JP5034601B2 - Heat pump water heater - Google Patents

Description

  The present invention relates to a hot water storage type heat pump water heater having a bath reheating function and a heating function.

  Conventionally, as this type of heat pump water heater, there is one having a bathtub reheating function using hot water in a hot water tank (see, for example, Patent Document 1).

  FIG. 7 is a configuration diagram of a conventional heat pump water heater described in Patent Document 1.

  In FIG. 7, a conventional heat pump water heater includes a compressor 1, a heat pump unit 4 including a hot water supply heat exchanger 2 and an evaporator 3 that are refrigerant-to-water heat exchangers, a hot water tank 5, and water-to-water heat exchange. And a hot water supply unit 7 provided with a bath heat exchanger 6 and the like. The hot water storage tank 5 stores hot water heated by the heat pump unit 4 using the hot water supply heat exchanger 2.

The bath heat exchanger 6 circulates the hot water in the hot water storage tank 5 to heat the hot water in the bathtub 8. That is, the hot water pumped out from the upper part of the hot water storage tank 5 by the heat source side circulation pump 9 is led to the bath heat exchanger 6 to heat the hot water or water in the bathtub 8 pumped out by the use side circulation pump 10. After that, the hot water tank 5 is returned to. Moreover, the hot water of the hot water storage tank 5 is poured into the bathtub 8 through the bathtub pouring pipe 11, and further, the hot water can be supplied by opening the faucet 12.
JP 2002-243275 A

  However, the configuration of the conventional heat pump water heater has the following problems.

  In many cases, the temperature of the bathtub 8 is about 40 ° C. when the bath is reheated, so that it is pumped from the upper part of the hot water tank 5 by the heat source side circulation pump 9 and led to the bath heat exchanger 6. The temperature when returning to the hot water tank 5 after heating the hot water in the bathtub 8 pumped out by the use side circulation pump 10 is around 50 ° C. The hot water returned to the hot water tank 5 is mixed with the hot water in the hot water tank 5, but the temperature of the hot water mixed differs depending on the hot water temperature at the return position of the hot water tank 5.

  In general, in the case of a heat storage type heat pump water heater, the entire hot water tank 5 is heated to a set temperature in the late-night time period (for example, from 23:00 to 7:00 of the next morning), which is a time period when electricity charges are low. .

  At this time, the low-temperature water sent from the lower part of the hot water tank 5 is heated by the hot water supply heat exchanger 2 to become high-temperature water, and is stored from above the hot water tank 5. The boundary between the hot water stored in the hot water and the original low-temperature water is not divided as a clear temperature layer, but there is a mixed layer that changes from high temperature to low temperature. For this reason, if the boiling operation which raises the whole hot water storage tank 5 to the set temperature is brought close to the completion of the boiling, this mixed layer will be heated. In this case, the characteristics of the heat pump vary greatly depending on the inlet water temperature of the hot water supply heat exchanger 2.

  In other words, the higher the inlet water temperature, the higher the discharge pressure of the compressor 1, and accordingly, the operating efficiency is deteriorated and the amount of power consumed is increased. Further, when the inlet water temperature becomes high, the discharge pressure rapidly increases. Therefore, in order to ensure the reliability of the compressor 1, the boiling operation is terminated when the inlet water temperature reaches a predetermined temperature. For example, in the winter season, since the hot water supply load is large, the hot water storage tank 5 is boiled to 80 ° C. to 90 ° C., but if the inlet temperature of the hot water supply heat exchanger 2 reaches 60 ° C., the operation is stopped because the whole amount has boiled. And the hot water stored in the middle of the night covers the daytime hot water supply load.

  If the hot water returned to the hot water tank 5 after heating the hot water in the bathtub 8 and the hot water in the hot water tank 5 are mixed, the temperature of the hot water is not less than the predetermined temperature (for example, 60 ° C.). The hot water will not be boiled up again. Therefore, the part of the mixed layer produced by the heating of the bathtub 8 is set so that the temperature of the whole hot water tank 5 is heated to the set temperature (about 80 ° C to 90 ° C in winter) in the middle of the night. There is a case where the boiling is completed as it is without being heated to the heated temperature. As described above, when almost the entire hot water tank 5 is not heated to a high temperature, it cannot cope with the hot water supply load in the daytime, and there is a problem in comfort and convenience due to running out of hot water.

  On the other hand, if the temperature of the hot water returned to the hot water tank 5 after heating the hot water in the bathtub 8 and the hot water mixed with the hot water of the hot water tank 5 is equal to or lower than the predetermined temperature (for example, 60 ° C.). The hot water is again boiled to a high temperature. However, since the water temperature returned to the hot water tank 5 by heating the water sent from the bathtub 8 is originally high, it is mixed with the hot water in the hot water tank 5 to raise the temperature of the hot water tank 5, which is below 60 ° C. However, there may be a relatively high temperature. In this case, as described above, there is a problem that the efficiency of the boiling operation is extremely deteriorated.

  The present invention solves the above-mentioned problem, and when there is a hot water supply request and a bath heating request at the same time, part or all of the hot water from the upper part of the hot water tank radiated by the bath heat exchanger is not returned to the hot water tank. It is an object of the present invention to provide a heat pump water heater that is used for direct hot water supply to improve the comfort and convenience by reducing the possibility of running out of hot water and to improve the operation efficiency.

In order to solve the above-described conventional problems, the heat pump water heater of the present invention includes a compressor, a hot water heater provided with a hot water heat exchanger, a hot water storage tank for storing hot water heated by the hot water heat exchanger, middle and hot water pipe connected to the upper portion of the hot water storage tank, one intermediate hot water pipe connected to an intermediate portion of the hot water tank, a water supply pipe connected to the lower portion of the hot water storage tank, the bath heat exchanger A bath heat exchanger forward pipe and a bath heat exchanger return pipe for connecting the upper part of the hot water tank and the lower part of the hot water tank, respectively, and using the hot water at the upper part of the hot water tank as a heat source. Bath heating means for heating hot water in the bathtub through an exchanger, flow rate control means for controlling the heat source flow rate circulating through the bath heating means, hot water supply temperature setting means for setting hot water supply temperature, the hot water pipe and the intermediate Mixing hot water from the hot water pipe and the water supply pipe Together with the a plurality of mixing valves adjusted to be hot water temperature set by the hot water supply temperature setting means, for connecting the other end of the bath heat exchanger return tube in the middle of the one of the intermediate tapping tube Te When there is a hot water supply request and a bath heating request at the same time, a part or all of the hot water from the upper part of the hot water tank radiated by the bath heat exchanger is directly used for hot water supply. It is possible to improve the comfort and convenience by reducing the possibility of running out of hot water, and the operation of the hot water generated by mixing the hot water from the bath heat exchanger and the hot water in the hot water tank is reduced. Efficiency can be improved.

  The heat pump water heater of the present invention can be directly used for hot water supply without returning to the hot water tank part or all of the hot water from the upper part of the hot water tank radiated by the bath heat exchanger when there is a hot water supply request and a bath heating request at the same time. Therefore, the possibility of running out of hot water is reduced to improve comfort and convenience, and the mixing ratio of hot water in the hot water tank and hot water returning from the bath heat exchanger is reduced, thus improving the operating efficiency. Can be planned.

1st invention is a hot water supply heating means provided with the compressor and the hot water supply heat exchanger, the hot water storage tank which stores the hot water heated with the said hot water supply heat exchanger, and the hot water pipe connected to the upper part of the said hot water storage tank, An intermediate hot water pipe connected to the intermediate part of the hot water tank, a water supply pipe connected to the lower part of the hot water tank, and a bath heat exchanger provided on the way from the upper part and the upper part of the hot water tank. A bath that has a bath heat exchanger forward pipe and a bath heat exchanger return pipe for connecting the lower part to the lower part, and uses the hot water in the upper part of the hot water tank as a heat source to heat the hot water in the bathtub through the bath heat exchanger. Mixing the heating means, the flow rate control means for controlling the flow rate of the heat source circulating through the bath heating means, the hot water supply temperature setting means for setting the hot water supply temperature, the hot water pipe, the intermediate hot water pipe, and hot water from the water supply pipe. To the hot water temperature set by the hot water temperature setting means. And a plurality of mixing valves to be adjusted to, with the other end is connected to the bath heat exchanger return tube in the middle of the one of the intermediate tapping tube, when the hot water supply request and the bath heating request had simultaneously, A part or all of the hot water from the upper part of the hot water tank radiated by the bath heat exchanger is directly used for hot water supply, and since the hot water can be used effectively, the possibility of running out of hot water is reduced and comfort is provided. Therefore, it is possible to improve the operation efficiency since the production of the intermediate warm water by mixing the intermediate warm water returning from the bath heat exchanger and the hot water in the hot water tank is reduced.

In addition, if there is a request for hot water supply and a request for bath heating at the same time, a part of or all of the hot water from the upper part of the hot water tank radiated by the bath heat exchanger can be directly used for hot water supply. It is possible to reduce the weight, size and reliability of the device.

In particular, the second invention is different in the connecting portion between the bath heat exchanger return pipe and the hot water tank connected to the bath heat exchanger of the first invention, and the connecting portion between the intermediate hot water pipe and the hot water tank. A bypass pipe for connecting the intermediate hot water pipe and the bath heat exchanger return pipe, and a hot water path in the upper part of the hot water storage tank where heat is exchanged by the bath heat exchanger, Switching means for selecting and switching between the exchanger return pipe and the hot water tank side, and a return position to the hot water tank during bath heating and a take-out position from the hot water tank during intermediate hot water Are independent of each other, so that efficient intermediate hot water and bath heating can be performed, and hot water from the upper part of the hot water tank radiated by the bath heat exchanger is stored when there is a hot water supply request and a bath heating request at the same time. Comfortable because it is used in the hot water supply terminal without returning to the tank And the improvement of convenience, and it is possible to improve the operating efficiency.

The third aspect of the invention is a switching means so that the hot water in the upper part of the hot water tank that has been heat-exchanged by the bath heat exchanger flows to the intermediate hot water discharge pipe side, particularly when the hot water supply request and the bath heating request of the second invention are simultaneously provided. When there is a hot water supply request and a bath heating request at the same time, hot water from the upper part of the hot water tank radiated by the bath heat exchanger is used by flowing it to the hot water supply terminal without returning it to the hot water tank, so it is possible to run out of hot water. And greatly improved comfort and convenience, and the medium hot water returning from the bath heat exchanger and the hot water in the hot water tank are mixed to reduce the production of hot water, thus greatly improving the operation efficiency. Can be achieved.

In particular, the fourth invention relates to an intermediate mixing valve that mixes hot water from the intermediate hot water pipe and hot water from the hot water pipe of any one of the first to third inventions, and hot water and a water supply pipe from the intermediate mixing valve. If there is a hot water supply request and a bath heating request at the same time, part or all of the hot water from the upper part of the hot water tank radiated by the bath heat exchanger is stored. Since it is possible to have a flow path configuration leading to the hot water supply terminal without returning to the tank, the hot water can be effectively used with a simple configuration.

The fifth aspect of the invention is a heat source side circulation pump that is provided on the heat source side of the bath heat exchanger and circulates the hot water in the hot water tank, particularly as the flow rate control means of any one of the first to fourth aspects of the invention. Part of the hot water from the upper part of the hot water tank radiated by the bath heat exchanger, even when there is a hot water supply request and a bath heating request at the same time, using a flow control valve provided on the heat source side of the heat exchanger Alternatively, it is possible to perform stable and reliable bath heating while effectively using hot water by flowing it to a hot water supply terminal without returning it all to the hot water tank.

In the sixth invention, in particular, when the hot water supply request and the bath heating request according to any one of the first to fifth inventions are simultaneously provided, the hot water in the upper part of the hot water storage tank heat-exchanged by the bath heat exchanger is connected to the intermediate hot water pipe. It is equipped with inflow prevention means that prevents it from passing back to the hot water storage tank, and when there is a hot water supply request and a bath heating request at the same time, all the hot water from the upper part of the hot water tank radiated by the bath heat exchanger is stored in the hot water storage tank. The hot water supply terminal is used instead of returning to the hot water supply terminal, so the possibility of running out of hot water is reduced, the comfort and convenience are greatly improved, and the medium hot water returned from the bath heat exchanger and hot water in the hot water tank are mixed. As a result, the production of medium temperature water is reduced, so that the operating efficiency can be greatly improved.

In the seventh invention, in particular, the target mixing temperature of the intermediate mixing valve of the fourth invention is determined based on the hot water supply set temperature set by the hot water supply temperature setting means and the temperature of the heat source side outlet of the bath heat exchanger. Thus, since a stable hot water supply temperature can be obtained, comfort and convenience can be improved, and driving efficiency can be improved.

In the eighth aspect of the invention, in particular, the target mixing temperature of the intermediate mixing valve of the fourth aspect of the invention is any one of the hot water supply set temperature set by the hot water supply temperature setting means and the heat source side outlet temperature of the bath heat exchanger. The temperature is set higher by a predetermined temperature than the higher temperature, and a stable hot water supply temperature can be obtained. Therefore, comfort and convenience can be improved, and driving efficiency can be improved.

According to a ninth aspect of the invention, in particular, the refrigerant circuit of the heat pump according to any one of the first to eighth aspects is a supercritical refrigerant circuit in which the pressure is equal to or higher than a critical pressure. For example, if carbon dioxide is used as a refrigerant, high efficiency and high environmental conservation can be achieved.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a configuration diagram of a heat pump water heater in the first embodiment of the present invention. In addition, about the same part as the said conventional heat pump water heater, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  In FIG. 1, a hot water supply heating means 13 which is a heat source of a heat pump water heater in the present embodiment constitutes a heat pump cycle including a compressor 1, a hot water supply heat exchanger 2, a decompression device 14, and an evaporator 3 that absorbs atmospheric heat. Heat pump heat source. And the water sent with the circulation pump 15 from the hot water tank 5 is comprised by comprising the boiling circuit which connects the upper part of the circulation pump 15, the hot water supply heat exchanger 2, and the hot water tank 5 from the lower part of the hot water tank 5 sequentially. The hot water supply heat exchanger 2 is heated by the refrigerant heat and is stored from above the hot water storage tank 5.

  Reference numeral 16 denotes boiling temperature detection means, which is provided at the water-side outlet of the hot water supply heat exchanger 2 in order to detect the temperature of the hot water heated by the heat pump heat source. The carbon dioxide whose refrigerant pressure on the high pressure side is equal to or higher than the critical pressure is used as the refrigerant.

  Water supply to the hot water storage tank 5 is made through a water supply pipe 17 connected to the lower part of the hot water storage tank 5, and hot water at the upper part of the hot water storage tank 5 passes through the hot water supply pipe 18 and is mixed with the water supply by the hot water supply mixing valve 19. Thus, the hot water is heated to a predetermined temperature, and then hot water is supplied from the faucet 12 which is one of the hot water supply terminals through the hot water supply pipe 20. The intermediate hot water pipe 21 connected to the intermediate portion of the hot water storage tank 5 is connected to an intermediate mixing valve 22 provided in the middle of the hot water pipe 18.

  The bath heating means 23 includes a bath heat exchanger 6 which is a water / water heat exchanger, a heat source side water circuit 23a and a use side water circuit 23b connected thereto, and a heat source side and use side water circuits 23a and 23b, respectively. The heat source side circulation pump 9 and the use side circulation pump 10 are provided. Further, the heat source side of the bath heat exchanger 6 is connected to the upper part of the hot water tank 5 by the bath heat exchanger forward pipe 24, and the bath heat exchanger return pipe 25 is connected to the lower part of the hot water tank 5 rather than the upper part. And is connected in the middle of the intermediate tap pipe 21.

  Heating of the bathtub 8 is sent from the hot water tank 5 to the bath heat exchanger 6 by the heat source side circulation pump 9 and from the bathtub 8 to the bath heat exchanger 6 by the use side circulation pump 10. This is done by exchanging heat with warm water or hot water.

  Further, the heat source side outlet temperature detecting means 27 for detecting the heat source side outlet temperature is provided at the heat source side outlet of the bath heat exchanger 6, and the use side inlet temperature detection for detecting the respective water temperatures at the inlet and outlet on the use side. Means 28 and utilization side outlet temperature detection means 29 are provided. Here, the heat source side circulation pump 9 is the flow rate control means 30.

  The control means 26, the heat source side circulation pump 9, the use side inlet temperature detection means 28, and the heat source side outlet temperature detection means 27 control the heat source side flow rate in the bath heating means 23, thereby controlling the heat in the bath heat exchanger 6. Control the heating capacity.

  Further, a hot water supply temperature detecting means 31 for detecting the hot water temperature mixed by the hot water supply mixing valve 19 is provided on the outlet side of the hot water supply mixing valve 19, and the intermediate mixing valve 22 is mixed on the outlet side of the intermediate mixing valve 22. An intermediate temperature detecting means 32 for detecting the hot water temperature is provided. Further, a hot water supply temperature setting means 33 for setting a desired hot water supply temperature with a remote controller (not shown) or the like, and a mixing valve control means 34 for controlling operations of the hot water supply mixing valve 19 and the intermediate mixing valve 22 are provided.

  Also, a bath pouring circuit is constituted by a pouring mixing valve 35 that mixes the hot water in the upper part of the hot water tank 5 and the water in the water supply pipe 17 to a predetermined temperature, and a pouring on / off valve 36, and the pouring temperature is detected. The means 37 detects the mixing temperature of the pouring mixing valve 35.

  About the heat pump water heater in this Embodiment comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  In FIG. 1, first, the hot water supply heating mode will be described. If there is a request (not shown) for boiling the hot water storage tank 5, a hot water supply heating operation using atmospheric heat is performed with a heat pump heat source. In this case, the high-temperature and high-pressure refrigerant discharged from the compressor 1 is heated to a hot water supply heat exchanger 2 where heat is exchanged with the water sent from the lower part of the hot water tank 5 to dissipate the heat. The pressure is reduced by the apparatus 14, and heat is absorbed from the atmosphere by the evaporator 3, gasified, and returned to the compressor 1. At this time, the number of revolutions of the circulation pump 15 is controlled so that the outlet water temperature of the hot water supply heat exchanger 2 becomes a predetermined temperature with the high-temperature refrigerant flowing into the hot water supply heat exchanger 2, and the hot water of the predetermined temperature is It flows in from and is stored.

  Next, the single hot water supply mode will be described. When the faucet 12 serving as a hot water supply terminal is opened, the mixing valve control means 34 fully opens the intermediate mixing valve 22 to the hot water tank 5 side (usually, this position is the initial setting position). Then, the hot water mixing valve 19 is opened based on the temperature obtained from the hot water temperature detecting means 31 so that the outlet (mixing) temperature of the hot water mixing valve 19 becomes the hot water temperature setting temperature set by the hot water temperature setting means 33. By controlling the degree, hot water of a predetermined hot water temperature is supplied from the tap 12.

  Further, the intermediate hot water supply mode will be described. When the faucet 12 serving as a hot water supply terminal is opened, the mixing valve control means 34 causes the outlet (mixing) temperature of the intermediate mixing valve 22 to be higher than the hot water supply set temperature set by the hot water supply temperature setting means 33 by a predetermined temperature. Thus, in order to adjust the mixing ratio of the hot water from the upper part of the hot water storage tank 5 and the hot water from the intermediate tap pipe 21, the opening degree of the intermediate mixing valve 22 is based on the temperature obtained from the intermediate temperature detecting means 32. To control. Further, the mixing ratio of hot water from the intermediate mixing valve 22 and water from the water supply pipe 17 is adjusted so that the outlet (mixing) temperature of the hot water supply mixing valve 19 becomes the hot water supply set temperature set by the hot water supply temperature setting means 33. Therefore, hot water having a predetermined hot water temperature is supplied from the faucet 12 by controlling the opening degree of the hot water mixing valve 19 based on the temperature obtained from the hot water temperature detecting means 31.

  Next, the bath pouring mode will be described. When there is a pouring request (not shown) to the bathtub 8 with a remote controller or the like, the pouring on / off valve 36 is opened. Based on the temperature obtained from the pouring temperature detecting means 37 so that the outlet (mixing) temperature of the pouring mixing valve 35 becomes a predetermined pouring temperature set by a remote controller (not shown) or the like. The opening degree of the mixing valve 35 is adjusted.

  Furthermore, the normal single bath heating mode will be described. Now, when there is a bath heating request (not shown), the use-side circulation pump 10 is driven. Then, the control means 26 drives the heat source side circulation pump 9. The water sent from the bathtub 8 by the use side circulation pump 10 is heated by exchanging heat with the hot water in the upper part of the hot water tank 5 sent by the heat source side circulation pump 9 in the bath heat exchanger 6. Return to 8.

  The hot water sent from the hot water storage tank 5 by the heat source side circulation pump 9 exchanges heat with the hot water in the bathtub 8 sent by the use side circulation pump 10 and the hot water stored in the bath heat exchanger 6. Return to tank 5. At this time, the control means 26 controls the flow rate of the heat source side circulation pump 9 in order to efficiently heat the bath with the necessary capacity.

For example, the flow rate of hot water on the heat source side is controlled according to the temperature difference between the heat source side outlet temperature of the bath heat exchanger 6 and the use side inlet temperature of the bath heat exchanger 6. That is, the control means 26 detects the heat source side outlet temperature and the use side inlet temperature of the bath heat exchanger 6 obtained from the heat source side outlet temperature detection means 27 and the use side inlet temperature detection means 28, and the temperature of both of them. The rotational speed of the heat source side circulation pump 9 is controlled so that the difference becomes a predetermined temperature (for example, 5K). By controlling in this way, even if the temperature of the bathtub 8 changes, the return temperature to the hot water tank 5 can be made relatively low, and the bath heating ability can be made relatively large.

  Next, the simultaneous hot water bath heating mode when there is a hot water request and a bath heating request will be described.

  First, when the faucet 12 serving as a hot water supply terminal is opened as a hot water supply request, the mixing valve control unit 34 determines that the outlet (mixing) temperature of the intermediate mixing valve 22 is higher than the hot water set temperature set by the hot water supply temperature setting unit 33. In order to adjust the mixing ratio of the hot water from the upper part of the hot water storage tank 5 and the hot water from the intermediate tap pipe 21 so as to reach a higher temperature, the intermediate mixing is performed based on the temperature obtained from the intermediate temperature detecting means 32. The opening degree of the valve 22 is controlled. Further, the mixing ratio of hot water from the intermediate mixing valve 22 and water from the water supply pipe 17 is adjusted so that the outlet (mixing) temperature of the hot water supply mixing valve 19 becomes the hot water supply set temperature set by the hot water supply temperature setting means 33. Therefore, hot water having a predetermined hot water supply temperature is supplied from the faucet 12 by controlling the opening degree of the hot water supply mixing valve 19 based on the temperature obtained from the hot water supply temperature detection means 31.

  Furthermore, since there is a bath heating request at the same time, the use-side circulation pump 10 is driven as in the single bath heating mode. And the control means 26 adjusts the rotation speed of the heat source side circulation pump 9 according to the temperature difference between the heat source side outlet temperature of the bath heat exchanger 6 and the use side inlet temperature of the bath heat exchanger 6, thereby Control the flow of hot water on the side. At this time, the water sent from the bathtub 8 by the use side circulation pump 10 is heated by exchanging heat with the hot water in the upper part of the hot water tank 5 sent by the heat source side circulation pump 9 in the bath heat exchanger 6. Then return to bathtub 8.

  Then, the hot water sent from the hot water storage tank 5 by the heat source side circulation pump 9 exchanges heat with the hot water in the bathtub 8 sent by the use side circulation pump 10 described above by the bath heat exchanger 6 and intermediate. It reaches the connection point with the tapping pipe 21. Then, as described above, all or a part of the hot water reaching the connection point is sent to the intermediate mixing valve 22 and mixed with the hot water from the upper part of the hot water tank 5, and the hot water supply mixing valve 19 further supplies the water supply pipe 17. The water is mixed with water from the faucet 12 so as to become hot water having a predetermined hot water supply temperature, and hot water is supplied from the tap 12. On the other hand, the remaining hot water that has reached the connection point with the intermediate hot water discharge pipe 21 and did not flow to the intermediate mixing valve 22 side returns to the hot water storage tank 5.

  In the case of the conventional heat pump water heater shown in FIG. 7, all the hot water in the hot water tank 5 used for heating the bath returns to the hot water tank 5 and is mixed with the hot water in the hot water tank 5, and finally heated to a high temperature again. It was. However, in this embodiment, part or all of the hot water in the hot water tank 5 used for bath heating is directly used for hot water supply, so all the amount of heat given to the hot water is used up and the efficiency is greatly improved. To do. In addition, since less hot water returns to the hot water tank 5, it is less likely to mix with the hot water or water in the hot water tank 5 to lower the temperature of hot water or to raise the temperature of cold water or water. It becomes difficult for hot water to run out or decrease in boiling efficiency.

  In the above embodiment, the mixing valve control means 34 is the temperature obtained from the intermediate temperature detection means 32 so that the target mixing temperature is set higher than the hot water supply set temperature set by the hot water supply temperature setting means 33. Based on the above, the opening degree of the intermediate mixing valve 22 is controlled. However, it is more preferable to determine from the hot water supply set temperature set by the hot water supply temperature setting means 33 and the temperature of the heat source side outlet of the bath heat exchanger 6. The hot water of the hot water storage tank 5 used for bath heating can be used effectively.

That is, when the target mixing temperature is lower than the heat source side outlet temperature of the bath heat exchanger 6, the opening of the intermediate mixing valve 22 is fully opened in the direction of the low temperature side inlet. At this time, when the hot water supply flow rate is large, there is a possibility that the flow rate control on the heat source side of the bath heat exchanger 6 cannot be performed, so the target mixing temperature of the intermediate mixing valve 22 is the heat source of the bath heat exchanger 6. It must be set higher than the side outlet temperature. Furthermore, since the hot water mixed by the intermediate mixing valve 22 enters the high temperature side inlet of the hot water supply mixing valve 19, the target mixing temperature of the intermediate mixing valve 22 is higher than the hot water supply set temperature set by the hot water supply temperature setting means 33. There is a need to. Eventually, the target mixing temperature of the intermediate mixing valve 22 is higher by a predetermined temperature than the higher one of the hot water supply set temperature set by the hot water supply temperature setting means 33 and the heat source side outlet temperature of the bath heat exchanger 6. What is necessary is just to set to temperature.

  In addition, when bath heating is performed in the simultaneous hot water bath heating mode, the bathtub temperature rises, the temperature of the hot water returning to the bathtub increases, and the person taking the bath may become uncomfortable. This is a case where the heat source side flow rate of the bath heat exchanger 6 is large and the capacity is excessive. In this case, it is necessary to lower the heat source side flow rate of the bath heat exchanger 6. Therefore, when the use side outlet temperature detection means 29 becomes a predetermined temperature (for example, 60 ° C.) or higher, the mixing valve control means 34 controls to increase the target mixing temperature of the intermediate mixing valve 22. In this way, the opening of the intermediate mixing valve 22 opens in the direction of the high temperature side inlet, and conversely, the low temperature side inlet closes, so that the heat source side flow rate of the bath heat exchanger 6 decreases, and the bath enters the bathtub. Since the temperature of returning hot water is lowered and hot water can be prevented from returning to the bathtub, the comfort can be improved.

  In addition, since the refrigerant used for the heat pump is carbon dioxide, hot water at a high temperature (approximately 90 ° C.) can be stored in the hot water tank 5, so that hot water can be prevented from running out and high efficiency can be achieved. And can protect the global environment.

  In addition, in the said description, it was set as the structure heated by the hot water of the hot water storage tank 5, However, It is applicable not only to bath heating but uses, such as heating using the heat of the hot water storage tank 5, and a bathroom heating dryer.

(Embodiment 2)
FIG. 2 is a configuration diagram of a heat pump water heater in the second embodiment of the present invention. The heat pump water heater in the present embodiment is provided with a flow control valve 38 in the middle of the bath heat exchanger return pipe 25, and the other configuration is the same as the heat pump water heater in the first embodiment. About the same part, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  Here, the heat source side circulation pump 9 and the flow rate control valve 38 form a flow rate control means 30. The control means 26, the heat source side circulation pump 9, the use side inlet temperature detection means 28, the heat source side outlet temperature detection means 27, and the flow rate control valve 38 control the heat source side flow rate in the bath heating means 23. To control the heating capacity in the bath heat exchanger 6.

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

  Note that the hot water supply heating mode, the single hot water supply mode, the intermediate hot water supply mode, the bath pouring mode, and the single bath heating mode are the same as those in the first embodiment, so the description thereof is omitted, and the hot water supply request and the bath heating request are simultaneously performed. The simultaneous hot water bath heating mode will be described.

  In this case, the control of the hot water supply mixing valve 19 is the same as that in the single hot water supply mode. First, the control means 26 sets the flow control valve 38 to an initial opening (for example, fully open). Then, the flow rate of the heat source side circulation pump 9 is controlled. That is, the flow rate of hot water on the heat source side is controlled according to the temperature difference between the heat source side outlet temperature of the bath heat exchanger 6 and the use side inlet temperature of the bath heat exchanger 6.

Furthermore, the mixing valve control means 34 is based on the temperature obtained from the intermediate temperature detection means 32 so that the target mixing temperature is set higher than the hot water supply set temperature set by the hot water supply temperature setting means 33. In addition, the opening degree of the intermediate mixing valve 22 is controlled. However, when the hot water supply flow rate increases, the heat source side flow rate of the bath heat exchanger 6 may not be controlled only by the heat source side circulation pump 9. That is, even if the rotation speed of the heat source side circulation pump 9 is the minimum rotation speed or stopped, the heat source side flow rate becomes too large, and the heat source side outlet temperature of the bath heat exchanger 6 and the use side inlet temperature of the bath heat exchanger 6 This is a case where it becomes impossible to control the temperature difference with the target temperature difference.

  In such a case, the opening degree of the flow control valve 38 is reduced to reduce the flow rate on the heat source side. That is, the control means 26 sets the rotation speed of the heat source side circulation pump 9 so that the temperature difference between the heat source side outlet temperature of the bath heat exchanger 6 and the use side inlet temperature of the bath heat exchanger 6 becomes a target temperature difference. As a result, even if the rotation speed of the heat source side circulation pump 9 is reduced to the minimum rotation speed or stopped, if the temperature difference becomes a predetermined temperature difference larger than the target temperature difference, the opening degree of the flow control valve 38 is increased. By controlling, the temperature difference is controlled to a target temperature difference.

  On the contrary, even if the opening degree of the flow control valve 38 is fully opened, if the temperature difference becomes a predetermined temperature difference smaller than the target temperature difference, the temperature difference is set to the target by the number of rotations of the heat source side circulation pump 9. Control the temperature difference.

  In the above embodiment, the flow control valve 38 is provided in the middle of the bath heat exchanger return pipe 25, but the intermediate hot water upstream of the connection position of the intermediate hot water pipe 21 and the bath heat exchanger return pipe 25. Even if the flow control valve 38 is provided on the pipe 21, the same effect can be obtained.

  In this way, even when the hot water flow rate is large or fluctuates, efficient or stable while improving efficiency by directly or partially using the hot water of the hot water storage tank 5 used for bath heating. Highly reliable bath heating can be realized.

(Embodiment 3)
FIG. 3 is a configuration diagram of a heat pump water heater in the third embodiment of the present invention. The heat pump water heater in the present embodiment prevents the flow in the hot water storage tank 5 in the middle of the intermediate hot water pipe 21 closer to the hot water tank 5 than the connection position between the bath heat exchanger return pipe 25 and the intermediate hot water pipe 21. Since the inflow prevention means 39 is provided and the other configuration is the same as that of the heat pump water heater in the first embodiment, the same portions are denoted by the same reference numerals and the description thereof is omitted.

  About the heat pump water heater in this Embodiment comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  Note that the hot water supply heating mode, the single hot water supply mode, the bath pouring mode, and the single bath heating mode are the same as those in the first embodiment, and the description thereof will be omitted. The intermediate hot water supply mode, the hot water supply request, and the bath heating request are simultaneously performed. The simultaneous hot water bath heating mode will be described.

  First, the intermediate hot water supply mode will be described. In this case, the flow path is opened by the inflow prevention means 39. Since the subsequent operations and actions are the same as those in the first embodiment, description thereof is omitted.

  Next, the simultaneous hot water bath heating mode will be described. In this case, the flow path is closed by the inflow prevention means 39. Then, as in the first embodiment, when the faucet 12 that is a hot water supply terminal is opened as a hot water supply request, the mixing valve control means 34 determines that the outlet (mixing) temperature of the intermediate mixing valve 22 is the hot water supply temperature setting means 33. In order to adjust the mixing ratio of the hot water from the upper part of the hot water storage tank 5 and the hot water from the intermediate hot water pipe 21 so as to be higher by a predetermined temperature than the hot water supply set temperature set in step 1, the intermediate temperature detection means 32 The opening degree of the intermediate mixing valve 22 is controlled based on the temperature obtained from the above.

Further, the mixing ratio of hot water from the intermediate mixing valve 22 and water from the water supply pipe 17 is adjusted so that the outlet (mixing) temperature of the hot water supply mixing valve 19 becomes the hot water supply set temperature set by the hot water supply temperature setting means 33. In order to do this, hot water having a predetermined hot water temperature is supplied from the tap 12 by controlling the opening of the hot water mixing valve 19 based on the temperature obtained from the hot water temperature detector 31. Furthermore, since there is a bath heating request at the same time, the use-side circulation pump 10 is driven as in the single bath heating mode.

  And the control means 26 adjusts the rotation speed of the heat source side circulation pump 9 according to the temperature difference between the heat source side outlet temperature of the bath heat exchanger 6 and the use side inlet temperature of the bath heat exchanger 6, thereby Control the flow of hot water on the side.

  At this time, the water sent from the bathtub 8 by the use side circulation pump 10 is heated by exchanging heat with the hot water in the upper part of the hot water tank 5 sent by the heat source side circulation pump 9 in the bath heat exchanger 6. Then return to bathtub 8. Then, the hot water sent from the hot water storage tank 5 by the heat source side circulation pump 9 exchanges heat with the hot water in the bathtub 8 sent by the use side circulation pump 10 described above by the bath heat exchanger 6 and intermediate. It reaches the connection point with the tapping pipe 21. And since the inflow to the hot water tank 5 side is prevented by the inflow prevention means 39, all the hot water that has reached this connection location is sent to the intermediate mixing valve 22 and mixed with the hot water from the upper part of the hot water tank 5, Further, it is mixed with water from the water supply pipe 17 by the hot water supply mixing valve 19 to become hot water having a predetermined hot water supply temperature, and hot water is supplied from the faucet 12.

  As described above, since all of the hot water in the hot water storage tank 5 used for bath heating is directly used for hot water supply, all the amount of heat given to the hot water is used up, and the efficiency is greatly improved. In addition, since there is no hot water returning to the hot water tank 5, the hot water in the hot water tank 5 or mixed with the water does not lower the temperature of the hot water or raise the temperature of the water. There is no decline.

  The flow rate control valve 38 described in the second embodiment is provided, and the heat source side circulation pump 9 and the flow rate control valve 38 form a flow rate control means 30. The control means 26, the heat source side circulation pump 9, Even if the heat source side flow rate in the bath heating unit 23 is controlled by the use side inlet temperature detection unit 28, the heat source side outlet temperature detection unit 27, and the flow rate control valve 38, the same operation and effect can be obtained.

  Further, as shown in FIG. 4, the high temperature side inlet of the hot water mixing valve 35 may be connected to the mixing (outlet) side of the intermediate mixing valve 22 instead of the upper part of the hot water storage tank 5. That is, when there is a request for hot water to the bathtub 8 and a bath heating request at the same time, the mixing valve control means 34 sets the outlet (mixing) temperature of the intermediate mixing valve 22 with a remote controller (not shown). In order to adjust the mixing ratio of the hot water from the upper part of the hot water storage tank 5 and the hot water from the intermediate tap pipe 21 so that the temperature is higher than the predetermined pouring temperature by a predetermined temperature, the intermediate temperature detecting means 32 The opening degree of the intermediate mixing valve 22 is controlled based on the obtained temperature. Further, in order to adjust the mixing ratio of the hot water from the intermediate mixing valve 22 and the water from the water supply pipe 17 so that the outlet (mixing) temperature of the hot water mixing valve 35 becomes the predetermined hot water temperature, Hot water of a predetermined pouring temperature is poured into the bathtub 8 by controlling the opening of the pouring mixing valve 35 based on the temperature obtained from the temperature detection means 37. In addition, since the operation | movement and effect | action of the bath heating means 23 are the same as that of the case of FIG. 3, description is abbreviate | omitted.

  In this way, a part or all of the hot water from the upper part of the hot water storage tank 5 radiated by the bath heat exchanger 6 can be used directly for the hot water of the bath, etc. It is possible to improve convenience and improve operation efficiency because the production of intermediate warm water by mixing the intermediate warm water returning from the bath heat exchanger 6 and the hot water in the hot water storage tank 5 is reduced.

(Embodiment 4)
FIG. 5 is a configuration diagram of a heat pump water heater in the fourth embodiment of the present invention.

  The difference between the heat pump water heater in the present embodiment and the heat pump water heater in the first embodiment shown in FIG. 1 is that the bath heat exchanger connected to the bath heat exchanger 6 is returned as shown in FIG. The pipe 25 is connected to the hot water tank 5, and the connection position is set to a position different from the connection position between the intermediate hot water pipe 21 and the hot water tank 5. Furthermore, a bypass pipe 40 connecting the middle of the intermediate hot water pipe 21 and the middle of the bath heat exchanger return pipe 25, and the hot water path in the upper part of the hot water storage tank 5 exchanged by the bath heat exchanger 6 are connected to the intermediate hot water pipe 21 side. And a switching means 41 for selecting and switching the connection portion between the bath heat exchanger return pipe 25 and the hot water storage tank 5, and the other configuration is the same as the heat pump water heater in the first embodiment. Since they are the same, the same parts are denoted by the same reference numerals and description thereof is omitted.

  About the heat pump water heater comprised as mentioned above, the operation | movement and an effect | action are demonstrated below. Since the hot water supply heating mode, the single hot water supply mode, and the bath pouring mode are the same as those in the first embodiment of FIG. 1, the description is omitted, and the single bath heating mode, the hot water supply request, and the bath heating request are simultaneously provided. The simultaneous hot water bath heating mode will be described.

  First, the single bath heating mode will be described. Now, when there is a bath heating request (not shown), the use-side circulation pump 10 is driven to switch the switching means 41 to the hot water tank 5 side. Then, the control means 26 drives the heat source side circulation pump 9.

  The water sent from the bathtub 8 by the use side circulation pump 10 is heated by exchanging heat with the hot water in the upper part of the hot water tank 5 sent by the heat source side circulation pump 9 in the bath heat exchanger 6. Return to 8. In addition, the hot water sent from the hot water storage tank 5 by the heat source side circulation pump 9 exchanges heat with the hot water in the bathtub 8 sent by the use side circulation pump 10 and the bath heat exchanger 6. It returns to the hot water tank 5 through the switching means 41. At this time, as described above, the control means 26 controls the flow rate of the heat source side circulation pump 9 in order to efficiently heat the bath with the necessary capacity.

  Next, the simultaneous hot water bath heating mode when there is a hot water request and a bath heating request will be described. First, when the faucet 12 serving as a hot water supply terminal is opened as a hot water supply request, the mixing valve control means 34 sets the outlet (mixing) temperature of the intermediate mixing valve 22 to a predetermined temperature than the hot water supply set temperature set by the hot water supply temperature setting means 33. In order to adjust the mixing ratio of the hot water from the upper part of the hot water storage tank 5 and the hot water from the intermediate tap pipe 21 so as to reach a high temperature only, the intermediate mixing valve based on the temperature obtained from the intermediate temperature detecting means 32 The opening degree of 22 is controlled.

  Further, the mixing ratio of hot water from the intermediate mixing valve 22 and water from the water supply pipe 17 is adjusted so that the outlet (mixing) temperature of the hot water supply mixing valve 19 becomes the hot water supply set temperature set by the hot water supply temperature setting means 33. Therefore, hot water having a predetermined hot water temperature is supplied from the faucet 12 by controlling the opening degree of the hot water mixing valve 19 based on the temperature obtained from the hot water temperature detecting means 31.

  Furthermore, since there is a bath heating request at the same time, the use-side circulation pump 10 is driven to switch the switching means 41 so as to communicate with the intermediate hot water discharge pipe 21 side. And the control means 26 adjusts the rotation speed of the heat source side circulation pump 9 according to the temperature difference between the heat source side outlet temperature of the bath heat exchanger 6 and the use side inlet temperature of the bath heat exchanger 6, thereby Control the flow of hot water on the side.

  At this time, the water sent from the bathtub 8 by the use side circulation pump 10 is heated by exchanging heat with the hot water in the upper part of the hot water tank 5 sent by the heat source side circulation pump 9 in the bath heat exchanger 6. Then return to bathtub 8.

And after exchanging heat with the hot water of the bathtub 8 sent by the utilization side circulation pump 10 and the hot water sent from the hot water storage tank 5 by the heat source side circulation pump 9 in the bath heat exchanger 6, It passes through the switching means 41 and reaches the connection point between the bypass pipe 40 and the intermediate hot water pipe 21. Then, all or a part of the hot water reaching the connection point is sent to the intermediate mixing valve 22 to be mixed with hot water from the upper part of the hot water storage tank 5 and further mixed with water from the water supply pipe 17 by the hot water supply mixing valve 19. Then, the hot water is supplied from the faucet 12 as hot water having a predetermined hot water temperature.

  On the other hand, the remaining hot water that has reached the connection point between the bypass pipe 40 and the intermediate hot water discharge pipe 21 and did not flow to the intermediate mixing valve 22 side returns to the hot water storage tank 5.

  In this way, the return position to the hot water tank 5 at the time of bath heating and the take-out position from the hot water tank 5 at the time of intermediate hot water are not influenced by each other, so that efficient intermediate hot water and bath heating can be performed respectively. And when there is a hot water supply request and a bath heating request at the same time, the hot water from the upper part of the hot water storage tank 5 radiated by the bath heat exchanger 6 is used without flowing back to the hot water storage tank 5 and is used for comfort and convenience. Improvement of driving performance and driving efficiency can be achieved.

  As shown in FIG. 5, if the flow rate control valve 38 described in the second embodiment of FIG. 2 is provided and the flow rate control means 30 is formed by the heat source side circulation pump 9 and the flow rate control valve 38, The effects described in the second embodiment can also be obtained.

  Furthermore, even if the inflow preventing means 39 described in the third embodiment in FIG. 3 is provided in the middle of the intermediate hot water pipe 21 closer to the hot water storage tank 5 than the connection point between the intermediate hot water pipe 21 and the bypass pipe 40, The effects described in the third embodiment can also be obtained.

  In FIG. 5, the connection position between the bath heat exchanger return pipe 25 and the hot water tank 5 is lower than the connection position between the intermediate hot water pipe 21 and the hot water tank 5, but the intermediate hot water pipe 21 and the hot water tank. Even if it is above or at the same height as the connection position with 5, the same action and effect can be obtained.

  Further, as shown in FIG. 6, the high temperature side inlet of the hot water mixing valve 35 may be connected to the mixing (outlet) side of the intermediate mixing valve 22 instead of the upper part of the hot water tank 5. That is, when there is a request for hot water to the bathtub 8 and a bath heating request at the same time, the mixing valve control means 34 sets the outlet (mixing) temperature of the intermediate mixing valve 22 with a remote controller (not shown). In order to adjust the mixing ratio of the hot water from the upper part of the hot water storage tank 5 and the hot water from the intermediate tap pipe 21 so that the temperature is higher than the predetermined pouring temperature by a predetermined temperature, the intermediate temperature detecting means 32 The opening degree of the intermediate mixing valve 22 is controlled based on the obtained temperature.

  Further, in order to adjust the mixing ratio of hot water from the intermediate mixing valve 22 and water from the water supply pipe 17 so that the outlet (mixing) temperature of the hot water mixing valve 35 becomes the predetermined pouring temperature. Hot water having a predetermined pouring temperature is poured into the bathtub 8 by controlling the opening of the pouring mixing valve 35 based on the temperature obtained from the hot water temperature detecting means 37.

  In addition, since the operation | movement and effect | action of the bath heating means 23 are the same as that of the case of FIG. 5, description is abbreviate | omitted. In this way, a part or all of the hot water from the upper part of the hot water tank 5 radiated by the bath heat exchanger 6 can be used directly for the hot water of the bath, etc. It is possible to improve convenience and improve operation efficiency because the production of intermediate warm water by mixing the intermediate warm water returning from the bath heat exchanger 6 and the hot water in the hot water storage tank 5 is reduced.

  As described above, the heat pump water heater according to the present invention is configured to directly use hot water whose temperature has decreased after heating a heat radiating means such as a bathtub with high-temperature hot water in a hot water tank for hot water supply. It is possible to improve the operation efficiency, and is applicable not only to bath heating but also to applications such as heating using stored hot water and bathroom heating dryer.

The block diagram of the heat pump water heater in the 1st Embodiment of this invention The block diagram of the heat pump water heater in the 2nd Embodiment of this invention The block diagram of the heat pump water heater in the 3rd Embodiment of this invention The block diagram of the heat pump water heater which shows the other Example in the 3rd Embodiment of this invention. The block diagram of the heat pump water heater in the 4th Embodiment of this invention The block diagram of the heat pump water heater which shows the other Example in the 4th Embodiment of this invention. Configuration diagram of conventional heat pump water heater

DESCRIPTION OF SYMBOLS 1 Compressor 2 Hot water supply heat exchanger 5 Hot water storage tank 6 Bath heat exchanger 8 Bathtub 17 Water supply pipe 18 Hot water supply pipe 19 Hot water supply mixing valve (mixing valve)
21 Intermediate tap pipe 22 Intermediate mixing valve (mixing valve)
23 Bath Heating Means 24 Bath Heat Exchanger Outgoing Pipe 25 Bath Heat Exchanger Return Pipe 30 Flow Control Means 33 Hot Water Supply Temperature Setting Means

Claims (9)

A hot water supply heating means provided with a compressor, a hot water supply heat exchanger, a hot water storage tank for storing hot water heated by the hot water supply heat exchanger, a hot water pipe connected to an upper part of the hot water storage tank, and an intermediate between the hot water storage tanks One intermediate hot water pipe connected to the section, a water supply pipe connected to the lower part of the hot water tank, and a bath heat exchanger provided in the middle to connect the upper part of the hot water tank and the lower part from the upper part, respectively Bath heating means comprising a bath heat exchanger forward pipe and a bath heat exchanger return pipe for heating the hot water in the bathtub through the bath heat exchanger using the hot water at the top of the hot water tank as a heat source, and the bath Flow rate control means for controlling the heat source flow rate circulating through the heating means, hot water supply temperature setting means for setting hot water supply temperature, hot water from the hot water pipe, the intermediate hot water pipe, and hot water from the water supply pipe to mix the hot water temperature setting means Adjust so that the hot water temperature set in And a plurality of mixing valve, with the other end is connected to the bath heat exchanger return tube in the middle of the one of the intermediate tapping tube, when the hot water supply request and the bath heating request was simultaneously the bath heat exchanger A heat pump water heater, wherein a part or all of the hot water from the upper part of the hot water tank radiated by a heater is directly used for hot water supply. A connection portion between the bath heat exchanger return pipe connected to the bath heat exchanger and the hot water tank, and a connection portion between the intermediate hot water pipe and the hot water tank, and the intermediate hot water pipe and the bath heat exchanger. A bypass pipe connecting the return pipe, and a hot water path in the upper part of the hot water tank exchanged by the bath heat exchanger is an intermediate hot water pipe side or a connection side of the bath heat exchanger return pipe and the hot water tank The heat pump water heater according to claim 1, further comprising switching means for selecting and switching between the two. If the hot water supply request and the bath heating requirements were simultaneously according to claim 2, characterized in that the controlling means switching to flow hot water tank upper portion of the hot water heat-exchanged in the bath heat exchanger to an intermediate tapping pipe side Heat pump water heater. An intermediate mixing valve that mixes hot water from the intermediate hot water pipe and hot water from the hot water pipe, and a hot water supply mixing valve that mixes hot water from the intermediate mixing valve and water from the water supply pipe are provided. The heat pump water heater of any one of Claims 1-3 . As the flow rate control means, the claims using a heat source-side circulation pump for circulating the hot water is provided to the heat-source-side of the bath heat exchanger the hot water storage tank, and a flow control valve also provided in the heat source side of the bath heat exchanger
The heat pump water heater in any one of 1-4 . If hot water demand and a bath heating requirements were simultaneously claim having an inflow preventing means the upper portion of the hot water of the hot water tank and the heat exchange with the bath heat exchanger from returning to the hot water storage tank through the intermediate tapping tube The heat pump water heater according to any one of 1 to 5 . The heat pump water heater according to claim 4 , wherein the target mixing temperature of the intermediate mixing valve is determined based on the hot water supply set temperature set by the hot water supply temperature setting means and the temperature of the heat source side outlet of the bath heat exchanger. The target mixing temperature of the intermediate mixing valve is set to a temperature that is higher by a predetermined temperature than the higher one of the hot water supply set temperature set by the hot water supply temperature setting means and the temperature of the heat source side outlet of the bath heat exchanger. The heat pump water heater according to claim 4 to be set. The heat pump water heater according to any one of claims 1 to 8 , wherein the refrigerant circuit of the heat pump is a supercritical refrigerant circuit whose pressure is equal to or higher than a critical pressure, and heats water with a refrigerant whose pressure is increased to the critical pressure or higher. .

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