Hot water storage unit

Abstract

To provide a storage water heater performing control for reducing electric power consumption during hot water storage so as not to repeat stop and resumption of electric power supply when storing hot water by receiving electric power supply from an electric storage device.SOLUTION: A storage water heater (1) includes: a heat pump heat source machine (2); a hot water storage tank (3) for storing hot water heated through a hot water storage operation performed by the heat pump heat source machine (2); an auxiliary heat source machine (4) heating hot water through a combustion operation for burning fuel gas; and control means (5) for controlling the hot water storage operation and the combustion operation. The control means (5) stores an electric current value of the heat pump heat source machine (2) during the hot water storage operation as an electric current storage value, receives supply of electric power from an external electric storage device to transition to an emergency mode of performing the hot water storage operation when power outage and fuel gas cut-off occur, and resumes the hot water storage operation within a range in which an electric current value smaller than the electric current storage value before stop of the supply of the electric power serves as an upper limit electric current value, when the heat pump heat source machine (2) is restarted through resumption of the electric power supply from the electric storage device after stop of the electric power supply from the electric storage device during the hot water storage operation in the emergency mode.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a hot water storage and hot water supply device that performs hot water storage operation by storing hot water heated by a heat pump heat source in a hot water tank, and in particular to a hot water storage and hot water supply device that performs hot water storage operation by receiving power from an emergency power source during a power outage. [Background technology]

[0002] Photovoltaic power generation systems that generate electricity using, for example, sunlight as a renewable energy source have been widely used in ordinary households. The generated electricity is used within the home, and any unused surplus electricity is sold via a commercial power source. Furthermore, the use of photovoltaic power generation and storage systems that store surplus electricity in a power storage device and supply electricity from the power storage device when, for example, solar power generation is not possible or when the commercial power source is out of service is expanding.

[0003] On the other hand, hot water storage systems are widely used, storing high-temperature hot water heated by an energy-efficient electric heat pump in a hot water tank and using the hot water from the tank to provide hot water. To reduce power consumption wasted when storing hot water, these hot water storage systems predict future hot water usage based on a learned and stored hot water usage history, and store the predicted amount of hot water before the predicted hot water usage time. To prevent a situation where hot water usage exceeds the predicted amount, such a hot water storage system is equipped with a combustion-type auxiliary heat source that uses the heat from the combustion of fuel gas to heat the hot water.

[0004] In the event of a disaster that causes a power outage and cutoff of the fuel gas supply, there is a risk that the power supply from the commercial power source and the fuel gas supply will not be restored in a short time. To be able to supply hot water even in such a case, a hot water storage and hot water supply system is known that receives power from a power storage device and stores hot water using a heat pump heat source.

[0005] For example, Patent Document 1 describes a control that suppresses power consumption according to the amount of stored electricity when storing electricity to heat water in a heat pump heat source machine during a commercial power outage. Patent Document 2 also describes increasing the amount of stored heat to prevent the heat pump heat source machine from frequently starting and stopping depending on the temperature of the hot water stored in the hot water tank. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 6709691 [Patent Document 2] Patent No. 5581361 Summary of the Invention [Problem to be solved by the invention]

[0007] The power that can be supplied from a power storage device is smaller than that from a commercial power source, and may also supply power to devices other than the hot water storage device, such as a refrigerator, so it is necessary to reduce the power consumption of the heat pump heat source device during hot water storage operation. Here, the total power consumption of multiple devices, including the hot water storage device, connected to receive power from the power storage device varies depending on the device connection configuration and the operation timing of each device. Therefore, even if the power consumption of the heat pump heat source device is kept low and hot water storage operation is performed, the total power consumption may exceed the power supply capacity of the power storage device.

[0008] In such a case, the power storage device is configured to temporarily stop the power supply and then restart the power supply after a while.The hot water storage / heating device is configured to restart the hot water storage operation when the power supply from the power storage device is restarted.However, if the equipment connection configuration has not changed since the power supply was stopped, the power supply from the power storage device will be stopped again when the hot water storage operation is restarted, and hot water cannot be stored by repeatedly restarting and stopping the power supply.

[0009] Even if control is performed to suppress power consumption according to the amount of electricity stored in the electricity storage device as in Patent Document 1, when the amount of electricity stored is large, the power consumption during hot water storage is large, so there is a risk that hot water cannot be stored due to repeated restarts and stops of power supply. Furthermore, in order to increase the amount of heat storage as in Patent Document 2, it is necessary to raise the temperature of the stored hot water, which actually increases the power consumption during hot water storage.

[0010] The object of the present invention is to provide a hot water storage and hot water supply device that, when receiving power supply from a power storage device to store hot water, performs control to reduce power consumption during hot water storage operation so that the power supply is not repeatedly stopped and restarted. [Means for solving the problem]

[0011] The hot water storage and hot water supply device of claim 1 is a hot water storage and hot water supply device having a heat pump heat source unit, a hot water storage tank for storing hot water heated by the hot water storage operation of the heat pump heat source unit, an auxiliary heat source unit for heating the hot water by combustion operation in which fuel gas is burned when there is no hot water of a usable temperature in the hot water storage tank, and a control means for controlling the hot water storage operation and the combustion operation, wherein the control means stores the current value supplied to the heat pump heat source unit during the hot water storage operation as a current memory value, and in the event of a power outage and fuel gas cutoff, transitions to an emergency mode in which power is supplied from an external storage device to perform the hot water storage operation, and during the hot water storage operation in the emergency mode, if the power supply from the storage device is stopped and then the power supply from the storage device is resumed and the heat pump heat source unit is restarted, the control means sets a current value smaller than the current memory value before the power supply to the heat pump heat source unit was stopped as an upper limit current value and resumes the hot water storage operation within a range below this upper limit current value.

[0012] According to the above configuration, in the event of a power outage and fuel gas shutoff, the hot water storage / heating device transitions to an emergency mode in which it receives power from an external power storage device and stores hot water in the hot water storage tank. In this emergency mode, if the power supply from the power storage device is interrupted during hot water storage operation and then the power supply is resumed and the heat pump heat source device is restarted, the control means sets the upper limit current value to a current value that is lower than the current value stored as the current value supplied to the heat pump heat source device before the power supply was interrupted. The control means then resumes hot water storage operation by the heat pump heat source device and stores hot water within a range equal to or less than the set upper limit current value. Therefore, after the heat pump heat source device is restarted, the power supplied to the heat pump heat source device from the external power storage device is reduced compared to before the power supply was interrupted, making it less likely to exceed the power supply capacity of the power storage device and preventing repeated interruptions and restarts of the power supply.

[0013] The hot water storage and hot water supply device of the invention of claim 2 is characterized in that, in the invention of claim 1, the hot water storage operation is resumed after a predetermined time has elapsed after the heat pump heat source unit is restarted. According to the above configuration, when power supply from the storage device is resumed, hot water storage operation is resumed avoiding a timing when power consumption is concentrated due to the restart of the equipment receiving this power supply, thereby preventing the power supply from being repeatedly stopped and resumed. [Effects of the Invention]

[0014] According to the hot water storage and hot water supply device of the present invention, when hot water is stored by receiving power supply from the power storage device, it is possible to prevent the power supply from being repeatedly stopped and restarted. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 2 is an explanatory diagram of the connection between the hot water storage tank heater and the power supply according to an embodiment of the present invention. [Figure 2] 1 is an explanatory diagram of a hot water storage tank heater according to an embodiment of the present invention; [Figure 3] 10 is a flowchart of a fuel gas supply cutoff determination according to an embodiment. [Figure 4]10 is a flowchart of hot water storage operation control in an emergency mode. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, the mode for carrying out the present invention will be described based on examples. [Example]

[0017] As shown in Figures 1 and 2, the hot water storage and hot water heater 1 has a hot water storage and hot water supply unit 10 equipped with a heat pump heat source device 2 and a hot water tank 3 covered with a heat insulating material (not shown). The hot water storage and hot water supply unit 10 is connected to receive power from a commercial power source B and, for example, a solar power generation and storage system C via a power switching unit A, and power is supplied from this hot water storage and hot water unit 10 to the heat pump heat source device 2. The power switching unit A has the function of a general distribution board connected to the commercial power source B and the function of switching the power received by the hot water storage and hot water heater 1 to power from the commercial power source B or power from the solar power generation and storage system C.

[0018] The photovoltaic power generation and storage system C has a solar cell panel D that generates electricity using sunlight, a storage device E that stores the generated electricity, and a power conditioner F that converts the generated and stored electricity from direct current to alternating current and supplies it to a power switching unit A. The electricity generated by the solar cell panel D is given priority for use within the home, and any unused surplus electricity is stored in the storage device E. If the surplus electricity cannot be stored in the storage device E, it is sold via commercial power source B. The storage device E functions as an emergency power source in the event of a power outage at commercial power source B.

[0019] The hot water storage and hot water supply unit 10 has a gas combustion type auxiliary heat source unit 4 and a control unit 5 (control means), and an operation remote control 6 for operating the hot water storage and hot water supply device 1 is connected to the control unit 5. The control unit 5 controls the hot water storage operation in which hot water is stored in the hot water storage tank 3 by the heat pump heat source unit 2, and the combustion operation of the auxiliary heat source unit 4. The hot water storage tank 3 is provided with a plurality of hot water storage temperature sensors 3a to 3f that detect the hot water temperature due to temperature stratification formed in the vertical direction.

[0020] The hot water storage and hot water supply device 1 has a bath heat exchanger 7 and is equipped with a bath reheating function that reheats the hot water in the bathtub 8 by heating and circulating hot water between the auxiliary heat source device 4 that is in combustion operation and the bath heat exchanger 7. The hot water storage and hot water supply device 1 also has a heating heat exchanger 9 and is equipped with a hot water heating function that heats and circulates hot water between the auxiliary heat source device 4 that is in combustion operation and the heating heat exchanger 9 to heat the heating heat medium (hot water) that is supplied to a heating terminal not shown.

[0021] A water supply passage 11 is connected to the bottom of the hot water storage tank 3 for supplying clean water to the hot water storage tank 3. The water supply passage 11 has a water supply temperature sensor 11a that detects the temperature of the clean water (water supply temperature) supplied to the hot water storage tank 3. In addition, in order to heat the hot water in the hot water storage tank 3 by the heat pump heat source unit 2 during hot water storage operation and store the hot water in the hot water storage tank 3, a supply passage 12 is connected from the bottom of the hot water storage tank 3 to the heat pump heat source unit 2, and a return passage 13 is connected from the heat pump heat source unit 2 to the top of the hot water storage tank 3. The supply passage 12 has a hot water storage pump 14 that is driven during hot water storage operation.

[0022] To dispense hot water from the hot water tank 3, a hot water tank outlet passage 15 is connected to the top of the hot water tank 3, and this hot water tank outlet passage 15 is connected to a mixing valve 16 for mixing the hot water. Connected to the mixing valve 16 are a water supply bypass passage 17 branching off from the water supply passage 11, and a hot water supply passage 19 that supplies the hot water mixed by the mixing valve 16 to, for example, a faucet 18. The hot water supply passage 19 has a hot water supply flow rate sensor 19a that detects the hot water supply flow rate, and a hot water supply flow rate adjustment valve 19b that adjusts the hot water supply flow rate. The hot water tank outlet passage 15 has a mixing valve inlet temperature sensor 15a located near the mixing valve 16 that detects the temperature of the hot water supplied to the mixing valve 16.

[0023] In the hot water supply flow rate adjustment valve 19b, a hot water supply passage 21 for supplying hot water to the bathtub 8 branches off from the hot water supply passage 19, and this hot water supply passage 21 is connected to a reheating passage 22 that circulates the hot water in the bathtub 8 between it and the bath heat exchanger 7. The hot water supply passage 21 has a hot water supply flow rate sensor 21a that detects the flow rate of the hot water supplied to the bathtub 8, and a hot water supply valve 21b as a solenoid valve that opens when hot water is being poured. The reheating passage 22 has a bath pump 22a that circulates the hot water in the bathtub 8 between it and the bath heat exchanger 7.

[0024] A circulation passage 24 is connected to the auxiliary heat source unit 4, connecting its outlet and inlet. The circulation passage 24 has a circulation pump 25 for supplying hot water to the auxiliary heat source unit 4, and a bath heat exchanger 7 and a heating heat exchanger 9 are provided in parallel to the circulation passage 24 for heat exchange with the hot water heated by the auxiliary heat source unit 4. A reheating valve 7a and a heating valve 9a are provided on the outlet side of the corresponding heat exchangers as solenoid valves for switching on / off the supply of hot water to the bath heat exchanger 7 and the heating heat exchanger 9.

[0025] A circulation flow rate sensor 24a is disposed in circulation passage 24 between circulation pump 25 and the inlet of auxiliary heat source unit 4. A three-way valve 26 for switching the flow path is disposed upstream of circulation pump 25, and a reheating passage 27 branching off from hot water storage tank outlet passage 15 is connected to circulation passage 24 via three-way valve 26. In addition, in order to supply hot water heated by auxiliary heat source unit 4 to mixing valve 16, an auxiliary heated hot water outlet passage 28 equipped with a flow rate adjustment valve 28a branches off from circulation passage 24 on the outlet side of auxiliary heat source unit 4, and is connected to hot water storage tank outlet passage 15 downstream of the branching point of reheating passage 27.

[0026] The auxiliary heat source unit 4 has a fuel gas supply unit 4a, a combustion fan 4b, a burner 4c that burns a mixture of combustion air and fuel gas supplied from the combustion fan 4b, and a heat exchange unit 4d. The sensible heat and latent heat of the high-temperature combustion gas generated by the burner 4c during combustion operation of the auxiliary heat source unit 4 is used to heat the hot water flowing through the heat exchange unit 4d.

[0027] Burner 4c has multiple combustion tubes with different combustion amounts and has multiple combustion stages in which the combination of combustion tubes to be burned is determined to adjust the combustion amount. For example, if burner 4c has first, second, and third combustion tubes with small, medium, and large combustion amounts, it has a first combustion stage consisting of only the first combustion tube, a second combustion stage combining the first and second combustion tubes, a third combustion stage combining the first and third combustion tubes, and a fourth combustion stage combining all combustion tubes. The fuel gas supply unit 4a has multiple gas solenoid valves 4e corresponding to the multiple combustion tubes of burner 4c and a gas flow control valve 4f for adjusting the flow rate of fuel gas supplied to burner 4c.

[0028] We will explain the bath reheating function. In bath reheating, the control unit 5 opens the reheating valve 7a and drives the circulation pump 25, and performs combustion operation in the auxiliary heat source unit 4, circulating heated water between the auxiliary heat source unit 4 and the bath heat exchanger 7. At the same time, the control unit 5 drives the bath pump 22a to circulate the hot water in the bathtub 8 through the reheating passage 22, and heats the hot water heated by the combustion operation with the hot water in the bathtub 8 by heat exchange in the bath heat exchanger 7, heating the hot water in the bathtub 8 and returning it to the bathtub 8.

[0029] The hot water heating function will be explained. In hot water heating, the control unit 5 opens the heating valve 9a and drives the circulation pump 25, performs combustion operation in the auxiliary heat source unit 4, and circulates heated water between the auxiliary heat source unit 4 and the heating heat exchanger 9. The control unit 5 then drives the heating pump 29a to circulate the heating heat medium through the heating passage 29 connecting the heating heat exchanger 9 and a heating terminal (not shown) (for example, a bathroom heating device or a floor heating device), and heats the heating heat medium by exchanging heat in the heating heat exchanger 9 between the hot water heated by the combustion operation and the heating heat medium. The circulating heating heat medium provides heating by radiating heat at the heating terminal, and the heating heat medium, whose temperature has dropped, is reheated in the heating heat exchanger 9.

[0030] Next, the hot water storage operation will be described. During normal operation when power is supplied from commercial power source B and fuel gas is supplied from a fuel gas pipe or gas cylinder, hot water storage and heating device 1 is set to a normal mode in which the heat pump heat source unit 2, which has excellent operating efficiency, is used to the maximum. In this normal mode, control unit 5 predicts future hot water usage based on past hot water usage history, and drives heat pump heat source unit 2 and hot water storage pump 14 to perform hot water storage operation in which an amount of heat sufficient to satisfy the predicted hot water usage amount is stored before the predicted hot water usage time.

[0031] The hot water usage history is learned and stored in the control unit 5 according to the hot water usage situation so that the hot water storage tank 3 can store just the right amount of hot water. During hot water storage operation, the control unit 5 stores, for example, the average current value every 10 seconds or the maximum current value during the current hot water storage operation as a stored current value. Note that most of the power consumption during hot water storage operation comes from the heat pump heat source unit 2, and the average current value or maximum current value of this heat pump heat source unit 2 may be stored in the control unit 5 as a stored current value. The stored current value is stored in a non-volatile memory provided in the control unit 5 and is not erased even if the power supply is stopped. Alternatively, the stored current value may be stored in the power supply unit of the heat pump heat source unit 2, and the control unit 5 may be able to refer to this stored current value.

[0032] Next, hot water supply will be described. The hot water stored in the hot water storage tank 3 is mixed with clean water by the mixing valve 16, and the temperature is adjusted to a hot water supply temperature set in advance, for example, by the operation remote controller 6, and supplied to, for example, the faucet 18. If the time of hot water use is earlier than predicted, or if the amount of hot water used is greater, there is no hot water of a usable temperature in the hot water storage tank 3, so hot water heated by the combustion operation of the auxiliary heat source unit 4 is adjusted to the hot water supply temperature by the mixing valve 16 and supplied to, for example, the faucet 18.

[0033] Next, the emergency mode will be described. For example, a disaster may occur, causing a power outage of the normally used commercial power source B and a cutoff in the supply of fuel gas. If the home is equipped with, for example, a power storage device E as an emergency power source, the user may wish to use power supplied from this power storage device E to provide hot water. Therefore, when the hot water storage and hot water supply device 1 is connected to receive power from the power storage device E and restarted, the operating mode can be shifted from the normal mode to an emergency mode that can reduce power consumption, for example, by a mode change operation using the operation remote controller 6. In this emergency mode, power is supplied from the power storage device E and heated hot water is stored in the hot water storage tank 3.

[0034] When switching to emergency mode through a mode change operation, the fuel gas supply status may be unknown, so the control unit 5 determines whether to cut off the fuel gas supply. This fuel gas supply cutoff determination will be explained with reference to Fig. 3. In the figure, Si (i = 1, 2, ...) represents a step.

[0035] First, in S1, it is determined whether a fuel gas supply cutoff has occurred. At this time, the control unit 5 supplies fuel gas and air to the burner 4c and attempts to ignite them. If ignition fails a predetermined number of times, it determines that a fuel gas supply cutoff has occurred. If the determination in S1 is Yes, the process proceeds to S2, where the system switches to an emergency mode (HP emergency mode) in which hot water is stored at a preset hot water temperature by hot water storage operation of the heat pump heat source unit 2, and the fuel gas supply cutoff determination is terminated. On the other hand, if ignition is successful and the determination in S1 is No, the process proceeds to S3, where the system switches to an emergency mode (BU emergency mode) in which hot water is stored in the hot water storage tank 3 at a preset hot water temperature by combustion operation of the auxiliary heat source unit 4, and the fuel gas supply cutoff determination is terminated. The hot water temperature can be set using the operation remote control 6.

[0036] The amount of stored power in the emergency power storage device E is limited, and the power that the storage device E can supply is also smaller than that of the commercial power source B. Other devices such as a refrigerator may also be connected to the storage device E, and when the total power consumption of the devices including the hot water storage and heating device 1 reaches the upper limit of the power supply capacity of the storage device E, the storage device E temporarily stops supplying power for safety reasons and resumes supplying power after a while.

[0037] If power supply and interruption from the power storage device E is repeated in this manner, hot water cannot be stored in the hot water storage operation, and there is a risk that other devices will not function. Therefore, in hot water storage operation in emergency mode (HP emergency mode), when the heat pump heat source unit 2 is restarted by resuming the power supply from the power storage device E, the drive of the heat pump heat source unit 2, which accounts for the majority of the power consumption, is limited, for example, by the current value. On the other hand, in combustion operation in emergency mode (BU emergency mode), the combustion of the burner 4c is limited to the maximum number of stages and the minimum combustion amount, and the rotation speed of the combustion fan 4b, which accounts for the majority of the power consumption in the combustion operation, is kept low to save power.

[0038] The hot water storage operation in the emergency mode (HP emergency mode) is performed until the maximum hot water storage amount is reached at a hot water storage temperature of 65° C., for example, to prevent a shortage of hot water. The control of the hot water storage operation in this emergency mode (HP emergency mode) will be described with reference to FIG.

[0039] When the emergency mode is initiated, the process waits in S11 for a preset time (e.g., 3 minutes) before proceeding to S12. Immediately after the start or resumption of power supply from the power storage device E, power consumption is likely to increase due to the restart of connected devices, so this step is intended to avoid this concentration of power consumption. Also, for safety reasons, if the heat pump heat source unit 2 is restarted after a power outage while in operation, the process waits until the pressure of the compressed refrigerant naturally decreases.

[0040] Next, in S12, it is determined whether the amount of hot water stored in the hot water tank 3 is less than a preset set amount. This is a determination step for starting hot water storage operation when the amount of hot water stored is small. The set amount of hot water stored is, for example, the amount of hot water stored corresponding to the hot water storage temperature sensor 3a, but it may also be the amount of hot water stored corresponding to another hot water storage temperature sensor, or it may be the maximum amount of hot water stored.

[0041] If the determination in S12 is No, the process proceeds to S23, where it is determined whether or not a mode change operation, for example, to return to normal mode, has been performed. If no mode change operation has been performed and the determination in S23 is No, the process returns to S12. If a mode change operation has been performed and the determination in S23 is Yes, the process proceeds to S24, where the operating mode is shifted and the emergency mode (HP emergency mode) is terminated. On the other hand, if the determination in S12 is Yes, the process proceeds to S13 to perform hot water storage operation.

[0042] In S13, the current memory value stored during the previous hot water storage operation is read, and the process proceeds to S14. Then, in S14, it is determined whether the current memory value is the current value at the completion of hot water storage operation. Hot water storage operation is performed according to a hot water storage operation table in which operating conditions are set in advance based on the hot water temperature before heating, the outside air temperature, the target hot water storage temperature, etc., for example, to increase operating efficiency, and the current value during hot water storage operation (the current value of the heat pump heat source unit 2) is set in the hot water storage operation table. For example, as hot water storage approaches completion, the current value decreases due to adjustments to the drive of the heat pump heat source unit 2, so it is possible to determine whether the current value is the current value at the completion of hot water storage operation or the current value during hot water storage operation.

[0043] If the determination in S14 is Yes, this means that hot water storage was completed in the previous hot water storage operation, and the process proceeds to S15. Then, in S15, the current value for normal hot water storage operation set in the operation table based on, for example, the hot water temperature before heating, the outside air temperature, and the target hot water storage temperature is set as the upper limit current value for the heat pump heat source unit 2, and the process proceeds to S17.

[0044] On the other hand, if the determination in S14 is No, this means that the previous hot water storage operation ended before the hot water storage was completed, i.e., the power supply that was temporarily stopped during the hot water storage operation has resumed and the hot water storage and water heating device 1 including the heat pump heat source unit 2 has restarted, and the process proceeds to S16. Then, in S16, a value that is lower than the current memory value by a predetermined value (e.g., 0.3 A) is set as the upper limit current value of the heat pump heat source unit 2, and the process proceeds to S17. As a result, if the previous hot water storage operation was terminated midway due to a stoppage of the power supply from the power storage device E due to excessive power consumption, the hot water storage operation can be resumed with less power consumption than the previous hot water storage operation.

[0045] Next, in S17, hot water storage operation is performed to drive the heat pump heat source unit 2 within a range limited to or below the set upper limit current value based on the hot water storage operation table, and the process proceeds to S18. Then, in S18, the current value of the heat pump heat source unit 2 during hot water storage operation is stored as a current memory value, and the process proceeds to S19, where it is determined whether or not a mode change operation has been performed from the operation remote controller 6, for example, to return to normal mode.

[0046] If there is no mode change operation and the determination in S19 is No, the process proceeds to S20, where it is determined whether the amount of hot water stored in the hot water tank 3 has reached the maximum amount. For example, if the heat pump heat source unit 2 has an inlet water temperature sensor at its hot water inlet, it is determined that the maximum amount of hot water has been stored when the temperature detected by this inlet water temperature sensor reaches the hot water storage temperature. If the determination in S20 is No, the process returns to S17, and hot water storage operation is performed to reach the maximum amount of hot water storage. If the determination in S20 is Yes, the process proceeds to S21, where the hot water storage operation is stopped and the process returns to S12.

[0047] On the other hand, if the determination in S19 is Yes (mode change operation has been performed), the process proceeds to S22, where hot water storage operation is stopped, and the process proceeds to S24, where the operation mode is changed and the emergency mode (HP emergency mode) is terminated. Note that the change in operation mode is not limited to a change to the normal mode, and it may be from the HP emergency mode to the BU emergency mode, or if there is another settable operation mode, it may be a change to that operation mode.

[0048] The operation and effect of the hot water storage and boiler device 1 will be described. In the event of a power outage and fuel gas cutoff, the hot water storage / heating device 1 transitions to an emergency mode (HP emergency mode) in which it receives power from an external power storage device E and stores hot water in the hot water storage tank 3. If the power supply from the power storage device E is stopped during hot water storage operation in this emergency mode, and then the power supply is resumed and the heat pump heat source unit 2 restarts, the control unit 5 sets the upper limit current value to a current value that is smaller than the current stored value before the power supply was stopped. The control unit 5 then resumes hot water storage operation by the heat pump heat source unit 2 and stores hot water within a range equal to or less than this set upper limit current value.

[0049] Therefore, after the heat pump heat source unit 2 is restarted, the power supplied from the external power storage device E to the heat pump heat source unit 2 is reduced compared to before the power supply was stopped, making it less likely to exceed the power supply capacity of the power storage device E and preventing repeated stopping and restart of the power supply. In addition, hot water storage operation is restarted after a preset time has elapsed after the heat pump heat source unit 2 is restarted. Therefore, when the power supply from the power storage device E is restarted, the hot water storage operation is restarted avoiding a timing when power consumption is concentrated due to the restart of the equipment receiving this power supply, and it is possible to prevent repeated stopping and restart of the power supply.

[0050] The transition to the emergency mode may be configured so that the control unit 5 automatically transitions the operating mode based on a signal transmitted from the power storage device E after the power storage device E is connected to receive power. A minimum current value required for hot water storage operation may be set, and hot water storage operation may be disabled when a set upper limit current value falls below this minimum current value. Hot water storage operation may also be disabled when the upper limit current value is lowered a predetermined number of times. For example, a portable power storage device or a home generator may be used as an emergency power source. Once the maximum amount of hot water storage is reached, hot water storage operation may be resumed when hot water use is detected, for example, by flow rate detection by the hot water supply flow rate sensor 19a. Those skilled in the art may incorporate various modifications to the above-described embodiment without departing from the spirit and scope of the present invention, and the present invention encompasses such modifications. [Explanation of symbols]

[0051] 1: Hot water storage unit 2: Heat pump heat source machine 3: Hot water tank 3a to 3f: Hot water temperature sensor 4:Auxiliary heat source machine 4a: Fuel gas supply section 4b: Combustion fan 4c: Burner 4d: Heat exchange section 4e: Gas solenoid valve 4f: Gas flow control valve 5: Control unit (control means) 6: Operation remote control 7: Bath heat exchanger 7a: Reheat valve 8: Bathtub 9: Heating heat exchanger 9a: Heating valve 10: Hot water storage unit 11:Water supply passage 12: Entry passage 13: Return passage 14: Hot water pump 15: Hot water tank outlet passage 16: Mixing valve 17: Water supply bypass passage 18: Karan 19: Hot water passage 19a: Hot water flow sensor 19b: Hot water flow control valve 21: Pouring passage 21a: Pouring flow rate sensor 21b:Pouring valve 22: Reheating passage 22a: Bath pump 24: Circulation passage 24a: Circulation flow sensor 25: Circulation pump 26: Three-way valve 27: Reheating passage 28: Auxiliary heating outlet passage 28a: Flow control valve 29: Heated aisle 29a: Heating pump

Claims

1. A hot water storage and hot water supply device having a heat pump heat source machine, a hot water storage tank for storing hot water heated by the hot water storage operation of the heat pump heat source machine, an auxiliary heat source machine for heating the hot water by a combustion operation that burns fuel gas when hot water of a usable temperature is not available in the hot water storage tank, and control means for controlling the hot water storage operation and the combustion operation, The control means stores a current value supplied to the heat pump heat source machine during the hot water storage operation as a current storage value, In the event of a power outage and fuel gas cutoff, the system switches to an emergency mode in which power is supplied from an external power storage device and the hot water storage operation is performed. A hot water storage and hot water supply device characterized in that, when the power supply from the storage device is stopped during the hot water storage operation in the emergency mode, and then the power supply from the storage device is resumed and the heat pump heat source unit is restarted, the hot water storage operation is resumed within a range below the upper limit current value, with a current value smaller than the current memory value before the power supply to the heat pump heat source unit was stopped.

2. The hot water storage heater according to claim 1, wherein the hot water storage operation is resumed after a preset time has elapsed after the heat pump heat source machine is restarted.

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