JP2019138601A - Water heater - Google Patents

Abstract

To provide a water heater enabling improvement of safety while using a combustible refrigerant.SOLUTION: A water heater includes: a heat pump device having a refrigerant-water heat exchanger and boiling up hot water by using the refrigerant-water heat exchanger using a combustible refrigerant; a hot water storage tank for storing the hot water boiled up by the refrigerant-water heat exchanger; and a control device for controlling the heat pump device. When a temperature of water flowing in the refrigerant-water heat exchanger reaches a freezing temperature or lower, the control device preferentially uses intermediate temperature water stored in an intermediate portion of the hot water storage tank over high temperature water stored in an upper portion of the hot water storage tank for hot water supply.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a hot water supply apparatus using a combustible refrigerant.

Conventionally, there is a hot water supply apparatus using a combustible refrigerant as a refrigerant to be circulated in a refrigerant circuit. When flammable refrigerant is used, countermeasures must be taken against refrigerant leakage.
As such, Patent Document 1 discloses a heat pump hot water supply apparatus that uses a combustible refrigerant as a refrigerant and includes a gas sensor that detects the presence of the combustible refrigerant.
Patent Document 2 uses a combustible refrigerant as a refrigerant, and includes at least one of a pressure relief valve that adjusts the water pressure in the water circuit and an air vent valve that discharges air in the water circuit. A heat pump cycle device that discharges a combustible refrigerant is disclosed.

JP 2013-047591 A JP 2013-167398 A

  In the technique described in Patent Document 1, when a crack or the like occurs in the heat exchanger or piping for some reason and the flammable refrigerant leaks to the outside of the refrigeration cycle, the leak can be detected by an installed gas sensor. it can. However, in the technique described in Patent Document 1, for example, when a partition wall where heat is exchanged between refrigerant and water in a condensing heat exchanger is torn and flammable refrigerant is mixed into the water side, flammability is caused by boiling operation of the heat pump. The refrigerant may reach the hot water storage tank, and the flammable refrigerant may be released from the faucet during hot water supply.

  The technique described in Patent Document 2 can discharge the combustible refrigerant from the pressure relief valve or the air vent valve when a large amount of the combustible refrigerant is mixed in the water circuit. However, in the technique described in Patent Document 2, when a pinhole or the like is opened and a slow leak of flammable refrigerant occurs, the pressure relief valve or the air vent valve may not operate. In that case, in the technique described in Patent Document 2, it is conceivable that the flammable refrigerant accumulates in the hot water storage tank, and the flammable refrigerant flows out together with the hot water during hot water supply.

  This invention is made | formed in view of the above situations, and it aims at providing the hot-water supply apparatus which suppressed combustible refrigerant | coolant flowing out with warm water.

  A hot water supply apparatus according to the present invention has a refrigerant-water heat exchanger, and uses a combustible refrigerant to heat up hot water in the refrigerant-water heat exchanger, and to boil up in the refrigerant-water heat exchanger. A hot water storage tank for storing hot water and a control device for controlling the heat pump device, the control device, when the temperature of the water flowing through the refrigerant-water heat exchanger becomes below the freezing temperature, The hot water stored in the intermediate part of the hot water storage tank is preferentially used for hot water supply over the hot water stored in the upper part of the hot water storage tank.

  The hot water supply apparatus according to the present invention gives priority to medium-temperature water when the temperature of the water flowing through the refrigerant-water heat exchanger is equal to or lower than the freezing temperature, even when the refrigerant detection is not properly performed due to a slow leak or the like. By using for, it can restrict | limit that a combustible refrigerant | coolant flows out into hot water supply with high temperature water.

It is a schematic block diagram which shows an example of a structure of the hot water supply apparatus which concerns on embodiment of this invention. It is a functional block diagram which shows the function structure of the hot water storage unit controller of the hot water supply apparatus which concerns on embodiment of this invention. It is a functional block diagram which shows the function structure of the heat pump unit controller of the hot water supply apparatus which concerns on embodiment of this invention. It is a flowchart which shows the flow of the process in the case of the minimum external temperature detection in the heat pump unit stop of the hot water supply apparatus which concerns on embodiment of this invention. It is a flowchart which shows the flow of the process in the case of the hot water supply operation according to the minimum outside air temperature. It is a flowchart which shows the flow of the process in the case of the normal hot water supply driving | operation which mixes and uses hot water and medium temperature water for hot water supply. It is a flowchart which shows the flow of the process in the case of the normal hot water supply driving | operation which mixes and uses hot water and medium temperature water for hot water supply. It is a flowchart which shows the flow of the process in the case of middle temperature water priority hot water supply driving | operation using only intermediate temperature water for hot water supply. It is a flowchart which shows the flow of a process in the case of transfer from a medium temperature water priority hot water supply operation to a normal hot water supply operation. It is a schematic block diagram which shows a part of structure of the modification 1 of the hot water supply apparatus which concerns on embodiment of this invention. It is a schematic block diagram which shows a part of structure of the modification 2 of the hot water supply apparatus which concerns on embodiment of this invention. It is a functional block diagram which shows the function structure of the heat pump unit controller of the hot water supply apparatus which concerns on the modification 2. It is a schematic block diagram which shows an example of the circuit structure at the time of the defrost operation of the hot water supply apparatus which concerns on embodiment of this invention. It is a flowchart which shows the flow of a process at the time of determining the possibility of freezing of a refrigerant | coolant-water heat exchanger with the evaporation temperature at the time of a defrost operation. It is a schematic block diagram which shows a part of structure of the modification 3 of the hot water supply apparatus which concerns on embodiment of this invention. It is a flowchart which shows the flow of the process in the middle temperature water priority hot water supply driving | operation of the hot water supply apparatus which concerns on the modification 3.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each drawing used in this embodiment, common elements are denoted by the same reference numerals. The present invention is not limited to the embodiments described below, and various modifications can be made without departing from the spirit of the present invention. In the present embodiment, “hot water” is a generic term for hot water and cold water. Further, the hot water in the bathtub 200 means hot water stored in the bathtub 200, and the hot water in the hot water storage tank 120 means hot water stored in the hot water storage tank 120.

  FIG. 1 is a schematic configuration diagram illustrating an example of a configuration of a hot water supply apparatus 100 according to an embodiment of the present invention. Based on FIG. 1, the structure of the hot water supply apparatus 100 is demonstrated. In FIG. 1, as an example of the hot water supply apparatus 100, a hot water storage type hot water supply apparatus that boils hot water with the heat pump unit 10 is illustrated as an example. In addition, in FIG. 1, the bathtub 200 connected to the hot water supply apparatus 100 is also illustrated.

<Configuration of hot water supply apparatus 100>
As shown in FIG. 1, the hot water supply apparatus 100 includes a heat pump unit 10 and a hot water storage unit 50. The hot water storage unit 50 is connected to a bathtub 200. Further, a hot water supply end 63 and a water supply end 64 are connected to the hot water storage unit 50.

(Heat pump unit 10)
The heat pump unit 10 is a heat source for heating low-temperature hot water supplied via the hot water storage tank 51. The heat pump unit 10 includes a compressor 11, a refrigerant-water heat exchanger 12, an expansion valve 13, and an evaporator 14. That is, the heat pump unit 10 includes a refrigerant circuit in which the compressor 11, the refrigerant-water heat exchanger 12, the expansion valve 13, and the evaporator 14 are connected by the refrigerant pipe 70. In this refrigerant circuit, a flammable refrigerant such as an HC refrigerant or an HFO refrigerant is circulated. The HC refrigerant is a hydrocarbon refrigerant such as R290. The HFO refrigerant is a hydrofluoroolefin refrigerant, and examples thereof include R1234yf, R1234ze, and R1233zd. A refrigerant circuit configuration in which the compressor 11, the refrigerant-water heat exchanger 12, the expansion valve 13, and the evaporator 14 are connected by a refrigerant pipe 70 may be referred to as a heat pump device.

  The heat pump unit 10 is connected to the hot water storage unit 50 via the refrigerant-water heat exchanger 12. Specifically, the heat pump unit 10 and the hot water storage unit 50 are connected via the heat pump water inlet pipe 71 and the heat pump hot water outlet pipe 72 connected to the water side of the refrigerant-water heat exchanger 12. In the refrigerant-water heat exchanger 12, heat exchange is performed between the refrigerant flowing through the refrigerant pipe 70 and the water flowing through the heat pump inlet pipe 71.

The compressor 11 compresses and discharges the refrigerant. The compressor 11 can be composed of a rotary compressor, a scroll compressor, or the like. The refrigerant discharged from the compressor 11 is sent to the refrigerant-water heat exchanger 12.
The refrigerant-water heat exchanger 12 is a high-temperature and high-pressure refrigerant that flows through the refrigerant pipe 70, and heats the water that flows through the heat pump inlet pipe 71. The refrigerant-water heat exchanger 12 can be constituted by, for example, a plate heat exchanger or a double pipe heat exchanger.

The expansion valve 13 expands and depressurizes the refrigerant that has passed through the refrigerant-water heat exchanger 12. The expansion valve 13 may be composed of an electric expansion valve that can adjust the flow rate of the refrigerant.
The evaporator 14 heat-exchanges between the refrigerant | coolant which passed through the expansion valve 13, and heat mediums, such as air, and evaporates a refrigerant | coolant. The evaporator 14 is a fin and tube heat exchanger, a microchannel heat exchanger, a shell and tube heat exchanger, a heat pipe heat exchanger, a double pipe heat exchanger, a plate heat exchanger, or the like. Can be configured. The evaporator 14 is provided with a blower 14 a that supplies air to the evaporator 14.

In addition, the heat pump unit 10 includes an outside air temperature sensor 90, an incoming water temperature sensor 91, and a hot water temperature sensor 92.
The outside air temperature sensor 90 is provided at the outside air inlet of the heat pump unit 10 and measures the temperature of the outside air taken into the heat pump unit 10.
The incoming water temperature sensor 91 is provided on the inlet side of the refrigerant-water heat exchanger 12 of the heat pump inlet pipe 71 and measures the temperature of the water flowing through the heat pump inlet pipe 71.
The hot water temperature sensor 92 is provided on the outlet side of the refrigerant-water heat exchanger 12 of the heat pump hot water piping 72 and measures the temperature of the water flowing through the heat pump hot water piping 72.
The measurement results of the outside air temperature sensor 90, the incoming water temperature sensor 91, and the hot water temperature sensor 92 are sent to the heat pump unit controller 32 described later.

(Hot water storage unit 50)
The hot water storage unit 50 stores hot water heated by the heat pump unit 10 in the hot water storage tank 51 and supplies hot water to the bathtub 200 and the hot water supply end 63. The hot water storage unit 50 includes a hot water storage tank 51, a bath heat exchanger 53, a tank side pump 54, a bathtub circulation pump 80, and an exhaust fan 62. The hot water storage unit 50 includes a three-way valve 59, a four-way valve 55, a medium hot water mixing valve 56, a general hot water mixing valve 58, a bath hot water mixing valve 57, a hot water on-off valve 81, a pressure relief valve 60, and an air vent valve 61. Prepare. Further, the hot water storage unit 50 includes a refrigerant sensor 93, a bathtub temperature sensor 94, and a bathtub going-out temperature sensor 95.

  The hot water storage tank 51 stores hot water, and a temperature stratification of a high temperature region and a low temperature region is formed from the upper part toward the lower part. The hot water storage tank 51 is made of metal such as stainless steel or resin. A heat insulating material (not shown) is disposed outside the hot water storage tank 51. Thereby, the hot water storage tank 51 can keep the hot water stored for a long time.

  A plurality of hot water storage temperature sensors 52 that measure the temperature of hot water stored in the hot water storage tank 51 are arranged on the outer surface of the hot water storage tank 51 so as to be lined up and down. In FIG. 1, the hot water storage temperature sensor 52a, the hot water storage temperature sensor 52b, the hot water storage temperature sensor 52c, and the hot water storage temperature sensor 52d are illustrated from the upper side to the lower side of the paper. The number of hot water storage temperature sensors 52 is not particularly limited. Further, when it is not necessary to distinguish between them, the hot water storage temperature sensor 52 will be described. The measurement result of the hot water storage temperature sensor 52 is sent to the hot water storage unit controller 31 described later.

  The hot water storage tank 51 is connected to a water supply pipe 21 communicating with the water supply end 64 at the lower part, and low temperature hot water is supplied from the lower part. In addition, the hot water storage tank 51 is connected to a tank water supply pipe 22 that communicates with the heat pump water intake pipe 71 at the lower part, and low temperature hot water is supplied to the heat pump unit 10 from the lower part. A hot water supply pipe 23 is connected to the upper part of the hot water storage tank 51, and hot hot water is supplied from the upper part. A hot water supply pipe 73 is connected to the high temperature hot water supply pipe 23. A hot water introduction pipe 77 is connected to the upper part of the hot water storage tank 51, and hot hot water is supplied to the bath heat exchanger 53 from the upper part. A tank pipe 25 is connected to the lower part of the side surface of the hot water storage tank 51. In addition, an intermediate hot water pipe 74 is connected to a side intermediate portion of the hot water storage tank 51.

  The bath heat exchanger 53 performs heat exchange between the hot water flowing in from the hot water introduction pipe 77 connected to the upper part of the hot water storage tank 51 and the bath water flowing in from the bathtub return pipe 79. The bath heat exchanger 53 can be constituted by, for example, a plate heat exchanger or a double pipe heat exchanger.

The tank-side pump 54 is installed on the downstream side of the outlet c1 of the three-way valve 59 in the heat pump inlet pipe 71, and circulates hot water between the hot water storage unit 50 and the heat pump unit 10.
The bathtub circulation pump 80 is installed in the bathtub return pipe 79 and circulates hot water between the hot water storage unit 50 and the bathtub 200.

  The exhaust fan 62 is provided at the discharge destination of the pressure relief valve 60 and the air vent valve 61, and when the refrigerant sensor 93 detects the refrigerant, the refrigerant is discharged from the exhaust port 50a to the outside so that the refrigerant does not fill the hot water storage unit 50. Are to be discharged.

  The three-way valve 59 includes an inlet a1, an inlet b1, and an outlet c1, and the hot water flowing from the inlet a1 or the inlet b1 flows out from the outlet c1. The inflow port a1 is connected to a tank water supply pipe 22 connected to the lower part of the hot water storage tank 51. The inlet b <b> 1 is connected to a hot water outlet pipe 76 connected to the bath heat exchanger 53. The outlet c1 is connected to the suction side of the tank-side pump 54 installed in the heat pump inlet pipe 71.

  The four-way valve 55 includes an inlet a2, an inlet b2, an outlet c2, and an outlet d2. The hot water flowing from the inlet a2 or the inlet b2 flows out from the outlet c2 or the outlet d2. is there. The inflow port a <b> 2 is connected to the heat pump discharge pipe 72. The inflow port b <b> 2 is connected to the discharge side of the tank-side pump 54 installed in the heat pump inlet pipe 71. The outlet c <b> 2 is connected to a tank pipe 25 that is connected to the lower side of the hot water storage tank 51. The outlet d <b> 2 is connected to a hot water supply pipe 73 connected to the upper part of the hot water storage tank 51.

  One of the medium temperature water mixing valves 56 is connected to the high temperature hot water pipe 75, one is connected to the medium temperature water pipe 74, and the other is connected to the second pipe 26. The medium temperature water mixing valve 56 mixes the high temperature hot water flowing out from the high temperature hot water pipe 75 and the medium temperature hot water flowing out from the medium temperature water pipe 74 and uses it for supplying hot water via the second pipe 26. The intermediate temperature water mixing valve 56 can be constituted by a three-way valve or the like.

  One of the general hot water supply mixing valves 58 is connected to the first branch pipe 26 a, one is connected to the hot water supply pipe 28, and the other is connected to the water supply pipe 27. The general hot water supply mixing valve 58 mixes the hot water mixed by the intermediate temperature water mixing valve 56 flowing through the first branch pipe 26 a and the water supply flowing through the water supply pipe 27 connected to the water supply end 64, and passes through the hot water supply pipe 28. The hot water is supplied to the hot water supply end 63. The general hot water mixing valve 58 can be constituted by a three-way valve or the like.

  One of the bath and hot water mixing valves 57 is connected to the second branch pipe 26 b, one is connected to the water supply pipe 27, and the other is connected to the third pipe 29. The bath hot water mixing valve 57 mixes the hot water mixed by the intermediate temperature water mixing valve 56 flowing through the second branch pipe 26 b and the water supplied through the water supply pipe 27 connected to the water supply end 64, into the bathtub outlet pipe 78. Hot water is supplied to the bathtub 200 through the connected third pipe 29. The bath hot water mixing valve 57 can be constituted by a three-way valve or the like.

  The hot water on / off valve 81 is provided in the third pipe 29 and opens and closes the third pipe 29 that becomes a flow path when hot water is filled in the bathtub 200.

  The pressure relief valve 60 is provided in the first branch pipe 24a, and discharges the amount of volume expansion when low-temperature water is boiled to high-temperature hot water by the heat pump unit 10. The pressure relief valve 60 can be configured by a two-way valve that mechanically opens and closes the first branch pipe 24a. In addition, the 1st branch piping 24a is one of the 1st piping 24 connected to the high temperature hot water piping 75 branched into two.

  The air vent valve 61 is provided in the second branch pipe 24b. For example, when the air dissolved in the water becomes high temperature, it becomes a bubble, and when the bubble accumulates in the upper part of the hot water storage tank 51, air is supplied by hot water from the high temperature hot water pipe 75. Are to be discharged. The air vent valve 61 can be constituted by a two-way valve that mechanically opens and closes the second branch pipe 24b. The second branch pipe 24b is one of the two branches of the first pipe 24 connected to the high temperature hot water pipe 75. In addition, the air vent valve 61 may be connected to a place where the high-temperature hot water pipe 75 is highest at a position in the hot water storage unit 50.

The refrigerant sensor 93 is provided at the discharge destination of the pressure relief valve 60 and the air vent valve 61, and detects the combustible refrigerant when the combustible refrigerant leaks to the water circuit side and is discharged from the upper part of the hot water storage tank 51. is there. The refrigerant sensor 93 may be installed in addition to the heat pump unit 10.
The bathtub temperature sensor 94 is provided between the downstream side of the bathtub circulation pump 80 and the upstream side of the bath heat exchanger 53, and measures the temperature of hot water at the installation position.
The bathtub going-out temperature sensor 95 is provided between the downstream side of the bath heat exchanger 53 and the upstream side of the bathtub 200, and measures the temperature of hot water at the installation position.
The measurement results of the refrigerant sensor 93, the bathtub temperature sensor 94, and the bathtub going-out temperature sensor 95 are sent to the hot water storage unit controller 31 described later.

(Control device)
The hot water supply device 100 has a control device that performs overall control. The control device includes a hot water storage unit controller 31 and a heat pump unit controller 32. The hot water storage unit controller 31 has a function of controlling the operation of the hot water storage unit 50 based on the operation information transmitted from the remote controller 210. The heat pump unit controller 32 has a function of controlling the operation of the heat pump unit 10 based on information transmitted from the hot water storage unit controller 31.

The hot water storage unit controller 31 and the heat pump unit controller 32 are configured to be communicable with each other by wire or wirelessly.
The hot water storage unit controller 31 and the heat pump unit controller 32 can be configured by hardware such as a circuit device that realizes the function. The hot water storage unit controller 31 and the heat pump unit controller 32 can also be configured by an arithmetic device such as a microcomputer and software executed thereon. It should be noted that the hot water supply device 100 may be centrally controlled by any one of the hot water storage unit controller 31 and the heat pump unit controller 32.

  The remote controller 210 receives instructions for operation information such as an operation mode of the hot water supply apparatus 100, a hot water supply set temperature, and a hot water supply set hot water amount. The remote controller 210 commands the hot water storage unit controller 31 from a user. The remote controller 210 may be an apparatus attached to the hot water supply apparatus 100, and may be a smartphone, a mobile phone, a PDA (Personal Digital Assistant), a personal computer, a tablet, or the like.

  FIG. 2 is a functional block diagram showing a functional configuration of the hot water storage unit controller 31 of the hot water supply apparatus 100. Based on FIG. 2, the function of the hot water storage unit controller 31 will be further described.

  As shown in FIG. 2, the hot water storage unit controller 31 functionally includes a measurement unit 31a, a calculation unit 31b, a control unit 31c, and a storage unit 31d. The measuring unit 31 a measures the temperature of the hot water and the refrigerant concentration based on information from the hot water storage temperature sensor 42, the bathtub going-out temperature sensor 95, the bathtub temperature sensor 94, and the refrigerant sensor 93. The calculation unit 31b calculates the instruction content to the control unit 31c using the measurement result of the measurement unit 31a. The control part 31c is based on the calculation result in the calculating part 31b, the tank side pump 54, the three-way valve 59, the four-way valve 55, the intermediate temperature water mixing valve 56, the general hot water mixing valve 58, the bath hot water mixing valve 57, the bathtub circulation pump. 80 and the operation of the exhaust fan 62 is controlled. The storage unit 31d stores the calculation result in the calculation unit 31b, the hot water supply set temperature, the hot water supply set hot water amount, and the like.

  The hot water storage unit controller 31 can communicate with the heat pump unit controller 32 in both directions. Furthermore, the hot water storage unit controller 31 can communicate with the remote controller 210 in both directions.

  FIG. 3 is a functional block diagram showing a functional configuration of the heat pump unit controller 32 of the hot water supply apparatus 100. Based on FIG. 3, the function of the heat pump unit controller 32 will be further described. The heat pump unit controller 32 can communicate with the hot water storage unit controller 31 in both directions.

  As shown in FIG. 3, the heat pump unit controller 32 functionally includes a measurement unit 32a, a calculation unit 32b, a control unit 32c, and a storage unit 32d. The measurement unit 32 a measures the temperature of the hot water and the outside air temperature based on information from the incoming water temperature sensor 91, the hot water temperature sensor 92, and the outside air temperature sensor 90. The calculating part 32b calculates the instruction content to the control part 32c using the measurement result in the measurement part 32a. The control part 32c controls operation | movement of the compressor 11, the expansion valve 13, and the air blower 14a based on the calculation result in the calculating part 32b. The storage unit 32d stores the calculation result in the calculation unit 32b, the hot water temperature, the outside air temperature, and the like.

<Operation of Hot Water Supply Device 100>
(Hot water storage operation)
The operation during hot water storage operation of the hot water supply apparatus 100 will be described with reference to FIG. Specifically, an operation during a hot water storage operation in which low-temperature water is boiled to a high temperature by the heat pump unit 10 and the boiled high-temperature hot water is stored in the hot water storage tank 51 will be described. During the hot water storage operation of the hot water supply device 100, the inflow port a1 and the outflow port c1 of the three-way valve 59 are communicated, and water flows from the lower part of the hot water storage tank 51 to the suction side of the tank side pump 54. In addition, in the four-way valve 55, the inflow port a <b> 2 and the outflow port d <b> 2 are communicated, and hot water flows from the heat pump hot water discharge pipe 72 to the upper part of the hot water storage tank 51.

  The refrigerant is compressed to a high temperature and a high pressure by the compressor 11 and is discharged from the compressor 11. The refrigerant discharged from the compressor 11 flows into the refrigerant side flow path of the refrigerant-water heat exchanger 12. The refrigerant that has flowed into the refrigerant-water heat exchanger 12 is cooled by exchanging heat with the water that has flowed into the refrigerant-water heat exchanger 12 via the heat pump inlet pipe 71. The cooled refrigerant is decompressed to a low temperature and a low pressure by the expansion valve 13 and flows to the evaporator 14. In the evaporator 14, the outside air guided by the blower 14a and the refrigerant exchange heat, and the refrigerant is heated. The refrigerant heated by the evaporator 14 evaporates and flows again to the compressor 11 to form a refrigeration cycle.

  The low-temperature water existing in the lower part of the hot water storage tank 51 passes through the three-way valve 59, is sucked into the tank-side pump 54 and pressurized, and passes through the heat pump inlet pipe 71 to the water-side flow path of the refrigerant-water heat exchanger 12. Water is sent. The water flowing into the refrigerant-water heat exchanger 12 is heated by exchanging heat with the refrigerant flowing into the refrigerant-water heat exchanger 12 via the refrigerant pipe 70. The heated water becomes boiled hot water and is stored in the upper part of the hot water storage tank 51 through the heat pump hot water discharge pipe 72 and the four-way valve 55.

  In the hot water storage operation, for example, the hot water storage temperature of the hot water storage tank 51 is determined to be 65 ° C., for example, according to the hot water supply set temperature of the remote controller 210. When the amount of heat stored in the hot water storage tank 51 falls below a preset heat pump boiling threshold, the boiling operation is started. The hot water storage unit controller 31 commands the target boiling temperature, which is the hot water storage temperature, to the heat pump unit controller 32. And when the heat storage amount of the hot water storage tank 51 becomes the target hot water storage amount, the heat pump unit 10 stops the boiling operation.

  The target hot water storage amount may be calculated from, for example, the difference between the hot water supply load predicted by a predetermined time from the present time and the current heat storage amount of the hot water storage tank 51. The hot water supply load may be determined by learning the hot water supply load for the past several days. The target hot water storage amount and hot water supply load may be set in advance. In addition, the target hot water storage amount and the hot water supply load may be changed.

  The compressor 11 is configured of an inverter type, and the rotation speed is adjusted by the heat pump unit controller 32 so as to have a predetermined heating capacity. The opening degree of the expansion valve 13 is adjusted by the heat pump unit controller 32 so that the refrigerant suction superheat degree of the refrigerant or the compressor discharge temperature becomes a predetermined temperature. The rotation speed of the tank-side pump 54 is adjusted by the heat pump unit controller 32 so that the hot water temperature of the refrigerant-water heat exchanger 12 detected by the hot water temperature sensor 92 becomes the target hot water storage temperature.

  In the hot water supply device 100, hot water is discharged from the pressure relief valve 60 to the outside of the hot water storage unit 50 due to the pressure increase due to the volume expansion of water during the hot water storage operation. Further, in the hot water supply device 100, when a large amount of gas is contained in the boiled hot water, the gas is discharged from the air vent valve 61 to the outside of the hot water storage unit 50.

(Operation when flammable refrigerant is detected)
Next, the operation of the hot water supply apparatus 100 when a combustible refrigerant is detected by the refrigerant sensor 93 will be described. The refrigerant sensor 93 detects the combustible refrigerant. Specifically, when the flammable refrigerant is discharged from the pressure relief valve 60 or the air vent valve 61, the flammable refrigerant is detected by the refrigerant sensor 93. When the refrigerant sensor 93 detects the flammable refrigerant, the heat pump unit controller 32 stops the operation when the heat pump unit 10 is in operation. Further, the heat pump unit controller 32 notifies the remote controller 210 that the flammable refrigerant has leaked via the hot water storage unit controller 31, and the hot water storage unit controller 31 operates the exhaust fan 62.

(Operation when detecting the minimum outside air temperature while the heat pump unit 10 is stopped)
Next, the operation at the time of detecting the minimum outside air temperature when the heat pump unit 10 is stopped will be described with reference to FIG. FIG. 4 is a flowchart showing the flow of processing when detecting the minimum outside air temperature while the heat pump unit 10 of the hot water supply apparatus 100 is stopped. In addition, the heat pump unit 10 being stopped means that the operation of the compressor 11 is stopped and the refrigerant is not circulating. And the flow of the process shown in FIG. 4 shall continue while the compressor 11 has stopped.

  When the heat pump unit 10 is stopped, the minimum outside air temperature is detected in order to determine the possibility of freezing of the refrigerant-water heat exchanger 12. Specifically, the heat pump unit controller 32 detects the outside air temperature with the outside air temperature sensor 90 at regular intervals (S101). The heat pump unit controller 32 compares the previously detected outside air temperature with the currently detected outside temperature (step S102). The previously detected outside temperature means the outside temperature detected one time before the current detection.

  When the outside air temperature detected this time is lower than the outside air temperature detected last time as a result of comparing the outside air temperature detected last time and the outside air temperature detected this time (S102; Yes), the outside air temperature detected this time is updated as the minimum outside air temperature. (S103). On the other hand, as a result of comparing the previously detected outside air temperature with the currently detected outside air temperature, when the currently detected outside air temperature is equal to or higher than the previously detected outside air temperature (S102; No), the outside air temperature detection is repeated at regular intervals. When the minimum outside air temperature is equal to or lower than the reference value, the heat pump unit controller 32 determines that the temperature of the water flowing through the refrigerant-water heat exchanger 12 is equal to or lower than the freezing temperature.

(Hot-water supply operation according to the minimum outside air temperature)
Next, a hot water supply operation according to the minimum outside air temperature will be described with reference to FIG. FIG. 5 is a flowchart showing the flow of processing during the hot water supply operation according to the minimum outside air temperature. In the hot water supply operation according to the minimum outside air temperature, the hot water storage unit controller 31 controls the intermediate temperature water mixing valve 56 when supplying hot water from the hot water storage tank 51 according to the minimum outside air temperature. The flow of treatment shown in FIG. 5 is performed after the hot water storage operation is completed and before the hot water supply is started.

  The hot water storage unit controller 31 determines whether or not the previous minimum outside air temperature during the stop of the heat pump unit 10 before the start of the hot water storage operation is equal to or higher than a preset reference value (step S201). When the hot water storage unit controller 31 determines that the previous minimum outside air temperature during the stop of the heat pump unit 10 before the start of the hot water storage operation is equal to or higher than a preset reference value (step S201; Yes), the process proceeds to the normal hot water supply operation ( Step S203). After that, the processing flow is not performed until the next hot water storage operation is completed.

  On the other hand, when the hot water storage unit controller 31 determines that the previous minimum outside air temperature is lower than a preset reference value (step S201; No), it determines whether a preset reference time has elapsed (step S202). ). When the preset reference time has elapsed (step S202; Yes), the routine proceeds to a normal hot water supply operation (step S203). On the other hand, when the preset reference time has not elapsed (step S202; No), the process shifts to the medium hot water priority hot water supply operation in which the medium warm water is preferentially used for hot water supply (step S204). Then, after a predetermined time, step S202 is determined again. The reference value for the minimum outside air temperature is, for example, about −5 ° C. below freezing.

(Normal hot water operation)
Next, a normal hot water supply operation in which hot water and medium hot water are mixed and used for hot water supply will be described with reference to FIG. FIG. 6 is a flowchart showing a flow of processing in a normal hot water supply operation in which hot water and medium temperature water are mixed and used for hot water supply. Here, a general hot water supply operation in which hot water is supplied from a currant or shower connected to the hot water supply end 63 will be described with reference to FIG.

  The hot water storage unit controller 31 detects the temperature of hot water at a position where the hot water tank 74 is connected to the hot water storage tank 51 with the hot water storage temperature sensor 52. Then, the hot water storage unit controller 31 determines whether or not the temperature at the intermediate hot water removal position is equal to or higher than a predetermined reference value (step S301). When it is determined that the temperature of the intermediate hot water take-out position is equal to or higher than a predetermined reference value (step S301; yes), the hot water storage unit controller 31 can use the intermediate hot water for hot water supply, so that the hot water and the intermediate hot water are mixed. The intermediate temperature water mixing valve 56 is controlled (step S302). At this time, the temperature after mixing the high-temperature hot water and the medium-temperature water may be higher by a predetermined temperature than the higher one of the general hot water supply set temperature or the bath hot water set temperature.

  On the other hand, when it is determined that the temperature at the intermediate hot water take-out position is lower than a predetermined reference value (step S301; No), the hot water storage unit controller 31 controls the intermediate hot water mixing valve 56 to fully open to the high temperature hot water side (step). S303). Next, the hot water storage unit controller 31 determines whether or not the hot water supply flow rate is greater than or equal to a predetermined reference value (step S304). The hot water supply flow rate may be measured by the hot water storage unit controller 31 based on, for example, the hot water supply flow rate detected by a flow rate sensor (not shown) at the hot water supply end 63.

  When the hot water supply flow rate is equal to or higher than a predetermined reference value (step S304; yes), hot water from the intermediate hot water mixing valve 56 and low temperature water from the water supply end 64 so that the general hot water supply mixing valve 58 has a predetermined hot water supply temperature. The mixture ratio is adjusted to supply hot water (step S305). The hot water supply temperature at this time is set by the user using the remote controller 210. Then, the hot water storage unit controller 31 determines whether or not the hot water supply flow rate is less than the reference value (step S306). When the hot water supply flow rate is less than the reference value (step S306; yes), the hot water storage unit controller 31 ends the normal hot water supply operation. On the other hand, when the hot water supply flow rate is equal to or higher than the reference value (step S306; No), the hot water storage unit controller 31 controls the general hot water supply mixing valve 58 (step S305).

(Normal hot water operation)
Next, a normal hot water filling operation in which hot water and medium hot water are mixed and used for hot water supply will be described with reference to FIG. FIG. 7 is a flowchart showing a flow of processing in a normal hot water supply operation in which hot water and medium temperature water are mixed and used for hot water supply. In addition, although step S401-step S403 which is control of the intermediate temperature water mixing valve 56 are described separately in FIG. 6 and FIG. 7, it is carried out in common with steps S301 to S303 of the normal hot water supply operation. . Therefore, here, the flow of processing from step S404 will be described.

  The hot water storage unit controller 31 determines whether or not there has been a hot water filling command (step S404). For example, when the user presses a hot water filling button on the remote controller 210, the remote controller 210 instructs the hot water storage unit controller 31 to fill the hot water. At this time, the hot water storage unit controller 31 determines that there has been a hot water filling command. If it is determined that there is a hot water filling command (step S404; Yes), the hot water storage unit controller 31 controls the hot water opening / closing valve 81 to open (step S405), and starts hot water filling.

  When hot water filling is started by opening the hot water on / off valve 81, hot water from the bath hot water mixing valve 57 flows through the bathtub going-out pipe 78 and the bathtub return pipe 79, and is supplied to the bathtub 200. At this time, the bathtub circulation pump 80 is not operated. Then, the hot water storage unit controller 31 adjusts the mixing ratio of hot water from the intermediate hot water mixing valve 56 and low temperature water from the water supply end 64 so that the bath hot water supply mixing valve 57 reaches a predetermined hot water supply temperature and supplies hot water (step S406). ). The hot water supply temperature at this time, that is, the hot water filling temperature is set by the user using the remote controller 210.

  Next, the hot water storage unit controller 31 determines whether or not the amount of hot water in the bathtub is equal to or greater than a predetermined reference value (step S407). The amount of hot water in the bathtub may be detected by, for example, a flow rate sensor (not shown) installed in the bathtub outlet pipe 78 or a water level sensor (not shown) installed in the bathtub 200. When the amount of hot water in the bathtub is equal to or greater than a predetermined reference value (step S407; yes), the hot water storage unit controller 31 closes the hot water on-off valve 81 (step S408).

(Medium hot water priority hot water supply operation)
Next, an intermediate hot water priority hot water supply operation using only intermediate hot water for hot water supply will be described with reference to FIG. FIG. 8 is a flowchart showing a flow of processing in the middle hot water priority hot water supply operation in which only intermediate hot water is used for hot water supply.

  The hot water storage unit controller 31 controls the intermediate warm water mixing valve 56 to fully open the intermediate warm water side (step S501). By doing in this way, it becomes possible to use only the hot water from the intermediate part of the hot water storage tank 51 without using the hot water in the upper part of the hot water storage tank 51 in the hot water supply operation. Step S502 and subsequent steps are the same as step S304 and subsequent steps in FIG. Similarly, in hot water filling operation, only hot water from the intermediate portion of the hot water storage tank 51 can be used. If it is determined that the hot water extraction position temperature is lowered and the hot water supply set temperature cannot be maintained during the intermediate hot water priority hot water supply operation, the hot water storage unit controller 31 stores hot water in the heat pump unit controller 32 even if there is remaining hot water in the upper part of the hot water storage tank 51. Instruct driving.

(Transition from medium hot water priority hot water supply operation to normal hot water supply operation)
Next, the transition from the medium hot water priority hot water supply operation to the normal hot water supply operation will be described with reference to FIG. FIG. 9 is a flowchart showing the flow of processing when shifting from the medium hot water priority hot water supply operation to the normal hot water supply operation.

  When the flammable refrigerant is accumulated in the upper part of the hot water storage tank 51, the hot water storage controller 31 may cause the flammable refrigerant to flow out of the hot water storage tank 51 together with the hot water. Open the hot side gradually. Specifically, when a predetermined time has elapsed in step S202 of FIG. 5, the hot water storage unit controller 31 first controls the high temperature side of the intermediate temperature water mixing valve 56 to be slightly opened to increase the ratio of high temperature water. (Step S601). Next, the hot water storage unit controller 31 determines whether or not the accumulated hot water flow rate of hot water supplied as general hot water and bath hot water is equal to or greater than a predetermined reference value (step S602).

  Here, the slight open control of the intermediate temperature water mixing valve 56 is continued until the integrated hot water supply flow rate of the general hot water supply and the bath hot water becomes equal to or higher than the reference value (step S602; No). Then, when the integrated hot water supply flow rate of the general hot water supply and the bath hot water is equal to or higher than the reference value (step S602; Yes), the hot water storage unit controller 31 controls to open the high temperature side of the intermediate hot water mixing valve 56 by a predetermined opening (step). S603). This is continued until it becomes equal to or higher than the high temperature side initial opening degree of the intermediate temperature water mixing valve 56 (step S604), and the routine proceeds to a normal hot water supply operation (step S605). The normal hot water supply operation is started at an initial opening degree at which the high temperature side of the intermediate hot water mixing valve 56 is opened by a predetermined opening degree.

(Effects of the hot water supply device 100)
When a pinhole or the like is opened in the partition wall where heat is exchanged between the refrigerant and water in the refrigerant-water heat exchanger 12, and the flammable refrigerant slowly leaks into the water circuit, the amount of refrigerant is very small, and the pressure relief valve during hot water storage operation 60 or the air vent valve 61 may not be able to release the refrigerant. In this case, it is also conceivable that the combustible refrigerant flows out to the hot water supply end 63 together with the high temperature hot water during the hot water supply. On the other hand, in the hot water supply device 100, when the outside air temperature is low and there is a possibility of freezing on the water side of the refrigerant-water heat exchanger 12, the hot water supply from the upper part of the hot water storage tank 51 is limited for a certain period of time. The hot water is gradually used. By doing so, according to the hot water supply apparatus 100, the combustible refrigerant accumulated in the upper part of the hot water storage tank 51 can be reliably detected.

  Further, even if there is remaining hot water in the upper part of the hot water storage tank 51, the hot water storage operation is performed again when the intermediate hot water take-out position temperature decreases during the intermediate hot water priority hot water supply operation. For this reason, according to the hot water supply apparatus 100, the outflow of the combustible refrigerant can be reliably prevented.

  Furthermore, as shown in the flowchart of FIG. 9, if it is determined that there is no leakage of the flammable refrigerant and it is safe, hot water suitable for the hot water supply set temperature is mixed with hot and medium hot water and used for hot water supply. ing. Therefore, according to hot water supply apparatus 100, it becomes possible to reduce energy consumption.

<Modification of Hot Water Supply Device 100>
(Configuration in which the air vent valve 61 is directly connected to the top of the hot water storage tank 51)
FIG. 10 is a schematic configuration diagram illustrating a part of the configuration of Modification 1 of the hot water supply apparatus 100. Based on FIG. 10, the modification 1 of the hot water supply apparatus 100 is demonstrated. FIG. 10 shows only the hot water storage unit 50 portion.

  Although FIG. 1 shows an example in which the air vent valve 61 is installed in the second branch pipe 24b, the air vent valve 61 may be directly connected to the top of the hot water storage tank 51 as shown in FIG. By doing so, a trace amount of combustible refrigerant can be reliably detected and can be reliably discharged.

(Freezing detection of the refrigerant-water heat exchanger 12 of the heat pump unit 10 that performs reverse cycle defrosting)
FIG. 11 is a schematic configuration diagram showing a part of the configuration of Modification 2 of the hot water supply apparatus 100. Based on FIG. 11, the modification 2 of the hot water supply apparatus 100 is demonstrated. Note that FIG. 11 shows only the heat pump unit 10 extracted.

  In FIG. 1, the heat pump device of the heat pump unit 10 in which the refrigerant circulates only in one direction is shown as an example. However, as shown in FIG. 11, a flow path switching device 15 is provided on the discharge side of the compressor 11 to flow the refrigerant. May be made invertible. In the flow path switching device 15, the port a3 is connected to the discharge side of the compressor 11, the port b3 is connected to the suction side of the compressor 11, the port c3 is connected to the refrigerant-water heat exchanger 12, and the port d3 is Connect to evaporator 14. By carrying out like this, in the heat pump unit 10, it becomes possible to perform a reverse cycle defrost operation. The flow path switching device 15 can be configured by, for example, a four-way valve, or a combination of a three-way valve or a two-way valve.

  When reverse cycle defrosting is performed, the refrigerant-water heat exchanger 12 functions as an evaporator during defrosting. For this reason, when the temperature of the refrigerant in the refrigerant-water heat exchanger 12 decreases, it may be frozen on the water side. If water freezes in the refrigerant-water heat exchanger 12, the partition wall for heat exchange between the refrigerant and water in the refrigerant-water heat exchanger 12 may be broken.

  As shown in FIG. 11, during hot water storage operation, the port a3 and the port c3 of the flow path switching device 15 are connected, and the discharge gas of the compressor 11 flows into the refrigerant-water heat exchanger 12, and the port b3 And the port d3 are connected, and the gas at the outlet of the evaporator 14 is sucked into the compressor 11. Further, a refrigerant temperature sensor 96 that detects the temperature of the refrigerant is provided between the port c3 of the flow path switching device 15 and the refrigerant-water heat exchanger 12. The temperature detected by the refrigerant temperature sensor 96 is used to control the expansion valve 13 so that the refrigerant discharge temperature of the compressor 11 becomes a predetermined temperature during the hot water storage operation.

FIG. 12 is a functional block diagram illustrating a functional configuration of the heat pump unit controller 32 of the hot water supply apparatus 100 according to the second modification. Based on FIG. 12, the function of the heat pump unit controller 32 will be described focusing on the differences from FIG.
As shown in FIG. 12, the measurement unit 32 a includes the temperature of the hot water and the outside air based on the information at the refrigerant temperature sensor 96 in addition to the information at the incoming water temperature sensor 91, the outgoing water temperature sensor 92, and the outside air temperature sensor 90. Measure temperature and refrigerant temperature. Moreover, the control part 32c controls not only operation | movement of the compressor 11, the expansion valve 13, and the air blower 14a but the flow-path switching apparatus 15 based on the calculation result in the calculating part 32b. Other configurations are the same as those in FIG.

  FIG. 13 is a schematic configuration diagram illustrating an example of a circuit configuration during the defrosting operation of the hot water supply apparatus 100. FIG. 14 is a flowchart showing the flow of processing when determining the possibility of freezing of the refrigerant-water heat exchanger 12 based on the evaporation temperature during the defrosting operation. Based on FIG.13 and FIG.14, the defrosting operation | movement of the hot water supply apparatus 100 which concerns on the modification 2 is demonstrated. FIG. 13 shows only the heat pump unit 10 portion.

  In the defrosting operation, the port a3 and the port d3 of the flow path switching device 15 are connected, the discharge gas of the compressor 11 flows into the evaporator 14, the port b3 and the port c3 are connected, and the refrigerant-water heat is connected. The gas at the outlet of the exchanger 12 is sucked into the compressor 11. At this time, the refrigerant temperature sensor 96 detects the evaporation temperature during the defrosting operation.

  The processing flow in FIG. 14 is performed after the defrosting operation is completed. The heat pump unit controller 32 determines whether the evaporation temperature during the current defrosting operation is equal to or higher than the evaporation temperature during the previous defrosting operation (step S701). If the evaporation temperature during the current defrosting operation is equal to or higher than the reference value during the previous defrosting operation (step S701; yes), the heat pump unit controller 32 shifts to the normal hot water supply operation (step S703). On the other hand, when the evaporating temperature during the current defrosting operation is lower than the evaporating temperature during the previous defrosting operation (step S701; No), the heat pump unit controller 32 determines whether or not a predetermined time has elapsed. Judgment is made (step S702).

  When a predetermined time has elapsed (step S702; Yes), the heat pump unit controller 32 shifts to a normal hot water supply operation (step S703). On the other hand, if the predetermined time has not elapsed (step S702; No), the heat pump unit controller 32 shifts to the medium hot water priority hot water supply operation (step S704).

  According to the flowchart shown in FIG. 14, even when the flammable refrigerant may have leaked to the water side during the defrosting operation, the flammable refrigerant can be prevented from flowing out to the hot water supply.

(When connecting the medium temperature water mixing valve 56 to medium temperature water and low temperature water)
FIG. 15 is a schematic configuration diagram illustrating a part of the configuration of Modification 3 of the hot water supply apparatus 100. FIG. 16 is a flowchart showing the flow of processing in the hot water supply operation of the medium temperature water priority hot water supply apparatus 100 according to the third modification. Based on FIG.15 and FIG.16, the modification 3 of the hot water supply apparatus 100 is demonstrated. FIG. 15 shows only the hot water storage unit 50 portion.

  In FIG. 1, the case where the intermediate temperature water mixing valve 56 is connected to the intermediate temperature water pipe 74, the high temperature hot water pipe 75, and the second pipe 26 is shown as an example, but in FIG. 15, the intermediate temperature water mixing valve 56 is connected to the water supply pipe 27, The hot water pipe 74 and the fourth pipe 30 are connected. The medium temperature water mixing valve 56 mixes medium temperature hot water flowing out from the medium temperature water pipe 74 and low temperature water supplied from the outside flowing through the water supply pipe 27, and supplies hot water via the fourth pipe 30 and the third pipe 29. It is used for. The fourth pipe 30 branches and is connected to the bath hot water mixing valve 57 and the general hot water mixing valve 58.

  In the medium hot water priority hot water supply operation, the hot water storage unit controller 31 controls the high temperature side of the general hot water supply mixing valve 58 to be fully closed in advance (step S801). Moreover, the hot water storage unit controller 31 performs temperature control with respect to the hot water supply set temperature with the intermediate hot water mixing valve (step S803). In addition, when the general hot water supply operation and the bath hot water operation occur independently during the medium hot water priority hot water supply operation, the intermediate warm water mixing valve temperature control is performed at each set temperature. When the general hot water supply operation and the bath hot water supply operation occur simultaneously, that is, when there are two or more hot water use locations, control is performed at the lower set temperature. This will ensure safety against burns. In addition, when the hot water priority hot water supply is being performed and there is a restriction on the hot water supply temperature, an external notification may be made via the remote controller 210.

  DESCRIPTION OF SYMBOLS 10 Heat pump unit, 11 Compressor, 12 Refrigerant-water heat exchanger, 13 Expansion valve, 14 Evaporator, 14a Blower, 15 Flow path switching device, 21 Water supply pipe, 22 Tank water supply pipe, 23 High temperature hot water supply pipe, 24 First piping, 24a First branch piping, 24b Second branch piping, 25 Tank piping, 26 Second piping, 26a First branch piping, 26b Second branch piping, 27 Water supply piping, 28 Hot water supply piping, 29 Third piping, 30 4th piping, 31 hot water storage unit controller, 31a measurement part, 31b calculation part, 31c control part, 31d storage part, 32 heat pump unit controller, 32a measurement part, 32b calculation part, 32c control part, 32d storage part, 42 hot water storage temperature Sensor, 50 Hot water storage unit, 50a Exhaust port, 51 Hot water storage tank, 52 Hot water storage temperature sensor 52a Hot water storage temperature sensor, 52b Hot water storage temperature sensor, 52c Hot water storage temperature sensor, 52d Hot water storage temperature sensor, 53 Bath heat exchanger, 54 Tank side pump, 55 Four-way valve, 56 Medium hot water mixing valve, 57 Bath hot water mixing valve, 58 General hot water supply Mixing valve, 59 Three-way valve, 60 Pressure relief valve, 61 Air vent valve, 62 Exhaust fan, 63 Hot water supply end, 64 Water supply end, 70 Refrigerant piping, 71 Heat pump inlet piping, 72 Heat pump outlet piping, 73 Hot water supply piping, 74 Medium hot water Piping, 75 Hot water piping, 76 Hot water outlet piping, 77 Hot water introduction piping, 78 Bathing piping, 79 Bathing return piping, 80 Bath circulation pump, 81 Hot water on / off valve, 90 Outside air temperature sensor, 91 Water temperature sensor, 92 Hot water Temperature sensor, 93 Refrigerant sensor, 94 Bathtub temperature sensor, 9 Bathtub temperature sensor, 96 refrigerant temperature sensor, 100 hot water supply device, 120 hot water storage tank, 200 bathtub, 210 remote control, a1 inlet, a2 inlet, a3 port, b1 inlet, b2 inlet, b3 port, c1 outlet, c2 outlet, c3 port, d2 outlet, d3 port.

Claims (8)

A heat pump device having a refrigerant-water heat exchanger and boiling hot water in the refrigerant-water heat exchanger using a flammable refrigerant;
A hot water storage tank for storing hot water boiled in the refrigerant-water heat exchanger;
A control device for controlling the heat pump device,
The controller is
When the temperature of the water flowing through the refrigerant-water heat exchanger is below the freezing temperature,
A hot water supply apparatus that uses medium hot water stored in an intermediate part of the hot water storage tank for hot water preferentially over hot water stored in an upper part of the hot water storage tank. The controller is
The hot water supply device according to claim 1, wherein whether or not a temperature of water flowing through the refrigerant-water heat exchanger is equal to or lower than a freezing temperature is determined based on an outside air temperature when the heat pump device is stopped. The controller is
The hot water supply device according to claim 1, wherein whether or not a temperature of water flowing through the refrigerant-water heat exchanger is equal to or lower than a freezing temperature is determined based on a refrigerant temperature during a reverse cycle defrosting operation of the heat pump device. An intermediate hot water mixing valve connected to the upper part of the hot water storage tank and the intermediate part of the hot water storage tank is provided,
The controller is
The ratio of the hot water stored in the upper part of the said hot water storage tank is increased by controlling the said intermediate temperature water mixing valve as the integrated hot water supply flow supplied to the hot water supply increases. Water heater. The controller is
When the accumulated hot water supply flow rate is equal to or higher than a predetermined reference value, the hot water temperature is adjusted in a state where the ratio of hot water stored in the upper part of the hot water storage tank is constantly increased by controlling the intermediate temperature water mixing valve. The hot water supply device according to claim 4. An intermediate hot water mixing valve connected to an intermediate portion of the hot water storage tank and a water supply pipe is provided,
The controller is
The hot water supply apparatus according to any one of claims 1 to 3, wherein the hot water temperature is adjusted by mixing the low temperature water supplied from the water supply pipe with the intermediate temperature water by controlling the intermediate temperature water mixing valve. The controller is
The hot water supply apparatus according to claim 6, wherein when there are two or more hot water use locations and the set temperatures are different, the middle temperature water mixing valve is controlled at a lower set temperature. The controller is
The hot water supply apparatus according to claim 6 or 7, wherein when there is a restriction on the hot water supply temperature, a notification is given to the outside.

Images