JP3913722B2 - Heat pump water heater - Google Patents

Description

  The present invention relates to a heat pump hot water supply apparatus with a reheating function that performs reheating and heat insulation of bathtub water in a bathtub by indirect heat exchange heating with high temperature water heated in a heat pump refrigerant circuit.

Conventionally, in this type of heat pump water heater with a reheating function, an electric heater is provided in the middle of the circulation path of the bath water, and reheating or keeping warm of the bath water by heating with this electric heater, A heat exchanger is disposed in the tank, and the water in the bathtub is circulated through the heat exchanger so as to retreat or keep warm without using an electric heater (see Patent Document 1), or outside the hot water storage tank A water-to-water heat exchanger is placed in the water-to-water heat exchanger, and hot water in the hot water storage tank is circulated to the heating part side of the water-to-water heat exchanger, and the bathtub water in the bathtub is heated to the heated part side of the water-to-water heat exchanger. There is known a method for recirculating or keeping warm without using an electric heater (see Patent Document 2).
JP 2002-22266 A JP 2003-243275 A

  By the way, using an electric heater to reheat and keep the bath water has the advantage of simplifying the structure for reheating, but it not only consumes much power but also has a low heating capacity during reheating. There was a problem.

  In addition, if a heat exchanger is placed in the hot water storage tank and the bath water in the bathtub is circulated through this heat exchanger to reheat or keep warm without using an electric heater, it can be used for heating during reheating. Since the hot water in the hot water storage tank is directly used, it is possible to increase the reheating heating capacity according to the heat exchange capacity (capacity) of the heat exchanger, but the reheating of the bathtub over a long period of time or frequently. When the function is activated, the temperature of the hot water in the hot water storage tank is lowered throughout the hot water storage tank, and there is a concern that hot water cannot be supplied to the use section when necessary.

  In addition, a water-to-water heat exchanger is placed outside the hot water storage tank, and hot water in the hot water storage tank is circulated to the heating part of the water-to-water heat exchanger, and the bath water in the bathtub is water-to-water heat exchanged. Even if it is circulated to the heated part side of the vessel and reheats or keeps the heat without using an electric heater, the hot water in the hot water storage tank can be used over a long period of time or frequently. Due to the decrease in temperature, there was a concern that hot water could not be supplied to the use section when needed.

  Accordingly, an object of the present invention is to solve the above-described problems of the prior art, and to reduce the use time of hot water supply, such as being unable to supply high-temperature hot water when necessary, while shortening the reheating operation time. .

  The invention described in claim 1 includes a hot water storage tank for storing hot water, a heat pump refrigerant circuit configured by annularly connecting a compressor, a refrigerant-to-water heat exchanger, a decompression device, and an evaporator, a hot water circulation pump, A refrigerant-to-water heat exchanger is connected in an annular shape, and the hot water in the lower part of the hot water tank is circulated to the refrigerant-to-water heat exchanger for heating, and the heated hot water is returned to the upper part of the hot water tank. A hot water storage circuit, a first flow path switching means provided in a hot water storage circuit upstream of the hot water storage circulation pump, a reheating pump and a reheating heat exchanger, The water in the tub is circulated to the heated portion side of the heat exchanger for reheating and heated, and the reheating circuit for returning the heated water to the tub is disposed downstream of the refrigerant-to-water heat exchanger. Second flow path switching hand provided in the hot water storage circuit And a hot water heated by the refrigerant-to-water heat exchanger at the time of reheating operation, with a start end connected to the second flow path switching means and a terminal end connected to the first flow path switching means, Heat is exchanged by flowing to a first heating section provided in the reheating heat exchanger, and the hot water after the heat exchange is for hot water storage upstream of the hot water circulation pump via the first flow path switching means. A second heating unit that has a first reheating heating circuit that returns to the circulation path and a reheating heating pump, and that provides hot water in the upper part of the hot water storage tank to the reheating heat exchanger during reheating operation. The hot water after the heat exchange is provided with a second reheating heating circuit for returning to the intermediate height position in the hot water storage tank.

  According to a second aspect of the present invention, in the heat pump hot water supply apparatus according to the first aspect, the first reheating heating circuit is configured to operate preferentially according to a renewal operation load during the renewal operation. It is characterized by that.

  According to a third aspect of the present invention, in the heat pump hot water supply device according to the first or second aspect, the first reheating heating circuit and the second reheating heating circuit are reheating operation loads during reheating operation. Accordingly, one of them can be operated alone, or both can be operated at the same time, or the operation can be switched.

  According to a fourth aspect of the present invention, in the heat pump hot water supply apparatus according to the first aspect, each of the first flow path switching means and the second flow path switching means is an electric three-way valve.

  In the present invention, when the reheating operation load is large, the heat pump operation of the heat pump unit is used, and at the same time, the reheating heat exchanging capacity of the reheating heat exchanger is increased by using the hot water in the upper part of the hot water storage tank. When the operation can be performed and the reheating operation load is small, the reheating operation using only the heat pump operation of the heat pump unit can be performed without using the hot water in the upper part of the hot water storage tank. It is possible to provide a heat pump hot water supply apparatus that is easy to use while reducing the restrictions on the use of hot water supply, such as being unable to supply hot water when necessary, while shortening.

  Hereinafter, a first embodiment of the present invention will be described with reference to FIG. 1 and FIG. 2. FIG. 1 is an overall configuration diagram showing a reheating operation of the heat pump hot water supply apparatus according to the first embodiment of the present invention. These are the whole block diagrams which show the time of a boiling operation similarly.

  1 and 2, reference numeral 1 denotes a heat pump hot water supply apparatus, and this heat pump hot water supply apparatus has a schematic configuration including a heat pump unit 2 and a hot water supply unit 3 connected to the heat pump unit 2 by inter-unit piping. Reference numeral 4 denotes a bathtub to which hot water is supplied from the heat pump hot water supply apparatus 1 through a hot water pipe (not shown), a faucet (not shown), and the like.

  The heat pump unit 2 includes a variable speed compressor 5, a refrigerant-to-water heat exchanger 6, a decompression device 7 including an electric expansion valve, an evaporator 8, an accumulator 9, a blower 10 that ventilates the evaporator 8, and a heat pump. The control device 11 and the like are accommodated in the exterior body 12.

The compressor 5, the heating unit 6 </ b> A of the refrigerant-to-water heat exchanger 6, the decompression device 7, the evaporator 8, the accumulator 9, and the like are sequentially connected in an annular manner through the refrigerant pipe 13, and mainly carbon dioxide (CO ₂ ). A heat pump refrigerant circuit 14 is used as a refrigerant. The carbon dioxide refrigerant, which is the natural refrigerant, is pressurized to the supercritical pressure by the compressor 5 and sent to the heating unit 6A of the refrigerant-to-water heat exchanger 6, so that the refrigerant-to-water heat exchange is performed. It is possible to heat the hot water flowing to the heated portion 6B side of the vessel 6 to 90 ° C. or higher by heat exchange. The refrigerant-to-water heat exchanger 6 is formed in a structure in which a heating unit 6A through which refrigerant flows and a heated unit 6B through which hot water from the hot water supply unit 3 flows are integrated in a heat exchange relationship.

  The hot water supply unit 3 includes a hot water storage tank 15 for storing hot water heated by the heat pump unit 2, a hot water circulation pump 16, and a reheating heat exchanger 17 for replenishing the bath water of the bathtub 4. The reheating pump 18 and the hot water storage unit control device 19 are accommodated in the outer case 20. The hot water storage tank 15 has a size having a hot water storage amount of about 240 to 370L.

  The hot water storage tank 15, the hot water circulation pump 16, and the heated portion 6 </ b> B of the refrigerant-to-water heat exchanger 6 are annularly connected by a hot water pipe 21 as an inter-unit pipe. A hot water storage circuit 22 is provided for boiling hot water. Here, the lower end portion of the hot water storage tank 15 is provided with an outlet 23 connected to the hot water storage circulation path 22 and a water supply pipe 24A connected to a water pipe (not shown) such as a city water supply, A hot water supply pipe 24 </ b> B for supplying hot water to a utilization part such as the bathtub 4 and a kitchen faucet (not shown) is provided at the top (upper part) of the hot water storage tank 15 and a return port 25 connected to the hot water circulation path 22. Is formed.

  When the hot water circulation pump 16 is in operation, the hot water storage circulation path 22 allows normal temperature water or low temperature water in the lower part of the hot water storage tank 15 to pass from the outlet 23 to the refrigerant-to-water heat exchanger 6 via the hot water circulation pump 16. It circulates to the heated part 6B side, and heat-exchanges with the high-temperature and high-pressure gas refrigerant flowing through the heating part 6A to heat to a high temperature of about 90 ° C. The heated high-temperature water is returned to the return port part 25 of the hot water storage tank 15. To the upper part of the hot water storage tank 15 again.

  Further, upstream of the hot water circulation pump 16 in the hot water circulation path 22, that is, between the hot water circulation pump 16 and the outlet 23, and to be heated 6 </ b> B of the refrigerant-to-water heat exchanger 6. The first electric three-way valve (first flow path switching means) 29A and the second electric three-way valve (for switching the flow path) are provided downstream, that is, between the heated portion 6B and the return port 25. Second flow path switching means) 29B is provided.

  The heated portion 17B of the reheating heat exchanger 17 and the bathtub 4 are connected in an annular shape by a bathtub piping 26A via a reheating pump 18, so as to recharge or keep warm the bathtub water in the bathtub 4. The temperature sensor S for detecting the temperature of the bath water flowing in the reheating circuit 26 is provided upstream of the reheating pump 18. Further, the reheating heat exchanger 17 has a heat exchange relationship between the first heating unit 17A and the second heating unit 17AA through which hot water for heating flows and the heated unit 17B through which bath water from the bathtub 4 flows. It has an integrated structure.

  The reheating circuit 26 is heated by circulating the bath water in the bathtub 4 to the heated portion 17B side of the reheating heat exchanger 17 by driving the reheating pump 18 during reheating operation or heat retention operation. Then, the heated bathtub water returns again into the bathtub 4 and raises the temperature of the bathtub water to a desired temperature.

  Reference numeral 27 denotes a first reheating heating circuit. The first reheating heating circuit 27 has a starting end connected to one connection portion of the second electric three-way valve 29B, and a middle portion of the first reheating heating circuit 27. It is connected to the first heating part 17A of the exchanger 17, and the terminal is connected to one connection part of the first electric three-way valve 29A. Then, the first reheating heating circuit 27 returns the hot water after heat exchange by the first heating unit 17A of the reheating heat exchanger 17 to the hot water storage circulation path 22 upstream of the hot water circulation pump 16. I am doing so.

  Further, the first electric three-way valve 29A communicates the end of the first reheating heating circuit 27 to the hot water storage circulation path 22 upstream of the hot water storage circulation pump 16 by the switching operation thereof, or is not It makes it communicate or operate.

  The second electric three-way valve 29B has a switching operation to switch the start end of the first reheating heating circuit 27 downstream of the heated portion 6B of the refrigerant-to-water heat exchanger 6 to the hot water storage circuit 22. It operates in such a way that it communicates with or does not communicate.

  Then, as shown in FIG. 2, both the first electric three-way valve 29A and the second electric three-way valve 29B are brought into a state of non-communication with the first reheating heating circuit 27, and a boiling operation is performed. is there.

  Reference numeral 28 denotes a second reheating heating circuit. This second reheating heating circuit 28 is provided at the upper part (top) of the hot water storage tank 15 and starts from the outlet 28A. A second heating unit 17AA of the heat exchanger 17 and a reheating heating pump P are provided, and a downstream end of the reheating heating pump P faces an intermediate height position in the hot water storage tank 15. .

  The first reheating heating circuit 28 drives the reheating heating pump P to draw out hot hot water in the upper part of the hot water storage tank 15 from the outlet portion 28A, so that the second reheating of the reheating heat exchanger 17 is performed. The hot water after the heat exchange is returned to the intermediate height position in the hot water storage tank 15 via the reheating and heating pump P.

  1 is a kitchen remote control installed in a kitchen or the like, 31 is a bath remote control installed near the bathroom, and these are all connected to the hot water storage unit control device 19 by a signal line 32. Various operation signals are exchanged with the hot water storage unit control device 19. The bath remote controller 31 includes a bath temperature setting means 33 for setting the temperature of the bath water, a reheating operation switch 34, a heat retention operation switch 35, and the like.

  Further, the heat pump control device 11 and the hot water storage unit control device 19 are connected by a signal line 36, and various control signals are exchanged between the control devices 11 and 19.

  The hot water storage unit controller 19 detects the set temperature set by the bath temperature setting means 33 and the temperature sensor S when an ON signal of the reheating operation switch 34 is input from the bath remote controller 31. The detected temperature (temperature of bath water) is compared by a comparison means (not shown), and if the temperature difference is equal to or greater than a predetermined value (when the reheating operation load is equal to or greater than a predetermined value) Since the demand is large, the first reheating heating circuit 27 and the second reheating pump 18 are controlled by driving the reheating pump 18 and controlling both the hot water recirculation pump 16 and the reheating heating pump P. A reheating operation is performed in which both reheating heating circuits 28 are used together.

  Further, when the temperature difference between the set temperature and the detected temperature is less than a predetermined value (when the reheating operation load is less than a predetermined value), since the heat requirement is small, the hot water storage unit control device 19 includes the reheating pump 18. And the hot water recirculation pump 16 is driven (the reheating heating pump P is stopped), and the reheating operation is performed in which the first reheating heating circuit 27 is operated with priority. To do.

  Next, the boiling operation in the first embodiment will be described with reference to FIG. During the heating operation, the first electric three-way valve 29A and the second electric three-way valve 29B are in the state shown in FIG. That is, the first electric three-way valve 29A is in a state where the hot water circulation pump 16 side and the outlet 23 side below the hot water tank 15 are in communication with each other, and the terminal of the first reheating heating circuit 27 is closed. In the second electric three-way valve 29B, the downstream side of the heated portion 6B of the refrigerant-to-water heat exchanger 6 and the upstream side of the return port portion 25 are in communication with each other, and the first reheating heating circuit 27 The starting end of is closed.

  When the hot water storage circulation pump 16 is driven in this state, the low temperature water in the lower part of the hot water storage tank 15 flows from the outlet 23 to the heated portion of the first electric three-way valve 29A, the circulation pump 16, and the refrigerant water heat exchanger 6. It is circulated to 6B. The low-temperature water circulated to the heated part 6B of the refrigerant water heat exchanger 6 is heated and heated to about 90 ° C. by exchanging heat with the high-temperature and high-pressure gas of the carbon dioxide refrigerant flowing through the heating part 6A. The heated high-temperature water does not flow to the first reheating and heating circuit 27 side because the start end of the first reheating and heating circuit 27 is closed by the second electric three-way valve 29B. It flows to the hot water storage tank 15 side via the three-way valve 29B, and is returned from the return port 25 to the upper part in the hot water storage tank 15.

  When the above-described boiling operation is continued, the hot water tank 15 moves from the upper part to the middle part and further to the lower part in the hot water tank 15, and the hot water is stored in most of the hot water tank 15. It becomes possible. The hot water stored in the hot water storage tank 15 in this manner is supplied to a use section such as the bathtub 4, kitchen, or washroom through the hot water supply pipe 24 </ b> B.

  Next, the bath water reheating operation will be described with reference to FIG. For example, when the reheating operation switch 34 of the bath remote controller 31 is turned on, the operation signal is input to the hot water storage unit control device 19. In response to the input of this operation signal, the hot water storage unit control device 19 switches the first electric three-way valve 29A and the second electric three-way valve 29B from the state shown in FIG. 2 to the state shown in FIG.

  That is, in the first electric three-way valve 29A, the hot water circulating pump 16 side and the outlet 23 side below the hot water tank 15 are closed, and the first reheating heating circuit 27 is terminated at the hot water circulating pump 16 side. The second electric three-way valve 29B is in communication with the upstream hot water storage circulation path 22, and the starting end of the first reheating heating circuit 27 is located downstream of the heated portion 6B of the refrigerant-to-water heat exchanger 6. While being in communication, the hot water storage circuit 22 upstream of the return port 25 is closed.

  When the above-described flow path switching operation of the first electric three-way valve 29A and the second electric three-way valve 29B is completed, the hot water storage unit controller 19 drives the hot water storage circulation pump 16 and the reheating pump 18. . Here, the bath water in the bathtub 4 circulates in the reheating circuit 26 by driving the reheating pump 18, and at this time, the temperature set by the bath temperature setting means 33 and the temperature sensor S are detected. When the difference from the detected temperature is equal to or greater than a predetermined value (for example, 5 deg or more), the hot water storage unit control device 19 drives both the hot water circulation pump 16 and the reheating heating pump P. Start driving.

  Then, the hot water circulation pump 16 is driven to circulate hot water in the hot water circulation path 22 through the circulation pump 16 to the heated portion 6B of the refrigerant body water heat exchanger 6, and this refrigerant body water heat. The hot water circulated to the heated part 6B of the exchanger 6 is heated to about 90 ° C. by exchanging heat with the high-temperature / high-pressure gas of the carbon dioxide refrigerant flowing through the heating part 6A. The heated high-temperature water does not flow to the hot water storage tank 15 side, flows to the first reheating heating circuit 27 side, and is circulated to the first heating unit 17A of the reheating heat exchanger 17. The high-temperature water circulated to the first heating unit 17A and the bath water circulated to the heated portion 17B of the reheating heat exchanger 17 through the reheating circuit 26 as the reheating pump 18 is driven. Heat exchange is performed and the temperature of the bath water is increased. The bathtub water heated by the heated portion 17B of the reheating heat exchanger 17 is returned to the bathtub 4 again, and the temperature of the entire bathtub water in the bathtub 4 is gradually increased. The hot water whose temperature has decreased after the heat exchange in the first heating unit 17A is returned to the hot water storage hot water circulation path 22 upstream of the hot water circulation pump 16 via the first electric three-way valve 29A.

  On the other hand, by driving the reheating heat pump P, the hot water in the upper part of the hot water storage tank 15 is led out from the outlet 28A to the second reheating heating circuit 28, and the second heat exchanger 17 of the reheating heat exchanger 17 is driven. It is circulated to the heating unit 17AA. The high-temperature water circulated to the second heating unit 17AA exchanges heat with the bath water flowing through the heated portion 17B, and combines the bath water with the heat exchange action in the first heating unit 17A. Heat up the temperature in a high state. Then, the hot water whose temperature has decreased after the heat exchange in the second heating unit 17AA is passed from the end of the reheating heat pump P facing the intermediate height position in the hot water storage tank 15 via the reheating heat pump P. It is returned to the hot water storage tank 15.

  The reheating operation described above is a renewal operation in which both the first reheating heating circuit 27 and the second reheating heating circuit 28 are used in combination to be in an operating state at the same time. This first reheating heating circuit The reheating operation using both the heat reheating circuit 27 and the second reheating heating circuit 28 has a high heat exchanging capacity of the reheating heat exchanger 17 and is effective for shortening the reheating time.

  During the reheating operation described above, the difference between the set temperature set by the bath temperature setting means 33 and the detected temperature detected by the temperature sensor S is less than a predetermined value (for example, less than 3 deg). Then, the hot water storage unit control device 19 shifts to a reheating operation in which the driving of the reheating and heating pump P is stopped while the drive of the revolving hot water pump 16 is continued.

  The reheating operation in which the driving of the reheating pump P is stopped is a reheating operation in which only the first reheating heating circuit 27 is in an operating state. Compared to the reheating operation in which the second reheating heating circuit 28 is operated simultaneously, the heat exchanging capacity of the reheating heat exchanger 17 is substantially halved, but the first reheating heating circuit 27 is independent. In the reheating operation in operation, there is an advantage that the hot water in the hot water storage tank 15 is not consumed.

  In the reheating operation described above, the reheating operation switch 34 of the bath remote controller 31 is pressed again to cancel the reheating operation, or the detection temperature of the temperature sensor S is set by the bath temperature setting means 33. It will automatically stop when it reaches temperature.

  Since the present invention is configured as described above, the difference between the set temperature set by the bath temperature setting means 33 and the detected temperature detected by the temperature sensor S during the reheating operation is determined in advance. In the case of the predetermined value or more (for example, 5 deg or more), the hot water storage unit control device 19 drives both the hot water storage circulation pump 16 and the reheating heating pump P to generate the first reheating heating circuit 27 and the second reheating heating circuit 27. Both of the reheating and heating circuits 28 are used in a simultaneous operation state, and while using the heat pump operation of the heat pump unit 2, the reheating operation of the bathtub water using the high temperature water in the upper part of the hot water storage tank 15 is executed. When the difference between the set temperature set by the bath temperature setting means 33 and the detected temperature detected by the temperature sensor S is less than a predetermined value (for example, less than 3 degrees), While continuing to drive the circulation pump 16, the operation is shifted to the reheating operation in which the driving of the reheating heating pump P is stopped, and the operation is switched to the reheating operation in which only the first reheating heating circuit 27 is in an operating state. . Therefore, when the reheating operation load is large, the heat exchange capacity of the reheating heat exchanger 17 is increased to shorten the reheating time, and when the reheating operation load is small, the first reheating heating is performed. The hot water in the hot water storage tank 15 can be operated without using the hot water in the hot water tank 15, and the hot water supply can be used when necessary, while shortening the time for the hot water operation. The restriction can be relaxed and a heat pump hot water supply device with excellent usability can be obtained.

  In addition, at the time of the warming operation of the bath water, the rotation speed of the compressor 5 of the heat pump unit 2 is lowered to a low rotation speed so as to perform the low output operation in which the heating capacity of the heat pump unit 2 is lowered and for the first reheating. It is preferable that the heating circuit 27 is operated alone.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention.

It is a whole lineblock diagram showing the time of reheating operation of the heat pump hot-water supply apparatus concerning the 1st example of the present invention. Similarly, it is the whole block diagram which shows the time of boiling operation of the heat pump hot-water supply apparatus which concerns on 1st Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heat pump hot-water supply apparatus 2 Heat pump unit 3 Hot-water supply unit 4 Bathtub 5 Compressor 6 Refrigerant-to-water heat exchanger 6A Heating part of refrigerant-to-water heat exchanger 6B Heated part of refrigerant-to-water heat exchanger 7 Decompression apparatus 8 Evaporator 14 Heat Pump Refrigerant Circuit 15 Hot Water Storage Tank 16 Hot Water Circulation Pump 17 Reheating Heat Exchanger 17A First Heating Section of Reheating Heat Exchanger 17AA Second Heating Section of Reheating Heat Exchanger 17B Reheating Heat Exchanger Heated part 18 Reheating pump 22 Hot water storage circuit 23 Outlet part 25 Return opening part 26 Reheating circuit 27 First reheating heating circuit 28 Second reheating heating circuit 28A Outlet part 29A First electric three-way valve (First flow path switching means)
29B Second electric three-way valve (second flow path switching means)
P Reheating heating pump

Claims (4)

A hot water storage tank for storing hot water, a heat pump refrigerant circuit configured by annularly connecting a compressor, a refrigerant-to-water heat exchanger, a decompression device, and an evaporator;
A circulation pump for hot water storage and a refrigerant-to-water heat exchanger are connected in an annular shape, and the hot water in the lower part of the hot water tank is circulated through the refrigerant-to-water heat exchanger for heating, and the heated hot water is stored in the hot water storage tank. A hot water storage circuit that returns to the upper part of the inside,
First flow path switching means provided in a hot water storage circulation path upstream of the hot water storage circulation pump;
A reheating pump and a reheating heat exchanger are configured, and the water in the bathtub is circulated to the heated portion side of the reheating heat exchanger to heat the heated water. A scooping circuit that returns to the bathtub,
Second flow path switching means provided in a hot water storage circuit downstream of the refrigerant-to-water heat exchanger;
A start end is connected to the second flow path switching means and a terminal end is connected to the first flow path switching means, and hot water heated by the refrigerant-to-water heat exchanger during the reheating operation is reheated. Heat is exchanged by flowing to the first heating section provided in the heat exchanger, and the hot water after the heat exchange is transferred to the hot water storage circulation path upstream of the hot water circulation pump via the first flow path switching means. A first reheating heating circuit to be returned;
A reheating pump is provided, and the hot water in the upper part of the hot water storage tank is flowed to the second heating part provided in the reheating heat exchanger during reheating operation, and heat is exchanged. The hot-pump hot-water supply apparatus is provided with a second reheating heating circuit for returning hot water to an intermediate height position in the hot water storage tank. 2. The heat pump hot water supply apparatus according to claim 1, wherein the first reheating heating circuit is preferentially operated in accordance with a renewal operation load during the renewal operation. The first reheating heating circuit and the second reheating heating circuit can be operated independently, or both can operate at the same time depending on the reheating operation load during reheating operation. The heat pump hot-water supply apparatus according to claim 1 or 2, wherein The heat pump hot water supply apparatus according to claim 1, wherein the first flow path switching means and the second flow path switching means are each an electric three-way valve.