Water heater, surplus power prediction method, and control method for water heater

Abstract

To provide a water heater capable of efficiently performing a daytime boiling operation utilizing surplus power in a photovoltaic power generation unit by predicting unit time basis surplus power on a boiling operation execution day and the next day of boiling operation execution prior to the boiling operation execution day, a surplus power prediction method, and a control method for the water heater.SOLUTION: In a water heater, a coil device 30 acquires predicted weather data on a boiling operation execution day and the next day of boiling operation execution prior to the boiling operation execution day and the next day of boiling operation execution, calculates from the predicted weather data unit time basis power generation prediction amounts on the boiling operation execution day and the next day of boiling operation execution for which power can be generated by a photovoltaic power generation unit 50, determines a unit time basis self-consumption power prediction amount on the boiling operation execution day, and predicts unit time basis surplus power on the boiling operation execution day and the next day of boiling operation execution from the unit time basis power prediction amounts and the unit time basis self-consumption power prediction amount.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a water heating apparatus that uses power generated by a photovoltaic power generation unit, a surplus power prediction method, and a method for controlling the water heating apparatus. [Background technology]

[0002] Patent document 1 proposes a storage-type water heater that connects a solar power generation system and a water heater, determines whether the solar power generation system is generating surplus electricity, and when there is surplus electricity, performs boiling operation with high heating capacity. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-122764 A Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, water heating is performed by determining whether or not there is surplus electricity during the daytime when the solar power device is generating electricity. However, with a storage water heater, the entire amount of hot water needs to be heated by the evening, when hot water is most often used.If there is insufficient surplus electricity from the solar power generation system, the shortfall in hot water must be heated by the evening of the same day, meaning that night-time electricity, when rates are cheaper, cannot be used.

[0005] Therefore, the present invention aims to provide a water heating apparatus, a surplus power prediction method, and a control method for a water heating apparatus that can efficiently perform daytime heating operation by utilizing surplus power from a solar power generation unit by predicting surplus power per unit time on the day when heating operation is executed and the day after the day when heating operation is executed before the day when heating operation is executed. [Means for solving the problem]

[0006] The hot water heating device of the present invention described in claim 1 is a hot water heating device that comprises a hot water storage tank 10, a heat pump unit that heats hot water in the hot water storage tank 10, and a control device 30, and uses electricity generated by a solar power generation unit 50, wherein the control device 30 obtains predicted weather data 60 for the day on which the hot water operation is executed and the day after the day on which the hot water operation is executed before the day on which the hot water operation is executed, calculates a predicted amount of power generation by unit time that can be generated by the solar power generation unit 50 on the day on which the hot water operation is executed and the day after the day on which the hot water operation is executed from the predicted weather data 60, determines a predicted amount of self-consumption power by unit time on the day on which the hot water operation is executed and the day after the day on which the hot water operation is executed, and predicts surplus power by unit time on the day on which the hot water operation is executed and the day after the day on which the hot water operation is executed from the predicted amount of power generation by unit time and the predicted amount of self-consumption power by unit time. The water heating device of the present invention as described in claim 2 is characterized in that, in the water heating device as described in claim 1, the control device 30 has a daytime time zone mode 31A in which heating operation is performed during daytime hours, calculates a predicted amount of hot water to be used on the day when the heating operation is performed and the day after the heating operation is performed, calculates a predicted amount of hot water to be heated with the surplus electricity per unit time on the day when the heating operation is performed and the day after the heating operation is performed, and if the predicted amount of hot water to be heated on the day after the heating operation is performed is less than the predicted amount of hot water to be used on the day after the heating operation is performed and if the predicted amount of hot water to be heated on the day when the heating operation is performed is greater than the predicted amount of hot water to be used on the day when the heating operation is performed, the amount of hot water to be heated in the daytime time zone mode 31A on the day when the heating operation is performed is greater than the predicted amount of hot water to be used on the day when the heating operation is performed. The water heating apparatus of the present invention described in claim 3 is characterized in that, in the water heating apparatus described in claim 2, the heating temperature in the daytime time zone mode 31A on the day when the heating operation is performed is increased, so that the amount of hot water heated in the daytime time zone mode 31A on the day when the heating operation is performed is made greater than the predicted daytime heating amount of hot water on the day when the heating operation is performed. The water heating apparatus of the present invention as described in claim 4 is the water heating apparatus as described in claim 1, wherein the control device 30 has a daytime time zone mode 31A in which heating operation is performed during daytime hours and a nighttime time zone mode 31B in which the heating operation is performed during nighttime hours, calculates a predicted amount of hot water to be used on the day when the heating operation is performed, calculates a predicted amount of hot water to be heated during the daytime that can be heated with the predicted surplus power per unit time, and if it is determined that the predicted amount of hot water to be heated during the daytime is less than the predicted amount of hot water to be used, performs the heating operation in the nighttime time zone mode 31B on the day when the heating operation is performed. The water heating apparatus of the present invention described in claim 5 is characterized in that, in the water heating apparatus described in claim 4, the amount of hot water heated at night in the nighttime time zone mode 31B is the amount of hot water calculated by subtracting the predicted amount of hot water to be heated during the day from the predicted amount of hot water to be used. The water heating apparatus of the present invention as described in claim 6 is characterized in that, in the water heating apparatus as described in claim 4 or claim 5, the predicted weather data 60 is a predicted amount of solar radiation and a predicted outside air temperature, the predicted amount of solar radiation is used to calculate the predicted amount of power generation per unit time, and the predicted outside air temperature is used to calculate the heating power by the heat pump unit. The water heating device of the present invention as described in claim 7 is characterized in that, in the water heating device as described in claim 4, the heat pump unit has a first boiling capacity requiring a first boiling power and a second boiling capacity requiring a second boiling power less than the first boiling power as boiling capacities, and the control device 30 predicts a first daytime operable time when the predicted surplus power per unit time will be greater than or equal to the first boiling power, and if the first daytime operable time is less than or equal to a set time, predicts a second daytime operable time when the predicted surplus power per unit time will be greater than or equal to the second boiling power, and the predicted daytime boiling water volume is calculated based on the second boiling capacity and the second daytime operable time. The hot water heating device of the present invention as described in claim 8 is characterized in that, in the hot water heating device as described in claim 4, the heat pump unit has a first boiling capacity requiring a first boiling power and a second boiling capacity requiring a second boiling power less than the first boiling power as boiling capacities, and the control device 30 predicts a first daytime operable time when the predicted surplus power per unit time will be equal to or greater than the first boiling power, predicts a second daytime operable time when the predicted surplus power per unit time will be equal to or greater than the second boiling power, and if the second daytime predicted boiling water volume to be boiled during the second daytime operable time with the second boiling capacity is equal to or greater than the first daytime predicted boiling water volume to be boiled during the first daytime operable time with the first boiling capacity, sets the second daytime predicted boiling water volume to the daytime predicted boiling water volume. The hot water heating device of the present invention as described in claim 9 is characterized in that, in the hot water heating device as described in claim 4, the heat pump unit has a first boiling capacity requiring a first boiling power and a second boiling capacity requiring a second boiling power less than the first boiling power as boiling capacities, and the control device 30 predicts a second daytime operable time during which the predicted surplus power per unit time will be equal to or greater than the second boiling power, and if the second daytime boiling predicted amount of hot water to be boiled during the second daytime operable time at the second boiling capacity is equal to or greater than the predicted amount of hot water used, the second daytime boiling predicted amount of hot water is set to the daytime boiling predicted amount of hot water. The surplus power prediction method of the present invention as described in claim 10 is a surplus power prediction method that utilizes power generated by a solar power generation unit 50 for a hot water supply device, and is characterized in that it obtains predicted weather data 60 for the day on which a water heating operation is executed and the day after the water heating operation is executed before the day on which a water heating operation is executed to heat up hot water in a hot water storage tank, calculates a predicted amount of power generation by unit time that can be generated by the solar power generation unit 50 on the day on which the water heating operation is executed and the day after the water heating operation is executed from the predicted weather data 60, determines a predicted amount of personal power consumption by unit time on the day on which the water heating operation is executed and the day after the water heating operation is executed, and predicts surplus power by unit time on the day on which the water heating operation is executed and the day after the water heating operation is executed from the predicted amount of power generation by unit time and the predicted amount of personal power consumption by unit time. A control method for a hot water supply device of the present invention as set forth in claim 11 is a control method for a hot water supply device that includes a hot water storage tank and a heat pump unit that heats hot water in the hot water storage tank, and that utilizes power generated by a photovoltaic power generation unit 50, and includes obtaining predicted weather data 60 for the day on which a water heating operation is to be performed and the day after the day on which the water heating operation is to be performed before a day on which a water heating operation is to be performed, calculating a predicted amount of power generation by unit time for the day on which the water heating operation is to be performed and the day after the day on which the water heating operation is to be performed that can be generated by the photovoltaic power generation unit 50 from the predicted weather data 60, determining a predicted amount of personal power consumption by unit time for the day on which the water heating operation is to be performed and the day after the day on which the water heating operation is to be performed from the predicted amount of power generation by unit time and the predicted amount of personal power consumption by unit time, The method is characterized in that it predicts surplus electricity per unit time on the day after the water heating operation is executed, calculates a predicted amount of hot water to be used on the day the water heating operation is executed and the day after the water heating operation is executed, calculates a predicted amount of daytime hot water to be heated with the surplus electricity per unit time on the day the water heating operation is executed and the day after the water heating operation is executed, and if the predicted amount of daytime hot water to be heated on the day after the water heating operation is executed is less than the predicted amount of hot water to be used on the day after the water heating operation is executed and if the predicted amount of daytime hot water to be heated on the day after the water heating operation is executed is greater than the predicted amount of hot water to be used on the day the water heating operation is executed, the amount of hot water to be heated in daytime time zone mode 31A on the day the water heating operation is executed is made greater than the predicted amount of daytime hot water to be heated on the day the water heating operation is executed. The present invention as described in claim 12 is characterized in that, in the control method of the water heating apparatus as described in claim 11, by increasing the heating temperature in the daytime time zone mode 31A on the day when the heating operation is performed, the amount of hot water heated in the daytime time zone mode 31A on the day when the heating operation is performed is made greater than the predicted daytime heating amount of hot water on the day when the heating operation is performed. Effect of the Invention

[0007] According to the present invention, by predicting the surplus power per unit time on the day when water heating operation is to be performed and the day after the day when water heating operation is to be performed before the day when water heating operation is to be performed, water heating operation can be efficiently performed during the day by utilizing the surplus power in the solar power generation unit. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a block diagram of a water heater according to an embodiment of the present invention; [Diagram 2] FIG. 13 is an explanatory diagram showing the surplus power per unit time and the possible operation time during the daytime in the hot water supply device. [Diagram 3] Flow diagram of the hot water supply system DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] In the hot water supply device according to the first embodiment of the present invention, the control device acquires forecasted weather data for the day on which the water heating operation is to be performed and the day after the day on which the water heating operation is to be performed before the day on which the water heating operation is to be performed, calculates a forecasted amount of power generation by unit time for the day on which the water heating operation is to be performed and the day after the day on which the water heating operation is to be performed from the forecasted weather data, determines a forecasted amount of private power consumption by unit time for the day on which the water heating operation is to be performed and the day after the day on which the water heating operation is to be performed, and predicts surplus power by unit time for the day on which the water heating operation is to be performed and the day after the day on which the water heating operation is to be performed from the forecasted amount of power generation by unit time and the forecasted amount of private power consumption by unit time. According to this embodiment, by predicting the surplus power by unit time for the day on which the water heating operation is to be performed and the day after the day on which the water heating operation is to be performed before the day on which the water heating operation is to be performed, the surplus power in the solar power generation unit can be used to efficiently perform daytime water heating operation.

[0010] In the second embodiment of the present invention, in the hot water supply device according to the first embodiment, the control device has a daytime time zone mode in which the hot water heating operation is performed during daytime hours, calculates the predicted amount of hot water to be used on the day when the hot water heating operation is performed and the day after the day when the hot water heating operation is performed, calculates the predicted amount of hot water to be heated with the surplus power per unit time on the day when the hot water heating operation is performed and the day after the day when the hot water heating operation is performed, and if the predicted amount of hot water to be heated on the day after the day when the hot water heating operation is performed is less than the predicted amount of hot water to be used on the day after the day when the hot water heating operation is performed and the predicted amount of hot water to be heated on the day when the hot water heating operation is performed is greater than the predicted amount of hot water to be used on the day when the hot water heating operation is performed. According to this embodiment, the daytime hot water heating operation can be performed on the day when the hot water heating operation is performed, taking into account the surplus power on the day when the hot water heating operation is performed and the day after the day when the hot water heating operation is performed, and the surplus power can be used effectively.

[0011] The third embodiment of the present invention is a hot water supply device according to the second embodiment, in which the heating temperature in the daytime time zone mode on a day when the heating operation is performed is increased, so that the amount of hot water to be heated in the daytime time zone mode on a day when the heating operation is performed is greater than the predicted amount of hot water to be heated in the daytime on the day when the heating operation is performed. According to this embodiment, the amount of heat to be heated in the daytime time zone mode on a day when the heating operation is performed can be increased.

[0012] In the fourth embodiment of the present invention, in the hot water supply device according to the first embodiment, the control device has a daytime time zone mode in which heating operation is performed during daytime hours and a nighttime time zone mode in which heating operation is performed during nighttime hours, calculates the predicted amount of hot water to be used on the day when heating operation is performed, calculates the predicted amount of hot water to be heated during daytime with the predicted surplus power per unit time, and performs heating operation in the nighttime time zone mode on the day when heating operation is performed if it is determined that the predicted amount of hot water to be heated during daytime is less than the predicted amount of hot water to be used. According to this embodiment, daytime heating operation can be performed using surplus power in the solar power generation unit, and the amount of hot water that is insufficient in daytime heating operation using surplus power can be effectively used at night by performing heating operation in the nighttime time zone mode.

[0013] In the fifth embodiment of the present invention, in the hot water supply device according to the fourth embodiment, the amount of hot water to be heated at night in the nighttime mode is the amount of hot water calculated by subtracting the amount of hot water to be heated during the day from the amount of hot water predicted to be used. According to this embodiment, the amount of hot water predicted to be used can be secured.

[0014] The sixth embodiment of the present invention is a hot water supply device according to the fourth or fifth embodiment, in which the predicted weather data is the predicted solar radiation and the predicted outdoor temperature, the predicted solar radiation is used to calculate the predicted power generation per unit time, and the predicted outdoor temperature is used to calculate the heating power by the heat pump unit. According to this embodiment, the surplus power in the solar power generation unit and the heating power by the heat pump unit can be calculated more accurately.

[0015] The seventh embodiment of the present invention is a hot water supply device according to the fourth embodiment, in which the heat pump unit has a first heating capacity that requires a first heating power and a second heating capacity that requires a second heating power less than the first heating power, and the control device predicts a first daytime operable time when the predicted surplus power per unit time is equal to or greater than the first heating power, and when the first daytime operable time is equal to or less than a set time, predicts a second daytime operable time when the predicted surplus power per unit time is equal to or greater than the second heating power, and calculates the predicted daytime hot water volume from the second heating capacity and the second daytime operable time. According to this embodiment, the surplus power in the solar power generation unit can be effectively used.

[0016] The eighth embodiment of the present invention is a hot water supply device according to the fourth embodiment, in which the heat pump unit has a first boiling capacity that requires a first boiling power and a second boiling capacity that requires a second boiling power less than the first boiling power, and the control device predicts a first daytime operable time when the predicted surplus power per unit time is equal to or greater than the first boiling power, predicts a second daytime operable time when the predicted surplus power per unit time is equal to or greater than the second boiling power, and sets the second daytime predicted hot water volume to be the daytime predicted hot water volume if the second daytime predicted hot water volume to be boiled at the second boiling capacity during the second daytime operable time is equal to or greater than the first daytime predicted hot water volume to be boiled at the first boiling capacity during the first daytime operable time. According to this embodiment, the efficiency of the heat pump unit is higher when the heat pump unit is operated at the second boiling capacity than when the heat pump unit is operated at the first boiling capacity, so that the heat pump unit can be operated efficiently.

[0017] A ninth embodiment of the present invention is a hot water supply device according to the fourth embodiment, in which the heat pump unit has a first heating capacity that requires a first heating power and a second heating capacity that requires a second heating power less than the first heating power, and the control device predicts a second daytime operable time when the predicted surplus power per unit time is equal to or greater than the second heating power, and if the second predicted daytime heating amount of hot water to be heated at the second heating capacity during the second daytime operable time is equal to or greater than the predicted amount of hot water used, the second predicted daytime heating amount of hot water is set as the predicted daytime heating amount of hot water. According to this embodiment, the efficiency of the heat pump unit is higher when the heat pump unit is operated at the second heating capacity than when the heat pump unit is operated at the first heating capacity, so that the heat pump unit can be operated efficiently.

[0018] A surplus power prediction method according to a tenth embodiment of the present invention obtains predicted weather data for the day on which the water in a hot water storage tank is heated and the day after the day on which the water is heated, calculates a predicted amount of power generation by unit time on the day on which the water is heated and the day after the day on which the water is heated that can be generated by a solar power generation unit from the predicted weather data, determines a predicted amount of private power consumption by unit time on the day on which the water is heated and the day after the day on which the water is heated, and predicts surplus power by unit time on the day on which the water is heated and the day after the day on which the water is heated from the predicted amount of power generation by unit time and the predicted amount of private power consumption by unit time. According to this embodiment, by predicting the surplus power by unit time on the day on which the water is heated and the day after the day on which the water is heated before the day on which the water is heated, the surplus power in the solar power generation unit can be used to efficiently perform daytime water heating operation.

[0019] A method for controlling a water heating apparatus according to an eleventh embodiment of the present invention includes obtaining predicted weather data for the day on which the water heating operation is to be executed and the day after the day on which the water heating operation is to be executed before the day on which the water heating operation is to be executed, calculating a predicted amount of power generation by unit time for the day on which the water heating operation is to be executed and the day after the day on which the water heating operation is to be executed that can be generated by a solar power generation unit from the predicted weather data, determining a predicted amount of personal power consumption by unit time for the day on which the water heating operation is to be executed and the day after the day on which the water heating operation is to be executed, predicting surplus power by unit time for the day on which the water heating operation is to be executed and the day after the day on which the water heating operation is to be executed from the predicted amount of power generation by unit time and the predicted amount of personal power consumption by unit time, and calculating a predicted amount of power generation by unit time for the day on which the water heating operation is to be executed and the day after the day on which the water heating operation is to be executed from the predicted amount of power generation by unit time and the predicted amount of personal power consumption by unit time, and calculating a predicted amount of power generation by unit time for the day on which the water heating operation is to be executed and the day after the day on which the water heating operation is to be executed from the predicted amount of power generation by unit time and the predicted amount of personal power consumption by unit time, and calculating the .... The system calculates the predicted amount of hot water to be used on the day when the water heating operation is performed and the day after the day when the water heating operation is performed, calculates the predicted amount of hot water to be heated in the daytime that can be heated with the surplus power per unit time on the day when the water heating operation is performed and the day after the day when the water heating operation is performed, and if the predicted amount of hot water to be heated in the daytime time zone mode on the day when the water heating operation is performed is less than the predicted amount of hot water to be used on the day after the day when the water heating operation is performed and the predicted amount of hot water to be heated in the daytime zone mode on the day when the water heating operation is performed is greater than the predicted amount of hot water to be used on the day when the water heating operation is performed. According to this embodiment, by predicting the surplus power per unit time on the day when the water heating operation is performed and the day after the day when the water heating operation is performed before the day when the water heating operation is performed, the surplus power in the solar power generation unit can be used to efficiently perform daytime water heating operation.

[0020] A twelfth embodiment of the present invention relates to a method of controlling a hot water supply apparatus according to the eleventh embodiment, and by increasing the heating temperature in daytime zone mode on a day when heating operation is performed, the amount of hot water to be heated in daytime zone mode on a day when heating operation is performed is made greater than the predicted amount of hot water to be heated in daytime on the day when heating operation is performed. According to this embodiment, the amount of heat to be heated in daytime zone mode on a day when heating operation is performed can be increased. EXAMPLES

[0021] An embodiment of the present invention will now be described with reference to the drawings. FIG. 1 is a configuration diagram of a hot water supply device according to this embodiment. The hot water supply system of this embodiment comprises a hot water storage tank 10, a heating device 20 for heating the hot water in the hot water storage tank 10, a control device 30 for controlling the heating device 20, an operating means 40 by which a user can set the setting conditions of the control device 30, and a solar power generation unit 50. The control device 30 can acquire forecast weather data 60 from an external database via a communication line. The forecast weather data 60 is a forecast solar radiation amount and a forecast outside air temperature. For example, data provided by the Japan Meteorological Agency, the Agro-Meteorological Grid Square Data (NARO) provided by the National Agriculture and Food Research Organization (NARO), or data provided by other organizations can be used as the forecast weather data 60.

[0022] The hot water in the hot water storage tank 10 is drawn from the bottom of the hot water storage tank 10 and passed through the boiling pipe 11 to the heating device 20, where it is heated to a high temperature and then introduced from the top of the hot water storage tank 10 and stored in the hot water storage tank 10. When the hot water tap 12 is opened, the hot water in the hot water storage tank 10 that has been heated to a high temperature is mixed with water supplied from the water supply pipe 14 by the mixing valve 13 to a predetermined temperature and is supplied from the hot water tap 12. When hot water is supplied from the hot water tap 12, any shortage in the hot water storage tank 10 is made by supplying it from a water supply pipe 14 connected to the bottom of the hot water storage tank 10, so that the hot water storage tank 10 is always filled with hot water. The boiling pipe 11 leading from the hot water storage tank 10 to the heating device 20 has a circulation pump 16. When the circulation pump 16 operates, the hot water in the hot water storage tank 10 is passed through the heating device 20 and stored in the hot water storage tank 10.

[0023] The hot water supply pipe 15 extending from the hot water storage tank 10 to the hot water tap 12 is provided with a hot water supply flow rate detection means 17 for detecting the amount of hot water supplied to the hot water tap 12 .

[0024] A heat pump device composed of a compressor, a radiator, a pressure reducer, and an evaporator is suitable for the heating device 20. When a heat pump device is used as the heating device 20, heat dissipated by the radiator is used as a heat source. By using the heating device 20 as a heat pump device, electric power can be used effectively. Furthermore, the hot water heater according to this embodiment receives power from the solar power generation unit 50, and can use the power obtained by the solar power generation unit 50 in the daytime time zone mode 31A. By linking with the solar power generation unit 50, the power obtained by the solar power generation unit 50 can be effectively used for boiling water in the daytime.

[0025] The control device 30 has a water heating operation mode 31. In the water heating operation mode 31, the heating device 20 heats the hot water in the hot water storage tank 10. The water heating operation mode 31 has a daytime period mode 31A in which the water heating operation is performed during daytime hours, and a nighttime period mode 31B in which the water heating operation is performed during nighttime hours. The control device 30 has a timer means 32. The timer means 32 measures time, and can determine the date and time. Therefore, the daytime period and the nighttime period are determined by the timer means 32. The daytime period and the nighttime period may be set in advance, or may be changed by operation of the operation means 40. For example, the daytime period is set from 9:00 to 16:00, and the nighttime period is set from 23:00 to 6:00.

[0026] The control device 30 has a hot water usage amount storage means 33A and a setting condition storage means 33B. The hot water usage storage means 33A stores the amount of hot water detected by the hot water supply flow rate detection means 17 together with the time measured by the timer means 32. The hot water usage storage means 33A stores the amount of hot water by time period for a specified period such as one day, one week, one month, and one year as a hot water usage history.

[0027] The set condition storage means 33B stores at least one set condition among a daytime operation start time, a daytime operation end time, or a daytime operation execution time, for which the daytime time slot mode 31A is executed. Furthermore, the set condition storage means 33B stores the solar panel capacity of the solar power generation unit 50 and the predicted private power consumption amount per unit time as set conditions. These setting conditions are set by the operation means 40. The predicted amount of personal power consumption by unit time can be calculated by storing personal power consumption by time period for a predetermined period such as one day, one week, one month, or one year as a history of power usage, and using the stored history of power usage as the predicted amount of personal power consumption by unit time. The personal power consumption does not include the power consumption by the heating device 20, but includes the power consumption by a television, refrigerator, and other electrical appliances.

[0028] The control device 30 has a predicted hot water usage calculation means 34A that calculates a predicted hot water usage amount on the day when the boiling-up operation is performed and on the day after the boiling-up operation is performed. The predicted hot water usage calculation means 34A calculates the predicted hot water usage on the day when the boiling operation is performed and the day after the boiling operation is performed based on the hot water usage history stored in the hot water usage storage means 33A.

[0029] The control device 30 also has a unit-time predicted power generation amount calculation means 34B that calculates a unit-time predicted power generation amount that can be generated by the solar power generation unit 50 on the day when the water heating operation is executed from predicted weather data, a unit-time predicted personal power consumption determination means 34C that determines a unit-time predicted personal power consumption amount on the day when the water heating operation is executed and the day after the water heating operation is executed, and a unit-time surplus power calculation means 34D that predicts a unit-time surplus power on the day when the water heating operation is executed and the day after the water heating operation is executed from the unit-time predicted power generation amount and the unit-time predicted personal power consumption amount. The unit-hour power generation forecast calculation means 34B calculates the unit-hour power generation forecast amount for the day when the water-heating operation is performed and the day after the day when the water-heating operation is performed from the predicted weather data 60 for the day when the water-heating operation is performed and the day after the day when the water-heating operation is performed that are acquired before the day when the water-heating operation is performed and the solar panel capacity of the solar power generation unit 50 stored in the setting condition storage means 33B. Note that by using the predicted solar radiation amount for the day when the water-heating operation is performed and the day after the day when the water-heating operation is performed in the unit-hour power generation forecast amount, the surplus power in the solar power generation unit 50 can be calculated more accurately.

[0030] The unit time-based personal power consumption predicted amount determining means 34C determines the unit time-based personal power consumption predicted amount stored in the setting condition storing means 33B. The unit-time surplus power calculation means 34D predicts surplus power by unit time on the day when the heating operation is performed and the day after the heating operation is performed, based on the predicted power generation amount by unit time calculated by the unit-time predicted power generation amount calculation means 34B and the predicted private power consumption amount by unit time determined by the unit-time predicted private power consumption amount determination means 34C. The control device 30 has a predicted daytime hot water volume calculation means 34E for calculating a predicted daytime hot water volume that can be heated with the surplus power per unit time predicted by the surplus power per unit time calculation means 34D.

[0031] The heating device 20 has, as boiling capacities, a first boiling capacity that requires a first boiling power and a second boiling capacity that requires a second boiling power that is less than the first boiling power. In this way, when the heating device 20 has a first boiling capacity and a second boiling capacity, the daytime boiling predicted hot water amount calculation means 34E predicts the first daytime operable time when the surplus power per unit time predicted by the unit time surplus power calculation means 34D is equal to or greater than the first boiling power, and when the first daytime operable time is equal to or less than the set time, predicts the second daytime operable time when the predicted surplus power per unit time is equal to or greater than the second boiling power, and the daytime boiling predicted hot water amount is preferably calculated using the second boiling capacity and the second daytime operable time. Here, the set time may be zero hours. In other words, when there is no first daytime operable time, the second daytime operable time is predicted. In this way, when the first daytime operating time is equal to or shorter than the set time, the predicted daytime water heating volume can be calculated using the second heating capacity and the second daytime operating time, thereby making effective use of surplus electricity in the solar power generation unit 50.

[0032] In addition, when the heating device 20 has a first boiling capacity and a second boiling capacity, the daytime boiling predicted hot water volume calculation means 34E predicts a first daytime operable time during which the surplus power per unit time predicted by the unit time surplus power calculation means 34D will be equal to or greater than the first boiling power, and predicts a second daytime operable time during which the surplus power per unit time predicted by the unit time surplus power calculation means 34D will be equal to or greater than the second boiling power, and if the second daytime predicted hot water volume to be boiled during the second daytime operable time with the second boiling capacity is equal to or greater than the first daytime predicted hot water volume to be boiled during the first daytime operable time with the first boiling capacity, it is preferable to set the second daytime predicted hot water volume as the daytime predicted hot water volume. In this way, if the second daytime predicted amount of hot water to be heated at the second heating capacity during the second daytime operable hour is equal to or greater than the first daytime predicted amount of hot water to be heated at the first daytime operable hour at the first heating capacity, then by setting the second daytime predicted amount of hot water as the daytime predicted amount of hot water, the efficiency of the heat pump unit is higher when operating at the second heating capacity than when operating at the first heating capacity, and the heat pump unit can be operated efficiently.

[0033] In addition, when the heating device 20 has a first boiling capacity and a second boiling capacity, the daytime boiling predicted hot water volume calculation means 34E predicts a second daytime operable time during which the surplus power per unit time predicted by the unit time surplus power calculation means 34D will be equal to or greater than the second boiling power, and if the second daytime boiling predicted volume of hot water boiled during the second daytime operable time at the second boiling capacity is equal to or greater than the predicted volume of hot water used, it is preferable to set the second daytime boiling predicted volume of hot water as the daytime boiling predicted volume of hot water. In this way, if the second daytime predicted hot water volume is equal to or greater than the predicted hot water usage volume, the second daytime predicted hot water volume is set as the daytime predicted hot water volume, and since operation at the second heating capacity is more efficient than operation at the first heating capacity, the heat pump unit can be operated efficiently.

[0034] The control device 30 has a hot water boiling volume comparison means 35 which compares the predicted hot water usage calculated by the predicted hot water usage volume calculation means 34A with the predicted daytime hot water boiling volume calculated by the predicted daytime hot water boiling volume calculation means 34E. When the boiling hot water volume comparison means 35 determines that the predicted daytime boiling hot water volume is less than the predicted hot water usage volume, boiling operation is performed in the nighttime mode 31b on the boiling operation execution day.

[0035] When the hot water volume comparison means 35 determines that the predicted amount of hot water to be heated during the day is less than the predicted amount of hot water to be used, the night operation time calculation means 36 calculates the night operation time in the night time zone mode 31B so as to satisfy the predicted amount of hot water to be used. The amount of hot water to be heated during the night in the night time zone mode 31B is the amount of hot water obtained by subtracting the predicted amount of hot water to be heated during the day from the predicted amount of hot water to be used. In this way, if the predicted amount of hot water to be heated during the day is less than the predicted amount of hot water to be used, the shortage of hot water can be eliminated by lengthening the nighttime operation time in nighttime time zone mode 31B on the day when heating operation is performed prior to daytime heating operation in daytime time zone mode 31A on the day when heating operation is performed, thereby ensuring the predicted amount of hot water to be used. The daytime operation time determination means 37 determines, as a daytime operation time, a time period during which the surplus power per unit time predicted by the surplus power per unit time calculation means 34D is equal to or greater than the water heating power. In this way, by predicting the surplus power per unit time on the day when the water heating operation is to be performed before the day when the water heating operation is to be performed, the surplus power in the photovoltaic power generation unit 50 can be utilized to efficiently perform the daytime water heating operation.

[0036] FIG. 2 is an explanatory diagram showing surplus power per unit time and possible daytime operation time in the hot water supply apparatus according to this embodiment. Figure 2(a) shows the case where the predicted solar radiation amount is high, and Figure 2(b) shows the case where the predicted solar radiation amount is low. To simplify the explanation, the predicted amount of self-power consumption per unit time is predicted to be a constant 1 kW. The line graph shows the predicted power generation amount per unit time on the day when the water heating operation is performed, which is calculated from the amount of solar radiation and the solar panel capacity on the day when the water heating operation is performed. The heating device 20 has, as boiling capacities, a first boiling capacity requiring 1 kW of power and a second boiling capacity requiring 0.8 kW of power.

[0037] 2(a), in the time slot from 11:00 to 15:00, the surplus power per unit time predicted by the unit time surplus power calculation means 34D exceeds 1 kW. Therefore, in the time slot from 11:00 to 15:00, the heating device 20 can be operated at the first boiling capacity, which requires 1 kW of power. And, since the predicted amount of hot water to be used is not met in the five hours from 11:00 to 15:00, boiling operation is performed at 5:00 in the night time slot mode 31B on the boiling operation execution day. 2(b), there is no time period during which the heating device 20 can be operated at the first boiling capacity, which requires 1 kW of power. In this case, operation at the second boiling capacity, which requires 0.8 kW of power, can be performed during the time period from 12:00 to 14:00. Therefore, the heating device 20 can be operated at the second boiling capacity requiring 0.8 kW of power in the time period from 12:00 to 14:00. And, since the predicted amount of hot water to be used is not met in the three hours from 12:00 to 14:00, boiling operation is performed from 3:00 to 5:00 in the night time period mode 31B on the day when the boiling operation is to be performed.

[0038] FIG. 3 is a flow diagram of the hot water supply device according to this embodiment. Prior to the day on which the water boiling operation is to be performed (the day before), it is possible to set whether or not daytime water boiling will be performed on the day on which the water boiling operation is to be performed (S1). This setting is performed using the operation means 40. If daytime water boiling is not set in S1 (No in S1), the water boiling operation is performed only in the nighttime mode 31B (S2). In S1, if the daytime heating setting is performed (Yes in S1), the predicted solar radiation and predicted outside air temperature on the day when heating operation is performed and the day after the heating operation is performed are obtained as predicted weather data 60, and the predicted power generation amount by unit time and the heating power by the heat pump unit on the day when heating operation is performed and the day after the heating operation is performed are predicted (S3).

[0039] In S4, it is determined whether or not to perform daytime heating on the day when the heating operation is to be performed, based on the predicted surplus power per unit time on the day when the heating operation is to be performed. If it is determined that heating will not be performed during the day on the operation execution day (No in S4), heating operation is performed only in the nighttime mode 31B (S5). If it is determined that daytime heating will be performed on the day when the water heater is in operation (Yes in S4), the predicted amount of hot water to be heated during the daytime on the day when the water heater is in operation is used to determine the predicted amount of hot water to be used on the day when the water heater is in operation (S6). If it is determined that the predicted amount of hot water to be heated during the day on which the boiling operation is performed is greater than the predicted amount of hot water to be used on the day on which the boiling operation is performed (Yes in S6), the predicted amount of hot water to be heated during the day on the day after the boiling operation is performed is used to determine the predicted amount of hot water to be used on the day after the boiling operation is performed (S7). If it is determined that the predicted amount of hot water to be heated in the daytime on the day after the heating operation is performed is less than the predicted amount of hot water to be used on the day after the heating operation is performed (No in S7), the amount of heat to be heated in the daytime time zone mode on the day when the heating operation is performed is increased (S8). To increase the amount of heat to be heated, the amount of hot water to be heated is made greater than the predicted amount of hot water to be heated in the daytime on the day when the heating operation is performed. By increasing the heating temperature in the daytime zone mode on the day when the heating operation is performed, the amount of hot water to be heated in the daytime zone mode on the day when the heating operation is performed can be made greater than the predicted amount of hot water to be heated in the daytime on the day when the heating operation is performed.

[0040] If it is determined that the predicted amount of hot water to be heated during the day on which the heating operation is performed is less than or equal to the predicted amount of hot water used on the day on which the heating operation is performed (No in S6), if it is determined that the predicted amount of hot water to be heated during the day on the day after the heating operation is performed is greater than or equal to the predicted amount of hot water used on the day after the heating operation is performed (Yes in S7), or if the amount of heat to be heated in the daytime time zone mode on the day on which the heating operation is performed is increased (S8), the heating capacity for the day on which the heating operation is performed is selected (S9).

[0041] When the boiling capacity for the day on which the boiling operation is to be performed is selected in S9, the daytime boiling time and the nighttime boiling time for the day on which the boiling operation is to be performed are determined (S10). On the day when water is to be boiled, water is boiled according to the nighttime boiling time determined in S10 (S11), and then water is boiled according to the daytime boiling time determined in S10 (S12). As described above, the control device 30 obtains predicted weather data for the day on which water-heating operation is to be performed and the day after the day on which water-heating operation is to be performed prior to the day on which water-heating operation is to be performed, calculates the predicted amount of power generation by unit time on the day on which water-heating operation is to be performed and the day after the day on which water-heating operation is to be performed from the predicted weather data, determines the predicted amount of personal power consumption by unit time on the day on which water-heating operation is to be performed and the day after the day on which water-heating operation is to be performed, and predicts the surplus power by unit time on the day on which water-heating operation is to be performed and the day after the day on which water-heating operation is to be performed from the predicted amount of power generation by unit time and the predicted amount of personal power consumption by unit time, thereby enabling efficient daytime water-heating operation to be performed by utilizing the surplus power in the solar power generation unit 50.

[0042] A surplus power prediction method according to one embodiment of the present invention obtains predicted weather data for the day on which the water in a hot water storage tank is heated and for the day after the water heating operation is executed prior to the day on which the water heating operation is executed to heat the water in the hot water storage tank, calculates a predicted amount of power generation per unit time for the day on which the water heating operation is executed and the day after the water heating operation is executed from the predicted weather data, determines a predicted amount of personal power consumption per unit time for the day on which the water heating operation is executed and the day after the water heating operation is executed, and predicts surplus power per unit time for the day on which the water heating operation is executed and the day after the water heating operation is executed from the predicted amount of power generation per unit time and the predicted amount of personal power consumption per unit time. According to the surplus power prediction method of this embodiment, by predicting the surplus power per unit time on the day when water heating operation is to be performed and the day after the day when water heating operation is to be performed before the day when water heating operation is to be performed, water heating operation can be efficiently performed during the day by utilizing the surplus power generated by the solar power generation unit.

[0043] Furthermore, a method for controlling a hot water supply device according to an embodiment of the present invention includes obtaining predicted weather data for the day on which the water heating operation is to be executed and the day after the day on which the water heating operation is to be executed before the day on which the water heating operation is to be executed, calculating a predicted amount of power generation by unit time on the day on which the water heating operation is to be executed and the day after the day on which the water heating operation is to be executed that can be generated by a solar power generation unit from the predicted weather data, determining a predicted amount of private power consumption by unit time on the day on which the water heating operation is to be executed and the day after the day on which the water heating operation is to be executed, predicting surplus power by unit time on the day on which the water heating operation is to be executed and the day after the day on which the water heating operation is to be executed from the predicted amount of power generation by unit time and the predicted amount of private power consumption by unit time, and calculating a predicted amount of power generation by unit time on the day on which the water heating operation is to be executed and the day after the day on which the water heating operation is to be executed. The system calculates the predicted amount of hot water to be used on the day when the water heating operation is performed and the day after the water heating operation is performed, calculates the predicted amount of hot water to be heated during the daytime that can be heated with the surplus electricity per unit time on the day when the water heating operation is performed and the day after the water heating operation is performed, and if the predicted amount of hot water to be heated during the daytime on the day after the water heating operation is performed is less than the predicted amount of hot water to be used on the day after the water heating operation is performed and the predicted amount of hot water to be heated during the daytime on the day when the water heating operation is performed is more than the predicted amount of hot water to be used on the day when the water heating operation is performed, the amount of hot water to be heated in the daytime time zone mode on the day when the water heating operation is performed is made greater than the predicted amount of hot water to be heated during the daytime on the day when the water heating operation is performed. According to the control method for a water heating device of this embodiment, by predicting the surplus power per unit time on the day when water heating operation is to be performed and the day after the day when water heating operation is to be performed in advance of the day when water heating operation is to be performed, water heating operation can be efficiently performed during the day by utilizing the surplus power generated by the solar power generation unit. Furthermore, a control method for a water heating apparatus according to one embodiment of the present invention further increases the heating temperature in daytime time zone mode on days when heating operation is performed, thereby making the amount of hot water heated in daytime time zone mode on days when heating operation is performed greater than the predicted amount of hot water to be heated in the daytime on days when heating operation is performed. According to the method for controlling a hot water supply apparatus of this embodiment, it is possible to increase the amount of heat generated by heating in the daytime mode on days when the heating operation is performed.

[0044] [Configuration supported by the above embodiment] The above embodiment supports the following configurations.

[0045] (Configuration 1) A hot water supply device comprising a hot water storage tank, a heat pump unit which heats the hot water in the hot water storage tank, and a control device, and which uses electricity generated by a solar power generation unit, wherein the control device obtains predicted weather data for the day on which a water heating operation is to be performed and the day after the day on which the water heating operation is to be performed before the day on which the water heating operation is to be performed, calculates a predicted amount of power generation by unit time for the day on which the water heating operation is to be performed and the day after the day on which the water heating operation is to be performed from the predicted weather data, determines a predicted amount of self-consumption power by unit time for the day on which the water heating operation is to be performed and the day after the day on which the water heating operation is to be performed, and predicts surplus power by unit time for the day on which the water heating operation is to be performed and the day after the day on which the water heating operation is to be performed from the predicted amount of power generation by unit time and the predicted amount of self-consumption power by unit time. According to this configuration, by predicting the surplus power per unit time on the day when the water heating operation is to be performed and the day after the day when the water heating operation is to be performed before the day when the water heating operation is to be performed, the surplus power in the solar power generation unit can be utilized to efficiently perform the water heating operation during the day.

[0046] (Configuration 2) The hot water supply device described in configuration 1, characterized in that the control device has a daytime time zone mode in which heating operation is performed during daytime hours, calculates a predicted amount of hot water to be used on the day when the heating operation is performed and the day after the heating operation is performed, calculates a predicted amount of hot water to be heated using the surplus electricity per unit time on the day when the heating operation is performed and the day after the heating operation is performed, and if the predicted amount of hot water to be heated on the day after the heating operation is performed is less than the predicted amount of hot water to be used on the day after the heating operation is performed and the predicted amount of hot water to be heated on the day when the heating operation is performed is greater than the predicted amount of hot water to be used on the day when the heating operation is performed, the amount of hot water to be heated in the daytime time zone mode on the day when the heating operation is performed is greater than the predicted amount of hot water to be used on the day when the heating operation is performed. According to this configuration, the daytime heating operation can be performed on the day when the heating operation is performed, taking into consideration the surplus power on the day when the heating operation is performed and the day after the heating operation is performed, thereby making effective use of the surplus power.

[0047] (Configuration 3) The water heating device described in configuration 2 is characterized in that by increasing the heating temperature in the daytime time zone mode on the day when the heating operation is performed, the amount of hot water heated in the daytime time zone mode on the day when the heating operation is performed is made greater than the predicted daytime heating amount of hot water on the day when the heating operation is performed. According to this configuration, the amount of heat generated by heating can be increased in the daytime mode on days when the heating operation is performed.

[0048] (Configuration 4) The hot water supply device of any one of configurations 1 to 3, characterized in that the control device has a daytime time zone mode in which heating operation is performed during daytime hours and a nighttime time zone mode in which the heating operation is performed during nighttime hours, calculates a predicted amount of hot water to be used on the day the heating operation is performed, calculates a predicted amount of hot water to be heated during the daytime that can be heated with the predicted surplus electricity per unit time, and if it determines that the predicted amount of hot water to be heated during the daytime is less than the predicted amount of hot water to be used, performs the heating operation in the nighttime time zone mode on the day the heating operation is performed. With this configuration, daytime heating operation can be performed using surplus power from the solar power generation unit, and the amount of hot water that is insufficient in daytime heating operation using surplus power can be made up by heating operation in nighttime mode, allowing for effective use of nighttime electricity.

[0049] (Configuration 5) The hot water supply device according to configuration 4, wherein the amount of hot water to be heated at night in the nighttime time zone mode is the amount of hot water obtained by subtracting the amount of hot water to be heated during the daytime from the amount of hot water to be predicted. With this configuration, the predicted amount of hot water to be used can be secured.

[0050] (Configuration 6) The predicted weather data is a predicted amount of solar radiation and a predicted outside air temperature, the predicted amount of power generation per unit time is calculated using the predicted amount of solar radiation, and the predicted outside air temperature is used to calculate the heating power by the heat pump unit. 6. The hot water supply device according to configuration 4 or 5. According to this configuration, the surplus power in the photovoltaic power generation unit and the heating power by the heat pump unit can be calculated more accurately.

[0051] (Configuration 7) The hot water supply device according to any one of configurations 4 to 6, characterized in that the heat pump unit has a first heating capacity requiring a first heating power and a second heating capacity requiring a second heating power less than the first heating power as heating capacities, and the control device predicts a first daytime operable time during which the predicted surplus power per unit time will be equal to or greater than the first heating power, and if the first daytime operable time is equal to or less than a set time, predicts a second daytime operable time during which the predicted surplus power per unit time will be equal to or greater than the second heating power, and the predicted daytime heating hot water amount is calculated based on the second heating capacity and the second daytime operable time. According to this configuration, surplus power in the photovoltaic power generation unit can be effectively utilized.

[0052] (Configuration 8) The hot water supply device according to any one of configurations 4 to 6, characterized in that the heat pump unit has a first heating capacity requiring a first heating power and a second heating capacity requiring a second heating power less than the first heating power as heating capacities, and the control device predicts a first daytime operable time during which the predicted surplus power per unit time will be equal to or greater than the first heating power, predicts a second daytime operable time during which the predicted surplus power per unit time will be equal to or greater than the second heating power, and if a second daytime predicted amount of hot water to be heated at the second heating capacity during the second daytime operable time is equal to or greater than a first daytime predicted amount of hot water to be heated at the first heating capacity during the first daytime operable time, sets the second daytime predicted amount of hot water to be the daytime predicted amount of hot water. According to this configuration, the efficiency of the heat pump unit is higher when the heat pump unit is operated at the second boiling capacity than when the heat pump unit is operated at the first boiling capacity, so that the heat pump unit can be operated efficiently.

[0053] (Configuration 9) The hot water supply device according to any one of configurations 4 to 6, characterized in that the heating capacities of the heat pump unit include a first heating capacity requiring a first heating power and a second heating capacity requiring a second heating power less than the first heating power, and the control device predicts a second daytime operable time during which the predicted surplus power per unit time will be equal to or greater than the second heating power, and if a second daytime predicted amount of hot water to be heated at the second heating capacity during the second daytime operable time is equal to or greater than the predicted amount of hot water used, the second daytime predicted amount of hot water is set to the predicted daytime hot water amount. According to this configuration, the efficiency of the heat pump unit is higher when the heat pump unit is operated at the second boiling capacity than when the heat pump unit is operated at the first boiling capacity, so that the heat pump unit can be operated efficiently.

[0054] (Configuration 10) A surplus power prediction method for using electricity generated by a solar power generation unit for a hot water heating device, comprising the steps of: obtaining predicted weather data for the day on which a water heating operation is performed and the day after the day on which the water in a hot water storage tank is heated before the day on which the water heating operation is performed and the day after the day on which the water heating operation is performed; calculating a predicted amount of power generation by unit time that can be generated by the solar power generation unit on the day on which the water heating operation is performed and the day after the day on which the water heating operation is performed from the predicted weather data; determining a predicted amount of personal power consumption by unit time on the day on which the water heating operation is performed and the day after the day on which the water heating operation is performed; and predicting surplus power by unit time on the day on which the water heating operation is performed and the day after the day on which the water heating operation is performed from the predicted amount of power generation by unit time and the predicted amount of personal power consumption by unit time. According to this configuration, by predicting the surplus power per unit time on the day when the water heating operation is to be performed and the day after the day when the water heating operation is to be performed before the day when the water heating operation is to be performed, the surplus power in the solar power generation unit can be utilized to efficiently perform the water heating operation during the day.

[0055] (Configuration 11) A control method for a hot water supply device that uses electricity generated by a photovoltaic power generation unit and includes: obtaining predicted weather data for a day on which a water heating operation is performed and a day after the day on which the water heating operation is performed before a day on which a water heating operation is performed; calculating a predicted amount of electricity generated by the photovoltaic power generation unit per unit time for the day on which the water heating operation is performed and the day after the day on which the water heating operation is performed from the predicted weather data; determining a predicted amount of private power consumption per unit time for the day on which the water heating operation is performed and the day after the day on which the water heating operation is performed from the predicted amount of electricity generated by the day on which the water heating operation is performed and the day after the day on which the water heating operation is performed; A method for controlling a water heating device, comprising: predicting surplus power; calculating a predicted amount of hot water to be used on the day when the heating operation is performed and the day after the heating operation is performed; calculating a predicted amount of hot water to be heated during the daytime that can be heated with the surplus power per unit time on the day when the heating operation is performed and the day after the heating operation is performed; and if the predicted amount of hot water to be heated during the day after the heating operation is performed is less than the predicted amount of hot water to be used on the day after the heating operation is performed and the predicted amount of hot water to be heated during the daytime According to this configuration, by predicting the surplus power per unit time on the day when the water heating operation is to be performed and the day after the day when the water heating operation is to be performed before the day when the water heating operation is to be performed, the surplus power in the solar power generation unit can be utilized to efficiently perform the water heating operation during the day.

[0056] (Configuration 12) A control method for a water heating apparatus as described in configuration 11, characterized in that by increasing the heating temperature in the daytime time zone mode on the day when the heating operation is performed, the amount of hot water heated in the daytime time zone mode on the day when the heating operation is performed is made greater than the predicted daytime heating amount of hot water on the day when the heating operation is performed. According to this configuration, the amount of heat generated by heating can be increased in the daytime mode on days when the heating operation is performed. [Industrial Applicability]

[0057] According to the present invention, surplus power from a solar power generation unit can be utilized to efficiently perform daytime heating operation. [Explanation of symbols]

[0058] 10 Hot water tank 11 Boiling piping 12 Hot water tap 13 Mixing valve 14 Water supply piping 15 Hot water piping 16 Circulation pump 17 Hot water flow rate detection means 20 Heating device 30 Control device 31 Boiling operation mode 31A Daytime mode 31B Nighttime mode 32 Timer means 33A Storage means for amount of hot water used 33B Setting condition storage means 34A Means for calculating predicted hot water usage 34B Means for calculating unit time-based power generation forecast amount 34C Means for determining predicted amount of self-power consumption by unit time 34D Calculation method for surplus power by unit time 34E Means for calculating predicted amount of hot water to be boiled during the day 35. Means for comparing the amount of boiled water 36 Night driving time calculation method 37 Means for determining daytime operation times 40 Operating means 50 Photovoltaic Units 60 Weather forecast data

Claims

1. The hot water storage tank includes a heat pump unit that heats the hot water in the hot water storage tank, and a control device. A hot water supply device that uses electricity generated by a solar power generation unit, The control device includes: Before the day the water heating operation is to be carried out, Obtaining predicted weather data for the day the water heating operation is performed and the day after the water heating operation is performed; calculating a predicted amount of power generation by unit time on the day when the water heating operation is performed and on the day after the day when the water heating operation is performed that can be generated by the solar power generation unit from the predicted weather data; A predicted amount of personal power consumption by unit time on the day when the heating operation is performed and on the day after the heating operation is performed is determined; From the predicted amount of power generation per unit time and the predicted amount of private power consumption per unit time, a surplus power per unit time on the day when the water heating operation is performed and the day after the day when the water heating operation is performed is predicted. A water heating apparatus characterized by the above.

2. The control device includes: A daytime mode is provided for performing a heating operation during daytime hours, Calculate the amount of hot water to be used on the day when the boiling operation is performed and the day after the boiling operation is performed; Calculating a predicted amount of hot water to be heated during the daytime using the surplus power per unit time on the day when the heating operation is performed and the day after the heating operation is performed; The predicted amount of hot water to be heated during the day on the day after the heating operation is performed is less than the predicted amount of hot water to be used on the day after the heating operation is performed, When the predicted amount of hot water to be heated during the day on the day on which the heating operation is performed is greater than the predicted amount of hot water to be used on the day on which the heating operation is performed, The amount of hot water to be heated in the daytime time zone mode on the day when the hot water heating operation is performed is made larger than the predicted amount of hot water to be heated in the daytime on the day when the hot water heating operation is performed. The water heater according to claim 1 .

3. By increasing the boiling temperature in the daytime time zone mode on the day when the boiling operation is performed, the amount of boiled hot water in the daytime time zone mode on the day when the boiling operation is performed is made larger than the predicted daytime boiling hot water amount on the day when the boiling operation is performed.

3. The water heater according to claim 2.

4. The control device includes: A daytime mode in which heating operation is performed during daytime hours; a nighttime mode in which the heating operation is performed during the nighttime; having Calculate the predicted amount of hot water to be used on the day the water heating operation is performed, A predicted amount of hot water that can be heated during the daytime using the predicted surplus power per unit time is calculated; When it is determined that the predicted amount of hot water to be heated during the day is less than the predicted amount of hot water to be used, the heating operation is performed in the nighttime mode on the day when the heating operation is performed. The water heater according to claim 1 .

5. The amount of hot water to be heated at night in the nighttime mode is the amount of hot water obtained by subtracting the predicted amount of hot water to be heated during the day from the predicted amount of hot water to be used.

5. The water heater according to claim 4.

6. The predicted weather data is a predicted amount of solar radiation and a predicted outside air temperature. Calculating the unit time power generation forecast amount using the predicted solar radiation amount; Calculate the heating power of the heat pump unit using the predicted outdoor air temperature 6. The hot water supply device according to claim 4 or 5.

7. The heat pump unit has a first boiling capacity that requires a first boiling power and a second boiling capacity that requires a second boiling power that is less than the first boiling power, The control device includes: predicting a first daytime operable time during which the predicted surplus power per unit time is equal to or greater than the first water heating power; When the first daytime operable time is equal to or shorter than a set time, predicting a second daytime operable time during which the predicted surplus power per unit time is equal to or greater than the second water heating power; The predicted daytime boiling water volume is calculated based on the second boiling capacity and the second daytime operable time.

5. The water heater according to claim 4.

8. The heat pump unit has a first boiling capacity that requires a first boiling power and a second boiling capacity that requires a second boiling power that is less than the first boiling power, The control device includes: predicting a first daytime operable time during which the predicted surplus power per unit time is equal to or greater than the first water heating power; predicting a second daytime operable time during which the predicted surplus power per unit time is equal to or greater than the second water heating power; If the second daytime predicted amount of hot water to be boiled at the second daytime operable time with the second boiling capacity is equal to or greater than the first daytime predicted amount of hot water to be boiled at the first daytime operable time with the first boiling capacity, the second daytime predicted amount of hot water is set as the daytime predicted amount of hot water.

5. The water heater according to claim 4.

9. The heat pump unit has a first boiling capacity that requires a first boiling power and a second boiling capacity that requires a second boiling power that is less than the first boiling power, The control device includes: predicting a second daytime operable time during which the predicted surplus power per unit time is equal to or greater than the second water heating power; If a second daytime predicted amount of hot water to be heated with the second heating capacity during the second daytime operable time is equal to or greater than the predicted amount of hot water to be used, the second daytime predicted amount of hot water is set as the predicted amount of hot water to be heated during the second daytime operable time.

5. The water heater according to claim 4.

10. A surplus power prediction method for utilizing power generated by a solar power generation unit for a hot water supply device, comprising: Before the day when the water heating operation is to be performed to heat up the hot water in the hot water storage tank, Obtaining predicted weather data for the day the water heating operation is performed and the day after the water heating operation is performed; calculating a predicted amount of power generation by unit time on the day when the water heating operation is performed and on the day after the day when the water heating operation is performed that can be generated by the solar power generation unit from the predicted weather data; A predicted amount of personal power consumption by unit time on the day when the heating operation is performed and on the day after the heating operation is performed is determined; From the predicted amount of power generation per unit time and the predicted amount of private power consumption per unit time, a surplus power per unit time on the day when the water heating operation is performed and the day after the day when the water heating operation is performed is predicted. A surplus power prediction method comprising:

11. A hot water storage tank and a heat pump unit that heats the hot water in the hot water storage tank. A method for controlling a hot water supply device that uses power generated by a solar power generation unit, comprising: Before the day the water heating operation is to be carried out, Obtaining predicted weather data for the day the water heating operation is performed and the day after the water heating operation is performed; calculating a predicted amount of power generation by unit time on the day when the water heating operation is performed and on the day after the day when the water heating operation is performed that can be generated by the solar power generation unit from the predicted weather data; A predicted amount of personal power consumption by unit time on the day when the heating operation is performed and on the day after the heating operation is performed is determined; predicting surplus power per unit time on the day when the water heating operation is performed and the day after the water heating operation is performed from the predicted power generation amount per unit time and the predicted private power consumption amount per unit time; Calculate the amount of hot water to be used on the day when the boiling operation is performed and the day after the boiling operation is performed; Calculating a predicted amount of hot water to be heated during the daytime using the surplus power per unit time on the day when the heating operation is performed and the day after the heating operation is performed; The predicted amount of hot water to be heated during the day on the day after the heating operation is performed is less than the predicted amount of hot water to be used on the day after the heating operation is performed, When the predicted amount of hot water to be heated during the day on the day on which the heating operation is performed is greater than the predicted amount of hot water to be used on the day on which the heating operation is performed, The amount of hot water to be heated in the daytime time zone mode on the day when the hot water heating operation is performed is made larger than the predicted amount of hot water to be heated in the daytime on the day when the hot water heating operation is performed. A method for controlling a hot water supply apparatus comprising:

12. By increasing the boiling temperature in the daytime time zone mode on the day when the boiling operation is performed, the amount of boiled hot water in the daytime time zone mode on the day when the boiling operation is performed is made larger than the predicted daytime boiling hot water amount on the day when the boiling operation is performed. The method for controlling a water heater according to claim 11.

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