JP5168384B2 - Heat pump water heater - Google Patents

Description

  The present invention relates to a heat pump water heater, and more particularly to a heat pump water heater provided with a hot water storage tank capable of supplying hot water to a bathtub, a kitchen or the like.

  As this type of heat pump type hot water supply apparatus, there is one conventionally provided with a hot water storage tank (see, for example, Patent Document 1). The heat pump water heater performs a boiling operation in which low temperature water flows out from the bottom of the hot water storage tank, and the low temperature water is boiled up by a heat pump heating source and returned to the upper part of the hot water storage tank. A hot water pipe is connected to the upper part of the hot water storage tank, and hot water (hot water) in the hot water storage tank is discharged through the hot water pipe when hot water is supplied. The hot water in the hot water storage tank is used as a heat source of a heat exchanger for bathing and keeping warm.

JP 2004-197958 A

  When the bath is reheated using hot water from the hot water storage tank as described above, high temperature hot water is supplied from the upper part of the hot water storage tank to the heat exchanger, where the heat is exchanged and the temperature drops. Then, warm water (medium hot water) with an intermediate temperature of about 30 ° C. to 50 ° C. is returned to the lower part of the hot water storage tank. For this reason, hot water storage tanks often store medium-temperature hot water in the middle in the vertical direction. In particular, when reheating from the remaining hot water of the previous day, the amount of hot water in the hot water storage tank is greatly reduced, and a large amount of medium-temperature hot water can be formed in the lower part of the hot water storage tank. At that time, in order to secure the amount of hot water, the heat pump heating source was operated due to a decrease in the amount of hot water in the hot water storage tank, but the medium hot water was returned to the lower part of the hot water storage tank. There wasn't. In addition, a large amount of hot water is generated in the middle portion of the hot water storage tank, the hot water temperature in the hot water storage tank is lowered, and the temperature boundary line in the hot water storage tank is disturbed. When the boiling operation is performed with the medium temperature hot water remaining, the medium temperature hot water is supplied to the heat pump heating source. When such medium temperature hot water is heated by a heat pump heating source, there is a problem that the efficiency is low and COP (energy consumption efficiency) is lowered.

  The present invention has been provided in view of the above-described problems, and suppresses the generation of hot water in the hot water storage tank during reheating of the bath and ensures the amount of hot water in the hot water storage tank during reheating, while boiling at night. The present invention provides a heat pump type water heater intended to improve the upper efficiency.

Therefore, in the heat pump hot water supply apparatus according to claim 1 of the present invention, low temperature water is caused to flow out from the bottom of the hot water storage tank 1, and the low temperature water is boiled by the heat pump heating source 3 and returned to the upper part of the hot water storage tank 1. Boiling operation or reheating operation in which high temperature hot water in the upper part of the hot water storage tank 1 is passed through the hot water circulation path 24 to exchange heat with hot water from the bathtub 30 in the external heat exchanger 25 provided in the hot water circulation path 24. When the heat pump heating source 3 is in an ON state and the reheating operation is performed when the heat pump heating source 3 is stable, hot water from the heat pump heating source 3 is used. directly supplies the hot water circulation path 24, to return the medium temperature water after the heat exchange in the hot water circulation channel 24 directly to the heat pump type heating source 3 without returning to the hot water storage tank 1, the heat pump type heating source 3 But I when not stable, the hot water from the heat pump heat source 3 not supplied to the hot water circulation path 24, is characterized in that it comprises a control means 41 for returning the lower portion of the hot water storage tank 1.

In the heat pump hot water supply apparatus according to claim 2 of the present invention, when the reheating operation is performed when the heat pump heating source 3 is not yet stable, the hot water in the hot water storage tank 1 is supplied with the hot water circulation path 24. It is characterized by supplying to .

In the heat pump hot water supply apparatus according to claim 3 of the present invention, after supplying the hot water having been supplied from the hot water storage tank 1 to the hot water circulation path 24 and heat-exchanged directly to the heat pump heating source 3, It returns to the lower part of the said hot water storage tank 1, It is characterized by the above-mentioned .

  According to the heat pump hot water supply apparatus of the first aspect of the present invention, the hot water from the heat pump heating source is directly supplied to the hot water circulation path, and the medium hot water after heat exchange in the hot water circulation path is Since it is directly returned to the heat pump type heat source without returning to the hot water storage tank, the hot water after the heat exchange to the external heat exchanger in the reheating operation is not returned to the hot water storage tank. Therefore, the hot water that has been cooled by the chasing operation does not flow into the hot water tank, and no hot water is generated in the hot water tank. The night boiling efficiency can be further improved while securing the amount of hot water in the hot water storage tank.

According to the heat pump type hot water supply apparatus of claim 2, the hot water from the hot water storage tank is supplied to the hot water circulation path until the heat pump type heating source is stabilized from the time of start-up, and the heat pump type heating source is stabilized. After that, high-temperature hot water from a heat pump heating source is supplied to the hot water circulation path, so that the reheating operation can be efficiently performed without interrupting the reheating operation .

According to the heat pump type hot water supply apparatus of claim 3, since hot water of medium or higher temperature heated by the heat pump type heating source is supplied to the lower part of the hot water storage tank, the generation of the intermediate hot water in the lower part of the hot water storage tank is generated. The amount of hot water in the hot water storage tank during the chasing operation can be secured .

It is a schematic block diagram of the heat pump type hot water heater in embodiment of this invention. It is a block diagram relevant to the chasing operation in the embodiment of the present invention. It is a flowchart in the case of performing a chasing operation in the embodiment of the present invention. It is a flowchart in the case of performing a chasing operation in the embodiment of the present invention. It is a piping lineblock diagram in an embodiment of the invention. It is a piping lineblock diagram in a 2nd embodiment of the present invention. It is a piping block diagram in the 3rd Embodiment of this invention. It is a piping block diagram in the 4th Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a simplified view of a main part of a heat pump type hot water heater. The heat pump type hot water heater includes a hot water storage tank 1 and can supply (hot water) the hot water in the hot water storage tank 1 to the bathtub 30 or supply (hot water) to a kitchen or a shower.

  In this case, hot water is stored in the hot water storage tank 1 using a heat pump type heating source 3 (hereinafter simply referred to as a heat pump 3) as a heat source unit having the refrigerant circuit S. The refrigerant circuit S is configured by sequentially connecting a compressor 4, a water heat exchanger 5, an expansion valve 6, and an air heat exchanger (evaporator) 7. A circulation path 8 is connected to the hot water storage tank 1, and a first water pump 9 and a heat exchange path 10 are interposed in the circulation path 8. In this case, the heat exchange path 10 is constituted by the water heat exchanger 5. As the refrigerant of the refrigerant circuit S, carbon dioxide gas (CO2) or the like whose high pressure side is operated at a supercritical pressure is used.

  The circulation path 8 includes a first circulation path 11 a having a first switching valve 21 including the first pump 9 and a three-way valve, and hot water (heated water) from the first circulation path 11 a to the hot water storage tank 1. And a second circulation path 11b to be returned. One end side of the first circulation path 11 a is connected to a water intake 12 opened at the bottom of the hot water storage tank 1, and the other end side is connected to the heat exchange path 10. The second circulation path 11b is provided with a second switching valve 22 comprising a three-way valve, one end of which is connected to the heat exchange path 10, and the other end is an upper hot water established at the top of the hot water storage tank 1. Connected to the inlet 13. The second switching valve 22 is connected with a bypass passage 15 having one end connected to the second switching valve 22 and the other end connected to the inlet 14 opened at the bottom of the hot water storage tank 1. Further, a hot water pipe 17 provided with an open / close valve 16 is connected to the upper hot water inlet 13 at the top of the hot water storage tank 1, and hot water is discharged from the hot water tank 1 from the top of the hot water storage tank 1, and the bathtub 30. Can be supplied (hot water supply) to a kitchen or shower (hot water supply). A water supply port 18 is opened at the bottom of the hot water storage tank 1, and a water supply pipe 19 is connected to the water supply port 18.

  By the way, the hot water of the hot water storage tank 1 is used as a heat source for chasing the bath and keeping warm. That is, as shown in FIG. 1, a hot water circulation path 24 is connected to the upper hot water inlet 13 and the first switching valve 21 established in the upper part of the hot water storage tank 1, and an external heat exchanger 25 is connected to the hot water circulation path 24. The heat exchange path 26 comprised by these is interposed. A recirculation circuit 27 for reheating is connected to the bathtub 30, and the heat recirculation path 28 constituted by the external heat exchanger 25 and a bath water recirculation pump are connected to the recirculation circuit 27. 29 is interposed.

  Next, the boiling operation of this heat pump type hot water heater will be described. While driving the compressor 4, the 1st pump 9 for water circulation is driven. Then, stored water (hot water) flows out from the water intake 12 provided at the bottom of the hot water storage tank 1 to the circulation path 8, and this flows through the heat exchange path 10 of the circulation path 8. Further, the refrigerant discharged from the compressor 4 returns to the compressor 4 through the water heat exchanger 5, the expansion valve 6, and the air heat exchanger 7 in order. Therefore, the water flowing through the heat exchange path 10 of the circulation path 8 is heated by the water heat exchanger 5. Accordingly, the low temperature water at the bottom of the hot water storage tank 1 flows out from the water intake 12, is heated by the water heat exchanger 5 to become high temperature hot water, and is returned from the upper hot water inlet 13. By continuously performing such an operation, hot water can be stored in the hot water storage tank 1.

  FIG. 2 is a block diagram of a related portion in the case of reheating a bath according to the present invention. A plurality of control devices 41 composed of a microcomputer are arranged in the vertical direction of the hot water storage tank 1 and the hot water storage tank. A tank hot water temperature sensor 42 (42a to 42c (refer to FIG. 1)) for detecting the hot water temperature of each layer in 1, a bath temperature sensor 43 for detecting the temperature of hot water in the bathtub 30, and a hot water amount in the bathtub 30 are detected. A hot water sensor 44 for detecting the temperature of hot water output from the heat pump 3 disposed in the circulation path 8 on the output side of the heat pump 3, and a reheating switch 47 for reheating. Etc. are input. The operation panel installed on the wall surface of the bathroom is provided with a bath set temperature operation unit 45 for arbitrarily setting the hot water temperature of the bathtub 30, and a signal from the bath set temperature operation unit 45 is provided. Is also input to the control device 41.

  The control device 41 controls the switching of the first switching valve 21, the second switching valve 22, and the third switching valve 23 described later, or the first pump 9, the second pump 32 described later, and the bath. The hot water circulation pump 29 is turned on and off. Furthermore, the heat pump 3 that is normally turned on and off automatically is forcibly operated by the control device 41 under a predetermined condition described later.

  Next, the control operation in the case of bathing will be described with reference to FIGS. 3, 4 and 5 showing flowcharts. First, when the heat pump 3 starts up (for example, when the hot water temperature output from the heat pump 3 does not reach a predetermined temperature), hot water is circulated through the path a shown in FIG. Here, the predetermined temperature is, for example, 5 ° C. lower than the target boiling temperature of the previous day in the heat pump 3 (hereinafter, the same applies to the predetermined temperature). That is, the control device 41 is circulated so that hot water from the heat pump 3 circulates along the path to the second switching valve 22, the bypass path 15, the hot water storage tank 1, the first switching valve 21, the first circulation path 11 a, and the heat pump 3. The first pump 9 is turned on, and the first switching valve 21 and the second switching valve 22 are switched.

  When hot water circulates through the path a and the temperature of the hot water output from the heat pump 3 reaches the predetermined temperature after a while, that is, when the heat pump 3 is stable, it is output from the heat pump 3. Hot water passes through the second switching valve 22, the second circulation path 11 b, the upper hot water inlet 13 of the hot water storage tank 1, the hot water storage tank 1, the first switching valve 21, the first circulation path 11 a, and the path b to the heat pump 3. The controller 41 turns on the first pump 9 so as to circulate, and controls to switch the first switching valve 21 and the second switching valve 22. In the subsequent hot water circulation path, the pump and the switching valve are controlled in accordance with the circulation path, and therefore the description of the operation of the first pump 9 and the first switching valve 21 is omitted.

  Next, in step S1 shown in FIG. 3, when there is a signal from the reheating switch 47, the process proceeds to step S2 to determine whether or not the heat pump 3 is currently in operation. If the heat pump 3 is in operation, the process proceeds to step S3, where it is determined whether or not the heat pump 3 is stable, that is, whether a predetermined capacity and a predetermined temperature have been reached. Here, the predetermined capacity of the heat pump 3 refers to, for example, the rated capacity of the heat pump 3, and refers to a case where the hot water temperature output from the heat pump 3 reaches 90 ° C., for example. It is determined from the temperature detection signal from the heat pump temperature sensor 46 whether the control device 41 has reached a predetermined capacity. If the heat pump 3 has reached the predetermined capacity and the predetermined temperature, the process proceeds to step S5, and the hot water from the heat pump 3 is transferred to the second switching valve 22, the second circulation path 11b, the hot water circulation path 24, the first switching valve 21, The chasing operation is performed on the first circulation path 11a and the path e returning to the heat pump 3. In other words, the circulation path e is a case where the reheating operation is performed without going through the hot water storage tank 1, and the hot water in the hot water storage tank 1 is not used, so that no hot water is generated in the hot water storage tank 1, The amount of hot water in the hot water storage tank 1 is also secured. And as shown to step S6, when the hot water temperature of the bathtub 30 turns into preset temperature, a chasing operation is complete | finished.

  In step S3, when the hot water from the heat pump 3 has not reached the predetermined temperature, the process proceeds to step S4, and the hot water is circulated along the path d shown in FIG. That is, the second switching valve 22, the bypass path 15, and the path from the lower part of the hot water storage tank 1 to the upper part, the hot water circulation path 24, the first switching valve 21, the first circulation path 11 a, and the heat pump 3. When the hot water from the heat pump 3 reaches a predetermined temperature, the process proceeds from step S3 to step S5, and the reheating operation is performed along the route e as described above.

  On the other hand, when the heat pump 3 is not operated in step S2, as shown in step S7 of FIG. 4, the control device 41 calculates the reheating time. That is, the reheating time is calculated using hot water only in the hot water storage tank 1 from the bath setting temperature at the start of reheating, the current hot water temperature, the amount of hot water, and the hot water temperature in the hot water storage tank 1. Here, the control device 41 takes in data from the bath set temperature operation unit 45, the bath temperature sensor 43, the bath water amount sensor 44, and the tank hot water temperature sensor 42 and performs calculation. Next, the process proceeds to step S8, and it is determined whether or not the calculation result of the chase time calculated in step S7 is equal to or longer than a time during which the heat pump 3 can sufficiently produce the capacity. Here, if the time until the hot water temperature of the bathtub 30 reaches the set temperature is within about 15 minutes, for example, if it is within about 15 minutes, the process proceeds to step S9 to perform the chasing operation on the route c. . If it is about 15 minutes or longer, the process proceeds to step S10 and the heat pump 3 is turned on.

  That is, in step S9, the heat pump 3 is continuously turned off, and as shown in FIG. 5, the hot water circulation path 24, the first switching valve 21, the first circulation path 11a, the heat pump 3, the first The reheating operation is performed in the circulation valve c below the 2 switching valve 22, the bypass path 15 and the hot water storage tank 1. Then, when the hot water temperature of the bathtub 30 reaches the set temperature, the chasing operation is ended (see step S6 in FIG. 3).

  After the heat pump 3 is turned on in step S10, the process proceeds to step S11, where it is determined whether or not the heat pump 3 has reached a predetermined capacity or a predetermined temperature. The process proceeds to S12, and the chasing operation is performed on the same route d as described above. When the heat pump 3 reaches the predetermined capacity and the predetermined temperature in step S11, the process proceeds to step S5 shown in FIG. 3, and the reheating operation is performed in the circulation path e without passing through the hot water storage tank 1 as described above. . Since step S5 and subsequent steps are the same as described above, description thereof is omitted.

  As described above, in this embodiment, when the reheating operation is performed and the heat pump 3 does not reach the predetermined capacity and the predetermined temperature (when the heat pump 3 starts up), the upper part of the hot water storage tank 1, the hot water circulation path. 24, the first switching valve 21, the first circulation path 11 a, the heat pump 3, the second switching valve 22, the bypass path 15, and a path d that circulates to the lower part of the hot water storage tank 1. In this case, hot water of medium or higher temperature warmed by the heat pump 3 is supplied to the lower part of the hot water storage tank 1, so that the generation of intermediate hot water in the lower part of the hot water storage tank 1 can be suppressed, and hot water storage during reheating operation is performed. The amount of hot water in the tank 1 can be secured.

  Furthermore, in the case of performing a reheating operation, when the heat pump 3 is stable and has reached a predetermined capacity and a predetermined temperature, the heat pump 3, the second circulation path 11b, the hot water circulation path 24, the first It becomes the path | route of e which circulates to the switching valve 21 and the 1st circulation path 11a. Therefore, in such a case, the hot water after the heat exchange with the external heat exchanger 25 in the reheating operation is not returned to the hot water storage tank 1, but is returned to the heat pump 3 side. Therefore, the hot water storage tank 1 There is no medium-temperature hot water that has become low in the reheating operation, and no hot water is generated in the hot water storage tank 1, ensuring the amount of hot water in the hot water storage tank 1 during the reheating operation. However, the night boiling efficiency can be further improved.

  Further, as shown in steps S10 to S12 of FIG. 4, the heat pump 3 is turned on and the reheating operation is performed along the circulation path d until the heat pump 3 is stabilized until the heat pump 3 reaches a predetermined temperature or the like. When the heat pump 3 has reached a predetermined temperature and is stable, as shown in step S5 in FIG. 3, high-temperature hot water is directly switched from the heat pump 3 to the hot water circulation path 24 without passing through the hot water storage tank 1, and the external heat exchanger 25 is supplied. Since the hot water after the heat exchange at the hot water is returned to the heat pump 3 without being returned to the hot water storage tank 1, the hot water operation is performed without interrupting the hot water operation. it can.

(Second Embodiment)
FIG. 6 shows a piping configuration of the second embodiment. Compared with FIG. 5, a return pipe 33 is connected between the hot water circulation path 24 and the bottom of the hot water storage tank 1, and a second pump is connected to the return pipe 33. 32, and other configurations are the same as those in FIG.

  Also in the case shown in FIG. 6, the control operation is the same as the flowchart shown in FIGS. 3 and 4. In the description of FIG. 6, the description will be made in the order of the circulation paths a to e according to predetermined conditions, not the order of the flowcharts. I will do it. First, in the case where there is no follow-up command, when the heat pump 3 has not reached the predetermined temperature, that is, when the heat pump 3 starts up, the hot water becomes a circulation path of a. In other words, the heat pump 3, the second switching valve 22, the bypass path 15, the bottom in the hot water storage tank 1, the first switching valve 21, the first circulation path 11 a, and the path a that circulates to the heat pump 3.

  Next, when the heat pump 3 reaches a predetermined temperature, that is, when the heat pump 3 is stable, the hot water becomes a circulation path of b. In other words, the heat pump 3, the second switching valve 22, the second circulation path 11 b, and the path b that circulates from the top of the hot water storage tank 1 to the bottom, the first switching valve 21, the first circulation path 11 a, and the heat pump 3.

  Next, there is a follow-up command, and when the heat pump 3 is off, it is the case of step S9 in FIG. 4, and the follow-up operation is performed along the circulation path c. That is, the reheating operation is performed in the upper part of the hot water storage tank 1, the hot water circulation path 24, the return pipe 33, and the path c returning to the bottom of the hot water storage tank 1.

  Next, there is an instruction for a chasing operation, and when the heat pump 3 does not reach the predetermined capacity and the predetermined temperature, that is, when the heat pump 3 starts up, in the case of steps S11 and S12 in FIG. Follow-up driving is performed on the route. That is, the upper part of the hot water storage tank 1, the hot water circulation path 24, the return pipe line 33, the bottom of the hot water storage tank 1, the first switching valve 21, the first circulation path 11a, the heat pump 3, the first switching valve 21, the bypass path 15 and the hot water storage. This is a path d that circulates from the bottom to the top of the tank 1.

  Further, there is an instruction for a reheating operation, when the heat pump 3 reaches a predetermined capacity and a predetermined temperature, that is, when the heat pump 3 is stable, and in the case of step S11 in FIG. 4 to step S5 in FIG. The re-running operation is performed in the circulation path e which does not go through 1. That is, it is a path e that circulates to the heat pump 3, the second switching valve 22, the second circulation path 11 b, the hot water circulation path 24, the first switching valve 21, the first circulation path 11 a, and the heat pump 3.

  Also in this embodiment, the same effect as the previous embodiment can be obtained. In other words, in the reheating operation, the medium-temperature hot water after being heat-exchanged to the external heat exchanger 25 is not returned to the hot water storage tank 1 but is returned to the heat pump 3 side, so that the hot water storage tank 1 is reheated. Medium temperature hot water that has become cold during operation does not flow in, and no hot water is generated in the hot water storage tank 1, while ensuring the amount of hot water in the hot water storage tank 1 during reheating operation, The boiling efficiency can be further improved.

(Third embodiment)
Next, a third embodiment will be described with reference to FIG. The configuration of FIG. 7 divides the first circulation path 11a side as the inflow side and the hot water circulation path 24 side as the outflow side in the upper part of the hot water storage tank 1 compared to the configuration of FIG. The lower configuration is the same as in FIG.

  First, in the case where there is no follow-up command, when the heat pump 3 has not reached the predetermined temperature, that is, when the heat pump 3 starts up, the hot water becomes a circulation path of a. That is, the heat pump 3, the second switching valve 22, the bypass path 15, the bottom of the hot water storage tank 1, the first switching valve 21, the first circulation path 11 a, and the path a that circulates to the heat pump 3.

  Next, when the heat pump 3 reaches a predetermined temperature, that is, when the heat pump 3 is stable, the hot water becomes a circulation path of b. That is, the heat pump 3, the second switching valve 22, the second circulation path 11 b, and the path b that circulates from the upper part to the lower part of the hot water storage tank 1, the first switching valve 21, the first circulation path 11 a, and the heat pump 3.

  Next, there is a follow-up command, and when the heat pump 3 is off, it is the case of step S9 in FIG. 4, and the follow-up operation is performed along the circulation path c. That is, the upper part of the hot water storage tank 1, the hot water circulation path 24, the first switching valve 21, the first circulation path 11 a, the heat pump 3, the second switching valve 22, the bypass path 15, c circulating from the bottom to the upper part of the hot water storage tank 1. This is the route.

  Next, there is an instruction for a chasing operation, and when the heat pump 3 has not reached the predetermined temperature, that is, when the heat pump 3 starts up, in the case of steps S11 and S12 in FIG. A whispering operation is performed. In the present embodiment, the heat pump 3 is stable when it reaches a predetermined temperature. Therefore, when the heat pump 3 starts up, it means that the predetermined temperature has not been reached. When referring to the flowcharts of FIGS. 3 and 4, the “predetermined capacity” portion is omitted. The same applies to the case of FIG. 8 described later.

  There is a command for reheating operation, and when the heat pump 3 starts up, the upper part of the hot water storage tank 1, the hot water circulation path 24, the first switching valve 21, the first circulation path 11a, the heat pump 3, the second switching valve 22, and the bypass path 15 are provided. This is a path d that circulates from the bottom to the top of the hot water storage tank 1.

  Next, there is an instruction for reheating operation, and when the heat pump 3 reaches a predetermined temperature, that is, when the heat pump 3 is stable, this corresponds to the case of step S11 in FIG. 4 to step S5 in FIG. Follow-up operation is performed in the circulation route. That is, it circulates to the upper part of the hot water storage tank 1, the hot water circulation path 24, the first switching valve 21, the first circulation path 11a, the heat pump 3, the second switching valve 22, the second circulation path 11b, and the upper part of the hot water storage tank 1. This is the route.

  Also in this embodiment, the same effect as the previous embodiment can be obtained. In other words, in the circulation path of e when the heat pump 3 is stable, the medium temperature hot water after the heat exchange to the external heat exchanger 25 in the reheating operation is returned to the heat pump 3 side without being returned to the hot water storage tank 1. Therefore, the hot water having a low temperature in the reheating operation does not flow into the hot water storage tank 1, and no intermediate hot water is generated in the hot water storage tank 1. While securing the amount of hot water in the tank 1, the night boiling efficiency can be further improved.

(Fourth embodiment)
FIG. 8 shows a fourth embodiment. The configuration of FIG. 8 is the same as the configuration of the lower side of the hot water storage tank 1 and FIG. First, in the case where there is no follow-up command, when the heat pump 3 has not reached the predetermined temperature, that is, when the heat pump 3 starts up, the hot water becomes a circulation path of a. That is, the heat pump 3, the second switching valve 22, the bypass path 15, the bottom of the hot water storage tank 1, the first switching valve 21, the first circulation path 11 a, and the path a that circulates to the heat pump 3.

  Next, when the heat pump 3 reaches a predetermined temperature, that is, when the heat pump 3 is stable, the hot water becomes a circulation path of b. That is, the heat pump 3, the second switching valve 22, the second circulation path 11 b, and the path b that circulates from the upper part to the lower part of the hot water storage tank 1, the first switching valve 21, the first circulation path 11 a, and the heat pump 3.

  Next, there is a follow-up command, and when the heat pump 3 is off, it is the case of step S9 in FIG. 4, and the follow-up operation is performed along the circulation path c. That is, the upper part of the hot water storage tank 1, the hot water circulation path 24, the return pipe 33, and the path c that circulates from the bottom to the upper part in the hot water storage tank 1.

  Next, there is an instruction for a chasing operation, and when the heat pump 3 has not reached the predetermined temperature, that is, when the heat pump 3 starts up, in the case of steps S11 and S12 in FIG. A whispering operation is performed. That is, the first switching valve 21, the first circulation path 11 a, the heat pump 3, the second switching valve 22, the bypass path 15 from the top of the hot water storage tank 1, the hot water circulation path 24, the return pipe 33, and the bottom of the hot water storage tank 1. This is a path d that circulates from the bottom to the top of the hot water storage tank 1.

  Next, there is an instruction for reheating operation, and when the heat pump 3 reaches a predetermined temperature, that is, when the heat pump 3 is stable, this corresponds to the case of step S11 in FIG. 4 to step S5 in FIG. Follow-up operation is performed in the circulation route. That is, it circulates to the upper part of the hot water storage tank 1, the hot water circulation path 24, the first switching valve 21, the first circulation path 11a, the heat pump 3, the second switching valve 22, the second circulation path 11b, and the upper part of the hot water storage tank 1. This is the route.

  Also in this embodiment, the same effect as the previous embodiment can be obtained. In other words, in the circulation path of e when the heat pump 3 is stable, the medium temperature hot water after the heat exchange to the external heat exchanger 25 in the reheating operation is returned to the heat pump 3 side without being returned to the hot water storage tank 1. Therefore, the hot water having a low temperature in the reheating operation does not flow into the hot water storage tank 1, and no intermediate hot water is generated in the hot water storage tank 1. While securing the amount of hot water in the tank 1, the night boiling efficiency can be further improved.

  1 .... Hot water storage tank, 3 .... Heat pump heating source, 24 ... Hot water circulation path, 25 ... External heat exchanger, 30 ... Bath, 41 ... Control device

Claims (3)

A boiling operation in which low-temperature water flows out from the bottom of the hot water storage tank (1), the low-temperature water is boiled by a heat pump heating source (3) and returned to the upper part of the hot water storage tank (1), or the hot water storage tank (1 The hot water at the top of the hot water circulation channel (24) flows into the hot water circulation path (24), and the external heat exchanger (25) provided in the hot water circulation path (24) exchanges heat with the hot water from the bathtub (30). When the heat pump heating source (3) is on and the reheating operation is performed when the heat pump heating source (3) is stable, the heat pump heating source (3 ) Is directly supplied to the hot water circulation path (24), and the medium temperature hot water after the heat exchange in the hot water circulation path (24) is not returned to the hot water storage tank (1) without being returned to the hot water storage tank (1). (3) to to return directly the heat pump type heating source When 3) is not yet stable, the hot water from the heat pump type heating source (3) not fed to the hot water circulation path (24), control means for returning the lower portion of the hot water storage tank (1) to (41) A heat pump type water heater characterized by comprising. When the reheating operation is performed when the heat pump heating source (3) is not yet stable, the hot water in the hot water storage tank (1) is supplied to the hot water circulation path (24). Item 2. A heat pump type water heater according to Item 1 . After the hot water supplied from the hot water storage tank (1) to the hot water circulation path (24) and heat-exchanged is directly supplied to the heat pump heating source (3), the hot water storage tank (1) is placed below the hot water storage tank (1). The heat pump type water heater according to claim 2, wherein the heat pump type hot water heater is returned .

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