JP2015161458A - Heat pump water heater and control method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize energy saving by setting an appropriate heat storage amount from past record of use and heating water using electricity in a time zone in which electric charges are relatively low.SOLUTION: In a case of changing a hot-water-storage-temperature target value and a hot-water-storage-amount target value for the next and the following days depending on use record data, then the hot-water-storage-temperature target value is preferentially reduced if it is determined that a minimum heat storage amount is excessive from the use record data, and the hot-water-storage-amount target value is reduced if the hot-water-storage-temperature target value reaches a lower limit. Furthermore, the hot-water-storage-amount target value is preferentially increased if it is determined that the minimum heat storage amount is insufficient from the use record data, and the hot-water-storage-temperature target value is increased if the hot-water-storage-amount target value reaches an upper limit. In this way, setting the target values so as to reduce a hot water storage temperature as much as possible and to increase a hot water amount as much as possible enables a heat pump to operate in an efficient operation region and energy saving to be realized.

Description

  The present invention relates to a heat pump type water heater and a control method thereof.

  Conventionally, a water heater disclosed in Patent Document 1 is known as a heat pump type water heater. Patent Document 1 stores the amount of heat used in the past several days, and when the current heat storage amount is smaller than the maximum amount of heat used in the past few days, it is determined that the amount of heat used is large and hot water is likely to run out. It is disclosed that the amount of remaining hot water at the start of heating is increased and the heating operation is started early so that hot water does not run out.

JP 2004-60948 A

  In the case of a heat pump type water heater, generally, a heat pump is operated in an inexpensive late-night charge zone (for example, between 0 o'clock and 8 o'clock) to store hot water in a hot water storage tank. At this time, it is desirable to use the power in the midnight rate zone as effectively as possible to avoid the heating operation in the daytime period when the power rate is relatively high.

  The present invention has been made in view of such circumstances, and sets an appropriate amount of heat storage based on past use results, and uses power during times when the power rate is relatively inexpensive as much as possible. An object of the present invention is to provide a heat pump type water heater that can realize energy saving and a control method thereof.

According to the first aspect of the present invention, the hot water in the hot water tank is heated as much as possible to a preset hot water storage temperature target value and hot water storage amount target value by using as much power as possible as long as the electricity rate is relatively low. A heat pump type hot water heater for obtaining a minimum heat storage amount in units of days from past usage record data including a heat storage amount or a remaining hot water amount and a hot water supply load, and the minimum heat storage amount is within a predetermined appropriate range. If it exceeds the target value changing means for changing at least one of the hot water storage temperature target value and the hot water storage amount target value, one of the hot water storage temperature target value and the hot water storage target value after the change and the past use record data. Using a hot water supply load of the day, and a trial calculation means for trial calculation of the minimum heat storage amount of the day, the target value changing means, when the minimum heat storage amount exceeds the upper limit value of the appropriate range, By the trial calculation means The hot water storage temperature target value is preferentially lowered until the calculated minimum heat storage amount falls within the appropriate range, and when the hot water storage temperature target value reaches a predetermined lower limit value, the hot water storage amount target value is set. If the minimum heat storage amount is less than the lower limit value of the appropriate range, the hot water storage amount target value is preferentially used until the minimum heat storage amount calculated by the trial calculation means falls within the appropriate range. It is a heat pump type hot water heater that increases the hot water storage temperature target value when the hot water storage amount target value reaches a predetermined upper limit.
Here, the minimum remaining hot water amount may be used instead of the minimum heat storage amount.

According to such a heat pump type water heater, when changing the hot water storage temperature target value and hot water storage target value from the next day according to the usage record data, when determining that the minimum heat storage amount is excessive from the usage record data The hot water storage temperature target value is preferentially reduced, and when the hot water storage temperature target value reaches the lower limit, the hot water storage amount target value is reduced. Also, if it is determined from the usage record data that the minimum heat storage amount is insufficient, the hot water storage amount target value is preferentially increased, and when the hot water storage amount target value reaches the upper limit value, the hot water storage temperature target value is increased. Let
In this way, by setting the target value so that the hot water storage temperature is as low as possible and the amount of hot water is as large as possible, the heat pump can be operated in an efficient operation region, and energy saving can be achieved. Moreover, precipitation of scale can be reduced by setting the temperature as low as possible.
Moreover, since the hot water storage temperature target value and the hot water storage amount target value are updated with reference to the usage result data periodically, there is no excess or deficiency in the heat storage amount, and energy saving can be achieved.

  In the heat pump type water heater, the hot water storage temperature target value and the hot water storage amount target value are set for each day of the week, the acquisition unit acquires the minimum heat storage amount for each day of the week, and the target value changing unit includes: In addition, it is possible to change at least one of the hot water storage temperature target value and the hot water storage amount target value for a day of the week when the minimum heat storage amount is outside the appropriate range.

  In the heat pump type water heater, the hot water storage temperature target value and the hot water storage amount target value are set separately for weekdays and holidays, and the acquisition means acquires the minimum heat storage amount separately for weekdays and holidays, respectively. The target value changing means changes at least one of the hot water storage temperature target value on weekdays and the hot water storage target value when the minimum heat storage amount on weekdays is outside the appropriate range, When the minimum heat storage amount is outside the appropriate range, at least one of the hot water storage temperature target value and the hot water storage target value on holidays may be changed.

  In the heat pump type hot water heater, the acquisition unit acquires the minimum heat storage amount from the use result data of the previous day, and the target value changing unit is configured to store the hot water storage when the minimum heat storage amount exceeds a predetermined appropriate range. It is also possible to change at least one of the temperature target value and the hot water storage amount target value and set the hot water storage temperature target value and the hot water storage target value for the next day.

  According to the second aspect of the present invention, the hot water in the hot water tank is heated as much as possible so that the hot water in the hot water tank becomes a preset hot water temperature target value and hot water amount target value by using as much as possible electric power in a time zone where the power rate is relatively low. A heat pump type hot water heater control method for obtaining a minimum heat storage amount in a day unit from past usage data including a heat storage amount, a remaining hot water amount, and a hot water supply load, and the minimum heat storage amount is predetermined. Target value changing process of changing at least one of the hot water storage temperature target value and the hot water storage amount target value, the changed hot water storage temperature target value, the hot water storage target value, and past use And a trial calculation process for calculating a daily minimum heat storage amount using the daily hot water supply load in the actual data, and in the target value changing process, the minimum heat storage amount exceeds the upper limit value of the appropriate range. In the case, the above estimation The hot water storage temperature target value is preferentially lowered until the minimum heat storage amount calculated in the process is within the appropriate range, and the hot water storage temperature target value is reached when the hot water storage temperature target value reaches a predetermined lower limit value. When the minimum heat storage amount is less than the lower limit value of the appropriate range, the hot water storage amount target value is prioritized until the minimum heat storage amount calculated in the trial calculation process is within the appropriate range. The heat pump type hot water heater control method increases the hot water storage temperature target value when the hot water storage amount target value reaches a predetermined upper limit.

  According to the present invention, there is an effect that energy saving can be achieved.

It is the figure which showed schematic structure of the heat pump type water heater which concerns on one Embodiment of this invention. It is a functional block diagram of the hot water supply control part shown in FIG. It is the figure shown about an example of the minimum heat storage amount for every day of the week acquired by the acquisition part shown in FIG. It is the figure which showed the relationship between the general coefficient of performance of a heat source machine, and hot water storage temperature. It is the flowchart shown about the procedure of the process performed by a schedule update part. It is the flowchart shown about the procedure of the process performed by a schedule update part. It is the flowchart shown about the procedure of the process performed by a schedule update part. It is the flowchart shown about the procedure of the process performed by a schedule update part. It is the figure which showed an example of the hot water supply load balance sheet produced based on the usage performance data for a certain day stored in the usage performance data storage part. It is the figure which showed an example of the hot water supply load balance sheet created from use performance data. In the hot water supply load balance sheet shown in FIG. 10, an example of the hot water supply load balance sheet when the hot water storage temperature target value and the hot water storage target value are changed so that the estimated minimum heat storage amount is within the appropriate range is shown. FIG. It is the figure which showed an example of the hot water supply load balance sheet created from use performance data. In the hot water supply load balance sheet shown in FIG. 12, an example of the hot water supply load balance sheet when the hot water storage temperature target value and the hot water storage target value are changed so that the estimated minimum heat storage amount is within the appropriate range is shown. FIG. In the hot water supply load balance sheet shown in FIG. 12, an example of the hot water supply load balance sheet when the hot water storage temperature target value and the hot water storage target value are changed so that the estimated minimum heat storage amount is within the appropriate range is shown. FIG.

Hereinafter, an embodiment of a heat pump type hot water heater and a control method thereof according to the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing a schematic configuration of a heat pump type water heater according to an embodiment of the present invention. As shown in FIG. 1, the heat pump hot water heater 1 includes a heat source device 2 that heats low-temperature water by a heat pump, and a hot water tank 3 that stores high-temperature water heated by the heat source device 2.

In the heat pump type hot water heater 1, low temperature water is supplied to the hot water storage tank 3 through the water supply pipe 4 by the water supply pump 5. The low temperature water supplied to the hot water storage tank 3 is sent to the circulation pipe 6, the flow rate of which is adjusted by a circulation pump (not shown) of the heat source unit 2 provided in the circulation pipe 6, and in a water heat exchanger (not shown), It is heated by exchanging heat with a high-temperature refrigerant. The heated hot water is returned to the hot water tank 3 from the upper part of the hot water tank 3 through the circulation pipe 6. The hot water stored in the hot water storage tank 3 is supplied to a hot water tap such as a hot water tap for a bathtub (not shown) through the hot water supply pipe 7.
The hot water storage tank 3 is provided with a hot water amount sensor (not shown) for measuring the remaining hot water amount and a temperature sensor (not shown) for measuring the hot water storage temperature, and the water supply pipe 4 is provided with a flow rate sensor for measuring the water supply amount. (Not shown) is provided, and the hot water supply pipe 7 is provided with a flow rate sensor (not shown) for measuring the hot water supply amount. The measured values of these sensors are transmitted to a hot water supply control unit 10 described later, stored as usage record data, and used in the control of a heat source machine and the like.

  The heating control of the low temperature water in the heat pump hot water heater 1 is performed by the hot water supply control unit 10. The hot water supply control unit 10 has, for example, a schedule in which a hot water storage temperature target value and a hot water storage target value for each day of the week are set, and the heat source device 2 and the water supply pump 5 are operated according to this schedule. The corresponding heat storage amount (hot water storage temperature x hot water storage amount) is stored in the hot water storage tank 3. Here, the low-temperature water heating operation by the heat source device 2 is performed by using as much power as possible in a time zone where the power rate is relatively low (for example, late-night power rate).

  In FIG. 2, the functional block diagram of the hot water supply control part 10 is shown. As shown in FIG. 2, the hot water supply control unit 10 includes a schedule storage unit 11 in which a schedule is stored, a use result data storage unit 12 in which past use result data is stored, and a schedule storage unit based on past use result data. 11 includes a schedule update unit 13 that updates the schedule stored in the table 11. The hot water supply control unit 10 includes a water supply pump control unit (not shown) that gives an operation command to the water supply pump 5, a heating control unit (not shown) that gives a command value such as a hot water target temperature to the heat source unit 2, and the like. ing. In addition, what is necessary is just to employ | adopt a well-known technique suitably about the flow control of the feed water pump 5 based on the hot water storage temperature target value and the hot water storage amount target value, and operation control of the heat-source equipment 2, Therefore Detailed description is abbreviate | omitted.

The schedule storage unit 11 is set with a hot water storage temperature target value and a hot water storage amount target value for each day of the week.
In the use record data storage unit 12, as past use record data, for example, a minimum heat storage amount, a remaining hot water amount, a hot water supply load, a heat source machine heating capacity, etc. for the past one week are stored in association with the date / day of the week. . Accordingly, for example, a hot water supply load balance sheet as shown in FIG. 9 can be created based on certain usage record data stored in the usage record data storage unit 12, and the amount of stored heat in the hot water storage tank in the day, hot water supply Transition of load and heat source machine heating capacity can be grasped.

The schedule update unit 13 includes an acquisition unit 21, a target value change unit 22, and a trial calculation unit 23.
The acquisition unit 21 acquires a minimum heat storage amount for each day of the week from past use record data stored in the use record data storage unit 12. For example, the acquisition unit 21 reads the usage record data for the past week from the usage record data storage unit 12 and acquires the minimum heat storage amount for each day of the week as shown in FIG.

  The target value changing unit 22 determines whether or not there is a day of the week when the minimum heat storage amount for each day of the week acquired by the acquiring unit 21 is outside the predetermined appropriate range set in advance. When there is, the hot water storage temperature target value and the hot water storage target value for the day of the week stored in the schedule storage unit 11 are changed. For example, if the minimum heat storage amount for each day of the week acquired by the acquisition unit 21 is a result as shown in FIG. 3, the hot water storage temperature target value and the hot water storage target value for Monday and Wednesday are changed.

Specifically, when the minimum heat storage amount exceeds the upper limit value of the appropriate range, the target value changing unit 22 stores hot water until the minimum heat storage amount calculated by the trial calculation unit 23 described later falls within the appropriate range. The temperature target value is preferentially lowered, and when the hot water storage temperature target value reaches a predetermined lower limit value, the hot water storage amount target value is reduced.
Further, when the minimum heat storage amount is less than the lower limit value of the appropriate range, the target value changing unit 22 sets the hot water storage amount target value until the minimum heat storage amount calculated by the trial calculation unit 23 described later falls within the appropriate range. When the hot water storage amount target value reaches a predetermined upper limit value, the hot water storage temperature target value is increased.

  As shown in FIG. 4, generally, in a heat source device having a heat pump, the coefficient of performance (COP) decreases when the hot water storage temperature rises. The coefficient of performance is a value obtained by dividing the heating capacity (kW) by the power consumption (kW), and the higher the coefficient of performance, the higher the efficiency. For this reason, in this embodiment, when changing the hot water storage temperature target value and the hot water storage amount target value, the hot water storage temperature is set as low as possible and the heat source unit 2 is operated in a highly efficient operation region. To reduce power consumption.

  Each time the target value changing unit 22 changes the hot water storage temperature target value or the hot water storage amount target value, the trial calculation unit 23 refers to the past usage record of the day of the week (specifically, the hot water supply load) and changes the value. Calculate the minimum heat storage amount when the hot water storage temperature target value or hot water storage amount target value is set. Specifically, the trial calculation unit 23 calculates the heat storage amount for each hour by multiplying the hot water storage temperature target value and the hot water storage amount target value in the changed operation pattern (operation time), and the past use of the day of the week. From the actual hot water supply load for each hour, the change in the hot water tank per day is calculated, and the minimum heat storage amount per day is calculated.

Next, a procedure of processing executed by the schedule update unit 13 of the hot water supply control unit 10 described above will be described with reference to FIGS. The schedule update unit 13 of the hot water supply control unit 10 performs the following processing, for example, once a week to update the schedule.
First, usage record data for the past week is read from the usage record data storage unit 12 (step SA1 in FIG. 5), and the minimum heat storage amount for each day of the week is acquired (step SA2).

Next, it is determined whether or not there is a day of the week when the minimum heat storage amount is outside the predetermined appropriate range (step SA3). If there is no day of the week that is outside the appropriate range, it is determined that there is no need to update the schedule. The process ends ("NO" in step SA3). On the other hand, if there is a day of the week when the minimum heat storage amount falls outside the predetermined appropriate range, the day of the week is extracted (step SA4), and the target value changing process is performed for each extracted day of the week (step SA5).
In the target value changing process, first, it is determined whether or not the extracted minimum heat storage amount for the day of the week is less than the lower limit value of the appropriate range (step SB1 in FIG. 6), and if the minimum heat storage amount is not less than the lower limit value of the appropriate range ( In step SB1, “NO”), it is determined that the minimum heat storage amount exceeds the upper limit value of the appropriate range, and target value change processing for the purpose of reducing the heat storage amount is performed (step SB2). If the minimum heat storage amount is less than the lower limit value of the appropriate range (“YES” in step SB1), target value changing processing for the purpose of increasing the heat storage amount is performed (step SB3).

  In the target value changing process for the purpose of lowering the heat storage amount, first, it is determined whether the current hot water storage temperature target value is a preset lower limit value of the hot water storage temperature (step SC1 in FIG. 7), and the hot water storage temperature target value. Is not the lower limit (“NO” in step SC1), the hot water storage temperature target value is changed to the lower limit (step SC2). Subsequently, the minimum heat storage amount is estimated using the changed target value (step SC3), and it is determined whether the calculated minimum heat storage amount is within an appropriate range (step SC4). As a result, if it is not within the appropriate range (“NO” in step SC4), it is determined whether or not the minimum heat storage amount calculated in step SC3 is larger than the upper limit value of the appropriate range (step SC5).

As a result, when the estimated minimum heat storage amount is larger than the upper limit value of the appropriate range (“YES” in step SC5), it is necessary to further reduce the heat storage amount. The value is changed (step SC6), and the process returns to step SC3. On the other hand, in step SC5, when the estimated minimum heat storage amount is equal to or less than the upper limit value of the appropriate range (“NO” in step SC5), it is determined that the minimum heat storage amount is less than the lower limit value of the appropriate range. That is, in this case, since the hot water storage temperature target value is changed to the lower limit value in step SC2, the heat storage amount becomes too low and the heat storage amount needs to be increased. The fixed amount β is increased (step SC7), and the process returns to step SC3. Thereby, the trial calculation of the minimum heat storage amount using the updated target value is performed again (step SC3). In step SC4, the loop from step SC3 to SC7 is repeated until the minimum heat storage amount is within the appropriate range. When the minimum heat storage amount is within the appropriate range (“YES” in step SC4), the schedule storage unit 11 The stored schedule is updated to the target value at that time (step SC8), and the process ends.
In this process, the hot water storage temperature target value is increased in step SC7. However, the amount of stored heat is sufficient even if the amount of stored hot water is increased by increasing the amount of stored hot water and the amount of stored hot water is increased to the upper limit. If not, the hot water storage temperature target value may be increased. With such a process, the hot water storage temperature target value can be set as low as possible, and the heat source device 2 can be operated in an efficient temperature zone.

  Further, in the target value changing process for the purpose of increasing the heat storage amount in step SB3 in FIG. 6, it is first determined whether or not the current hot water storage amount target value is a preset upper limit value of the hot water storage amount (FIG. 8). In step SD1), if the hot water storage target value is not the upper limit (“NO” in step SD1), the hot water storage target value is changed to a value increased by a predetermined amount α (step SD2). At this time, the hot water storage amount target value is increased with the upper limit value of the hot water storage amount as the upper limit. Subsequently, the minimum heat storage amount is estimated using the changed target value (step SD3), and it is determined whether the calculated minimum heat storage amount is within an appropriate range (step SD4). As a result, when it is not within the appropriate range (“NO” in step SD4), the process returns to step SD1.

  As a result, the processes of steps SD1 to SD4 are repeated until the estimated minimum heat storage amount is within the appropriate range or the hot water storage amount target value reaches the upper limit value, and the hot water storage target value increases stepwise. Is done. If the hot water storage amount reaches the upper limit before the minimum heat storage amount calculated in step SD3 falls within the appropriate range (“YES” in step SD1), the hot water storage temperature target value is the upper limit value. (Step SD5). As a result, when the hot water storage temperature target value is not the upper limit value ("NO" in step SD5), the hot water storage temperature target value is changed to a value increased by a predetermined amount β (step SD6). At this time, the hot water storage temperature target value is increased with the upper limit value of the hot water storage temperature as the upper limit. Then, the minimum heat storage amount is calculated using the changed target value (step SD7), and it is determined whether or not the calculated minimum heat storage amount is within an appropriate range (step SD8).

  As a result, if the estimated minimum heat storage amount is within the appropriate range (“YES” in step SD8), the schedule is updated by writing the target value at this time in the schedule (step SD9). On the other hand, when the minimum heat storage amount is not within the appropriate range in step SD8, the process returns to step SD5. Thus, the process for increasing the hot water storage temperature target value is repeatedly performed until the estimated minimum heat storage amount falls within the appropriate range or the hot water storage temperature target value reaches the upper limit value. If the minimum heat storage amount is within the appropriate range before the hot water storage temperature target value reaches the upper limit (“YES” in step SD8), the schedule is updated by writing the target value at that time in the schedule, and the process Exit.

  On the other hand, if the hot water storage temperature target value reaches the upper limit before the minimum heat storage amount falls within the appropriate range, the heat storage amount cannot be increased any further. In this case, for example, the schedule is updated by writing the hot water storage temperature target value and the upper limit value of the hot water storage amount target value in the schedule. In this case, since it is highly possible that the amount of heat stored in the hot water tank 3 using the nighttime power is less than the amount used, measures such as operating the heat pump during the day to increase the amount of hot water stored in the hot water tank, etc. It is necessary to take In this case, for example, it is possible to take measures such as operating the heat source device 2 when the amount of remaining hot water in the hot water storage tank 3 becomes a predetermined threshold value or less.

  9 to 14 are diagrams showing an example of a daily hot water supply load balance sheet. FIG. 9 shows a case where the minimum heat storage amount on this day is within an appropriate range. FIG. 10 is a diagram showing an example of a hot water supply load balance sheet created from usage record data, and shows a case where the minimum heat storage amount on this day exceeds the upper limit value of the appropriate range. In such a case, the target value changing process for the purpose of lowering the heat storage amount shown in FIG. 7 is performed, so that the estimated minimum heat storage amount is within an appropriate range as shown in FIG. Thus, the hot water storage temperature target value and the hot water storage amount target value are changed.

  FIG. 12 is a diagram showing an example of a hot water supply load balance sheet created from usage record data, and shows a case where the minimum heat storage amount on this day is less than the lower limit value of the appropriate range. In such a case, the target value changing process for the purpose of increasing the heat storage amount shown in FIG. 8 is performed, so that the estimated minimum heat storage amount is within an appropriate range as shown in FIG. Thus, the hot water storage temperature target value and the hot water storage amount target value are changed. For example, in FIG. 13, since the hot water storage target value has increased, it can be seen that the operation time of the heat source unit 2 is extended by 1 hour and the operation is stopped at 9 o'clock. As described above, if the hot water storage temperature target value and the hot water storage amount target value set in the schedule cannot be reached only by operating the heat source machine 2 during the midnight charge period, even in the normal charge time period. It is necessary to operate the heat source unit 2. Further, in FIG. 13, a predetermined heat storage amount is secured by continuously extending the operation time of the heat source device 2, but in FIG. 14, the heat source device 2 of 8:00 when the midnight fee time period ends. The operation is temporarily stopped, and the heat source unit 2 is operated again in a time zone where the hot water supply load increases (here, from 18:00 to 19:00) to increase the amount of heat stored.

As explained above, according to the heat pump type water heater 1 according to the present embodiment, when changing the hot water storage temperature target value and the hot water storage target value for the next day or later according to the usage record data, the heat storage amount from the usage record data. Is determined to be excessive, the hot water storage temperature target value is preferentially reduced, and when the hot water storage temperature target value reaches the lower limit, the hot water storage amount target value is reduced. In addition, when it is determined from the usage record data that the heat storage amount is insufficient, the hot water storage amount target value is preferentially increased, and when the hot water storage amount target value reaches the upper limit value, the hot water storage temperature target value is increased. .
In this way, by setting the hot water storage temperature as low as possible and setting the amount of hot water as large as possible, the heat source device 2 can be operated in an efficient operation region, and energy saving can be achieved. Moreover, scale precipitation can be reduced by setting the hot water storage temperature as low as possible.
In addition, since the schedule is periodically updated with reference to the usage record data, there is no excess or deficiency in the amount of heat storage, and heating can be performed efficiently. Thereby, energy saving can be achieved.

In the present embodiment, the hot water storage temperature target value and the hot water storage target value are set for each day of the week. However, the present invention is not limited to this, and for example, the hot water storage temperature target value and hot water storage of the next day based on the use result data of the previous day. The amount target value may be set, or the hot water storage temperature target value and the hot water storage amount target value may be set separately for weekdays and holidays. In this case, an average value may be used for the minimum heat storage amount on weekdays and holidays, or the minimum heat storage amount in the average value may be used.
In this embodiment, the hot water storage temperature target value and the hot water storage target value are changed using the minimum heat storage amount, but the same hot water storage temperature target value and hot water storage target are used instead of the minimum heat storage amount. The value may be changed.

  The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the invention.

DESCRIPTION OF SYMBOLS 1 Heat pump type hot water heater 2 Heat source machine 3 Hot water storage tank 4 Water supply pipe 5 Water supply pump 6 Circulation pipe 7 Hot water supply pipe 10 Hot water supply control part 11 Schedule memory | storage part 12 Use result data memory | storage part 13 Schedule update part 21 Acquisition part 22 Target value change part 23 Trial Calculation Department

Claims (6)

A heat pump type hot water heater that heats hot water in a hot water tank as much as possible by using electricity during a time period when the electricity price is relatively low as much as possible, so that the hot water storage temperature target value and hot water storage amount target value are set in advance. And
An acquisition means for acquiring a minimum heat storage amount in units of days from past use record data including a heat storage amount or a remaining hot water amount, and a hot water supply load;
A target value changing means for changing at least one of the hot water storage temperature target value and the hot water storage amount target value when the minimum heat storage amount exceeds a predetermined appropriate range;
Using the hot water storage temperature target value and the hot water storage target value after the change and the hot water supply load of the day in the past use record data, and a trial calculation means for calculating the minimum heat storage amount of the day,
The target value changing means includes
When the minimum heat storage amount exceeds the upper limit value of the appropriate range, the hot water storage temperature target value is preferentially lowered until the minimum heat storage amount calculated by the trial calculation means falls within the appropriate range. When the hot water storage temperature target value reaches a predetermined lower limit, the hot water storage amount target value is reduced,
When the minimum heat storage amount is less than the lower limit value of the appropriate range, the hot water storage amount target value is preferentially increased until the minimum heat storage amount calculated by the trial calculation means is within the appropriate range, A heat pump type hot water heater that increases the hot water storage temperature target value when the hot water storage amount target value reaches a predetermined upper limit value. The hot water storage temperature target value and the hot water storage amount target value are set for each day of the week,
The acquisition means acquires the minimum heat storage amount every day of the week,
The heat pump hot water heater according to claim 1, wherein the target value changing means changes at least one of the hot water storage temperature target value and the hot water storage target value for a day of the week when the minimum heat storage amount is outside the appropriate range. The hot water storage temperature target value and the hot water storage amount target value are set separately for weekdays and holidays,
The acquisition means acquires the minimum heat storage amount separately for weekdays and holidays,
When the minimum heat storage amount on weekdays is outside the proper range, the target value changing means changes at least one of the hot water storage temperature target value on weekdays and the hot water storage amount target value, and the minimum heat storage on holidays The heat pump type water heater according to claim 1, wherein when the amount is out of the proper range, at least one of the hot water storage temperature target value and the hot water storage amount target value on a holiday is changed. The acquisition unit acquires the minimum heat storage amount from the usage record data of the previous day,
When the minimum heat storage amount exceeds a predetermined appropriate range, the target value changing means changes at least one of the hot water storage temperature target value and the hot water storage amount target value, and the hot water storage temperature target value of the next day. And the heat pump type hot water heater of Claim 1 which sets hot water storage amount target value.   The heat pump type hot water heater according to any one of claims 1 to 4, wherein a minimum remaining hot water amount is used instead of the minimum heat storage amount. Control of a heat pump water heater that heats the hot water in the hot water tank to a preset value for the hot water storage temperature and the target value for hot water storage, using as much electricity as possible during periods of relatively low electricity rates. A method,
An acquisition process for acquiring a minimum heat storage amount in units of days from past usage record data including a heat storage amount or a remaining hot water amount, and a hot water supply load;
A target value changing process for changing at least one of the hot water storage temperature target value and the hot water storage amount target value when the minimum heat storage amount exceeds a predetermined appropriate range;
Using the hot water storage temperature target value and the hot water storage target value after the change and the hot water supply load of the day in the past use record data, and a trial calculation process for calculating the minimum heat storage amount of the day,
In the target value changing process,
When the minimum heat storage amount exceeds the upper limit value of the appropriate range, the hot water storage temperature target value is preferentially decreased until the minimum heat storage amount calculated in the trial calculation process is within the appropriate range. When the hot water storage temperature target value reaches a predetermined lower limit, the hot water storage amount target value is reduced,
When the minimum heat storage amount is less than the lower limit value of the appropriate range, the hot water storage amount target value is preferentially increased until the minimum heat storage amount calculated in the trial calculation process is within the appropriate range, A control method of a heat pump type hot water heater that increases the hot water storage temperature target value when the hot water storage amount target value reaches a predetermined upper limit value.

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