JP4084272B2 - Heat pump water heater - Google Patents

Description

  The present invention relates to an instantaneous water heating type heat pump hot water supply apparatus that can generate hot water using a heat pump cycle and can discharge the generated hot water as it is without storing it in a hot water storage tank.

In a hot water supply apparatus that uses a heat pump cycle, frost formation occurs in the evaporator depending on the outside air temperature and operating conditions, and therefore, defrosting operation is performed by detecting frost formation.
The prior art heat pump water heater shown in Patent Document 1 is a hot water storage type heat pump water heater that includes a hot water storage tank and uses hot water previously stored in the hot water storage tank, and operates the heat pump cycle to store the hot water tank. When hot water is being stored, if frost formation is detected immediately before the completion of hot water storage and switching to defrosting operation, hot water storage completion is delayed.To prevent this, defrosting operation is required when hot water storage is not complete. Then, the remaining heating amount of water in the hot water storage tank is detected, and if the remaining heating amount is equal to or less than a predetermined amount, the request for the defrosting operation is masked for a predetermined time, and the hot water storage operation is given priority.
That is, as shown in the flowchart of FIG. 4, hot water storage is started when the refrigerant circuit starts operation (step 41). Then, it is determined whether or not the hot water storage is completed (step 42). When the hot water storage is completed, a defrosting operation is performed in preparation for the next hot water storage operation (step 43), and then the hot water storage operation is terminated (step 44). ). On the other hand, if the hot water storage is not completed, it is determined whether or not there is a defrost request (frost formation) (step 45). When the defrosting operation is requested at this time, it is determined whether the remaining heating amount is equal to or less than a predetermined amount (step 46). If it is less than the predetermined amount, mask the request for defrosting operation for a predetermined time, enter the heating priority mode for preferentially storing hot water, start the timer and perform the heating priority mode for a predetermined time (step 48) Thereafter, a defrosting operation is performed (step 47).
JP 2001-255003 A

  However, the above-described conventional configuration is intended for a hot water storage type heat pump water heater, and in an instantaneous water heater type heat pump water heater that can discharge generated hot water without storing it in a hot water tank, When the frost formation is detected during hot water supply of hot water generated by operating and the defrosting operation is performed as it is, there is a problem that hot water shortage may occur.

  This invention solves such a conventional subject, and it aims at providing the heat pump hot-water supply apparatus which suppresses generation | occurrence | production of a hot-water supply in the instantaneous hot water type heat pump hot-water supply apparatus.

The heat pump hot water supply apparatus of the present invention according to claim 1 is a refrigerant circuit in which a compressor, a hot water heat exchanger, a decompressor, and an evaporator are connected in an annular shape to flow a refrigerant, and the supplied water is used as the hot water heat exchanger. A hot water storage tank for storing hot water generated by heat exchange with the refrigerant, and mixing means for mixing the hot water stored in the hot water storage tank with the hot water generated in the water supply heat exchanger and the directly supplied water A heat pump hot water supply apparatus comprising a hot water supply circuit for supplying hot water and hot water supply control means for controlling a mixing ratio of the mixing means so as to obtain a predetermined hot water supply temperature and amount of hot water, and detects frost formation on the evaporator Detection means, defrosting means for defrosting the evaporator when detecting frost formation, and remaining hot water amount detection means for detecting the remaining hot water amount of hot water stored in the hot water storage tank, the hot water supply control means, When frost formation is detected, the amount of remaining hot water above the specified temperature is a specified value. With in the case of lower performing defrosting operation is delayed a predetermined time, the defrosting operation during the period in which a predetermined time delay, when the remaining hot water is detected to be equal to or greater than a predetermined value, the predetermined time The defrosting operation is performed by shortening .
The heat pump hot water supply apparatus of the present invention according to claim 2 comprises a refrigerant circuit in which a compressor, a hot water heat exchanger, a decompressor, an evaporator are connected in an annular shape to flow a refrigerant, and the supplied water is used as the hot water heat exchanger. A hot water storage tank for storing hot water generated by heat exchange with the refrigerant, and mixing means for mixing the hot water stored in the hot water storage tank with the hot water generated by the water supply heat exchanger and the directly supplied water A heat pump hot water supply apparatus comprising a hot water supply circuit for supplying hot water and hot water supply control means for controlling a mixing ratio of the mixing means so as to obtain a predetermined hot water supply temperature and amount of hot water, and detects frost formation on the evaporator Detecting means, defrosting means for defrosting the evaporator when detecting frost formation, remaining hot water amount detecting means for detecting the remaining hot water amount of hot water stored in the hot water storage tank, and remaining hot water amount detecting means detected by the remaining hot water amount detecting means Delay time setting to set a delay time corresponding to the amount of hot water And means, in said hot water supply control means, if it detects frost and performing defrosting operation after the delay time set by the delay time setting means.
According to a third aspect of the present invention, in the heat pump hot water supply apparatus according to the second aspect , the remaining hot water amount becomes a predetermined value or more during the period in which the defrosting operation is delayed by the delay time in the hot water supply control means. When this is detected, the delay time is shortened to perform the defrosting operation.
According to a fourth aspect of the present invention, in the heat pump hot water supply device according to any one of the first to third aspects, the hot water supply control means causes the hot water supply control means to delay the defrosting operation. The hot water supply amount is controlled to a predetermined value or less.
According to a fifth aspect of the present invention, in the heat pump water heater according to any one of the first to fourth aspects, carbon dioxide is used as the refrigerant, and the high pressure side of the refrigerant circuit is operated in a supercritical pressure state. It is characterized by that.

Even if the frost formation of the evaporator is detected during hot water supply, the present invention can suppress the occurrence of hot water out by delaying the start of the defrosting operation when the amount of remaining hot water in the hot water storage tank is small. Further, when it is detected that the amount of remaining hot water has exceeded a predetermined value during a period in which the defrosting of the evaporator is delayed for a predetermined time, the predetermined time is shortened, and the defrosting means performs the defrosting of the evaporator. In addition, the defrosting operation can be performed while suppressing the occurrence of running out of hot water.
Furthermore, when frost formation is detected by the frost detection means, an appropriate delay time is set by performing defrosting of the evaporator after the delay time set by the delay time setting means has elapsed, and the occurrence of hot water is highly accurate. It is possible to perform the defrosting operation while suppressing the pressure.

The heat pump hot water supply apparatus according to the first embodiment of the present invention includes a frost detection means for detecting frost formation on the evaporator, a defrosting means for defrosting the evaporator upon detection of frost formation, and hot water storage in a hot water storage tank. and having a remaining hot water detecting means for detecting the hot water of remaining hot water in the hot water supply control means, if Jo Tokoro temperature higher than the remaining hot water in the case of detecting the frost is below a predetermined value defrosting is delayed a predetermined time When performing the operation and detecting that the amount of remaining hot water has exceeded a predetermined value during a period in which the defrosting operation is delayed for a predetermined time, the defrosting operation is performed by shortening the predetermined time. . According to the present embodiment, when the amount of remaining hot water in the hot water storage tank is small even when frost formation is detected during hot water supply, the occurrence of hot water shortage is suppressed by delaying the start of the defrosting operation. be able to. Further, the defrosting operation can be performed while suppressing the occurrence of hot water shortage.
The heat pump water heater according to the second embodiment of the present invention includes frost detection means for detecting frost formation on the evaporator, defrosting means for defrosting the evaporator upon detection of frost formation, and hot water storage in a hot water storage tank. And a delay time setting means for setting a delay time corresponding to the remaining hot water amount detected by the remaining hot water amount detection means. The hot water supply control means detects frost formation. In this case, the defrosting operation is performed after the delay time set by the delay time setting means has elapsed. According to the present embodiment, when the frost formation of the evaporator is detected during hot water supply and the amount of remaining hot water in the hot water tank is small, the defrosting is performed by appropriately setting the delay time when moving to the defrosting operation. Thus, the defrosting operation can be performed while suppressing the occurrence of hot water shortage with high accuracy.
According to a third embodiment of the present invention, in the heat pump hot water supply apparatus according to the second embodiment, the hot water supply control means has a remaining hot water amount of a predetermined value or more during a period in which the defrosting operation is delayed for a delay time. When it has been detected, the defrosting operation is performed with a reduced delay time. According to the present embodiment, it is possible to prevent the wasteful delay and to perform the defrosting operation early while suppressing the occurrence of running out of hot water.
According to a fourth embodiment of the present invention, in the heat pump hot water supply apparatus according to any of the first to third embodiments, the hot water supply control means has a hot water supply amount by the hot water supply control means during a period in which the defrosting operation is delayed. Is controlled below a predetermined value. According to this embodiment, even when the hot water supply capacity of the heat pump is reduced due to frost formation and the amount of remaining hot water in the hot water storage tank is small, hot water can be supplied while suppressing the occurrence of hot water shortage.
In the heat pump water heater according to the first to fourth embodiments, the fifth embodiment of the present invention uses carbon dioxide as the refrigerant and operates the high pressure side of the refrigerant circuit in a supercritical pressure state. . According to this Embodiment, since hot water can be produced | generated, a hot water storage tank can be reduced in size.

A heat pump water heater in the first embodiment will be described. FIG. 1 is a circuit configuration diagram showing a heat pump hot water supply apparatus according to a first embodiment of the present invention.
The heat pump hot water supply apparatus of the present embodiment includes a refrigerant circuit, a hot water supply circuit, and hot water supply control means. The refrigerant circuit includes a compressor 1 that compresses the refrigerant, a heat exchanger 2 for hot water supply that condenses the refrigerant and heats the water with the heat of condensation, a decompressor 3 that decompresses the refrigerant, and an evaporator 4 that evaporates the refrigerant. A heat pump circuit formed by connection, a bypass circuit 5 for performing defrosting of the evaporator 4, and an on-off valve 6 provided in the bypass circuit 5 are configured. The refrigerant circuit is operated so that an appropriate amount of carbon dioxide is sealed as a refrigerant and the high pressure side is in a supercritical pressure state.
On the other hand, the hot water supply circuit includes, for example, a hot water storage tank 7 for storing hot water generated by exchanging water supplied from a water supply with a refrigerant in the hot water supply heat exchanger 2, and hot water stored in the hot water storage tank 7 and heat for water supply. A first mixing valve 8 that mixes the hot water generated in the exchanger 2 at a variable ratio; a second mixing valve 9 that mixes the hot water that has passed through the first mixing valve 8 and the directly supplied water at a variable ratio; A control valve 10 that controls the amount of water supply, check valves 11 and 12 that prevent backflow of water in the flow path, and a variable capacity water pump 13 and an on-off valve 14 for storing hot water in the hot water tank 7. Composed.
Further, the hot water supply control means receives the temperature sensors 15 to 17 for detecting the remaining hot water amount in the hot water storage tank 7, receives the temperature signals of these temperature sensors 15 to 17, determines the remaining hot water amount, and sends out the remaining hot water amount signal. The remaining hot water detection circuit 18, the flow rate sensor 19 for detecting the amount of hot water supply on the use side, the temperature sensor 20 for detecting the hot water supply temperature, and the hot water supply temperature detected by the temperature sensor 20 in response to the flow rate signal of the flow rate sensor 19 are predetermined. The hot water supply control circuit 21 that controls the mixing ratio of the first mixing valve 8 and the second mixing valve 9 so that the temperature becomes the temperature, the temperature sensor 22 that detects the temperature of the evaporator 4, and the temperature signal of the temperature sensor 22 The defrost control circuit 23 for judging the frost formation of the evaporator 4 and opening the on-off valve 6 of the bypass circuit 5 to defrost the evaporator 4, and the main control for controlling the entire heat pump water heater according to the control flow Like device 24 Constructed.

Next, operation | movement of this heat pump hot-water supply apparatus is demonstrated. First, a hot water storage operation for storing hot water in the hot water tank 7 will be described.
During the hot water storage operation, the main controller 24 closes the flow paths of the first mixing valve 8 and the second mixing valve 9 of the hot water supply circuit, opens the open / close valve 14, and turns on the variable capacity water pump 13. Further, the compressor 1 of the refrigerant circuit is turned on. As a result, the lowermost water in the hot water tank 7 flows into the hot water supply heat exchanger 2 from the capacity variable water pump 13 and exchanges heat with the refrigerant to become hot hot water. Flow into. At this time, the temperature of the hot water flowing into the hot water tank 7 is detected by a temperature sensor or the like (not shown) so that the hot water flowing into the hot water tank 7 has a predetermined temperature, and the capacity of the capacity variable water pump 13 is changed. .
In this embodiment, if 80 ° C. hot water is generated, the water in the hot water storage tank 7 is replaced with 80 ° C. hot water from the upper part to the lower part. When the temperature sensor 15 disposed in the lower part reaches 80 ° C., the remaining hot water amount detection circuit 18 determines that the hot water storage is completed and sends a signal, and the main controller 24 turns off the variable capacity water pump 13 and the compressor 1. To do.

Next, the hot water supply operation will be described. When the use-side currant 25 or the like is opened, the flow rate sensor 19 detects the start of hot water supply, the hot water supply control circuit 21 sends a hot water supply start signal to the main controller 24, and the main controller 24 turns on the compressor 1. Then, the capacity variable water pump 13 is turned off and the on-off valve 14 is closed. The hot water supply control circuit 21 receives signals from the flow rate sensor 19 and the temperature sensor 20, and controls the opening degree of each flow path of the first mixing valve 8 and the second mixing valve 9 so that the hot water supply temperature becomes a predetermined temperature. To do.
Water flowing through the hot water supply circuit at this time is supplied from the water supply and passes through the control valve 10 to branch, one of which flows into the second mixing valve 9 through the check valve 11 and the other from the lower part of the hot water tank 7. It flows into the heat exchanger 2 for hot water supply through the check valve 12. Then, heat is exchanged with the refrigerant in the hot water supply heat exchanger 2 to obtain hot water of medium temperature (for example, about 45 ° C.) and flows into the first mixing valve 8. Further, hot water (for example, about 80 ° C.) stored in the hot water tank 7 is pushed by the water passing through the lower portion and flows into the first mixing valve 8. Accordingly, the first mixing valve 8 mixes hot and medium hot water at a variable ratio so that the temperature detected by the temperature sensor 20 becomes a predetermined temperature (for example, 42 ° C.), and further the second mixing valve 9. Then, the hot water control for obtaining a predetermined hot water supply temperature is performed by mixing the mixed hot water and low-temperature water directly supplied from the water supply at a variable ratio.

Next, control when the temperature sensor 22 detects frost formation on the evaporator 4 during the hot water supply operation will be described with reference to FIG. FIG. 2 is a flowchart showing hot water supply control of the heat pump hot water supply apparatus shown in FIG.
As shown in the figure, when the currant 25 is opened, the flow rate sensor 19 detects the amount of hot water supply and the hot water supply control circuit 21 determines the start of hot water supply (step 1). Turn on to start hot water supply operation (step 2). When the temperature sensor 22 detects the temperature of the evaporator 4 during the hot water supply operation and the defrost control circuit 23 determines that frost is formed (step 3), there is a remaining hot water amount in the hot water storage tank 7 that exceeds a predetermined amount. The remaining hot water detection circuit 18 determines whether or not (step 4).
During the defrosting operation, medium temperature hot water cannot be generated by the hot water supply heat exchanger 2, and during that time, more hot water from the hot water tank 7 is used. Therefore, even in this case, it is necessary to determine a sufficient amount of remaining hot water that does not run out by experimentation. In this embodiment, if the hot water temperature T1 in the hot water tank 7 detected by the temperature sensor 16 disposed in the intermediate part is 80 ° C. or higher (step 4), the hot water tank above the intermediate part has a temperature of 80 ° C. It is determined that the above hot water is stored and a sufficient amount of remaining hot water is secured, and the defrost control circuit 23 opens the on-off valve 6 to perform the defrosting operation (step 5).
On the other hand, if T1 is less than 80 ° C. (step 4), hot water may run out during the defrosting operation. Therefore, the timer starts counting (step 6), and the hot water supply amount is reduced to a predetermined amount or less. Thus, the hot water supply control circuit 21 controls the first mixing valve 8 and the second mixing valve 9 (step 7). In addition, the structure which omits hot water supply amount control of step 7 may be sufficient.
If it is determined that the time τ from the start of the timer count exceeds the predetermined time τ1 (step 8), the process proceeds to the defrosting operation (step 5). Further, until the count time τ of the timer elapses for a predetermined time τ1, flow rate detection is performed to confirm the continuation of hot water supply, and the transition to the defrosting operation is delayed to continue the hot water supply operation (steps 8 and 9). repeat). Furthermore, before τ becomes τ1, when the flow sensor 19 detects the closing of the currant 25 and determines that the hot water supply has been completed (step 9), the process proceeds to the hot water storage operation as it is (step 10).
And if it judges that (tau) became tau 1 during hot water storage operation (Step 11), it will shift to defrosting operation (Step 5). Further, during the hot water storage operation, even before τ becomes τ1 (step 11), if the hot water temperature T1 in the hot water tank 7 detected by the temperature sensor 16 is 80 ° C. or higher (step 12), defrosting is performed. Even if the currant is opened during operation and hot water supply is started, the amount of remaining hot water that does not cause hot water shortage is secured, so the predetermined time is shortened and the defrosting operation is performed (step 5). Further, before τ becomes τ1, and if the hot water temperature T1 is less than 80 ° C., the hot water storage operation is continued (steps 11 and 12 are repeated).

  As described above, in the first embodiment of the present invention, when the amount of remaining hot water in the hot water storage tank is small even if frost formation of the evaporator is detected during hot water supply, the defrosting operation is delayed so that the hot water runs out. Occurrence can be suppressed. Further, when it is detected that the amount of remaining hot water has exceeded a predetermined value during the period in which the defrosting of the evaporator is delayed for a predetermined time, the predetermined time is shortened and the defrosting means performs the defrosting of the evaporator. In addition, the defrosting operation can be performed while suppressing the occurrence of hot water shortage.

Next, a heat pump water heater in the second embodiment will be described. The configuration of the heat pump water heater of this embodiment is the same as that of the first embodiment shown in FIG. And about operation | movement of the heat pump hot-water supply apparatus of a present Example, the point different from 1st Example is taken up, ie, about the control in case the temperature sensor 22 detects the frost formation of the evaporator 4 at the time of hot-water supply driving | operation, FIG. Will be described. FIG. 3 is a flowchart showing hot water supply control of the heat pump hot water supply apparatus according to the second embodiment of the present invention.
As shown in the figure, when the currant 25 is opened, the flow rate sensor 19 detects the flow rate (step 21) and starts the hot water supply operation (step 22). When frosting of the evaporator 4 is detected during the hot water supply operation (step 23), a delay time τ1 for delaying the transition to the defrosting operation is set corresponding to the amount of remaining hot water in the hot water tank 7 (step 23). 24).
During the defrosting operation, medium temperature hot water cannot be generated by the hot water supply heat exchanger 2, and during that time, more hot water from the hot water tank 7 is used. Therefore, τ1 is determined by experiment or the like according to the amount of remaining hot water so that hot water can be avoided as much as possible.

In the present embodiment, τ1 is determined by determining the amount of remaining hot water using the temperature sensor 16 disposed in the intermediate portion and the temperature sensor 17 disposed in the upper portion. That is, if the hot water temperature T1 in the hot water tank 7 detected by the temperature sensor 16 is 80 ° C. or higher, hot water of 80 ° C. or higher is stored above the middle portion, and a sufficient remaining hot water amount is secured. And τ1 = 0 is set (step 24). Then, it is determined that time τ = τ1 = 0 and time τ is the predetermined time τ1 (step 27), and the defrosting operation is immediately performed (step 28).
On the other hand, if T1 is less than 80 ° C. and the hot water temperature T2 detected by the temperature sensor 17 is T2 ≧ 80 ° C., τ1 = a is set, and if T2 <80 ° C., τ1 = b (b>a> 0) is set (step 24). Then, the timer starts counting (step 25), and the hot water supply control circuit 21 controls the first mixing valve 8 and the second mixing valve 9 so that the hot water supply amount is reduced to a predetermined amount or less (step 26). Note that the configuration may be such that the aperture control in step 26 is omitted.
Next, when it is determined that the count time τ of the timer has exceeded the predetermined time τ1 (step 27), the process proceeds to the defrosting operation (step 28). Further, until the set delay time τ1 of the timer count time τ elapses, the hot water supply operation is continued after delaying the transition to the defrosting operation (steps 27 and 29 are repeated).
Furthermore, before τ becomes τ1, when the flow sensor 19 detects the closing of the currant 25 and determines that the hot water supply has been completed (step 29), the flow proceeds to the hot water storage operation as it is (step 30).
When it is determined that τ has become τ1 during the hot water storage operation (step 31), the process proceeds to the defrosting operation (step 28). Further, during the hot water storage operation, even if τ is not equal to τ1, if the hot water temperature T1 in the hot water storage tank 7 detected by the temperature sensor 16 is 80 ° C. or higher (step 32), the defrosting operation is performed. Since the amount of remaining hot water that does not cause the hot water to run out is ensured during the period, the delay time is shortened and the operation proceeds to the defrosting operation (step 28). Further, before τ becomes τ1, and the hot water temperature T1 is less than 80 ° C., the hot water storage operation is continued (steps 31 and 32 are repeated).

  As described above, in the second embodiment of the present invention, when frost formation is detected by the frost detection means, the evaporator is defrosted after the delay time set by the delay time setting means has elapsed, so that an appropriate delay time can be obtained. The defrosting operation can be performed while suppressing occurrence of hot water with high accuracy.

  In the above embodiment, the case where carbon dioxide is used as the refrigerant has been described, but other refrigerants such as R410A refrigerant and HC refrigerant may be used.

  As described above, the present invention is applied to a heat pump hot water supply device that generates hot water using a heat pump cycle and discharges the generated hot water as it is without storing it in a hot water storage tank. For example, an instantaneous water heater for home use Suitable for

The circuit block diagram which shows the heat pump hot-water supply apparatus of 1st Example by this invention The flowchart which shows the hot_water | molten_metal supply control of the heat pump hot-water supply apparatus shown in FIG. The flowchart which shows the hot_water | molten_metal supply control of the heat pump hot-water supply apparatus of 2nd Example by this invention. The flowchart which shows the hot water supply control of the conventional heat pump hot water supply apparatus

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Compressor 2 Heat exchanger for hot water supply 3 Decompressor 4 Evaporator 5 Bypass circuit 6, 14 On-off valve 7 Hot water storage tank 8 First mixing valve 9 Second mixing valve 10 Control valve 11, 12 Check valve 13 Capacity variable water pump 15, 16, 17, 20, 22 Temperature sensor 18 Remaining hot water amount detection circuit 19 Flow rate sensor 21 Hot water supply control circuit 23 Defrost control circuit 24 Main controller 25 Karan

Claims (5)

A compressor, a hot water supply heat exchanger, a decompressor, and an evaporator are connected in an annular shape to flow a refrigerant circuit, and hot water generated by heat exchange of the supplied water with the refrigerant in the hot water supply heat exchanger is stored. A hot water storage tank, a hot water supply circuit for supplying hot water with mixing means for mixing hot water stored in the hot water storage tank, hot water generated in the heat exchanger for water supply and water directly supplied, and a predetermined hot water supply temperature and amount of hot water A heat pump hot water supply apparatus comprising a hot water supply control means for controlling the mixing ratio of the mixing means so as to obtain frost formation detecting means for detecting frost formation of the evaporator, and detecting the frost formation of the evaporator. A defrosting means for performing defrosting, and a remaining hot water amount detecting means for detecting a remaining hot water amount of hot water stored in the hot water storage tank, and when the hot water supply control means detects frost formation, the remaining hot water amount equal to or higher than a predetermined temperature. when but performs defrosting operation in the case of less than the predetermined value is delayed a predetermined time Moni, the defrosting operation during the period in which a predetermined time delay, the remaining hot water is detects that equal to or greater than a predetermined value, and performs the defrosting operation by shortening the predetermined time Heat pump water heater.   A compressor, a hot water supply heat exchanger, a decompressor, and an evaporator are connected in an annular shape to flow a refrigerant circuit, and hot water generated by heat exchange of the supplied water with the refrigerant in the hot water supply heat exchanger is stored. A hot water storage tank, a hot water supply circuit for supplying hot water with mixing means for mixing hot water stored in the hot water storage tank, hot water generated in the heat exchanger for water supply and water directly supplied, and a predetermined hot water supply temperature and amount of hot water A heat pump hot water supply apparatus comprising a hot water supply control means for controlling the mixing ratio of the mixing means so as to obtain frost formation detecting means for detecting frost formation of the evaporator, and detecting the frost formation of the evaporator. Defrosting means for performing defrosting, remaining hot water amount detecting means for detecting the remaining hot water amount of hot water stored in the hot water storage tank, and delay time setting means for setting a delay time corresponding to the remaining hot water amount detected by the remaining hot water amount detecting means The hot water supply control means detects frost formation. The heat pump water heater if you which is characterized in that the defrosting operation after the delay time set by the delay time setting means. In the hot water supply control means, when it is detected that the remaining hot water amount has become a predetermined value or more during a period in which the defrosting operation is delayed, the defrosting operation is performed with the delay time shortened. The heat pump hot-water supply apparatus according to claim 2 , In the hot water supply control means, during the period in which delays the defrosting operation, according to any one of claims 1 to 3, wherein the controller controls the hot water supply amount to a predetermined value or less by the hot water supply control means Heat pump water heater. The heat pump hot water supply apparatus according to any one of claims 1 to 4 , wherein carbon dioxide is used as the refrigerant, and the high pressure side of the refrigerant circuit is operated in a supercritical pressure state.

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