JP2006214658A - Heat pump hot-water supply device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat pump hot-water supply device capable of providing a high performance by a simple structure at low cost without lowering the COP of a refrigerant circuit. <P>SOLUTION: This heat pump hot-water supply device comprises a refrigerant circulation circuit 20 having a compressor 21, a radiator 22, a pressure reducing means 23, and a heat sink 24, a water/refrigerant heat exchanger 30 having the radiator 22 and a water flow passage for heat exchange, a hot water storage tank 27 stored hot water heated by the water/refrigerant heat exchanger 30, a laminated pump 25 taking out water from the bottom part of the hot water storage tank 27 and returning the water to the upper part of the hot water storage tank 27 after the water is heated by the water/refrigerant heat exchanger 30, and a latent heat storage part 33 suppressing the rise of the temperature of the water at the bottom part of the hot water storage tank 27. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a heat pump water heater.

  As a first example of a conventional heat pump hot water supply apparatus, as shown in FIG. 6, 1 is a refrigerant circuit in which the refrigerant circulates and performs a heat pump cycle operation, and 2 is heat exchange between the refrigerant of the refrigerant circuit 1 and water. A water / refrigerant heat exchanger 3 is a hot water storage tank for storing hot water heated at a high temperature in the water / refrigerant heat exchanger. A heat pump hot water supply apparatus is known in which water is taken from the bottom of the hot water storage tank 3 and heated to a high temperature with a water / refrigerant heat exchanger, then stored in the hot water storage tank 3 and discharged from the hot water storage tank 3 as necessary. (For example, refer to Patent Document 1).

As a second example, as shown in FIG. 7, 11 is a refrigerant circuit that circulates refrigerant and performs heat pump cycle operation, 12 is a heat storage means, 13 is a heat medium circuit in which a heat medium such as water circulates, and 14 is The heat source side heat exchanger performs heat exchange between the refrigerant in the refrigerant circuit 11 and the heat medium in the heat medium circuit 13. The heat storage means 12 includes a high temperature side heat storage material 15 and a low temperature side heat storage material 16 made of a latent heat storage material having a melting point lower than that of the high temperature side heat storage material 15, and the heat medium circuit 13 converts the heat medium into a high temperature side heat storage material. A heat pump hot water supply apparatus is known that can prevent the COP of the refrigerant circuit from being lowered during heat storage by causing the low-temperature heat storage material 16 to dissipate heat after flowing to 15 and flowing into the heat source side heat exchanger 14. (For example, refer to Patent Document 2).
JP 2001-82803 A JP 2003-232563 A

  However, in the heat pump water heater of the first conventional example, when the water in the hot water storage tank 3 is boiled up to high temperature hot water, the hot water coming down from the top of the hot water storage tank 3 and the hot water storage tank 3 A relatively high temperature mixed layer is formed that exists at the interface with the unboiled water. When the water in the mixed layer is led to the water / refrigerant heat exchanger and heated, the water temperature of the mixed layer is high, so that the heat capacity of the heat pump cycle is lowered and the coefficient of performance (COP) of the heat pump cycle is deteriorated. There was a problem.

  Moreover, in the heat pump hot water supply apparatus of the second example, by storing all the required heat amounts in the high temperature side heat storage material 15 and the low temperature side heat storage material 16, the heat exchanger for the high temperature side heat storage material and the low temperature side heat storage material are used. Since each of the heat exchangers is indispensable, there is a problem that the configuration of the hot water supply apparatus becomes complicated. Moreover, since the high temperature side heat storage material 15 and the low temperature side heat storage material 16 which have different melting | fusing points are each required and these are integrated in a hot water supply apparatus, a hot water supply apparatus becomes heavy and in each process of manufacture, conveyance, and installation, a heat storage material. It was difficult to handle and there was a problem of high cost.

  Therefore, the present invention solves the above-described conventional problems, and provides a high-performance heat pump hot water supply device that has a simple configuration and is low in cost without causing a COP drop in the refrigerant circuit.

  In order to solve the conventional problems, the heat pump hot water supply apparatus of the present invention is configured such that the water and heat supplied from the first water flow path and the water supply pipe that exchanges heat at the bottom of the hot water storage tank and flows the water to the water / refrigerant heat exchanger. The heat storage means comprises at least a second flowing water channel for exchanging and discharging hot water.

  As a result, when the water storage means boils the water in the hot water storage tank to hot water, it exchanges heat with a relatively high temperature mixed layer of, for example, 30 ° C. to 60 ° C. that descends from the top of the hot water storage tank. Since the temperature can be reduced to about 20 ° C. to 30 ° C., the water temperature at the inlet of the water / refrigerant heat exchanger can be kept low, and the COP reduction of the refrigerant circuit can be prevented. Moreover, the heat taken in and the low temperature water from a water supply pipe can be heat-exchanged and used for hot water.

  ADVANTAGE OF THE INVENTION According to this invention, there is no fall of COP of a refrigerant circuit, and it can provide a low-cost high-performance heat pump hot-water supply apparatus with a simple configuration.

  The first aspect of the invention relates to a refrigerant circulation circuit including a hot water storage tank, a compressor and a radiator, a water / refrigerant heat exchanger in heat exchange relation with the radiator, and water taken out from the bottom of the hot water tank to the water / A stack pump that heats and returns to the upper part of the hot water tank through the refrigerant heat exchanger, a water supply pipe that supplies water from the lower part of the hot water tank, and heats the water at the bottom of the hot water tank to flow to the water / refrigerant heat exchanger The heat storage means comprises at least a first flowing water channel and a second flowing water channel that exchanges heat with water supplied from a water supply pipe and discharges hot water.

  As a result, water is taken from the bottom of the hot water tank, heated to a high temperature with a water / refrigerant heat exchanger, returned to the top of the hot water tank, and when the water in the hot water tank is boiled to hot water, When a mixed layer having a relatively high temperature, for example, 30 ° C. to 60 ° C., present at the interface between hot water coming from the top and unboiled water comes down to the bottom of the hot water storage tank, Since the temperature rise of the water taken in can be suppressed to, for example, about 20 ° C. to 30 ° C., the water temperature at the inlet of the water / refrigerant heat exchanger can be suppressed low, and the COP reduction in the refrigerant circuit can be prevented. Moreover, the heat taken in and the low temperature water from a water supply pipe can be heat-exchanged and used for hot water.

  In this way, a high-performance heat pump hot water supply apparatus can be provided with a simple configuration at a reduced cost simply by providing heat storage means for suppressing the temperature rise of the water at the bottom of the hot water storage tank.

  In particular, the second invention is the heat pump water heater of the first invention, wherein a hot water discharge pipe for discharging hot water stored in the hot water storage tank is provided at an upper portion of the hot water storage tank, and the second flowing water passage and the hot water discharge pipe are connected. A hot water bypass pipe is provided.

  As a result, the amount of heat stored in the heat storage means can be effectively used to preheat the water supply through the hot water bypass pipe, and a high-performance heat pump hot water supply apparatus that achieves both high efficiency and compactness can be provided.

  The third invention is the heat pump water heater of the second invention, in particular, in which the heat storage means forms a first flow channel and a second flow channel by stacking a flat heat storage plate as a latent heat storage material in a stack. To do.

  As a result, the first and second flow channels are formed only by the process of laminating the heat storage plates, the complicated work process is eliminated, and the manufacturing time is shortened.

  In the fourth aspect of the invention, in particular, in the heat pump hot water supply apparatus of the third aspect of the invention, the melting point of the latent heat storage agent is set near the annual average water temperature.

  As a result, by setting the melting point of the latent heat storage agent near the annual average water temperature, the hot water in the mixed layer can easily take a temperature difference when exchanging heat with the latent heat storage agent, and the heat exchange performance can be improved. The temperature of the hot water in the mixed layer can be lowered to near the average water temperature annually, and the water / refrigerant heat exchanger water temperature in the heat pump cycle can be kept low, so that high efficiency operation of the heat pump cycle can be realized.

  According to a fifth aspect of the invention, in particular, in the heat pump hot water supply apparatus according to the first to fourth aspects of the invention, the heat storage means is provided separately from the hot water storage tank.

  According to the present embodiment, by setting the heat storage means separately from the hot water storage tank, the capacity, shape, etc. of the heat storage means can be set according to the hot water storage tank capacity, main use pattern, etc., so the heat storage amount and temperature level are optimal. It is possible to provide a high-efficiency heat pump hot water supply device that can be designed to a value and has a high degree of design freedom. Moreover, by installing separately, the installation property of a heat pump hot-water supply apparatus, maintainability, etc. can be improved, and a more reliable high-performance heat pump hot-water supply apparatus can be provided.

  In a sixth aspect of the invention, in particular, in the heat pump hot water supply apparatus of the first to fourth aspects of the invention, the heat storage means is installed at the bottom of the hot water storage tank. Thereby, the installation place of the heat storage means can be saved, and the effect of the present invention can be obtained even when the installation place is limited.

  The seventh aspect of the invention is that, in particular, in the heat pump water heater of any one of the first to sixth aspects, the refrigerant is carbon dioxide and the pressure is equal to or higher than the critical pressure.

  According to the present embodiment, by setting the pressure to be equal to or higher than the critical pressure, the refrigerant carbon dioxide in the entire water / refrigerant heat exchanger is not condensed even if the temperature is lowered due to heat deprived by water. It is easy to form a temperature difference, and water can be efficiently heated and stored up to the required high temperature level. By reducing the incoming water temperature of the water / refrigerant heat exchanger, a highly efficient operation of the heat pump cycle can be realized, and a highly efficient heat pump water heater can be provided.

(Embodiment 1)
FIG. 1 is a system configuration diagram of a heat pump hot water supply apparatus according to the first embodiment of the present invention, FIG. 2 is an enlarged view of a main part configuration of the heat pump hot water supply apparatus, and FIG. 3 is a water / refrigerant heat exchanger for boiling. 4 is a heat storage density comparison diagram showing the amount of heat storage per unit volume.

  1 and 2, the refrigerant circulation circuit 20 includes a compressor 21, a radiator 22, a decompression unit 23, and a heat absorber 24. The refrigerant circulation circuit 20 constitutes a heat pump cycle and encloses a refrigerant such as carbon dioxide in which the high-pressure side refrigerant pressure is equal to or higher than the critical pressure. 25 is a laminated pump, 26 is a hot water storage pipe that transports hot water that has been exchanged with the refrigerant flowing through the radiator 22, and 27 is a hot water storage tank that communicates with the hot water storage pipe 26. Tap water, which is water, is supplied and discharged from an outlet pipe 29 at the top. Reference numeral 30 denotes a water / refrigerant heat exchanger in which water sent from the bottom of the hot water storage tank 27 by the stacking pump 25 exchanges heat with the refrigerant in the radiator 22, and in the water / refrigerant heat exchanger 30, water is predetermined. It becomes hot and is transported to the top of the hot water storage tank 27 via the hot water storage pipe 26. A mixing valve 31 mixes hot water from the hot water supply pipe 29 and water supply from the water supply pipe 28, and hot water having a predetermined flow rate and temperature is sent to the hot water supply terminal 32 through the mixing valve 31.

  Reference numeral 33 denotes a latent heat storage section which is a heat storage means provided at the bottom of the hot water storage tank 27. The latent heat storage section 33 includes a heat storage plate 34 containing a latent heat storage agent such as sodium sulfate hydrate, and these heat storage plates. And a flow channel 35 formed by laminating the plates 34. The melting point of the latent heat storage agent contained in the heat storage plate 34 is set low, and is set, for example, around the annual average water temperature. 36 is a hot water bypass pipe communicating with the hot water pipe 29 provided corresponding to the latent heat storage section 33, and 37 is a bypass flow rate electromagnetic valve for adjusting the flow rate provided in the hot water bypass pipe 36.

  In FIG. 3, the horizontal axis represents the boiling operation elapsed time, the left vertical axis represents the incoming water and the boiling temperature, and the right vertical axis represents the heat pump cycle coefficient of performance (COP). In the figure, case A does not have a latent heat storage part, and case B shows a case where a latent heat storage part is used.

  In the heat storage density comparison diagram of FIG. 4, the horizontal axis represents the operating temperature, and the vertical axis represents the heat storage amount per unit volume. In the figure, the amount of heat storage with respect to the temperature of water and sodium sulfate hydrate is displayed in a graph. In the case of sodium sulfate hydrate, the calculation was performed assuming that the ratio (filling rate) of sodium sulfate hydrate filled in a unit volume was 74% and the remaining 26% was water. In the figure, as an example, the melting point of sodium sulfate hydrate is 32 ° C., but this example is not limited to that melting point.

  Next, the operation and action will be described. Low temperature water, for example, 17 ° C. is led out from the bottom of the hot water storage tank 27 by the operation of the laminated pump 25 and led to the water / refrigerant heat exchanger 30. On the other hand, in the heat pump cycle, the high-temperature and high-pressure refrigerant gas discharged from the compressor 21 flows into the radiator 22 and heats the cold water flowing from the hot water storage tank 27. The hot water heated by the water / refrigerant heat exchanger 30 and boiled up to, for example, 80 ° C. is returned from the hot water storage pipe 26 to the top of the hot water storage tank 27 and stored. So-called layered boiling is performed. The refrigerant cooled by the radiator 22 is decompressed by the decompression means 23 and flows into the heat absorber 24, where it absorbs natural energy such as atmospheric heat, solar heat, and underground heat to evaporate and returns to the compressor 21.

  When there is a demand for hot water supply, hot water stored in the hot water storage tank 27 is supplied to the hot water supply terminal 32 used by the user through the hot water supply pipe 29. In accordance with the temperature level of the hot water supply demand, the mixing valve 31 mixes with tap water or the like to supply a predetermined temperature.

  By the way, when the water in the hot water storage tank 27 is boiled up to high temperature hot water, the comparison exists between the high temperature hot water coming down from the top of the hot water storage tank 27 and the unboiling water in the hot water storage tank 27. A mixed layer having a high target temperature, for example, 30 ° C. to 60 ° C. is formed. If this mixed layer is boiled up to a target boiling temperature, for example, 80 ° C., as shown in case A of FIG. 3, the heating capacity of the heat pump cycle is lowered and the performance efficiency COP is deteriorated.

  Therefore, as in the present embodiment, in the latent heat storage unit 33 provided at the bottom of the hot water storage tank 27, the hot water having a high mixed layer temperature flows through the water flow path 35 and the latent heat storage agent contained in the heat storage plate 34 is stored. Heat exchange with sodium sulfate hydrate. Then, sodium sulfate hydrate absorbed heat from the hot water in the mixed layer and absorbed latent heat in the vicinity of the melting point. On the other hand, the hot water in this mixed layer further dissipates heat to the sodium sulfate hydrate, so that the temperature further decreases, and is slightly higher than the temperature level close to the annual average water temperature, for example, about 20 ° C.

  As shown in FIG. 4, in order to secure a constant heat storage amount, for example, 200 kJ / L, it is necessary to keep the temperature up to 65 ° C. in the case of water, whereas it is about 32 ° C. in the case of sodium sulfate hydrate. Can be realized. Further, when compared at the same temperature level, although depending on the temperature zone, sodium sulfate hydrate has a heat storage amount about twice that of water. Thus, when the latent heat storage agent is used, a predetermined amount of heat can be stored at a low temperature level.

  Then, as shown in case B of FIG. 3, by using the latent heat storage unit 33 that suppresses the rise in the water temperature of the mixed layer in the present embodiment, the water having a relatively high temperature in the mixed layer is activated by the latent heat storage unit 33. Thus, since the temperature rise can be suppressed, the water temperature at the inlet of the water / refrigerant heat exchanger 30 can be kept low, and the COP reduction of the refrigerant circuit can be prevented.

  Further, when there is a hot water discharge request from the hot water supply terminal 32, the bypass flow rate electromagnetic valve 37 is opened at a predetermined opening, and the hot water bypass pipe 36 is allowed to pass through the water supply pipe 28. In this way, by passing the water supply through the water flow path 35 of the latent heat storage unit 33, the amount of heat of a part of the mixed layer stored in the latent heat storage agent of the latent heat storage unit 33 is preheated. Then, the water supply preheated by the latent heat storage agent is mixed with the hot water supplied from the hot water outlet pipe 29 or the water supplied from the water supply pipe 28 to obtain a desired hot water supply temperature and supplied to the hot water supply terminal 32.

  In this manner, by providing the latent heat storage unit 33 that is a heat storage unit that suppresses the temperature rise of the water at the bottom of the hot water storage tank 27, a high-performance heat pump hot water supply apparatus can be provided with a simple configuration at a reduced cost.

  Further, the amount of heat stored in the latent heat storage unit 33 can be used without waste by effectively using the amount of heat stored in the latent heat storage agent by preheating the water supply through the hot water bypass pipe 36 so that the hot water does not run out. It is possible to provide a high-performance heat pump hot water supply device that achieves both high efficiency and compactness.

  In addition, by setting the melting point of the latent heat storage agent near the annual average water temperature, the hot water in the mixed layer can easily take a temperature difference when exchanging heat with the heat storage plate 34, and by improving the heat exchange performance, A heat storage part that is compact and lightweight can be realized, and the temperature of the mixed layer can be lowered to around the average water temperature annually, and the water / refrigerant heat exchanger 30 of the heat pump cycle can be kept low at the time of boiling. Highly efficient operation can be realized with certainty.

  In addition, by using carbon dioxide as the refrigerant in the heat pump cycle, it is possible to conserve the global environment, and by setting the pressure above the critical pressure, the carbon dioxide in the refrigerant will condense even if its temperature drops due to water being deprived of heat. In addition, it becomes easier to form a temperature difference between the refrigerant and water throughout the water / refrigerant heat exchanger, and the water can be efficiently heated to the required high temperature level. Compactness can be achieved. In addition, by reducing the incoming water temperature of the water / refrigerant heat exchanger, a highly efficient operation of the heat pump cycle can be realized, and a highly efficient heat pump water heater can be provided.

(Embodiment 2)
FIG. 5 is a system configuration diagram showing a heat pump hot water supply apparatus according to the second embodiment of the present invention.

  In this embodiment, the difference from the first embodiment is that a latent heat storage unit 38 is newly provided separately from the hot water storage tank 27 between the inlet of the water / refrigerant heat exchanger 30 and the bottom of the hot water storage tank 27. That is. In this latent heat storage section 38, a preceding hot water discharge passage 39 communicating with the hot water supply pipe 29, a heat storage plate 40 containing a latent heat storage agent, and a low temperature passage 41 communicating with the inlet of the water / refrigerant heat exchanger 30 are alternately arranged. It is configured by laminating.

  In addition, the thing of the same code | symbol as 1st Embodiment has the same structure, and abbreviate | omits description.

  When the water in the hot water storage tank 27 is boiled up to the high temperature hot water, the relatively high temperature existing at the interface between the hot water coming down from the top of the hot water storage tank 27 and the unboiling water in the hot water storage tank 27. For example, a mixed layer having a high temperature of 30 ° C. to 60 ° C. is formed. The hot water in the mixed layer portion flows from the bottom of the hot water storage tank 27 through the low-temperature flow path 41 of the latent heat storage unit 38 and exchanges heat with sodium sulfate hydrate of the latent heat storage agent contained in the heat storage plate 40. The water / refrigerant heat exchanger 30 flows to the inlet. Then, sodium sulfate hydrate absorbed heat from the hot water in the mixed layer and absorbed latent heat in the vicinity of the melting point. On the other hand, the temperature of the hot water in the mixed layer is reduced by releasing heat to the sodium sulfate hydrate, and the temperature level is close to the annual average water temperature, for example, about 20 ° C.

  Thus, by using the latent heat storage unit 38 that suppresses the rise in the water temperature of the mixed layer, water having a relatively high temperature in the mixed layer can suppress an increase in temperature by the action of the latent heat storage unit 38. / The water temperature at the inlet of the refrigerant heat exchanger 30 can be kept low, and the COP drop of the refrigerant circuit can be prevented.

  Further, when there is a hot water discharge request from the hot water supply terminal 32, the bypass flow rate electromagnetic valve 37 is opened at a predetermined opening, and the hot water bypass pipe 36 is allowed to pass through the water supply pipe 28. In this way, by passing the water supply through the preceding hot water flow path 39 of the latent heat storage unit 38, the amount of heat of the mixed layer stored in the latent heat storage agent of the latent heat storage unit 38 is preheated. Then, the water supply preheated by the latent heat storage agent is mixed with the hot water supplied from the hot water outlet pipe 29 or the water supplied from the water supply pipe 28 to obtain a desired hot water supply temperature and supplied to the hot water supply terminal 32.

  In this way, a high-performance heat pump hot water supply apparatus can be provided with a simple configuration at a reduced cost simply by providing the latent heat storage section 38, which is a heat storage means for suppressing the temperature rise of the water at the bottom of the hot water storage tank 27.

  In addition, the amount of heat stored in the latent heat storage unit 38 can be used without waste by effectively using the amount of heat stored in the latent heat storage agent by preheating the water supply through the hot water bypass pipe 36, so that the hot water does not run out. It is possible to provide a high-performance heat pump hot water supply device that achieves both high efficiency and compactness.

  Furthermore, since the latent heat storage unit 38 is separately provided from the hot water storage tank 27 in this way, the capacity, size, installation mode, etc. of the latent heat storage unit 38 can be set according to the hot water storage tank capacity and usage frequency. Therefore, it is possible to provide a high-efficiency heat pump hot water supply apparatus that can design the temperature level to an optimum value and does not run out of hot water with high design freedom.

  Moreover, by installing separately, the installation property of a heat pump hot-water supply apparatus, maintainability, etc. can be improved, and a more reliable high-performance heat pump hot-water supply apparatus can be provided.

  Furthermore, by providing it separately, it is not necessary to provide the outlet of the bypass hot water discharge pipe 36 in the hot water storage tank 27, and the manufacturing cost of the hot water storage tank 27 can be reduced.

  In each of the above embodiments, the first fluid is a carbon dioxide refrigerant and the second fluid is water. However, the same effect can be obtained by using other fluids.

  In each of the above embodiments, the water heated in the water flow path is transported to the hot water storage tank. However, after the water flowing through the water flow path is heated to a predetermined temperature, the water does not flow to the hot water storage tank, and the user directly You may supply to the hot-water supply faucet etc. to be used.

  Moreover, in each said embodiment, although the heat storage means was set as the latent heat storage part comprised by the heat storage plate, for example, as a latent heat storage part comprised by the spherical capsule shape packed with the latent heat storage material instead of the heat storage plate Also good.

  In each of the above embodiments, the mixed layer is formed at the interface between the heated hot water and the non-boiling water. The same effect can be obtained for the mixed layer formed by the temperature drop in the tank.

  As described above, the heat pump cycle hot water supply apparatus according to the present invention does not decrease the COP of the refrigerant circuit, and can provide a low-cost, high-performance heat pump hot water supply apparatus with a simple configuration.

  In addition, it can be widely applied to applications such as heat exchange and heat transfer.

The system block diagram of the heat pump hot-water supply apparatus in Embodiment 1 of this invention The principal part enlarged view of the heat pump hot-water supply apparatus in Embodiment 1 of this invention Temperature-COP characteristic diagram in operation elapsed time of heat pump water heater in embodiment 1 of the present invention Heat storage density comparison diagram showing heat storage amount per unit volume in Embodiment 1 of the present invention The principal part enlarged view of the heat pump hot-water supply apparatus in Embodiment 2 of this invention Configuration diagram of conventional heat pump water heater Configuration diagram of conventional heat pump water heater

Explanation of symbols

DESCRIPTION OF SYMBOLS 20 Refrigerant circuit 21 Compressor 22 Radiator 23 Depressurization means 24 Heat absorber 25 Laminated pump 27 Hot water storage tank 30 Water / refrigerant heat exchanger 33, 38 Latent heat heat storage part 36 Hot water bypass pipe

Claims (7)

A refrigerant circulation circuit comprising a hot water storage tank, a compressor and a radiator, a water / refrigerant heat exchanger in heat exchange relationship with the radiator, and water / refrigerant heat exchange of water taken from the bottom of the hot water storage tank A stacking pump that heats and returns to the upper part of the hot water storage tank, a water supply pipe that supplies water from the lower part of the hot water storage tank, and water at the bottom of the hot water storage tank for heat exchange to the water / refrigerant heat exchanger A heat pump hot water supply apparatus comprising: a heat storage means configured to include at least a first flowing water channel that flows and a second flowing water channel that generates heat by exchanging heat with water supplied from the water supply pipe. The heat pump hot water supply apparatus according to claim 1, further comprising: a hot water discharge pipe for discharging hot water stored in the hot water storage tank, provided at an upper portion of the hot water storage tank; and a hot water bypass pipe connecting the second flowing water channel and the hot water discharge pipe. The heat pump hot-water supply apparatus according to claim 2, wherein the heat storage means forms a first flow path and a second flow path by stacking flat heat storage plates, which are latent heat storage materials, in a stacked manner. The heat pump hot-water supply device according to claim 3, wherein the melting point of the latent heat storage material is set to an annual average water temperature. The heat pump hot water supply apparatus according to any one of claims 1 to 4, wherein the heat storage means is provided separately from the hot water storage tank. The heat pump hot water supply apparatus according to any one of claims 1 to 4, wherein the heat storage means is configured at the bottom of the hot water storage tank. The heat pump hot water supply apparatus according to any one of claims 1 to 6, wherein the refrigerant is carbon dioxide, and the pressure is equal to or higher than a critical pressure.

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