JP2005351538A - Heat pump water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat pump water heater capable of storing the hot water of high temperature even at a lower part of a hot water storage tank with high efficiency without rising a discharge pressure of a compressor, effectively utilizing a capacity of the hot water storage tank, and preparing the hot water of high temperature for supplying the hot water with high efficiency even when an outside air temperature is high. <P>SOLUTION: This heat pump water heater comprises an auxiliary heat exchanger 38 constituted by successively connecting a compressor 31, a heat radiator 32, a main throttling device 33 and an evaporator 34, and exchanging the heat between a refrigerant between the heat radiator 32 and the main throttling device 33 and a refrigerant between the evaporator 34 and the compressor 31, an opening/closing valve 39 or a sub-throttling device mounted between the auxiliary heat exchanger 38 and the compressor 31, and a connecting part 40 for connecting the evaporator 34 and the compressor 31 in a state of bypassing the auxiliary heat exchanger 38. Thus the heat exchanging quantity in the auxiliary heat exchanger 38 can be increased and decreased, the discharge pressure and a discharge temperature of the compressor 31 can be controlled, and the operation of high efficiency appropriate for the temperature of produced hot water can be performed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a heat pump hot water supply apparatus.

  Conventionally, this type of heat pump hot water supply apparatus is shown in FIG. FIG. 3 is a cycle configuration diagram of a conventional heat pump water heater. In FIG. 3, a refrigerant circulation circuit comprising a compressor 1, a hot water supply heat exchanger 2, an expansion device 3 and an evaporator 4, a hot water storage tank 5, a circulation pump 6, the hot water supply heat exchanger 2 and an auxiliary heater 19 are provided. The high-temperature and high-pressure superheated gas refrigerant discharged from the compressor 1 flows into the hot water supply heat exchanger 2 and heats the hot water supplied from the circulation pump 6.

The condensed and liquefied refrigerant is decompressed by the expansion device 3 and flows into the evaporator 4, where it absorbs atmospheric heat to evaporate and returns to the compressor 1. On the other hand, the hot water heated by the hot water supply heat exchanger 2 flows into the upper part of the hot water storage tank 5 and is gradually stored from above. When the inlet water temperature of the hot water supply heat exchanger 2 reaches a set value, the water temperature detector 20 detects it, stops the heat pump operation by the compressor 1, and switches to the independent operation of the auxiliary heater 19. Yes (see, for example, Patent Document 1).
JP 60-164157 A

  However, in the conventional configuration as described above, a hot water mixed layer is formed at the portion where the hot water in the hot water tank 5 is in contact with water as the boiling operation time elapses, and the layer gradually expands. This occurs due to heat conduction and convection in high temperature hot water and low temperature water. Heat is transferred from the high temperature hot water to the low temperature water, and the temperature of the high temperature hot water decreases at the boundary portion, while the temperature of the low temperature water increases. Accordingly, when the boiling operation is nearly completed, the temperature of the water flowing into the hot water supply heat exchanger 2 becomes high, so that the discharge pressure of the compressor 1 rises and the durability of the compressor 1 becomes a problem.

  Therefore, since the operation was stopped in a state where the temperature of the water flowing into the hot water supply heat exchanger was low, the operation was stopped with the lower part of the hot water tank 5 being in a state of low temperature water, and the hot water in the hot water tank 5 was The capacity could not be used effectively, so the amount of hot water stored was decreasing. In addition, in order to increase the amount of stored hot water, after stopping the heat pump operation, when the amount of stored hot water is increased by the independent operation of the auxiliary heater 19, heating is performed by an electric heater, so that power consumption increases and efficiency decreases. It was.

  Furthermore, when the outside air temperature is high, in order to keep the hot water supply water temperature high, it is necessary to keep the discharge temperature of the compressor 1 high. However, since the outside air temperature is high, the evaporation temperature rises, and the compressor Since the compression ratio of 1 was small and the discharge temperature did not rise, a high hot water supply water temperature could not be obtained. In this case, conventionally, the opening of the expansion device is reduced to make it difficult for the refrigerant to flow, the discharge pressure of the compressor is increased, the suction pressure is decreased to increase the compression ratio, and the discharge temperature is increased. As a result, the operation was inefficient.

  The present invention solves the above-described conventional problems, and does not increase the discharge pressure of the compressor, stores hot water to the lower part of the hot water tank with high efficiency, and can effectively use the capacity of the hot water tank. An object of the present invention is to provide a heat pump hot water supply apparatus that can generate a hot water supply water temperature with high efficiency and high temperature even at high outside temperatures.

  In order to solve the conventional problems, a heat pump water heater of the present invention includes a refrigerant circuit in which at least a compressor, a radiator, a main throttle device, and an evaporator are sequentially connected, and the refrigerant circuit includes the radiator and the radiator. An auxiliary heat exchanger for exchanging heat between the refrigerant between the main expansion devices and the refrigerant between the evaporator and the compressor, and between the evaporator and the auxiliary heat exchanger, or the auxiliary heat exchanger And an on-off valve or a sub-throttle device, and a connecting portion for connecting the evaporator and the compressor so as to bypass the auxiliary heat exchanger. The amount of heat exchange in the auxiliary heat exchanger can be increased or decreased, and the discharge pressure and discharge temperature of the compressor can be controlled to enable highly efficient operation suitable for the temperature of hot water to be generated.

  According to the present invention, there is no increase in the discharge pressure of the compressor, high-temperature hot water is stored at the lower part of the hot water tank with high efficiency, and the capacity of the hot water tank can be effectively used. It is possible to provide a heat pump hot water supply apparatus that can efficiently generate a hot water supply water temperature.

  A first invention includes a refrigerant circuit in which at least a compressor, a radiator, a main throttle device, and an evaporator are sequentially connected, and the refrigerant circuit includes a refrigerant between the radiator and the main throttle device, and the evaporator. An auxiliary heat exchanger for exchanging heat with the refrigerant between the compressors, an on-off valve or an auxiliary valve between the evaporator and the auxiliary heat exchanger, or between the auxiliary heat exchanger and the compressor. A throttling device and a connecting portion for connecting the evaporator and the compressor so as to bypass the auxiliary heat exchanger are provided, and the amount of heat exchange in the auxiliary heat exchanger is It is possible to increase / decrease, control the refrigerant dryness at the inlet of the evaporator and the compressor intake gas temperature, and control the discharge pressure and discharge temperature of the compressor, thereby enabling highly efficient operation.

  A second aspect of the invention includes a hot water supply circuit in which at least a hot water storage tank and a radiator are sequentially connected, an incoming water temperature sensor that detects the temperature of hot water flowing into the radiator from the hot water storage tank, and detection of the incoming water temperature sensor And a control device that controls the opening / closing of the on-off valve or the opening of the sub-throttle device by comparing the temperature with a preset water-in temperature value. Accordingly, the amount of heat exchange in the auxiliary heat exchanger can be increased or decreased, and it is possible to control the discharge pressure and discharge temperature of the compressor by controlling the refrigerant dryness at the evaporator inlet and the compressor intake gas temperature. Thus, high-efficiency operation suitable for the temperature of the hot water to be generated becomes possible.

  In addition, even when the incoming water temperature rises near the completion of the boiling operation, the hot water supply can be easily heated to a high temperature while reducing the discharge pressure and discharge temperature of the compressor, making the heat pump safe. And it can be operated with high efficiency. Moreover, hot water can be stored up to the bottom of the hot water tank, and the capacity of the hot water tank can be used effectively.

  In the third aspect of the invention, the control device compares the detected temperature of the incoming water temperature sensor with a preset incoming water temperature value, and the detected temperature of the incoming water temperature sensor is higher than the preset incoming water temperature value. In addition, the on-off valve is opened or the opening degree of the sub-throttle device is increased, and the intake gas refrigerant circulation flowing into the auxiliary heat exchanger when the incoming water temperature is high and high-temperature hot water supply is required The amount of heat exchange can be increased by increasing the amount, the degree of dryness at the inlet of the evaporator can be lowered, the amount of refrigerant held there can be increased, and hot water can be generated with high efficiency while keeping the discharge pressure of the compressor low. be able to.

According to a fourth aspect of the present invention, a refrigerant temperature sensor for detecting a refrigerant temperature at a radiator outlet is compared with a detection temperature of the refrigerant temperature sensor and a preset refrigerant temperature value, and the opening / closing of the on-off valve or the sub-throttle And a control device for controlling the opening degree of the device, wherein the amount of heat exchange in the auxiliary heat exchanger can be increased / decreased according to the refrigerant temperature at the radiator outlet, and the refrigerant at the evaporator inlet It is possible to control the discharge pressure and the discharge temperature of the compressor by controlling the dryness and the compressor intake gas temperature, and it is possible to perform a highly efficient operation suitable for the temperature of the hot water to be generated.

  In addition, even when the incoming water temperature rises near the completion of the boiling operation, the hot water supply can be easily heated to a high temperature while reducing the discharge pressure and discharge temperature of the compressor, making the heat pump safe. And it can be operated with high efficiency. Moreover, hot water can be stored up to the bottom of the hot water tank, and the capacity of the hot water tank can be used effectively.

  The fifth invention is characterized in that the control device opens the on-off valve or increases the opening of the sub-throttle device when the temperature detected by the refrigerant temperature sensor is higher than a preset refrigerant temperature value. Therefore, when the incoming water temperature is high and high-temperature hot water supply is required, the amount of refrigerant circulating into the auxiliary heat exchanger can be increased to increase the heat exchange amount, and the dryness of the evaporator inlet can be lowered. Thus, the refrigerant hold amount can be increased, and high-temperature hot water supply can be generated with high efficiency while keeping the discharge pressure of the compressor low.

  According to a sixth aspect of the present invention, a discharge temperature sensor for detecting a refrigerant temperature discharged from a compressor is compared with a detection temperature of the discharge temperature sensor and a preset discharge temperature value, and the opening / closing of the on-off valve or the A control device for controlling the opening degree of the sub-throttle device, and opening / closing the on-off valve or increasing / decreasing the opening degree of the sub-throttle device, The amount of heat exchange can be controlled, and it becomes possible to control the discharge temperature suitable for the hot water supply temperature.

  The seventh invention is characterized in that the control device opens the on-off valve or increases the opening of the sub-throttle device when the detected temperature of the discharge temperature sensor is lower than a preset discharge temperature value. Therefore, when the outside air temperature is high and high temperature hot water supply is required, the heat exchange amount in the auxiliary heat exchanger can be increased, and the discharge temperature can be increased by increasing the suction temperature of the compressor. The operation suitable for hot water supply becomes possible.

  The eighth aspect of the invention uses carbon dioxide as a refrigerant, and realizes high temperature of hot water supply with high efficiency, and even when the refrigerant leaks to the outside, the influence on global warming is very small. .

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments. In each embodiment, portions having the same configuration and the same operation are denoted by the same reference numerals, and detailed description thereof is omitted.

(Embodiment 1)
FIG. 1 shows a configuration diagram of a heat pump hot water supply apparatus and a control method thereof according to the first embodiment of the present invention.

  In FIG. 1, a compressor 31, a radiator 32, a main throttle device 33, and an evaporator 34 are sequentially connected in an annular form, and carbon dioxide gas is sealed as a refrigerant to form a refrigerant circulation circuit. The evaporator 34 blows outside air. Fan 35 is provided. Further, a hot water supply circuit in which the hot water tank 36, the circulation pump 37, and the radiator 32 are connected in order is formed, and the high-temperature and high-pressure superheated gas refrigerant discharged from the compressor 31 flows into the radiator 32, where the circulation pump The hot water supplied from 37 is heated. Furthermore, the piping between the radiator 32 and the main throttle device 33 and the piping between the evaporator 34 and the compressor 31 are indirectly heat-exchanged via an auxiliary heat exchanger 38. Further, an open / close valve 39 is provided between the evaporator 34 and the auxiliary heat exchanger 38, and a pipe 40 that directly connects the evaporator 34 and the compressor 31 is provided so as to bypass the auxiliary heat exchanger 38. It has been.

Furthermore, an incoming water temperature sensor 41 that detects the incoming temperature of hot water flowing into the radiator 32 from the circulation pump 37 and a control device 42 that detects the temperature and controls the opening and closing of the on-off valve 37 are provided. The control device 42 compares the temperature of the incoming water temperature sensor 41 with a preset temperature and controls to open the on-off valve 39 when the incoming water temperature is higher than the set temperature. Further, carbon dioxide gas is sealed as the refrigerant.

  About the heat pump hot water supply apparatus comprised as mentioned above and its control method, the operation | movement and an effect | action are demonstrated below.

  The refrigerant (carbon dioxide gas) compressed to a supercritical state of high temperature and high pressure by the compressor 31 exchanges heat with water flowing in the hot water supply circuit by the radiator 32 and becomes a medium temperature and high pressure refrigerant and passes through the auxiliary heat exchanger 38. Then, after being decompressed by the main throttle device 33, it flows into the evaporator 34, where it exchanges heat with the outside air blown by the fan 35, thereby evaporating gas.

  In normal cases, the incoming temperature of the hot water supplied by the circulation pump 37 is low, and in this case, the on-off valve 39 is closed. Therefore, the refrigerant is operated in a normal heat pump cycle in which all the refrigerant passes through the pipe 40 and returns to the compressor 31 without passing through the auxiliary heat exchanger 38.

  On the other hand, the hot water supplied by the circulation pump 37 is heated by the radiator 32, and the generated hot water flows into the upper part of the hot water storage tank 36 and is gradually stored from above.

  On the other hand, as the boiling operation time elapses, a hot water mixed layer is formed at a portion where the hot water in the hot water storage tank 36 is in contact with water, and the layer expands to the lower part of the hot water storage tank 36. The temperature of the water flowing into the radiator 32 from the lower part through the circulation pump 37 becomes higher. In this case, when the incoming water temperature detected by the incoming water temperature sensor 41 rises above the temperature preset in the control device 42, the on-off valve 39 is operated in the opening direction. In this way, a part of the relatively low temperature refrigerant that has left the evaporator 34 flows into the auxiliary heat exchanger 38 through the on-off valve 39.

  On the other hand, the high-temperature and high-pressure refrigerant discharged from the compressor 31 exchanges heat with high-temperature hot water in the radiator 32 and then flows into the auxiliary heat exchanger 38 where the relatively low-temperature refrigerant discharged from the evaporator 34 is discharged. By exchanging heat with a part of the refrigerant, its temperature decreases and enthalpy decreases.

  Thus, when the incoming water temperature is high, in the case of a normal heat pump cycle, the outlet temperature of the radiator 32 also rises, and the refrigerant hold amount of the radiator 32 and the evaporator 34 decreases, so the high pressure tends to rise. As in the present invention, the auxiliary heat exchanger 38 exchanges heat with the low-temperature refrigerant exiting the evaporator 34 and cools the refrigerant exiting the radiator 32, thereby reducing the refrigerant enthalpy and increasing its density. In addition, since the dryness at the inlet of the evaporator 34 is reduced and the refrigerant hold of the evaporator 34 is increased, the heat pump cycle can be safely operated without increasing the high pressure. Therefore, since continuous operation can be performed even when the incoming water temperature becomes high, hot water can be stored up to the lower part of the hot water tank 36, and the capacity of the hot water tank 36 can be effectively used.

  Moreover, by opening the on-off valve 39, the refrigerant passage area from the evaporator 34 to the compressor 31 is expanded, the pressure loss therebetween is reduced, the suction pressure of the compressor 31 is increased, and the compressor 31 The compression ratio is reduced and the compression power is reduced, so that highly efficient operation is possible.

On the other hand, when the incoming water temperature detected by the incoming water temperature sensor 41 is lower than the temperature preset in the control device 42, the on-off valve 39 is operated in the closing direction. By doing so, the refrigerant that has left the evaporator 34 does not flow to the auxiliary heat exchanger 38 through the on-off valve 39, but is all sucked into the compressor 31 through the pipe 39 in a normal high-efficiency heat pump cycle. Driven. In the normal operation where the incoming water temperature is low, when the on-off valve 39 is operated while being opened, the intake gas temperature of the compressor 31 is not in an optimal state, and therefore the incoming water temperature is high as in the present invention. It is desirable to open the on-off valve 39. ,
Further, the on-off valve 39 has the same effect as a sub-throttle device. In this case, when the incoming water temperature detected by the incoming water temperature sensor 41 is higher than the temperature preset in the control device 42, Operate in a direction to increase (open) the opening of the sub-throttle device. In this way, similarly, a part of the relatively low temperature refrigerant that has left the evaporator 34 flows into the auxiliary heat exchanger 38 through the sub-throttle device, and even if the incoming water temperature increases due to the same action, Safe and efficient operation is possible.

Here, the auxiliary heat exchanger 38 may have a configuration in which a tube and a tube are brazed, a configuration of a double tube, and the like, which are all included in the present invention.
Moreover, even if the on-off valve 39 is provided between the auxiliary heat exchanger 38 and the compressor 31, it has the same effect, and these are also included in the present invention.

  Furthermore, instead of the incoming water temperature sensor 41, the outlet refrigerant temperature of the radiator 32 may be used. That is, when the incoming water temperature is high, the radiator outlet refrigerant temperature is also high, and the tendency of temperature rise and fall is the same, and these are also included in the present invention.

(Embodiment 2)
FIG. 2 shows a configuration diagram of a heat pump hot-water supply apparatus in the second embodiment of the present invention. In FIG. 2, components having the same functions as those in FIG. 1 shown in the first embodiment have the same numbers.

  In the present embodiment, a discharge temperature sensor 51 that detects the discharge gas temperature of the compressor 31 and a control device 53 that detects the temperature and controls the opening degree of the sub-throttle device 52 are provided. The control device 53 compares the temperature of the discharge temperature sensor 51 with a preset discharge temperature and controls to increase the opening of the sub-throttle device 52 when the discharge temperature is lower than the set temperature. . Further, carbon dioxide gas is sealed as the refrigerant.

  About the heat pump hot-water supply apparatus comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  The refrigerant (carbon dioxide gas) compressed to a supercritical state of high temperature and high pressure by the compressor 31 exchanges heat with water flowing in the hot water supply circuit by the radiator 32 and becomes a medium temperature and high pressure refrigerant and passes through the auxiliary heat exchanger 38. Then, after being decompressed by the main throttle device 33, it flows into the evaporator 34, where it exchanges heat with the outside air blown by the fan 35, thereby evaporating gas.

  When the outside air temperature is relatively low, since the evaporation temperature in the evaporator 34 is also low, the suction pressure of the compressor 31 is reduced, and the compression ratio in the compressor 31 can be increased, so that the discharge temperature of the compressor 31 is increased. High temperature hot water supply can be easily generated.

  On the other hand, when the outside air temperature is high, the evaporation temperature in the evaporator 34 also increases, so the suction pressure of the compressor 31 increases and the compression ratio in the compressor 31 decreases, so the discharge temperature of the compressor 31 Cannot be made high, and hot water cannot be generated. Therefore, conventionally, the opening of the main throttle device 33 is further reduced to make it difficult for the refrigerant to flow, the discharge pressure of the compressor 31 is increased, the suction pressure is decreased, the compression ratio is increased, and the discharge temperature is increased. I was letting.

  In the present invention, the temperature of the discharge temperature sensor 51 is compared with a preset discharge temperature, and when the discharge temperature is lower than the set temperature, control is performed so that the opening degree of the sub-throttle device 52 is increased. By doing so, a part of the relatively low-temperature refrigerant that has left the evaporator 34 flows into the auxiliary heat exchanger 38 through the on-off valve 39.

  On the other hand, the high-temperature and high-pressure refrigerant discharged from the compressor 31 exchanges heat with hot water in the radiator 32 and then flows into the auxiliary heat exchanger 38 where the relatively low-temperature refrigerant discharged from the evaporator 34 Heat is exchanged with a part of the refrigerant, and the temperature of the refrigerant that has left the evaporator 34 is raised. By doing so, the opening temperature of the main throttle device 33 can be reduced, the discharge pressure of the compressor 31 can be increased, and the discharge temperature can be increased without decreasing the suction pressure and increasing the compression ratio. Hot water can be generated at high efficiency. Therefore, even when the outside air temperature is high, hot water can be easily heated to a high temperature, the heat pump can be operated safely and with high efficiency, and the capacity of the hot water tank can be effectively used.

  Further, by opening the sub-throttle device 52, the refrigerant passage area from the evaporator 34 to the compressor 31 is expanded, the pressure loss therebetween is reduced, the suction pressure of the compressor 31 is increased, and the compressor 31 is increased. Since the compression ratio is further reduced and the compression power is reduced, high-efficiency operation is possible.

  On the other hand, the temperature of the discharge temperature sensor 51 is compared with a preset discharge temperature, and when the discharge temperature is higher than the set temperature, the opening of the sub-throttle device 52 is controlled to be small. By doing so, the refrigerant that has left the evaporator 34 does not flow to the auxiliary heat exchanger 38 through the open / close valve 39, and most of the refrigerant is sucked into the compressor 31 through the pipe 39. The temperature does not increase excessively and is operated with a normal high-efficiency heat pump cycle.

  The sub-throttle device 39 has the same effect as an on-off valve. In this case, the discharge temperature sensor 51 is compared with a preset discharge temperature, and the discharge temperature is lower than the set temperature. Control to open the on-off valve. By doing so, the opening temperature of the main throttle device 33 can be reduced, the discharge pressure of the compressor 31 can be increased, and the discharge temperature can be increased without decreasing the suction pressure and increasing the compression ratio. Hot water can be generated at high efficiency.

  Here, the auxiliary heat exchanger 38 may have a configuration in which a tube and a tube are brazed, a configuration of a double tube, and the like, which are all included in the present invention. Further, even if the sub-throttle device 52 is provided between the auxiliary heat exchanger 38 and the compressor 31, it has the same effect, and these are also included in the present invention.

  As described above, the heat pump hot water supply apparatus according to the present invention can easily heat the hot water supply to a high temperature while reducing the discharge pressure of the compressor of the refrigerant circuit. It is useful for an air conditioner that obtains high temperature air.

The block diagram of the heat pump hot-water supply apparatus in Embodiment 1 of this invention The block diagram of the heat pump hot-water supply apparatus in Embodiment 2 of this invention Configuration diagram of conventional heat pump water heater

Explanation of symbols

DESCRIPTION OF SYMBOLS 31 Compressor 32 Radiator 33 Main throttle device 34 Evaporator 35 Fan 36 Hot water storage tank 37 Circulation pump 38 Auxiliary heat exchanger 39 On-off valve 40 Piping 41 Water inlet temperature sensor 42, 53 Control device 51 Discharge temperature sensor 52 Sub throttle device

Claims (8)

A refrigerant circuit in which at least a compressor, a radiator, a main throttle device, and an evaporator are sequentially connected; and the refrigerant circuit includes a refrigerant between the radiator and the main throttle device, and between the evaporator and the compressor. An auxiliary heat exchanger for exchanging heat with the refrigerant, an on-off valve or a sub-throttle device between the evaporator and the auxiliary heat exchanger, or between the auxiliary heat exchanger and the compressor, and the auxiliary A heat pump hot water supply apparatus comprising a connecting portion for connecting the evaporator and the compressor so as to bypass the heat exchanger. At least a hot water storage circuit including a hot water storage tank and a radiator connected in sequence, a water temperature sensor for detecting the temperature of hot water flowing into the radiator from the hot water storage tank, and a detection temperature of the water temperature sensor are set in advance. The heat pump hot-water supply device according to claim 1, further comprising a control device that controls the opening / closing of the on-off valve or the opening of the sub-throttle device by comparing with an incoming water temperature value. The control device compares the detected temperature of the incoming water temperature sensor with a preset incoming water temperature value, and when the detected temperature of the incoming water temperature sensor is higher than the preset incoming water temperature value, 3. The heat pump hot water supply apparatus according to claim 2, wherein the opening of the opening or the sub-throttle device is increased. The refrigerant temperature sensor for detecting the refrigerant temperature at the outlet of the radiator and the detected temperature of the refrigerant temperature sensor and a preset refrigerant temperature value are compared to control the opening / closing of the on-off valve or the opening of the sub-throttle device The heat pump hot-water supply apparatus of Claim 1 provided with the control apparatus which performs. 5. The control device according to claim 4, wherein when the detected temperature of the refrigerant temperature sensor is higher than a preset refrigerant temperature value, the control device opens the on-off valve or increases the opening of the sub-throttle device. Heat pump water heater. Comparing the discharge temperature sensor for detecting the refrigerant temperature discharged from the compressor with the detected temperature of the discharge temperature sensor and a preset discharge temperature value, the opening / closing of the on-off valve or the opening of the sub-throttle device The heat pump hot-water supply apparatus of Claim 1 provided with the control apparatus which controls this. 7. The control device according to claim 6, wherein when the detected temperature of the discharge temperature sensor is lower than a preset discharge temperature value, the control valve opens the opening / closing valve or increases the opening of the sub-throttle device. Heat pump water heater. The heat pump hot water supply device according to any one of claims 1 to 7, wherein carbon dioxide gas is used as the refrigerant.

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