JP7467822B2 - Hot water storage system - Google Patents

Description

The present invention relates to a heat pump hot water supply system equipped with a solar power generation device, and to an improved restart control of the heat pump unit when power generation by the solar power generation device is unstable due to poor sunlight.

A typical hybrid hot water supply system has a hot water storage tank unit, a heat pump unit, and an auxiliary heat source unit, and typically hot water heated by the heat pump unit is stored in the hot water storage tank. Approximately one week's worth of hot water consumption patterns are memorized through learning, and the required amount of hot water is stored in the hot water storage tank approximately one hour before the scheduled time of hot water consumption. The auxiliary heat source unit is operated when reheating the bath or when a large amount of hot water is unexpectedly consumed.

A hybrid hot water supply system that can supply power from a solar power generation device via a power conditioner has also been put into practical use.
In this case, when there is sufficient sunlight during the day, hot water storage operation is possible using the solar power generation device and heat pump unit, and at night or when sunlight is unstable, the hybrid hot water system operates using power supplied from a commercial power source.

Techniques for controlling hybrid hot water systems are described in various publications.
Patent Literature 1 describes a technique for stopping the operation of a hot water supply device while a solar power generation device is generating power in order to increase the amount of power sold.
Patent Document 2 describes a technique for stopping the operation of a heat pump when the number of times that the heat pump operation has been stopped reaches a predetermined number.

Patent Document 3 describes a technique for setting the heating temperature low when restarting a heat pump.
Patent Document 4 describes a technique for restarting a compressor of a heat pump unit that has stopped due to an abnormality in refrigerant high pressure, at a frequency lower than the frequency at normal start-up.

Patent No. 5874502 Patent Publication 2011-191056 Patent No. 4874138 Patent Publication 2009-264715

If it were possible to power a hybrid hot water system from a solar power generation system, the commercial power supply would be cut off during a power outage, and the hot water system would have to be operated using power supplied by the solar power generation system. Power outages are rare in large cities and their suburbs, but as global warming leads to an increase in large typhoons and river flooding, the number of power outages in areas other than those mentioned above tends to increase and the duration of the outages to become longer.

When a hybrid hot water system is operated using only power supplied from a solar power generation device during a power outage, the heat pump unit will frequently start and stop if the solar radiation becomes unstable, such as on a cloudy day, which not only has a negative effect on the heat pump unit (especially the compressor), but also reduces its efficiency. In particular, when the solar radiation is unstable, the higher the load on the compressor of the heat pump unit, the more frequently it will stop.

Moreover, in cases like the above, the control unit will also frequently start and stop repeatedly, making the control of the heat pump unit more complicated and making it difficult to perform the desired control. In this way, when the power generation capacity of the solar power generation device is unstable, it is desirable to take measures such as delaying the restart of the heat pump unit in the hope that sunlight will return, or limiting output to reduce the probability of it stopping.

The object of the present invention is to provide a heat pump hot water supply system that, when it is determined that the heat pump unit is being operated with power from a solar power generation device in emergency operation mode, delays restart for a certain period of time in the hope that sunlight will return.

The heat pump hot water supply system according to claim 1 is a heat pump hot water supply system including a heat pump unit, a hot water storage tank unit, a solar power generation device, and a control means,
The heat pump hot water supply system is configured to be able to heat hot water using power supplied from a solar power generation device and power supplied from a commercial power source, and has a normal operation mode and an emergency operation mode to which it switches from the normal operation mode in the event of an emergency, and the control means is characterized in that when the heat pump unit is operating in the emergency operation mode, when it detects the heat pump unit starting and stopping a predetermined number of times or more within a set time, it determines that the heat pump unit is being operated using power supplied from the solar power generation device and delays the restart of the heat pump unit for a predetermined time.

According to the above configuration, when the heat pump unit is operating in emergency operation mode during a power outage, for example, if the start and stop of the heat pump unit is detected a predetermined number of times or more within a set time, it is determined that the heat pump unit is operating with power supplied from the solar power generation device. This determination makes it possible to simply and easily know that the heat pump unit is operating with power supplied from the solar power generation device.

In the above case, restarting the heat pump unit is delayed by a specified time, increasing the probability that sunlight will return and power generation will stabilize. This reduces the frequency of starting and stopping the heat pump unit, stabilizing its operation.

The heat pump hot water supply system of claim 2 is the invention of claim 1, characterized in that it is provided with a notification means for notifying the user that the heat pump unit is operating on power supplied from a solar power generation device when it is determined that the heat pump unit is operating on power supplied from a solar power generation device, and a selection operation means for selecting whether to continue operating the heat pump unit or to put it into standby.

With the above configuration, the notification means can notify the user that the system is operating using power supplied from the solar power generation device, and the selection operation means can select whether to continue operating the heat pump unit or to put it into standby.

The heat pump hot water supply system of claim 3 is the invention of claim 1 or 2, characterized in that the heat pump hot water supply system is equipped with an auxiliary heat source unit, and when it is determined that the heat pump unit is operated by power supplied from a solar power generation device, the control means puts the operation of the heat pump unit on hold for a certain period of time and permits the operation of the auxiliary heat source unit during the hold.

With the above configuration, hot water cannot be heated while the heat pump unit is on standby, so by allowing the auxiliary heat source unit to operate, hot water can be heated.

The present invention provides the various effects described above.

1 is a configuration diagram of a heat pump hot water supply system according to an embodiment of the present invention. FIG. 2 is a configuration diagram of a heat pump unit and a hot water tank unit. 13 is a flowchart of emergency heat pump operation control when the emergency operation mode is set. 4 is a part of a flowchart of heat pump restart control during a power outage. 11 is a remaining part of the flowchart of the heat pump restart control.

The following describes the embodiment of the present invention with reference to the drawings.

First, the overall configuration of the heat pump hot water supply system 1 will be described.
1 and 2, the heat pump hot water supply system 1 includes a heat pump unit 2, a hot water storage tank unit 3, and a solar power generation device 4. The hot water storage tank unit 3 includes a hot water storage tank 11 that stores hot water heated by the heat pump unit 2 through hot water storage operation, a combustion-type auxiliary heat source device 12 that reheats the hot water in the hot water storage tank 11, and a control unit 13 (control means) that performs various controls including hot water storage operation control that predicts future hot water use and stores the required amount of heat in the hot water storage tank 11 before hot water use.

Based on a command for hot water storage operation from the control unit 13, the heat pump unit 2 absorbs heat from the outside air to heat the hot water in the hot water storage tank 11, and returns the heated hot water to the hot water storage tank 11 for storage.

The solar power generation device 4 includes a junction box 6 connected to combine the DC power generated by the solar panels 5 that generate power from sunlight, a power conditioner 7 connected to convert the DC power from the junction box 6 into AC power (generated power), and a distribution board 8 connected so that the generated power from the power conditioner 7 can be distributed to points of use within the home. The distribution board 8 also distributes AC power from the commercial power line 9 to points of use within the home.

The distribution board 8 also serves as a power measuring means for measuring the power generated by the photovoltaic power generation device 4 and the power used in the home. The power surplus after the power generated by the power conditioner 7 is distributed within the home is sent from the distribution board 8 via a commercial power line 9 to the outside and sold.
Conversely, when the power generated by the power conditioner 7 alone is insufficient to cover the total required power, power from the commercial power line 9 is also used in combination.

A portion of the power distributed from the distribution board 8 is supplied to the hot water tank unit 3 via power line 3a, and is supplied from the hot water tank unit 3 to the heat pump unit 2 via power line 2a. The heat pump unit 2 and the hot water tank unit 3 are powered by the generated power and/or commercial power distributed from the distribution board 8.

The hot water storage tank unit 3 uses the hot water stored in the hot water storage tank 11 during hot water storage operation for hot water supply and for filling the bathtub 29. In addition, when the temperature of the hot water in the hot water storage tank 11 is low or when the bathtub 29 is in reheating operation, the hot water heated by burning fuel in the auxiliary heat source unit 12 is used for hot water supply and reheating operation, etc.

A hot water outlet passage 14 is connected to the top of the hot water storage tank 11 for discharging the hot water stored in the hot water storage tank 11. The hot water outlet passage 14 is connected to a hot water mixing valve 15 and is equipped with an outlet hot water temperature sensor 14a for detecting the temperature of the hot water supplied to the hot water mixing valve 15. A water supply passage 16 is connected to the bottom of the hot water storage tank 11 for supplying clean water from a clean water source to the hot water storage tank 11. A water supply temperature sensor 16a for detecting the temperature of the clean water is provided in the water supply passage 16.

The hot and cold water mixing valve 15 mixes the hot water in the hot water outlet passage 14 with clean water in a bypass passage 17 that branches off from the water supply passage 16 and is connected so that clean water can be supplied to the hot and cold water mixing valve 15. The hot water supply temperature is adjusted by adjusting the mixing ratio of this hot and cold water mixing valve 15. A hot water supply passage 18 is connected to the hot and cold water mixing valve 15, and the hot water mixed by the hot and cold water mixing valve 15 flows through the hot water supply passage 18 during hot water supply and is supplied to a hot water tap (not shown), etc., and during filling the bath, it is supplied to the bathtub 29 via a hot water filling passage 19 that branches off from the hot water supply passage 18 and connects to the reheating circuit 32. A hot water supply temperature sensor 18a is arranged in the hot water supply passage 18 to detect the hot water supply temperature.

An upstream heating passage 21a that supplies hot water to the heat pump unit 2 is connected to the bottom of the hot water storage tank 11, and a downstream heating passage 21b that returns hot water heated by the heat pump unit 2 to the hot water storage tank 11 is connected to the top of the hot water storage tank 11, forming a circulation heating circuit 21 in which hot water can be circulated between the hot water storage tank 11 and the heat pump unit 2 by a circulation pump 22. A bypass passage 21c that connects a midway portion of the upstream heating passage 21a to a midway portion of the downstream passage 21b, and a three-way valve 21d that is located at the connection portion of this bypass passage 21c and the upstream heating passage 21a are provided. A temperature sensor 23a is provided in the upstream heating passage 21a, and a temperature sensor 23b is provided in the downstream heating passage 21b.

During normal hot water storage operation, the hot water in the hot water storage tank 11 is heated to the hot water storage temperature set by the heat pump unit 2 and stored from the top of the hot water storage tank 11. During boiling operation as described below, all of the hot water in the hot water storage tank 11 is heated to the hot water storage temperature set by the heat pump unit 2 and stored.

A number of hot water temperature sensors 11a-11d that detect the temperature and amount of hot water in the hot water tank 11 are provided at predetermined intervals in the vertical direction around the outer periphery of the hot water tank 11. These hot water temperature sensors 11a-11d and the hot water tank 11 are covered with a heat insulating material (not shown) that reduces heat radiation from the hot water tank 11.

The auxiliary heating passage 24 for heating the hot water in the hot water storage tank 11 with the auxiliary heat source unit 12 branches off from the hot water outlet passage 14 and is connected to the auxiliary heat source unit 12. The auxiliary hot water outlet passage 25 for outletting the hot water heated by the auxiliary heat source unit 12 is connected to the hot water outlet passage 14 downstream of the branch point of the auxiliary heating passage 24 via a water proportioning valve 26. A three-way valve 27 and a pump 28 for sending hot water to the auxiliary heat source unit 12 are provided in the auxiliary heating passage 24.

The heat exchanger passage 30 branching off from the auxiliary hot water outlet passage 25 is connected to a three-way valve 27. The three-way valve 27 is switched so that the hot water in the hot water storage tank 11 or the hot water in the heat exchanger passage 30 can be supplied to the auxiliary heat source unit 12. A heat exchanger 30a and an on-off valve 30b are arranged in the heat exchanger passage 30. In addition, a branch passage section 16b branching off from the water supply passage 16 is connected between the on-off valve 30b of the heat exchanger passage 30 and the three-way valve 27. The heat exchanger 30a is used for reheating operation in which the hot water in the bathtub 29 flowing through the reheating circuit 32 by the operation of the reheating pump 31 is heated by heat exchange with the hot water heated by the auxiliary heat source unit 12.

The heat pump unit 2 is equipped with a heat pump circuit 37 in which a compressor 33, a condensing heat exchanger 34, an expansion valve 35, and an evaporating heat exchanger 36 are connected by refrigerant piping. In this heat pump unit 2, the refrigerant sealed in the refrigerant piping is compressed and heated by the compressor 33, and the hot water circulating in the circulating heating circuit 21 is heated by heat exchange with the high-temperature refrigerant in the condensing heat exchanger 34, and the hot water is stored in the hot water storage tank 11. After the heat exchange, the refrigerant expands in the expansion valve 35 to a temperature lower than the outside air, absorbs heat from the outside air in the evaporating heat exchanger 36, and is then introduced back into the compressor 33.

The evaporative heat exchanger 36 is equipped with an outdoor air temperature sensor 36a that detects the outdoor air temperature, and a blower 36b. The heat pump unit 2 is also equipped with an auxiliary control unit 38 that controls the compressor 33, the expansion valve 35, the blower 36b, etc. The auxiliary control unit 38 is communicatively connected to the control unit 13, which is the main control means of the heat pump hot water supply system 1, and controls the heat pump unit 2 based on commands from the control unit 13.

Pumps 22, 28, 31, valves, sensors, etc. are connected to the control unit 13. An operation terminal 13a (setting means) is connected to the control unit 13, and the user can set and operate the hot water supply temperature and other settings.

The control unit 13 includes a microcomputer including a CPU, ROM, and RAM, an input/output interface, and the like, and various control programs are stored in the ROM.
This control unit 13 controls the hot water supply operation etc. based on detection signals from the outlet hot water temperature sensor 14a etc., and also learns and stores hot water usage conditions such as the amount of hot water supplied and various temperatures in past hot water usage, the start time of hot water usage, etc., as well as past power information etc. It has a hot water usage prediction function that predicts future hot water usage based on this hot water usage condition, and a surplus power prediction function that predicts future surplus power based on this power information.

Next, the heat pump emergency operation control that is executed when the emergency operation mode is set via the operation terminal 13a during a power outage or the like will be described with reference to the flowchart in FIG. 3. The control program for the heat pump emergency operation control is pre-stored in the control unit 13. In addition, in the flowchart in FIG. 3, Si (i=1, 2, ...) indicates each step, and "HP" means the heat pump.

When this emergency operation mode is set, the heat pump unit 2 and the hot water tank unit 3 are driven only by the electricity generated by the solar power generation device 4, so the heat pump unit 3 can continue to operate when there is sufficient sunlight, but when the sunlight is unstable, appropriate control is required. Note that hereinafter, the heat pump unit 2 will be referred to as the heat pump 2.

When this control is started, in S1, it is determined whether or not the heat pump 2 has been started and stopped m times within the past hour. Here, m is 2 or 3.
If the determination is Yes, it is assumed that the sunlight is stable, and the operation of the heat pump 2 continues in S2, and the process returns from S2.

If the determination in S1 is No, in S3 it is determined that the power supply is from the photovoltaic power generation device 4, the heat pump 2 is switched to a standby state, and the operation of the auxiliary heat source unit 12 is permitted during the standby state.
Next, in S4, a display is displayed on the operation terminal 13a informing the user that the system is operating using only power from the solar power generation device 4. This display also includes a display prompting the user to select whether or not to continue operating the heat pump 2.

Next, in S5, it is determined whether the user has selected to continue operating the heat pump 2. If the determination is Yes, in S6, the heat pump 2 is restarted after a predetermined delay (e.g., 30 minutes), and then the process returns.

If the determination in S5 is No (the user does not select to continue operating the heat pump 2), in S7 it is determined whether n hours (e.g., 1 hour or 2 hours) have passed since the heat pump 2 started to be in standby mode, and S7 is repeated until the n hours have passed. If the determination in S7 is Yes, in S8 the heat pump 2 is restarted, and then the process returns.

Next, the action and effect of the above-described heat pump emergency operation control will be described.
By a simple judgment such as S1, it can be determined that the heat pump 2 is being operated by power supplied from the solar power generation device 4, and it can be known simply and easily that the heat pump 2 is being operated by power supplied from the solar power generation device 4.

As shown in S4, the operation terminal 13a can notify the user that the heat pump 2 is operating using power supplied from the solar power generation device 4, and the operation terminal 13a can also be used to select whether to continue operating the heat pump 2 or to put it into standby.
As shown in S6, a predetermined delay is imposed when restarting the heat pump 2, so that the probability that sunlight will return and power generation will stabilize is increased.
Therefore, the frequency of starting and stopping the heat pump 2 can be reduced, and the operation of the heat pump 2 can be stabilized.

If the heat pump 2 is restarted without waiting for n hours as in S7 above, there is a high probability that the heat pump 2 will not be able to be restarted due to lack of sunlight, or that it will stop soon after being restarted. In other words, the frequency of starting and stopping the heat pump 2 will increase.
However, if the heat pump 2 is restarted after waiting for n hours as in S7, the probability that sunlight will have returned increases, and it is possible to suppress an increase in the frequency of starting and stopping the heat pump 2. In this way, it is possible to minimize the adverse effects of repeatedly starting and stopping the heat pump 2. In addition, since hot water cannot be heated while the heat pump 2 is on standby, it is possible to heat hot water by permitting the operation of the auxiliary heat source unit 12.

Next, the heat pump restart control during a power outage, which is executed when the emergency operation mode is not set via the operation terminal 13a, will be described with reference to the flowcharts in Figures 4 and 5. The control program for this heat pump restart control is stored in advance in the control unit 13. Note that Si (i = 10, 11, ...) in the flowchart indicates each step.

When the power generation voltage of the solar power generation device 4 drops to a level at which the heat pump 2 cannot be driven (for example, about 90 V), the heat pump 2 stops and the control calculation processing also stops, but the data, flags, and count values stored in memory including the EPROM are retained.
Then, when sunlight returns and the generated voltage of the photovoltaic power generation device 4 is restored, the control calculation process is restarted from the first step, and the heat pump 2 is restarted.

When the power generation voltage of the solar power generation device 4 is restored, the power supply of the heat pump 2 and the control unit 13 is switched ON in S10, and then in S11 it is determined whether the start delay flag F = 2 or not. If the determination is Yes, the process proceeds to S12, and if the determination is No, the process proceeds to S13. In S12, the start delay timer is set to 30 minutes, and then the process proceeds to S15.

In S13, it is determined whether the start delay flag F = 1. If the determination is Yes, the start delay timer is set to 10 minutes in S14 and the process proceeds to S15. If the determination in S13 is No, the process proceeds directly to S15. The start delay timer is a timer that sets the time to delay the restart of the heat pump 2.

Next, in S15, the start delay flag F is set to 2. Next, in S16, the start delay timer is started and begins to count down.
Next, in S17, it is determined whether the operation command to the heat pump 2 (command from the hot water tank unit 3) is operation and the start-up delay timer has timed out. If the determination in S17 is No, S17 is repeated. If the determination in S17 becomes Yes, the process proceeds to S18.

S18 to S22 are steps for determining an output change counter that indicates the operating output at the time of restarting the heat pump 2 before restarting it. The output change counter has a lower limit and an upper limit that is the standard target output.

In S18, it is determined whether the output change counter is between -1 and +1. If the output change counter is -1, 0, or +1, the determination in S18 becomes Yes and the process moves to S24. If the determination in S18 is No, in S19 it is determined whether the output change counter is -2. If the determination is Yes, in S20, the target output of the compressor 33 of the heat pump 2 is reduced by "-0.1 kW" as an output limit for the heat pump 2, and then the process moves to S23.

If the determination in S19 is No, then in S21 it is determined whether the output change counter is 2 or greater. If the determination is Yes, then in S22 the target output of the compressor 33 is increased by +0.1 kW, and the output of the compressor 33 is adjusted back to the target value, and then the process moves from S22 to S23. Also, if the determination in S21 is No, then the process moves to S23. In S23, the output change counter is reset to 0.

Next, in S24, the heat pump 2 is restarted. Next, in S25, it is determined whether or not the heat pump 2 has been started and stopped m times within the past hour, and if the determination is No (if there has been m times), the start delay flag F is set to "1" in S26.
That is, if the process proceeds to restarting the heat pump 2, it is determined that the sunlight is relatively stable or only slightly unstable, and the delay time for the next start is set to a small value, so the start delay flag F is set to "1." If the determination in S25 is Yes, the operation of the heat pump 2 continues in S27, and the process proceeds to S28.

Next, in S28, it is determined whether the operating state of the heat pump 2 is in the heating mode. The heating mode is a mode in which hot water is stored until the entire hot water storage tank 11 is fully charged. If the determination in S28 is No, S28 is repeated. If the heating mode is entered and the determination in S28 becomes Yes, the start delay flag F is set to 0 in S29.
That is, if the heating mode is reached, it is determined that there is a lot of sunshine and a considerable amount of power generation, and the start-up delay flag F is set to 0 to allow normal start-up the next time.

Next, in S30, the output change counter is changed by "-1". Then, in the next step S31, it is determined whether or not one hour has passed since the heat pump 2 was restarted. If one hour has passed since the heat pump 2 was restarted, the output change counter is changed by "+1" in S32.

If a voltage drop occurs in the solar power generation device 4 once while counting in S31, the process will move to S24 to S31 via S10 to S18 after the next restart of control. However, if another voltage drop occurs in the solar power generation device 4 while counting in S31, the value of the output change counter will become "-2", so after the next restart of control, the process will move to S19 and S20, and the target output of the compressor 33 of the heat pump 2 will be reduced by "-0.1 kW". In this way, when sunlight is unstable, the frequency of stopping the heat pump 2 can be reduced by lowering the target output of the compressor 33.

Next, in S32, since the operation time of heat pump 2 has exceeded one hour as shown in S31 and the amount of sunlight is relatively stable, the output change counter, which was decreased in S30, is incremented by "+1" and returned to "0."

In the next step S33, it is determined whether one hour has passed since the output change counter was incremented in S32. If the determination is No, S33 is repeated. If the determination in S33 is Yes, the process moves to S34. In S34, "+1" is added to the output change counter. In other words, if operation can be continued for a long period of time, it is determined that the output of the compressor 33 of the heat pump 2 can be restored, and "+1" is added to the output change counter for each hour of continuous operation.

Next, in S35, it is determined whether the operation command is standby or not, and if the determination is No, the process returns to S33, and if the determination in S35 is Yes, the process proceeds to S36, where the heat pump 2 is switched to a stopped state and control ends.

Next, the operation and effect of the above-described heat pump restart control during a power outage will be described.
When the start and stop of the heat pump 2 is detected a predetermined number of times or more within a set time, the sunlight is unstable. In this case, if a predetermined time is delayed before restarting the heat pump 2, the probability that sunlight will return and power generation by the photovoltaic power generation device will stabilize increases, and the frequency of start and stop of the heat pump 2 can be reduced to stabilize the operation of the heat pump 2.

In addition, when sunlight is unstable as described above, restarting with output restriction can reduce the probability of heat pump 2 stopping and stabilize the operation of heat pump 2.

For example, the stability or instability of sunlight can be estimated from the state before heat pump 2 is stopped, such as the continuous operation time of heat pump 2, so measures can be taken such as shortening the delay time until restart when sunlight is stable and lengthening the delay time until restart when sunlight is unstable.

For example, the stability or instability of sunlight can be estimated from the state before heat pump 2 is stopped, such as the continuous operating time of heat pump 2 and the frequency of start-up and stoppage. Therefore, measures can be taken such as lowering the level of output restriction or eliminating the output restriction when sunlight is stable, and raising the level of output restriction when sunlight is unstable.

For example, the stability or instability of sunlight can be estimated from the operating state when the heat pump 2 is stopped, such as the continuous operating time of the heat pump 2 and the frequency of starting and stopping. Depending on the degree of instability of sunlight, measures such as delaying restart and/or limiting output can be taken.
If the heat pump 2 enters the heating mode during operation, it can be assumed that the amount of sunlight is stable, and therefore the output restriction can be lifted.

Next, an example in which the above embodiment is partially modified will be described.
(1) In the case where the sunlight is unstable, the target output of the compressor of the heat pump 2 is changed as the output limit of the heat pump 2, but the hot water storage temperature setting may be changed as the output limit. That is, in S20 of Fig. 4, the target hot water storage temperature may be changed lower by "-5°C" as the output limit of the heat pump 2, and in S22, the target hot water storage temperature may be changed higher by "+5°C".

(2) In S28, it may be configured to determine whether the boiling mode has continued for a predetermined period of time.
(3) In S36, instead of stopping the heat pump 2, the control may wait for a predetermined time and then return. In this case, the control may be configured to return from S27.
(4) In addition, a person skilled in the art can implement the above-described embodiments by making various modifications without departing from the technical spirit of the present invention, and the present invention also includes such modifications.

1 Heat pump hot water supply system 2 Heat pump unit 3 Hot water tank unit 4 Solar power generation device 12 Auxiliary heat source unit 13 Control unit

Claims (3)

A heat pump hot water supply system including a heat pump unit, a hot water tank unit, a solar power generation device, and a control means,
The heat pump hot water supply system is configured to be capable of heating hot water using power supplied from a solar power generation device and power supplied from a commercial power source, and has a normal operation mode and an emergency operation mode which is switched from the normal operation mode in an emergency,
The heat pump hot water supply system is characterized in that, when the control means detects the start and stop of the heat pump unit a predetermined number of times or more within a set time when the heat pump unit is operating in emergency operation mode, it determines that the heat pump unit is being operated using power supplied from a solar power generation device and delays the restart of the heat pump unit for a predetermined time. The heat pump hot water supply system according to claim 1, further comprising: a notification means for notifying the user that the heat pump unit is operating on power supplied from a solar power generation device when it is determined that the heat pump unit is operating on power supplied from a solar power generation device; and a selection operation means for selecting whether to continue operating the heat pump unit or to put the heat pump unit into standby. The heat pump hot water supply system includes an auxiliary heat source unit,
A heat pump hot water supply system as described in claim 1 or 2, characterized in that when it is determined that the heat pump unit is being operated using power supplied from a solar power generation device, the control means puts the operation of the heat pump unit into standby for a certain period of time, and during that standby period allows the auxiliary heat source unit to operate.