fins and tightly joined to the fins and in which the refrigerant flows. The heat transfer tubes are arranged in at least two rows on the leeward side and the leeward side, and the fins arranged on the most leeward side are shorter in length in the vertical direction than the fins arranged on the leeward side. It is a fin-and-tube heat exchanger, and the main flow direction of the gas, that is, the column direction is installed in the horizontal direction, the perpendicular direction to the main flow direction of the gas, that is, the step direction is installed in the vertical direction, and the upper end of the fin on the leeward side is It is positioned vertically lower than the upper end of the fin on the leeward side, suppresses the growth of ice on the lower end of the fin on the leeward side of the evaporator under frosting conditions, reduces the heat dissipation performance of the evaporator, and It is possible to operate the refrigeration cycle apparatus with high energy efficiency even under frosting conditions while suppressing a decrease in air volume, and to continue normal operation without the blower fan coming into contact with ice.

  In the second invention, in particular, the lower end of the fin on the leeward side of the first invention is vertically above the lower end of the fin on the leeward side, and the lower end of the fin on the leeward side and the lower end of the fin on the leeward side The vertical distance at the lower end is smaller than the vertical distance between the upper end of the fin on the leeward side and the upper end of the fin on the leeward side. Suppresses growth, suppresses the heat dissipation performance of the evaporator and the airflow, and can operate the refrigeration cycle device with high energy efficiency even under frosting conditions, and the blower fan comes into contact with ice The operation can be continued normally.

  In particular, the third invention is provided with a rotary blower for introducing gas into the evaporator of the first or second invention, and the center of gravity of the evaporator is lower than the rotation center of the rotary blower in the vertical direction. It suppresses the growth of ice on the leeward fin bottom of the evaporator under frosting conditions, suppresses the heat dissipation performance of the evaporator and the airflow, and even under frosting conditions. The refrigeration cycle apparatus can be operated with high energy efficiency, and the operation can be continued normally without the blower fan coming into contact with ice.

  In the fourth aspect of the invention, in particular, a casing is arranged in the wind circuit on the leeward side of the evaporator according to any one of the first to third aspects, and the upper end of the casing is in the most leeward row of the evaporator. It is on the lower side in the vertical direction than the heat transfer tube arranged at the lowest stage, increasing the air volume on the upper side in the vertical direction of the evaporator to suppress the growth of ice on the fin bottom on the leeward side, and the heat dissipation performance of the evaporator The refrigeration cycle apparatus can be operated with high energy efficiency even under frosting conditions, and the operation can be continued normally without the blower fan coming into contact with ice. .

  In the fifth invention, in particular, the heat transfer tube according to any one of the first to fourth inventions is configured such that the refrigerant flows in order from the leeward side to the leeward side, and is attached to the fin on the leeward side. Since frost is melted and removed early during defrosting operation, it is difficult for unmelted parts to be generated, ice growth is suppressed, deterioration of the heat dissipation performance of the evaporator and reduction in air flow are suppressed, In this case, the refrigeration cycle apparatus can be operated with high energy efficiency, and the operation can be continued normally without the blower fan coming into contact with ice.

  In the refrigeration cycle apparatus according to any one of the first to fifth inventions, the sixth invention is the one in which the refrigerant circulates in the order of the compressor, the radiator, the decompression mechanism, and the evaporator during the defrosting operation. Even in a refrigeration cycle apparatus that does not have a means for reversing the refrigerant circulation direction such as a valve, the defrosting operation can be performed with little energy without melting, the refrigeration cycle apparatus can be operated with high energy efficiency, and air blowing The fan can continue to operate normally without contacting the ice.

  According to a seventh aspect of the invention, in particular, in the refrigeration cycle apparatus according to any one of the first to fifth aspects, during the defrosting operation, the refrigerant discharged from the compressor is supplied to the evaporator, bypassing at least the radiator. Therefore, it is possible to suppress the heat radiation of the refrigerant in the radiator, etc., to perform the defrosting operation with little energy and without melting, to operate the refrigeration cycle apparatus with high energy efficiency, and the blower fan and the ice. The operation can be continued normally without contact.

  In the eighth invention, in particular, as the refrigerant of any one of the first to seventh inventions, a substance that can be in a supercritical state on the high pressure side is used. The fluid can be efficiently heated.

  In the ninth aspect of the invention, carbon dioxide is used as the refrigerant of the eighth aspect of the invention, and the risk of ignition or explosion of the refrigerant can be eliminated.

  Hereinafter, a refrigeration cycle apparatus according to an embodiment of the present invention will be described with reference to the drawings. Although the embodiment will be described using a refrigeration cycle apparatus equipped with a heat pump water heater as an example, the embodiment of the present invention is not limited to a heat pump water heater, and is an air conditioner or a vehicle air conditioner. It may be a device or the like. In addition, this invention is not limited by the following embodiment.

(Embodiment 1)
FIG. 1 is a perspective view of an evaporator of a refrigeration cycle apparatus according to the first embodiment of the present invention, and FIG. 2 is a front view of a heat pump unit of the refrigeration cycle apparatus. In addition, about the same part as the said conventional refrigeration cycle apparatus, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  In the refrigerant circuit 5, carbon dioxide circulates as a refrigerant, and there is no means for reversing the refrigerant circulation direction such as a four-way valve.

  A refrigeration cycle apparatus (here, a refrigeration cycle apparatus mounted on a heat pump water heater) in the present embodiment includes the refrigerant circuit 5 and the boiling circuit 55.

  1 and 2, reference numeral 13 denotes a refrigerant inflow pipe, reference numeral 14 denotes a refrigerant outflow pipe, and in FIG. 2, reference numeral 16 denotes a blower fan which is a rotary blower, 17 denotes a gas cooler cover which is a casing covering the gas cooler 2, and 18. Is a power box.

  As shown in FIG. 1, in the evaporator 4, the leeward fin 12 has a shorter vertical fin 32 than the leeward fin 11, and the vertical distance between the lower end of the leeward fin 12 and the lower end of the upwind fin 11. L2 is arranged so as to be smaller than the vertical distance L1 between the upper end of the leeward fin 12 and the upper end of the leeward fin 11 (L1> L2).

Further, the gas cooler cover 17 is arranged in the wind circuit, and the refrigerant inflow pipe 13 inserted in the lowermost stage of the leeward fin 12 is arranged to be vertically higher than the upper end of the gas cooler cover 17. The blower fan 16 is arranged so that the center of gravity of the evaporator 4 is vertically lower than the rotation center. Further, as shown in FIG. 1, the refrigerant inflow pipe 13 is inserted and arranged at the lowest stage of the leeward fin 12, and the refrigerant outflow pipe 14 is inserted and arranged in the upwind fin 11. .

  Next, the operation and action of the refrigeration cycle apparatus in the present embodiment configured as described above will be described. Since the basic operation during the heating operation is the same as that of the conventional refrigeration cycle apparatus, the characteristic operation and action in the present invention will be described.

  The defrosting operation for melting and removing the frost attached to the evaporator 4 will be mainly described. When the frosting on the evaporator 4 proceeds by the heating operation, the defrosting operation for removing the attached frost is started. The start of the defrosting operation is determined by, for example, the refrigerant evaporation temperature in the evaporator 4. When the defrosting operation is started, the compressor 1, the expansion valve 3 and the stacking pump 52 are operated at a predetermined setting during the defrosting operation without changing the circulation direction of the refrigerant in the refrigerant circuit 5.

  In particular, the stacking pump 52 is operated so as to suppress the flow rate of water circulating in the boiling circuit 55, thereby suppressing the heat radiation of the refrigerant in the gas cooler 2. When the defrosting operation is started and a refrigerant having a temperature of 0 ° C. or higher is supplied to the evaporator 4, the frost is melted by the heat energy of the refrigerant, and the drain pan (not shown) travels through the fins 32 of the evaporator 4. ) And drops as water. At this time, the frost adhering to the periphery of the refrigerant inflow pipe 13 inserted into the leeward fin 12 of the evaporator 4 is sequentially melted, and finally the frost adhering to the periphery of the refrigerant outflow pipe 14 is melted. Note that the end of the defrosting operation is determined by, for example, the refrigerant evaporation temperature in the evaporator 4. When the end of the defrosting operation is determined, the compressor 1, the expansion valve 3 and the laminated pump 52 are returned to the operation state during the normal heating operation, and the heating operation is resumed.

  When the heating operation is restarted, the water droplets remaining due to the surface tension in the fin 32 at the lower end of the leeward fin 12 and the air flow path 33 sandwiched between the fins 32 are cooled and frozen again. 11 and a gas cooler cover 17 disposed below the wind circuit, the wind speed of the air flowing above the lee fin 12 is higher than that around the lower end of the lee fin 12. Therefore, it is possible to suppress water droplets from growing into ice. Furthermore, since the blower fan 16 is disposed above the center of gravity of the evaporator 4, the wind speed of the atmosphere flowing above the leeward fin 12 is increased.

  In addition, by arranging the refrigerant inflow pipe 13 of the evaporator 4 at the lowermost end of the leeward fin 12 and inserting the refrigerant outflow pipe 14 into the leeward fin 11, early after the defrosting operation is started. Since the frost adhering to the leeward fins 12 melts, it takes a long time to resume the heating operation, and water drops dripping from the upper part of the fins 32 hardly remain in the atmospheric flow path 33.

  By constituting the evaporator 4 and the gas cooler cover 17 as described above, it is possible to suppress the growth of ice at the lower end of the leeward fin 12 under the frosting condition. It is possible to suppress a decrease in the air volume.

  By doing in this way, the fall of the performance of the evaporator 4 by the ice column growth to the lower end of the leeward fin 12 can be prevented, the refrigeration cycle apparatus can be operated with high energy efficiency, and the blower fan 16 can be operated with ice. The operation can be continued normally without contact.

According to the present embodiment, as described above, the refrigeration cycle in which the leeward fin 12 is shorter in the vertical direction than the leeward fin 11 and the lower end of the leeward fin 12 is above the lower end of the upwind fin 11. Also in the apparatus, the distance L2 between the lower end of the leeward fin 12 and the lower end of the leeward fin 11 is made smaller than the distance L1 between the upper end of the leeward fin 12 and the upper end of the windward fin 11 (L1> L2), and the defrosting operation is performed. Sometimes, by configuring the heat transfer tube 31 so that the refrigerant flows from the leeward side to the leeward side, frost remaining on the evaporator 4 and ice growth on the lower ends of the fins 32 are suppressed even under frosting conditions. Therefore, the refrigeration cycle apparatus can be operated with high energy efficiency, and the operation can be continued normally without the blower fan 16 coming into contact with ice.

(Embodiment 2)
FIG. 3 is a configuration diagram of a refrigeration cycle apparatus equipped with a heat pump water heater in the second embodiment of the present invention. In addition, about the same part as the refrigerating-cycle apparatus in the said 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  As shown in FIG. 3, the refrigeration cycle apparatus in the present embodiment includes a bypass circuit 22 having a bypass valve 21 between the discharge side of the compressor 1 and the refrigerant inlet pipe 13 connected to the evaporator 4. The configuration of the evaporator 4 is the same as that of the first embodiment.

  Next, the operation and action of the refrigeration cycle apparatus in the present embodiment configured as described above will be described.

  In the present embodiment, when the start of the defrosting operation is determined, the refrigerant discharged from the compressor 1 through the bypass circuit 22 by opening the bypass valve 21 is supplied to the evaporator 4 without passing through the gas cooler 2. Is done. When the end of the defrosting operation is determined, the bypass valve 21 is closed and the normal heating operation is resumed.

  Since the bypass valve 21 is operated and operated as described above, a high-temperature refrigerant can be supplied to the refrigerant inflow pipe 13 inserted in the lowermost stage of the leeward fin 12 of the evaporator 4. Ice growth to the lower end can be suppressed. The effects that can be obtained by the present embodiment are the same as those of the first embodiment, and the description thereof is omitted.

  The refrigeration cycle apparatus according to the present invention has the effect that it can be operated with high energy efficiency and can continue to operate normally without the blower fan coming into contact with ice, and is installed in a heat pump water heater. This is useful for a general refrigeration cycle apparatus using a refrigerant that can be in a supercritical state on the high pressure side, such as a refrigeration cycle apparatus or a refrigeration cycle apparatus mounted on an air conditioner.

The perspective view of the evaporator of the refrigeration cycle apparatus in Embodiment 1 of this invention Front view of the heat pump unit of the refrigeration cycle apparatus Configuration diagram of a refrigeration cycle apparatus equipped with a heat pump water heater in Embodiment 2 of the present invention Configuration diagram of a conventional refrigeration cycle system equipped with a heat pump water heater Perspective view of the evaporator of the refrigeration cycle apparatus A perspective view showing an example of another evaporator

Explanation of symbols

1 Compressor 2 Gas cooler (heat radiator)
3 Expansion valve (pressure reduction mechanism)
DESCRIPTION OF SYMBOLS 4 Evaporator 5 Refrigerant circuit 11 Upwind fin 12 Downwind fin 13 Refrigerant inflow pipe 14 Refrigerant outflow pipe 15, 33 Atmospheric flow path 16 Blower (rotary blower)
17 Gas cooler cover (frame)
DESCRIPTION OF SYMBOLS 18 Power supply box 21 Bypass valve 22 Bypass circuit 31 Heat transfer tube 32 Fin 41 Heat pump unit 42 Hot water storage unit 51 Hot water storage tank 52 Laminated pump 53 Three-way valve 54 Mixing valve 55 Boiling circuit

Claims (9)

At least a compressor, a radiator, a decompression mechanism, and an evaporator are connected in order to form a refrigeration cycle in which refrigerant circulates, and the evaporators are stacked in parallel at a constant pitch and air is interposed therebetween. A plurality of plate-like fins through which a gas flows, and heat transfer tubes inserted into the fins at a predetermined pitch substantially perpendicular to the fins and in close contact with the fins, in which a refrigerant flows. Are arranged in at least two rows on the leeward side and the leeward side, and the fins arranged on the most leeward side are fin-and-tube type heats that are shorter in the vertical direction than the fins arranged on the leeward side. It is an exchanger, and the main flow direction of the gas, that is, the row direction is installed in the horizontal direction, and the direction perpendicular to the main flow direction of the gas, that is, the step direction is installed in the vertical direction. Refrigeration cycle apparatus is characterized in that is positioned vertically lower than the upper end of the fin. The lower end of the leeward fin is vertically above the lower end of the fin on the leeward side, and the vertical distance between the lower end of the fin on the leeward side and the lower end of the fin on the leeward side of the fin on the leeward side is The refrigeration cycle apparatus according to claim 1, wherein the refrigeration cycle apparatus is smaller than a vertical distance between the upper end and the upper end of the fin on the windward side. The rotary blower means for introducing gas into the evaporator is provided, and the center of gravity of the evaporator is vertically below the rotation center of the rotary blower means. Refrigeration cycle equipment. A casing is arranged in a wind circuit on the leeward side of the evaporator, and an upper end of the casing is vertically lower than a heat transfer tube arranged in the lowest stage of the most leeward row of the evaporator. The refrigeration cycle apparatus according to any one of claims 1 to 3. The refrigeration cycle apparatus according to any one of claims 1 to 4, wherein the heat transfer tube is configured such that refrigerant flows in order from the leeward side to the leeward side. 6. The refrigeration cycle apparatus according to claim 1, wherein during the defrosting operation, the refrigerant circulates in the order of a compressor, a radiator, a decompression mechanism, and an evaporator. 6. The refrigeration cycle apparatus according to claim 1, wherein during the defrosting operation, the refrigerant discharged from the compressor is supplied to the evaporator while bypassing at least the radiator. The refrigeration cycle apparatus according to any one of claims 1 to 7, wherein a substance that can be in a supercritical state on a high-pressure side is used as the refrigerant. The refrigeration cycle apparatus according to claim 8, wherein carbon dioxide is used as the refrigerant.

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