# Patent

## Title
Operation planning method, and heat pump hot water supply and heating system operation method

## Abstract

An operation planning method performed in a system including a power generation device, a first electric load operating using power generated by the power generation device, and a second electric load which generates heat using power generated by the power generation device. The operation planning method is performed to design an operation plan for the second electric load and includes: predicting, for individual unit time periods, a power generation amount by the power generation device and a power consumption amount by the first and second electric loads; and designing the operation plan for the second electric load to operate during an operation period including the time period with the largest amount of reverse power, calculated by subtracting the first and second power consumption amounts from the power generation amount.

## Background
TECHNICAL FIELD
The present invention relates to a device relating to power generation such as a photovoltaic device (solar power generation device), and to a system which includes a device that consumes power such as a heat pump.
BACKGROUND ART
Power generation devices, such as a solar or wind power generation devices, are devices designed to create energy. Solar power is generated by transforming solar energy into electricity and is supplied to homes as a natural source of energy. The amount of power generation continuously fluctuates with weather and meteorological conditions.
A heat pump hot water heater heats a refrigerant by absorbing heat from the atmosphere and compressing the refrigerant using electricity, and then transfers the heat to the water via a heat exchanger, thereby creating hot water. With this method, the hot water supply system uses less energy than with an electric hot water heater in which heating is done by an electric heater.
The heat pump hot water supply system including the power generation device constitutes a combination of the above devices, and supplies a consumer with power and heat. An example of a conventional heat pump hot water supply and heating system including a power generation device is disclosed in PTL 1.
PTL 1 discloses an invention which obtains weather forecast information from a server using a weather information obtaining means, and switches to use solar generated power to boil the water in the CO2 heat pump hot water heater instead of late night power from a commercial power source when the obtained information is set up as a condition for operation. Operating using power harnessed from natural energy allows for a power efficient, low-energy electric hot water heater which can reduce electricity costs.
CITATION LIST


    [PTL 1] Japanese Unexamined Patent Application Publication No. 2008-2702
    [PTL 2] Japanese Unexamined Patent Application Publication No. 2006-158027


Technical Problem
However, the conventional device does not take into consideration the amount of consumption of the reverse power derived from the constantly fluctuating photovoltaic device and an electric load of the consumer. As a number of homes simultaneously generating reverse power increases with the growing prevalence of solar power generation, the voltage of a power grid will increase, causing the grid to become unstable. Moreover, the consumer, who is located on the downstream side of the grid, cannot flow reverse power when the voltage of the grid is high, causing the power generated by the photovoltaic device to go to waste.
Moreover, the voltage of the reverse power is converted according to the electricity distribution system which causes a significant conversion loss in the process. Transmitting the power to another consumer also causes a transmission loss in the process as well. As such, it is more environmental for the consumer to consume the generated power on location.
Furthermore, with the device proposed in PTL 2, the heat pump unit is operated when the amount of generated power exceeds the amount of power used. However, the heat pump unit is not operated in response to the amount of excess power, nor does it effectively reduce the amount of power flowing in reverse to the grid.
The present invention is conceived to solve the above-described problems and is designed to provide an operation planning method for a system including a power generation device in which the system maintains a low-energy performance characteristic and reduces the amount of reverse power.
Solution to Problem
An operation planning method according to the first embodiment of the present invention is performed in a system including a power generation device, a first electric load which operates using power generated by the power generation device, and a second electric load which generates heat using power generated by the power generation device, the second electric load including a heat generation unit which generates heat using power generated by the power generation device, the operation planning method being performed to design an operation plan for the second electric load. Specifically, the second electric load includes a heat generation unit which generates heat using power generated by the power generation device, a heat storage unit which stores heat generated by the heat generation unit, a first radiator unit which radiates heat stored in the heat storage unit, and a second radiator unit which directly radiates heat generated by the heat generation unit. The operation planning method comprises: predicting, for individual unit time periods, an amount of power to be generated by the power generation device, a first amount of power to be consumed by the first electric load, and a second amount of power to be consumed by the heat generation unit to generate heat to be radiated by the second radiator unit; and designing the operation plan for the second electric load to cause the second electric load to operate during an operation period which includes, among the time periods, a time period in which an amount of reverse power is the largest, the reverse power being calculated by subtracting the first amount of power to be consumed and the second amount of power to be consumed from the amount of power to be generated.
With this configuration, damage to a power grid can be reduced by predicting a time period in which the amount of reverse power will peak, and operating the second electric load in the predicted time period.
The power generation device may be a photovoltaic device, for example. In the predicting, an amount of heat to be radiated in reverse flow standby by the first radiator unit during a reverse flow standby time period is further predicted, the reverse flow standby time period being a time period in which the amount of power to be consumed exceeds the amount of power to be generated, and in the designing, an operation plan for the heat generation unit to operate during the operation period is designed such that an amount of heat is stored in the heat storage unit, the amount of heat corresponding to the amount of heat to be radiated in reverse flow standby as predicted by the predicting unit.
Moreover, in the designing, the operation plan may be designed for the operation period which is determined by selecting one or more of the time periods in descending order of the amount of reverse power until a total amount of time of the one or more selected time periods exceeds an amount of time required for the heat generation unit to generate the amount of heat corresponding to the amount of heat to be radiated in reverse flow standby.
Moreover, in the designing, a reverse power threshold value may be set to be the amount of reverse power with the lowest value among the one or more selected time periods, and the operation plan may be designed such that operation of the heat generation unit is started at a point in time at which the reverse power as actually measured becomes equal to or exceeds the reverse power threshold value during the operation period.
In the designing, the operation plan may further be designed such that operation of the heat generation unit is stopped at a point in time at which the amount of heat corresponding to the amount of heat to be radiated in reverse flow standby is generated during the operation period.
Moreover, the heat storage unit may include a thermal storage medium whose temperature varies according to the amount of heat stored. Furthermore, the heat generation unit may include a heat pump capable of heating the thermal storage medium to a first temperature, and a heater capable of heating the thermal storage medium beyond the first temperature. Additionally, in the designing, with respect to the amount of heat corresponding to the amount of heat to be radiated in reverse flow standby, the operation plan may be designed to cause the heat pump to generate an amount of heat until the thermal storage medium reaches the first temperature, and cause the heater to generate an amount of heat after the thermal storage medium reaches the first temperature.
Moreover, in the predicting, the amount of heat to be radiated by the radiator unit during the reverse flow standby time period may be predicted as the amount of heat to be radiated in reverse flow standby, the reverse flow standby time period being a time period delimited by a reverse flow standby start time and a predetermined assumed time at which the radiator unit will stop radiating heat, and the reverse flow standby start time being a time when the amount of reverse power changes from a positive value to a non-positive value.
An operation method for a heat pump hot water supply and heating device according to the first embodiment of the present invention is an operation method for a heat pump hot water supply and heating system including a photovoltaic device and a heat pump hot water supply and heating device. The heat pump hot water supply and heating device includes a heat pump which generates heat using power generated by the photovoltaic device, a hot water supply tank which stores hot water heated using heat generated by the heat pump, and a heating device which heats a space using heat generated by the heat pump. The system includes an operation planning device. The operation planning device controls the system, including: predicting an amount of power to be generated by the power generation device, a first amount of power to be consumed by an electric load, and a second amount of power to be consumed by the heat pump to generate heat to be radiated by the heating device; calculating an amount of reverse power by subtracting the first amount of power to be consumed and the second amount of power to be consumed from the amount of power to be generated; predicting an amount of heat (the amount of heat to be radiated in reverse flow standby) required in a reverse flow standby time period during which the amount of reverse power is zero; and designing an operation plan which causes the heat pump hot water supply and heating device to operate to store the predicted amount of heat during an operation period which includes a time period in which the amount of reverse power is the largest.
Moreover, in the designing, a heat storage target temperature to store the predicted amount of heat may be determined and a reverse power threshold value may be set to the amount of reverse power with the lowest value among the one or more selected time periods.
Moreover, based on the heat storage target temperature and the reverse power threshold value determined and set in the designing, operation of the heat pump hot water supply and heating device may be started at a point in time at which the reverse power as measured reaches or exceeds the reverse power threshold value during the operation period, and operation of the heat pump hot water supply and heating device may be stopped at a point in time at which the predicted amount of heat is generated during the operation period.
Moreover, in the designing, the heat storage target temperature for storing the predicted amount of heat in a hot water supply tank may be determined, and a thermal storage medium inside the hot water supply tank may be heated to a first temperature with a heat pump included in the heat pump hot water supply and heating device, then the thermal storage medium may be heated to a second temperature which is higher than the first temperature with a heater installed in the hot water supply tank.
Moreover, the heat pump hot water supply and heating device includes a hot water supply and heating control device. The hot water supply and heating control device may be set up to receive operation information for the heat pump hot water supply and heating device from a remote control as well as from the operation planning device. When received from the operation planning device, the hot water supply and heating control device may give the operation information from the operation planning device priority over the operation information from the remote control, and may control the heat pump hot water supply and heating device based on the operation information from the operation planning device.
Moreover, the operation information may be an operation mode for the heat pump hot water supply and heating device, and a hot water supply temperature setting for the hot water supply tank.
Moreover, the heat pump hot water supply and heating device may further include a heat exchanger which facilitates heat exchange between a refrigerant in the heat pump and the thermal storage medium, and a switching device which switches supply of the thermal storage medium supplied from the heat exchanger to one of the hot water supply tank and the heating device. In the controlling, when the switching device is switched to the heating device and the temperature of the thermal storage medium is below the first temperature at a point in time at which operation of the heat pump hot water supply and heating device starts, the switching device may be switched to the hot water supply tank.
Advantageous Effects of Invention
The present invention can reduce damage to a power grid by predicting a time period in which the amount of reverse power will peak, and operating the system in the predicted time period.



BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a flowchart showing a principle of the present invention.
FIG. 2 is a block diagram of the heat pump hot water supply and heating system including the power generation device according to the first embodiment.
FIG. 3 is a block diagram of the heat pump hot water supply and heating device.
FIG. 4 is a diagram of the flow of data in the heat pump hot water supply and heating system.
FIG. 5 is a table showing remote control setting categories and setting information.
FIG. 6 is a block diagram of the operation planning device.
FIG. 7 is a table showing a format of the information stored in the storage means.
FIG. 8 is a graph showing a predicted amount of load power, a predicted amount of heating load power, a predicted amount of photovoltaic generated power (hereinafter also referred to as predicted amount of PV-generated power), and a predicted amount of reverse power for each time.
FIG. 9 is a table showing the priority for each time period assigned in descending order by predicted amount of reverse power.
FIG. 10 is a flowchart of an operation planning process.
FIG. 11 is a flowchart of a load prediction process.
FIG. 12 is a flowchart of a control parameter calculation process in the operation planning means.
FIG. 13 is a flow chart showing an exemplary operation of the heat pump hot water supply and heating system.
FIG. 14 is a flow chart showing another example of an operation of the heat pump hot water supply and heating system.
FIG. 15 is an exemplary graph showing power consumption values under different control methods.



DESCRIPTION OF EMBODIMENTS
First Embodiment
Hereinafter, embodiments of present invention are described with reference to the drawings. As shown in FIG. 1, with the present invention, the amount of reverse power is predicted (S104) from the prediction of an amount of load power (S101) which is an amount of power consumed within a home, the prediction of an amount of heating load power (S102), and the prediction of an amount of PV-generated power (S103) which is an amount of power generated by photovoltaics. The heat pump (hereinafter also referred to as HP) is then made to operate during a time period with the peak predicted amount of reverse power (S106). The heat pump duration of operation is determined from the predicted amount of hot water supply heat (S105). As a result, the amount of power flowing in reverse to the power grid can be decreased, and the effect the power flowing in reverse has on the power grid can be effectively reduced.
FIG. 2 is a block diagram explaining a heat pump hot water supply and heating system 9000 including the power generation device. As shown in FIG. 2, the heat pump hot water supply and heating system 9000 according to the first embodiment includes a heat pump hot water supply and heating device 900, a power distribution device 905, an operation planning device 910, and a photovoltaic device 911. The power distribution device 905 is connected to a first electric load 906 and a power meter 907 via an energy supplier 908. The operation planning device 910 is connected to a server 909 via the Internet.
The energy supplier 908 (source of electric power) as shown in FIG. 2 supplies power via a power grid to homes. The power grid is a network that provides a stable supply of power. A power meter 907 measures the amount of power supplied via the power grid that is consumed in a home. Moreover, the power meter 907 is set up to consume power generated by a photovoltaic device 911 in-home, and sell excess power to the grid.
The house shown in FIG. 2 is equipped with the first electric load 906, the heat pump hot water supply and heating device 900 (the second electric load), the operation planning device 910, the photovoltaic device 911, and the power distribution device 905.
The heat pump hot water supply and heating device 900 includes at least a heat pump unit 901a, a heat exchanger 902, a hot water supply device 903, and a heating device 904. Here, the hot water supply device (the first radiator unit) 903 has an internal hot water supply tank (not shown in FIG. 2) which functions as a heat storage unit. The hot water supply device 903 stores the heat generated by the heat pump unit 901a (heat generation unit) in the hot water supply tank, and ejects the hot water inside the hot water supply tank as requested by a user, that is, radiates the heat stored in the heat storage unit. On the other hand, the heating device 904 (the second radiator unit) is connected to the heat pump unit 901a via the heating circuit (not shown in FIG. 2), and directly radiates the heat generated by the heat pump unit 901a, that is, directly radiates the heat without storing it in the heat storage unit.
Moreover, the heat generation unit is connected to the first and the second radiator unit via a switching device (three-way valve), and depending on the setting of the switching device, supplies heat to one of the first radiator unit and the second radiator unit. In other words, the heat generation unit cannot supply heat to both the first and the second radiator unit at the same time.
That is, while the first radiator unit which radiates heat stored in the heat storage unit can radiate heat while the heat generation unit is not operating or while the switching device is switched to the second radiator unit, the second radiator unit which directly radiates heat generated by the heat generation unit can only radiate heat while the heat generation unit is operating and while the switching device is switched to the second radiator unit.
The photovoltaic device 911 is a device which converts energy from the sun into electric power. The photovoltaic device 911 converts energy from the sun into electric power and outputs the power (PV-generated power).
The power distribution device 905 obtains power from the photovoltaic device 911 and a commercial power source supplied by the energy supplier 908 then distributes the power to the heat pump hot water supply and heating device 900 and the first electric load 906 on demand. The heat pump hot water supply and heating device 900 can operate off power from the photovoltaic device 911 as well as off power bought from a commercial power source (grid power).
The power distribution device 905 can measure the amount of power distributed to the heat pump hot water supply and heating device 900 and the first electric load.
The power distribution device 905 obtains the PV-generated power from the photovoltaic device 911. The power distribution device 905 measures the load power which is power consumed by the first electric load 906, the heating load power which is power consumed by the heat pump hot water supply and heating device 900 in order to generate heat to be consumed by the heating device 904, and the hot water supply power which is power consumed by the heat pump hot water supply and heating device 900 in order to generate heat to be consumed by the hot water supply device 903. When the sum of the load power, the heating load power, and the hot water supply power exceeds the PV-generated power, power purchased from the power grid is obtained via the power meter 907. That is, the power distribution device 905 obtains the PV-generated power and the purchased power, then supplies the heating load power and the hot water supply power to the heat pump hot water supply and heating device 900, and the load power to the first electric load 906. Moreover, when the PV-generated power exceeds the sum of the heating load power, the hot water supply power, and the load power, surplus power can be transmitted as reverse power and sold to the energy supplier 908.
The power distribution device 905 also includes a converter and inverter which, when obtained power is transmitted as described above, converts the voltage and performs AC-DC and DC-AC conversion of the obtained power accordingly so the obtained power conforms to the transmitted power. Moreover, the power distribution device 905 transmits the load power actually consumed by the first electric load 906 and the PV-generated power actually generated by the photovoltaic device 911 to the operation planning device 910.
A server 909 is a device which transmits the current amount of solar radiation in the consumer's residence and a predicted future amount of solar radiation via the Internet. According to the first embodiment, the server 909 transmits via the Internet an amount of solar radiation measured in the area of the consumer's residence at a predetermined time interval.
Moreover, the server 909 calculates a predicted value of an amount of solar radiation for each hour for 24 hours from the start of the day at 00:00 using the weather forecast for the day and a history of past amounts of solar radiation measured in the area of the consumer's residence, and transmits the predicted values via the Internet once a day at 00:00.
The energy supplier 908 supplies purchased power at the demand of the power distribution device 905 installed in the consumer's residence. Additionally, when reverse power is input into the power distribution device 905, the energy supplier 908 transmits that power via the power grid to other consumer residences.
The first electric load 906 is an electric load inside the residence of a consumer, and refers to appliances such as televisions, air conditioners, refrigerators, washing machines, or lights which operate by using power supplied from the power distribution device 905. Furthermore, the sum total of the power used by these appliances is defined herein as load power.
Moreover, as shown in FIG. 4, with the heat pump hot water supply and heating system 9000 according to the first embodiment, the consumer (user) can switch between hot water supply and heating, for example, by using a remote control 1101. As shown in FIG. 5, the remote control 1101 is equipped with functions to set the heat generated by the heat pump 901 to be used for heating (“heating”) or for hot water supply (“hot water”), and to turn the heat pump 901 off (“off”). When the user sets the operation mode to any one of these settings, the remote control 1101 outputs the selected operation mode to a hot water supply and heating control device 1001. The user can also set the hot water supply temperature and the heating temperature with the remote control 1101. When the operation mode is set to “heating”, the temperature of the water (hot water) to be put in the heating circuit 904a (to be described later) is set to be the heating temperature setting input by the user. On the other hand, when the operation mode is set to “hot water”, the temperature inside a hot water supply tank 903a (to be described later) is set to be the hot water supply temperature setting input by the user.
FIG. 3 is a block diagram explaining the details of the heat pump hot water supply and heating device 900. The heat pump hot water supply and heating device 900 mainly includes the hot water supply and heating control device 1001, the heat pump 901, the hot water supply device 903, the heating device 904, and a three-way valve 1010 (switching device). The heat pump 901 includes a heat pump unit 901a and the heat exchanger 902. The heat pump hot water supply and heating device 900 operates using power received from the power distribution device 905, and transmits information pertaining to the amount of heating load power to the power distribution device 905.
The heat pump unit 901a (not shown in the drawings) includes an evaporator which facilitates heat exchange between outside air and low temperature-low pressure liquid refrigerant to generate a low temperature-low pressure vaporized refrigerant, a motor-driven compressor which compresses the low temperature-low pressure vaporized refrigerant into a high temperature-high pressure vaporized refrigerant, a condenser which facilitates heat exchange between the high temperature-high pressure vaporized refrigerant and circulating water (thermal storage medium) to generate a low temperature-high pressure liquid refrigerant, an expansion valve which decreases the pressure of the low temperature-high pressure vaporized refrigerant to generate a low temperature-low pressure liquid refrigerant, and a fan to accelerate the heat conversion between the refrigerant in the evaporator and the outside air, for example.
The hot water supply tank 903a stores heat supplied by the hot water supply load. A hot water supply heater 903h is located inside the hot water supply tank 903a and heats the water therein. The heating circuit 904a is a channel of the heating apparatus for the hot water supplied by the heating load. The heat exchanger 902 facilitates heat exchange between the refrigerant heated by the heat pump unit 901a and the downstream water cycle filled with water. The three-way valve 1010 is a switching device for controlling the channel so the water heated by the heat exchanger 902 flows to one of the hot water supply tank 903a and the heating circuit 904a. 
According to the first embodiment, the refrigerant used in the heat pump 901 is 410 A refrigerant. As a result of a property of this refrigerant, the temperature at the exit the water cycle side of the heat exchanger 902 peaks at 55° C., so the upper temperature limit of the heating temperature setting is set to 55° C.
The hot water supply tank 903a is equipped with an internal heat exchanger coil. This heat exchanger coil is expressed as the dashed line inside the hot water supply tank 903a in FIG. 3. When the three-way valve 1010 is set to the channel for the hot water supply tank 903a, the water heated by the heat exchanger 902 flows through the heat exchanger coil and heats the water inside the hot water supply tank 903a. Because the temperature at the exit of the water cycle side of the heat exchanger 902 peaks at 55° C., when the temperature of the hot water supply tank 903a is 50° C. or higher, heat exchange via the each exchange coil is practically nonexistent.
For this reason, when the temperature of the water inside the hot water supply tank 903a is heated to 50° C. or higher, the water is heated by supplying electricity to the hot water supply heater 903h. Here, the capacity of the hot water supply tank 903a is 200 L, the heating capacity of the hot water supply heater 903h is 3 kW, and the upper temperature limit of the hot water supply temperature setting is 80° C.
In other words, the heat pump unit 901a can heat the water inside the hot water supply tank 903a to around 50° C. (the first temperature), and the hot water supply heater 903h can heat the water inside the hot water supply tank 903a beyond 50° C. (the second temperature). It is to be noted that while water was given as an example of the thermal storage medium stored in the hot water supply tank 903a in the first embodiment, the thermal storage medium is not limited to this example. Any type of thermal storage medium which changes in temperature in response to an amount of stored heat can be used.
The hot water supply and heating control device 1001 is a device which, based on set information, controls the entirety of the heat pump hot water supply and heating device 900 system. As shown in FIG. 4, the hot water supply and heating control device 1001 obtains operation information from the remote control 1101 and the operation planning device 910.
The hot water supply and heating control device 1001 obtains the operation mode, the heating temperature setting, and the hot water supply temperature setting from the remote control 1101 as operation information. The hot water supply and heating control device 1001 obtains the priority operation mode and the priority hot water supply temperature setting from the operation planning device 910 as operation information. The priority operation mode has priority over the operation mode obtained from the remote control 1101. Similarly, the priority hot water supply temperature setting has priority over the hot water supply temperature setting obtained from the remote control 1101. In other words, even if the hot water supply and heating control device 1001 obtains the operation mode from the remote control 1101, the priority operation mode from the operation planning device 910 is given priority when obtained.
As shown in FIG. 4, the hot water supply and heating control device 1001 transmits the amount of hot water supply heat and temperature information for the hot water supply tank to the operation planning device 910. The operation planning device 910 receives information pertaining to the amount of load power, the amount of heating load power, and the amount of PV-generated power from the power distribution device 905. The operation planning device 910 is also set up to receive information pertaining to the amount of solar radiation and the predicted amount of solar radiation via the Internet.
When the operation mode is set to “heating”, the hot water supply and heating control device 1001 switches the three-way valve 1010 to the heating circuit 904a channel, and when the operation mode is set to “hot water”, the hot water supply and heating control device 1101 switches the three-way valve 1010 to the hot water supply tank 903a channel. When the operation mode is set to “stop”, the three-way valve 1010 is left unchanged.
Moreover, when the operation mode is set to “heating”, the hot water supply and heating control device 1001 switches on the heat pump unit 901a and brings the exit temperature of the heat exchanger 902 to the heating temperature setting by adjusting the number of rotations of the compressor and the diameter, for example, of the expansion valve in the heat pump unit 901a. 
Moreover, when the temperature of the hot water supply tank 903a drops 5° C. or more below the hot water supply temperature setting (hot water supply temperature setting −5° C. or more), the water inside the hot water supply tank 903a is heated by supplying electricity to the hot water supply heater 903h. Once the temperature of the hot water supply tank 903a reaches the hot water supply temperature setting, electricity to the hot water supply heater 903h is shut off.
Moreover, when the operation mode is set to “hot water” and the temperature inside the hot water supply tank 903a is 50° C. or below and 5° C. or more below the hot water supply temperature setting (hot water supply temperature setting −5° C. or more), the hot water supply and heating control device 1001 switches the three-way valve 1010 to the hot water supply tank 903a channel and controls the heat pump 901 to bring the exit temperature of the heat exchanger 902 to 55° C. This is because, as previously stated, when the temperature inside the hot water supply tank 903a is 50° C. or higher, heat exchange (heating) via the hot water supply tank 903a is practically nonexistent.
Moreover, when the temperature of the hot water supply tank 903a is 50° C. or higher and 5° C. or more below the hot water supply temperature setting (hot water supply temperature setting −5° C. or more), the water inside the hot water supply tank 903a is heated by supplying electricity to the hot water supply heater 903h. Once the temperature of the hot water supply tank 903a reaches the hot water supply temperature setting, electricity to the hot water supply heater 903h is shut off.
Moreover, when the hot water supply and heating control device 1001 obtains the priority operation mode and the priority hot water supply temperature setting from the operation planning device 910, these settings have priority over the operation mode and hot water supply temperature setting settings input by the user with the remote control 1101. Therefore, the hot water supply and heating control device 1001 uses the priority operation mode obtained from the operation planning device 910 for the operation mode, and the priority hot water supply temperature setting obtained from the operation planning device 910 for the hot water supply temperature setting, and operates accordingly.
As shown in FIG. 1, the operation planning device 910 designs an operation plan for the heat pump hot water supply and heating device 900 which reduces the amount of reverse power and controls operation thereof. Next, details with respect to the configuration of the operation planning device 910 will be described with reference to FIG. 6. As shown in FIG. 6, the operation planning device 910 includes a storage means 301, a load prediction means 302, an operation planning means 303, and an operation control means 304.
The storage means 301 stores the amount of load power consumed per hour by the first electric load 906, the amount of heating load power consumed per hour by the heat pump hot water supply and heating device 900 in order to generate heat to be consumed by the heating device 904, the amount of hot water supply heat consumed per hour by the hot water supply device 903, the amount of PV-generated power generated per hour by the photovoltaic device 911, and the amount of solar radiation per hour which is a current value of an amount of solar radiation.
Any means of storage capable of recording data may be used as the storage means 301, such as dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), flash memory, or ferrodielectric memory.
The load prediction means 302 calculates the predicted amount of load power to be consumed per hour by the first electric load 906, the predicted amount of heating load power to be consumed per hour by the heat pump hot water supply and heating device 900 in order to generate heat to be consumed by the heating device 904, the predicted amount of hot water supply heat to be consumed per hour by the hot water supply device 903, and the predicted amount of PV-generated power to be generated per hour by the photovoltaic device 911.
The operation planning means 303 designs an operation plan for the heat pump hot water supply and heating device 900 which minimizes the amount of reverse power, and calculates the control parameters which control the operation of the heat pump hot water supply and heating device 900. Lastly, the operation control means 304 controls the operation of the heat pump hot water supply and heating device 900 based on control parameters.
(Storage Means)
First, the storage means 301 stores values corresponding to the consumer's amount of load power, amount of heating load power, amount of hot water supply heat, amount of PV-generated power, and amount of solar radiation. More specifically, as shown in the history table in FIG. 7, the storage means 301 stores, for a predetermined period of time only (four weeks in the example shown in FIG. 7), a value of load power measured per hour (amount of load power) in a load power history, a value of heating load power measured per hour (amount of heating load power) in a heating load power history, a value of an amount of hot water supply heat measured per hour in a hot water supply heat history, a value of PV-generated power measured per hour (amount of PV-generated power) in a PV-generated power history, and a value of an amount of solar radiation measured per hour in a solar radiation history. History information (load power, heating load power, amount of hot water supply heat, PV-generated power, and amount of solar radiation) for each day of the week for four weeks is stored in this history table. Information for each hour of each day is further stored in more detail. The numbers 0, 1, 2, and so on represent the hours of the day 00:00, 01:00, 02:00, and so on. Moreover, the history information for the hours of the day is accumulated information. The load power history for the hour 0 is the accumulated amount of load power for the hour 00:00.
The load prediction means 302 is set up to be able to obtain desired information from the storage means 301, such as the amount of load power for 15:00 to 16:00 from the previous week, or the amount of hot water supply heat for 18:00 to 22:00 from two weeks ago, for example. The same is also true for the amount of load power, the PV-generated power, and the amount of solar radiation as well.
The operation planning device 910 obtains the amount of load power and the amount of PV-generated power from the power distribution device 905, the heating load power and the amount of hot water supply heat from the heat pump hot water supply and heating device 900, and the amount of solar radiation from the offsite server 909 via the Internet. Here, the amount of solar radiation is an amount of solar radiation for the consumer's area of residence.
The amount of hot water supply heat refers to an amount of heat consumed (radiated) per hour by the hot water supply device 903. The amount of heating load power refers to an amount of power consumed per hour by the heat pump hot water supply and heating device 900 in order to generate heat to be consumed by the heating device 904. This amount of power is the total amount of power required to operate the heat pump 901 and the water pump, for example. The amount of load power refers to an amount of power consumed per hour by the first electric load 906. The amount of PV-generated power refers to an amount of power generated per hour by the photovoltaic device. The amount of solar radiation refers to a current amount of solar radiation per unit area for the consumer obtained from the server 909.
Moreover, the operation planning device 910 accumulates each piece of information in one hour units obtained throughout the previous day and stores values for the previous four weeks (28 days) in the storage means 301.
(Load Prediction Means)
The load prediction means 302 calculates a predicted value of the amount of load power to be consumed per hour by the first electric load 906 (predicted amount of load power), a predicted value of the amount of heating load power to be consumed per hour by the heat pump hot water supply and heating device 900 in order to generate heat to be consumed by the heating device 904 (amount of load power), a predicted value of the amount of hot water supply heat to be consumed per hour by the hot water supply device 903 (predicted amount of hot water supply heat), and a predicted value of the amount of PV-generated power to be generated per hour by the photovoltaic device 911 (predicted amount of PV-generated power).
The load prediction means 302 predicts the amount of load power, the amount of heating load power, and the amount of hot water supply heat for each time period to be equivalent to the average of the power consumption values stored in the storage means 301 measured over four previous weeks from a corresponding time period on the same day of the week. For example, when predicting the amount of load power, the amount of heating load power, and the amount of hot water supply heat from 19:00 to 20:00 on a Tuesday, the load prediction means 302 obtains values measured from 19:00 to 20:00 on Tuesday over four previous weeks from the storage means 301, and uses the average of those values as the predicted value.
The load prediction means 302 obtains the predicted amount of solar radiation for each time period for the prediction target day from the server 909 via the Internet. The load prediction means 302 then, for each time period, predicts the amount of PV-generated power to be equivalent to, from among previously measured amounts of PV-generated power, the amount of PV-generated power during a time period with an amount of solar radiation that is closest to the predicted amount of solar radiation. That is, the load prediction means 302 searches the solar radiation history stored in the storage means 301 for a time period having a value that is the same as or closest to the predicted amount of solar radiation, then obtains the amount of PV-generated power measured for that time period from the PV-generated power history, and makes the obtained amount of PV-generated power the predicted amount of PV-generated power for the target time period.
The load prediction means 302 performs the prediction process described above once a day at 00:00, and calculates a predicted value for each hour for 24 hours.
(Operation Planning Means)
The operation planning means 303 designs an operation plan for the heat pump hot water supply and heating device 900 which minimizes the amount of reverse power, and calculates the control parameters for the heat pump hot water supply and heating device 900.
According to the first embodiment, the operation planning means 303 obtains the predicted amount of load power, the predicted amount of heating load power, the predicted amount of hot water supply heat, and the predicted amount of PV-generated power from the load prediction means 302. The operation planning means 303 further obtains from the heat pump hot water supply and heating device 900 the hot water supply temperature setting (the current temperature setting) thereof. The operation planning means 303 performs an operation plan designing process once a day at, for example, 00:00.
First, for each time period (00:00, 01:00 . . . 22:00, 23:00), the operation planning means 303 calculates the predicted amount of reverse power by subtracting the predicted amount of load power and the predicted amount of heating load power from the corresponding predicted amount of PV-generated power. The lower limit of the predicted amount of reverse power is zero. In the evening, the predicted amount of PV-generated power becomes zero, and reverse power is not generated. The time when the predicted amount of reverse power for each time period first becomes zero counting backwards from 24:00, in other words, the time at which the predicted amount of reverse power changes from a positive value to a non-positive value, is defined as the reverse flow standby start time.
Next, FIG. 8 will be explained in detail. The horizontal axis represents time, and the vertical axis represents amount of power. The black diamonds represent the predicted amount of load power, the X's represent the predicted amount of heating load power, the shaded squares represent the predicted amount of PV-generated power, and the black triangles represent the predicted amount of reverse power. The predicted amount of reverse power (black triangle) is yielded by subtracting the predicted amount of load power and the predicted amount of heating load power from the predicted amount of PV-generated power. Each amount of power for a given time is represented as an accumulated value. For example, if the time is 12:00, the amount of power shown for 12:00 (from 12:00 to 13:00) is an accumulated amount.
As shown in FIG. 8, the reverse flow standby start time, the time at which the predicted amount of reverse power becomes zero, is 17:00. When the amount of heat obtained by accumulating each predicted amount of hot water supply heat (amount of heat to be radiated in reverse flow standby) from the reverse flow standby start time of 17:00 to 24:00 (reverse flow standby time period) is stored in the hot water supply tank 903a by the reverse flow standby start time in advance using the reverse power, heating the hot water supply tank 903a after the reverse flow standby start time becomes unnecessary, thereby avoiding consumption of extra power. The predicted amount of hot water supply heat can be calculated, for example, by obtaining the amounts of hot water supply heat from the same day of the week measured between 17:00 and 24:00 over four weeks from the hot water supply heat history and averaging the amounts.
The temperature calculated by dividing this accumulated predicted amount of hot water supply heat for the time period between 17:00 and 24:00 by the capacity of the hot water supply tank 903a (for example 200 L) is set as the heat storage target temperature. In short, the heat pump 901 to generates heat so that the hot water supply tank 903a can reach this heat storage target temperature. In other words, the heat pump 901 stops generating heat when the hot water supply tank 903a reaches this temperature.
There are cases when an upper temperature limit is set for the heat stored in the hot water supply tank 903a. If the heat storage target temperature exceeds this upper temperature limit, the heat storage target temperature setting is replaced by the upper temperature limit. Here, the upper temperature limit for the heat stored in the hot water supply tank 903a is set to 80° C.
The amount of heat to be stored in the hot water supply tank 903a in reverse flow can be calculated from the heat storage target temperature and the current temperature setting of the heat pump hot water supply and heating device 900 (hot water supply temperature setting). The amount of heat to be generated in reverse flow, which is the amount of heat generated by the heat pump 901 during the reverse flow of power and stored in the hot water supply tank 903a, is calculated using Equation 1 described below. This amount of heat to be generated in reverse flow is equivalent to the amount of heat to be radiated in reverse flow standby which is radiated by the hot water supply device 903 in the reverse flow standby time period (from 17:00 to 24:00).

amount of heat to be generated in reverse flow=(heat storage target temperature−hot water supply temperature setting)×hot water supply tank capacity  (Equation 1)

Next, the operation planning means 303 calculates the reverse flow heat generation time, which is the amount of time required for the heat pump 901 to generate the amount of heat to be generated in reverse flow, using Equation 2 described below.
Also, the HP average capacity is 9 kW. The HP average capacity is an average heating capacity of the heat pump 901, and is a value that is saved in advance. The scaling ratio for converting from amount of heat (kcal) to power (kW) is 0.86.

reverse flow heat generation time=(amount of heat to be generated in reverse flow/0.86/1000)/HP average capacity  (Equation 2)

Next, as shown in FIG. 9, the operation planning means 303 calculates the predicted amount of reverse power for each time period. FIG. 9 expresses the values from the graph in FIG. 8 in table form. The predicted amount of reverse power for any given time period is expressed as an accumulated value of that time period. For example, in the case of the time 00:00, as previously stated, the value expressed is an accumulated value of the predicted reverse power between 00:00 and 01:00. Also, priority in FIG. 9 is assigned in descending order by predicted amount of reverse power.
Next, the operation planning means 303 determines the operation period which is the time period the heat pump 901 operates, and the reverse power threshold value which is for determining when the heat pump 901 actually begins generating heat. The operation period includes the time period having the largest predicted amount of reverse power. Specifically, the operation planning means 303 selects, as the operation period, a number of one or more time periods in descending order of amount of reverse power (that is, in descending order of priority) until the selection exceeds the reverse flow heat generation time. The reverse power threshold value is equal to the value of the operation period with the smallest amount of reverse power.
For example, when the reverse flow heat generation time is calculated to be 0.5 hours, the time period in FIG. 9 with the highest priority (12:00) is selected as the operation period. In this case, the heat storage start time reverse power is 1.68 kW. However, when the reverse flow heat generation time is calculated to be 3.2 hours, the time is rounded up and time periods totaling 4 hours are acquired. In short, the operation period becomes the time period from 10:00 through 13:00, or in other words, the four time periods with the priorities 1 through 4. In this case, the heat storage start time reverse power is 1.00 kW.
The operation planning means 303 then transmits the determined heat storage target temperature, the operation period, and the reverse power threshold value as control parameters to the operation control means 304.
As shown in FIG. 4, the heat pump hot water supply and heating system 9000 according to the first embodiment is configured to be able to switch channels between the hot water supply tank 903a and the heating circuit 904a via the three-way valve 1010 after the heat exchanger 902 facilitates heat exchange. Moreover, because the heat exchanger 902 can only heat the hot water supply tank 903a to approximately 50° C., the hot water supply tank 903a is provided with the hot water supply heater 903h therein in order to heat itself beyond 50° C.
In other words, with respect to the amount of heat corresponding to the amount of heat to be radiated in reverse flow standby, the operation planning device 910 designs an operation plan to cause the heat pump unit 901a to generate an amount of heat until the temperature of the water inside the hot water supply tank 903a reaches 50° C., and cause the hot water supply heater 903h to generate an amount of heat after the temperature of the water reaches 50° C. The calculation method for determining the amount of heat needed in reverse flow is described hereinafter.
(1) When the hot water supply temperature setting (the current temperature setting for the hot water supply tank 903a) is below 50° C.:
When the hot water supply temperature setting is below 50° C., the operation planning means 303 uses Equation 3 below to calculate the reverse flow HP generated heat, which is an amount of heat to be generated by the heat pump 901 in reverse flow, and Equation 4 below to calculate the reverse flow heater generated heat, which is an amount of heat generated by the hot water supply heater 903h in reverse flow.

reverse flow HP generated heat=(50−hot water supply temperature setting)×hot water supply tank capacity  (Equation 3)

reverse flow heater generated heat=(heat storage target temperature−50)×hot water supply tank capacity  (Equation 4)

(2) When the hot water supply temperature setting (the current temperature setting for the hot water supply tank 903a) is 50° C. or higher:
When the hot water supply temperature setting is 50° C. or higher, the operation planning device 910 uses Equation 5 below to calculate the reverse flow heater generated heat, which is an amount of heat to be generated by the hot water supply heater 903h. 

reverse flow heater generated heat=(heat storage target temperature−hot water supply temperature setting)×hot water supply tank capacity  (Equation 5)

Next, the operation planning means 303 uses Equation 6 below to calculate the reverse flow HP heat generation time t(HP), which is the amount of time required for the heat pump 901 to generate the reverse flow HP generated heat, and Equation 7 below to calculate the reverse flow heater heat generation time t(HT), which is the amount of time required for the hot water supply heater 903h to generate the reverse flow heater generated heat.
It is to be noted that the HP average capacity is 9 kW. The HP average capacity is an average heating capacity of the heat pump 901, and is a value that is saved in advance. Moreover, the heating capacity of the heater, which is the average heating capacity of the hot water supply heater 903h, is 3 kW. The scaling ratio for converting from amount of heat (kcal) to power (kW) is 0.86.

t(HP)=(reverse flow HP generated heat/0.86/1000)/HP average capacity  (Equation 6)

t(ht)=(reverse flow heater generated heat/0.86/1000)/heating capacity of the heater  (Equation 7)

Next, the operation planning means 303 calculates the reverse flow heat generation time by adding the reverse flow HP heat generation time and the reverse flow heater heat generation time (t(HP)+t(HT)). The operation planning means 303 designs the operation plan for the heat pump 901 from the calculated reverse flow heat generation time. Moreover, heating via the hot water supply heater 903h is done following the operation of the heat pump 901, but the operation plan is designed so operation of the hot water supply heater 903h is also stopped before the reverse flow standby start time.
(1) When the reverse power is below the reverse power threshold value:
Both priority operation mode and priority hot water supply temperature settings are obtained to be “absent”. In this case, the heat pump hot water supply and heating system 9000 operates according to the settings received from the remote control 1101.
(2) When the reverse power is the same as or higher than the reverse power threshold value:
(i) When the temperature of the hot water supply tank is below 50° C.:
The priority operation mode is obtained to be “hot water”, and the priority hot water supply temperature setting is obtained to be “heat storage target temperature”. In this case, because the temperature can be reached with just the heating capacity of the heat pump 901, the heat pump hot water supply and heating device 900 sets the operation mode to “hot water” and uses the heat pump 901 to heat the water inside the hot water supply tank 903a. 
(ii) When the temperature of the hot water supply tank is 50° C. or higher:
The priority operation mode is obtained to be “absent”, and the priority hot water supply temperature setting is obtained to be “heat storage target temperature”. In this case, because the temperature exceeds the heating capacity of the heat pump 901 (50° C.), the heat pump hot water supply and heating device 900 leaves the operation mode as received from the remote control 1101, and uses the hot water supply heater 903h to heat the water inside the hot water supply tank 903a. There is no other option but to use the hot water supply heater 903h to heat the water inside the hot water supply tank, even if the setting on the user remote control is “heating” or “hot water”.
(Operation Control Means)
The operation control means 304 controls the operation of the heat pump hot water supply and heating device 900 based on the control parameters generated by the operation planning means 303. The operation control means 304 obtains the reverse power threshold value, the operation period, and the heat storage target temperature for the hot water supply tank 903a from the operation planning means 303, obtains the current amount of load power and the current amount of PV-generated power from the power distribution device 905, and obtains the current heating load power and the current temperature of the hot water supply tank 903a (hot water supply tank temperature) from the heat pump hot water supply and heating device 900. The operation control means 304 calculates the reverse power by subtracting the load power and the heating load power from the PV-generated power. These processes are performed, for example, every minute.
Even if it is mid-operation period, operation of the heat pump 901 will not be started if the calculated current reverse power is short of the reverse power threshold value. Once the calculated current reverse power reaches the reverse power threshold value, operation of the heat pump 901 will be started. Moreover, because the operation control means 304 obtains the temperature of the hot water supply tank 903a in one minute intervals, operation of the heat pump 901 is stopped when the hot water supply tank 903a reaches the heat storage target temperature.
By operating the heat pump 901 according to the operation plan designed by the operation planning device 910 in a time period with the peak amount of reverse power, the reverse power for that time period can be reduced (peak-cut). As a result, the effect power flowing in reverse has on the power grid can be effectively reduced. Moreover, the amount of heat to be radiated in reverse flow standby predicted to be needed after the reverse flow standby start time (17:00 in FIG. 8) can be provided with natural energy. As a result, energy can be saved as there is no need to purchase power from the energy supplier 908.
Operation of the First Embodiment
Hereinafter, an exemplary operation according to the first embodiment of the heat pump hot water supply and heating system is described. The description will be given on the premise that the current time is 00:00, and the heat pump hot water supply and heating system has been operating for 4 weeks (28 days) or more. The hot water supply temperature setting is set to 45° C. Also, the temperature inside the hot water supply tank 903a at 00:00 is an even 50° C.
(Update Process of the Operation Planning Device at 00:00)
FIG. 10 is a flowchart of an operation planning process performed by the operation planning device 910 every day at 00:00. First, when the current time becomes 00:00, the operation planning device 910 begins the once daily operation planning process (S601).
Next, the operation planning device 910 updates the storage means 301 (S602). The amount of load power, the amount of heating load power, the amount of hot water supply heat, the amount of PV-generated power, and the amount of solar radiation for the past 24 hours are newly added to the storage means 301 as hourly accumulated values.
Moreover, because the heat pump hot water supply and heating system has been operating over the past 28 days or more, the load power history, the heating load power history, the hot water supply heat history, the PV-generated power history, and the solar radiation history for 28 days are stored in the storage means 301 in one hour units. Each history is updated by discarding the oldest days worth of data from each history, then adding the most recent days worth of data to each history.
Next, the operation planning device 910 performs a prediction process using the load prediction means 302 (S603). FIG. 11 is a flowchart of the prediction process performed by the load prediction means 302 (S603). First, the load prediction means 302 begins the prediction process (S701).
Next, the load prediction means 302 obtains data necessary for load prediction (S702). The load prediction means 302 obtains the predicted amount of solar radiation from the server 909 as well as necessary data from the load power history, the heating load power history, the hot water supply heat history, the PV-generated power history, and the solar radiation history for the past 28 days stored in the storage means 301.
Next, the load prediction means 302 calculates the predicted amount of load power for each hour (S703). As previously stated, the load prediction means 302 calculates the predicted amount of load power for each time period for a 24 hour period by obtaining, from the load power history, four amounts of load power from the same time period and day of the week as the prediction target day, and setting the predicted value as the average of the four obtained amounts.
Next, the load prediction means 302 calculates the predicted amount of heating load power for each hour (S704). As previously stated, the load prediction means 302 calculates the predicted amount of heating load power for each time period for a 24 hour period by obtaining, from the heating load power history, four amounts of heating load power from the same time period and day of the week as the prediction target day, and setting the predicted value as the average of the four obtained amounts.
Next, the load prediction means 302 calculates the predicted amount of hot water supply heat (S705). As previously stated, the load prediction means 302 calculates the predicted amount of hot water supply heat for each time period for a 24 hour period by obtaining, from the hot water supply heat history, four amounts of hot water supply heat from the same time and day of the week as the prediction target day, and setting the predicted value as the average of the four obtained amounts.
Next, the load prediction means 302 calculates the predicted amount of PV-generated power (S706). As previously stated, the load prediction means 302 searches the solar radiation history for a time period having a value that is the same as or closest to the per hour predicted amount of solar radiation. Then, the load prediction means 302 calculates the predicted amount of PV-generated power for each time period a 24 hour period by obtaining, from the PV-generated power history, an amount of PV-generated power corresponding to the found time period, and setting that value as the predicted value.
This completes the load prediction process (S603) of the load prediction means 302 (S707).
(Operation Planning Means)
Next, the operation planning device 910 performs a control parameter calculation process using the operation planning means 303 (S604). FIG. 12 is a flowchart of the control parameter calculation process performed by the operation planning means 303 (S604). First, the operation planning means 303 begins the control parameter calculation process (S801).
Next, the operation planning means 303 obtains data necessary for the control parameters (S802). The operation planning means 303 obtains the hot water supply temperature setting from the heat pump hot water supply and heating device 900, and obtains the predicted amount of load power, the amount of heating load power, the predicted amount of hot water supply heat, and the predicted amount of PV-generated power from the load prediction means 302.
Next, the operation planning means 303 calculates the reverse flow standby start time (S803). As previously stated, the operation planning means 303 calculates the predicted amount of reverse power, which is a value with a lower limit of zero, by subtracting the predicted amount of load power and the predicted amount of heating load power from the predicted amount of PV-generated power.
As shown in the example in FIG. 8, because the predicted amount of PV-generated power becomes zero from the evening on and reverse power is not generated, the time when the value of the predicted amount of reverse power for each time period first becomes zero counting backwards from 24:00 is set as the reverse flow standby start time. For example, the reverse flow standby start time in the example in FIG. 8 is 17:00.
Next, the operation planning means 303 calculates the heat storage target temperature (S804). As previously stated, the operation planning means 303 sets the heat storage target temperature as the lower of the upper temperature limit of the hot water supply temperature setting (80° C.) and the temperature calculated by dividing the amount of heat obtained through accumulating the predicted amount of hot water supply heat between the reverse flow standby start time and 24:00 by the capacity of the hot water supply tank 903a (200 L).
For example, when the amount of heat obtained by accumulating the predicted amount of hot water supply heat between the reverse flow standby start time and 24:00 is 15000 kcal, the temperature calculated by dividing this by the 200 L tank capacity is 75° C. Thus, because 75° C. is lower than the upper temperature limit of the hot water supply temperature setting (80° C.), the heat storage target temperature will be set to 75° C.
Next, the operation planning means 303 calculates the amount of heat to be generated in reverse flow (S805). The operation planning means 303 calculates the amount of heat to be generated in reverse flow which is the amount of heat to be generated by the heat pump 901. This amount of heat to be generated in reverse flow is equivalent to the amount of heat to be radiated in reverse flow standby.
For example, using Equation 1, when the heat storage target temperature of the hot water supply tank 903a is 75° C. and the hot water supply temperature setting is 45° C., the amount of heat to be generated in reverse flow is calculated to be 6000 kcal.
Next, the operation planning means 303 calculates the reverse flow heat generation time (S806). As previously described, the operation planning means 303 uses Equation 2 to calculate the reverse flow heat generation time, which is the amount of time required for the heat pump 901 to generate the amount of heat to be generated in reverse flow. For example, using Equation 2, the reverse flow HP heat generation time is calculated to be 0.78 hours with respect to the value calculated above (6000 kcal).
Next, the operation planning means 303 calculates the operation period and the reverse power threshold value (S807). As previously described, the operation planning means 303 selects, as the operation period, a number of one or more time periods in descending order of predicted amount of reverse power until the selection exceeds the reverse flow heat generation time. Moreover, the predicted amount of reverse power among the one or more selected time periods included in the operation period with the lowest value is set as the reverse power threshold value. For example, if the result of arranging the predicted amount of reverse power in descending order is like the example shown in FIG. 9, when the calculated reverse flow heat generation time is 0.78 hours, time period 12:00 having a reverse power threshold value of 1.68 kW is selected as the operation period.
With the above processes, the operation planning means 303 completes (S808) the control parameter calculation process (S604), and the operation planning device 910 completes (S605) the operation planning process.
The operation planning device 910 performs an operation control process of the heat pump hot water supply and heating device 900 using the operation control means 304 in one minute intervals during the time period from the completion of the operation planning process until 00:00 of the next day.
After the completion of the operation planning process, the operation control means 304 obtains the heat storage target temperature, the operation period, and the reverse power threshold value from the operation planning means 303, and obtains the load power and the PV-generated power in one minute intervals from the power distribution device 905, and obtains the heating load power and the temperature of the hot water supply tank 903a in one minute intervals from the heat pump hot water supply and heating device 900. Each time information is obtained per minute, the operation control means 304 calculates the reverse power by subtracting the load power and the heating load power from the PV-generated power.
Even if it is mid-operation period, operation of the heat pump 901 will not be started if the calculated current reverse power is short of the reverse power threshold value. Once the calculated current reverse power reaches the reverse power threshold value, operation of the heat pump 901 will be started. Moreover, because the operation control means 304 obtains the temperature of the hot water supply tank 903a in one minute intervals, operation of the heat pump 901 is stopped when the hot water supply tank 903a reaches the heat storage target temperature.
Moreover, the operation planning device 910 performs a process in which each of the various pieces of information is stored in predetermined time intervals in the storage means 301 during the time period from the completion of the operation planning process until 00:00 of the next day. The amount of hot water supply heat and the amount of heating load power obtained from the heat pump hot water supply and heating device 900, the amount of load power obtained from the power distribution device 905, the amount of PV-generated power obtained from the photovoltaic device 911, and the amount of solar radiation obtained from the server 909 are stored in the storage means 301.
The obtained respective values are accumulated hourly, and when the time changes according to the time information stored internally, the accumulated values for the past hour coupled with the time are stored in the storage means 301, whereby the accumulated value is reset to 0.
According to the first embodiment, using the operation planning means 303, the operation planning device 910 stores an amount of heat in the hot water supply tank 903a at the reverse flow standby start time that corresponds to the predicted amount of hot water supply heat between the reverse flow standby start time and 24:00 based on the prediction information from the load prediction means 302.
On a day having a low predicted amount of hot water supply heat, for instance, radiant heat loss occurs when the hot water supply tank 903a is heated to the set upper temperature limit (80° C.) in order to use up all of the reverse power. However, according to the first embodiment, because a necessary amount of heat is predicted, heat which would go to waste is not generated, and a low-energy performance characteristic is maintained.
Following the configuration according to the present invention as outlined above allows for a low-energy performance characteristic to be maintained whereby the amount of reverse power generated is decreased in the system including the photovoltaic device 911 and the heat pump hot water supply and heating device 900.
Specific Example
Hereinafter, an operation of the heat pump hot water supply and heating system 9000 according to the first embodiment is described. The description will be given on the premise that the current time is 00:00, and the heat pump hot water supply and heating system 9000 has been operating for 4 weeks (28 days) or more. Moreover, on the remote control 1101, the operation mode information is “heating”, the heating temperature setting is “50° C.”, and the hot water supply temperature setting is “45° C.”. Also, the temperature inside the hot water supply tank 903a at 00:00 is an even 50° C.
First, when the hot water supply temperature setting is below 50° C., the operation planning means 303 uses Equation 3 to calculate the reverse flow HP generated heat, which is the amount of heat to be generated by the heat pump 901, and Equation 4 to calculate the reverse flow heater generated heat, which is the amount of heat to be generated by the hot water supply heater 903h. 
For example, when the heat storage target temperature is 75° C. and the hot water supply temperature setting is 45° C., because the hot water supply temperature setting is below 50° C., Equation 3 and Equation 4 are calculated to get a reverse flow HP generated heat of 1000 kcal and a reverse flow heater generated heat of 5000 kcal. For both Equation 3 and Equation 4, a storage tank capacity of 200 L was used.
Next, the operation planning means 303 calculates the reverse flow heating time. The operation planning means 303, as previously stated, uses Equation 6 to calculate the reverse flow HP heat generation time, which is the amount of time required for the heat pump 901 to generate the reverse flow HP generated heat, and Equation 7 to calculate the reverse flow heater heat generation time, which is the amount of time required for the hot water supply heater 903h to generate the reverse flow heater generated heat.
For example, with respect to the above calculated reverse flow HP generated heat and the reverse flow heater generated heat, the reverse flow HP heat generation time t(HP)=0.13 hr, and the reverse flow heater heat generation time t(HT)=1.94 hr.
Next, the operation planning means 303 calculates the reverse flow heating time by adding the reverse flow HP heat generation time and the reverse flow heater heat generation time (t(HP)+t(HT)). For example, with respect to the above calculated t(HP) and t(HT), the reverse flow heating time is calculated to be 2.07 hr.
In this case, with respect to the figures in FIG. 9, the operation period is set to the time period from 11:00 through 13:00, or in other words, the time periods with the priorities 1 through 3, whereby the selected operation period with the lowest predicted amount of reverse power is set as the reverse power threshold value (1.38 kW).
Hereinafter, an operation of the heat pump hot water supply and heating device 900 according to the first embodiment is described. FIG. 13 is a flow chart showing an operation of the heat pump hot water supply and heating device 900.
First, the hot water supply and heating control device 1001 monitors the reverse power and starts the operation of the heat pump hot water supply and heating device 900 when the reverse power reaches the reverse power threshold value (S1601). When the operation is started, if the temperature of the hot water supply tank (the current temperature of the hot water supply tank 903a) is 50° C. or above (S1602), heat is generated by the hot water supply heater 903h (S1603), and when the water inside the hot water supply tank 903a reaches the heat storage target temperature (S1604), the generation of heat via the hot water supply heater 903h is stopped (S1605).
In contrast, when the temperature of the hot water supply tank is below 50° C. (S1602), heat is first generated by the heat pump unit 901a. At this time, if the heat storage target temperature is below 50° C. (S1606), heat will only be generated by the heat pump unit 901a (S1609). When the water inside the hot water supply tank 903a reaches the heat storage target temperature (S1610), the generation of heat via the heat pump unit 901a is stopped (S1611).
However, if the heat storage target temperature is 50° C. or above (S1606), heat is generated by the heat pump unit 901a until the temperature of the water inside the hot water supply tank 903a reaches 50° C. (S1607). Furthermore, after the temperature of the water inside the hot water supply tank 903a reaches the upper temperature limit of 50° C. (S1608), heat is generated by the hot water supply heater 903h until the heat storage target temperature is reached (S1603). Once the water inside the hot water supply tank 903a reaches the heat storage target temperature (S1604), the generation of heat via the hot water supply heater 903h is stopped (S1605).
Hereinafter, other examples of an operation of the heat pump hot water supply and heating device 900 according to the first embodiment is described. FIG. 14 is a flow chart showing an operation of the heat pump hot water supply and heating system 9000 according to the first embodiment. This flow chart shows a method of controlling the heat pump hot water supply and heating system 9000 at a time in which the storage of heat in the hot water supply tank 903a is to be started, when the heat pump unit 901a is already operating in order to supply heat to the heating device 904.
First, the hot water supply and heating control device 1001 monitors the reverse power and starts the operation of the heat pump hot water supply and heating device 900 when the reverse power reaches the reverse power threshold value (S1701). For example, when the heat storage target temperature is 75° C., if the temperature of the hot water supply tank 903a is already 50° C. or above (YES in S1702), the remaining amount of heat to be stored is generated by the hot water supply heater 903h (S1703).
However, if the temperature of the hot water supply tank 903a is below 50° C. (NO in S1702), first it is determined whether or not the heat pump unit 901a is being used to supply heat to the heating device 904 (S1706). If the heat pump unit 901a is not being used, the heat pump unit 901a is operated to generate heat to increase the temperature of the water inside the hot water supply tank 903a. However, if the heat pump unit 901a is being used to supply heat to the heating device 904, the hot water supply tank 903a is given priority over the heating device 904, and heat is stored in the hot water supply tank 903a. In other words, as is shown in the flow chart, the three-way valve 1010 is switched from the heating device 904 to the hot water supply tank 903a (S1707), and the heat pump unit 901a is operated to store heat in the hot water supply tank 903a (S1708).
The temperature of the hot water supply tank 903a is measured in one minute intervals, and the heat pump unit 901a is made to continue generating heat until the temperature of the hot water supply tank 903a reaches 50° C. When the hot water supply tank 903a reaches 50° C., as is shown in the flow chart, the hot water supply heater 903h is used for storing the remaining heat (S1703), and when the heat storage target temperature is reached (S1704), storage of the heat by the hot water supply heater 903h is completed (S1705).
Hereinafter, an advantage of the heat pump hot water supply and heating system 9000 according to the first embodiment is described.
The operation planning device 910 according to the first embodiment predicts the amount of load power, the amount of heating load power, the amount of hot water supply heat, and the amount of PV-generated power for each time period for the prediction target day, and designs an operation plan for heating the hot water supply tank 903a using reverse power based on the predicted information. The operation planning device 910 then selects, as the operation period, a number of one or more time periods in descending order of amount of reverse power, and sets the amount of reverse power with the lowest value among the selected time periods as the reverse power threshold value.
For example, as described above with respect to the figures in FIG. 9, when the reverse flow heat generation time is 2.07 hr, the operation period is the time period from 11:00 through 13:00. Because the predicted amount of reverse power is for 11:00, 12:00, and 13:00 is 1.44 kW, 1.68 kW, and 1.38 kW, respectively, the reverse power threshold value is set to the smallest value among the three of 1.38 kW.
The operation planning device 910 then gives the above determined control parameters priority over the setting information according to the remote control 1101, and uses the control parameters to control the heat pump hot water supply and heating device 900.
As a result, an operation can be achieved in which as little reverse power as possible is output to the energy supplier 908, even when the water inside the hot water supply tank 903a is heated by the heat pump hot water supply and heating device 900.
FIG. 15 is a comparison of the power consumption required to heat the water inside the hot water supply tank 903a when the load prediction means 302 is not used for the sake of example.
With results of the present invention in FIG. 15, it is clear that by operating according to the operation plan using the prediction results of the load prediction means, the amount of reverse power is minimized.
Following the configuration according to the present invention as outlined above allows for a low-energy performance characteristic to be maintained whereby the amount of reverse power generated is reduced in the heat pump hot water supply and heating system 9000 including the photovoltaic device 911.
(Other Configurations)
Hereinbefore, the heat pump hot water supply and heating system according the embodiments of the present invention provided with the power generation device were described. However, the following embodiments are also acceptable.
While the photovoltaic device is used as an example of the power generation device, a plurality of photovoltaic devices coupled together may also be used as the power generation device.
Moreover, the operation planning device is set up outside the hot water supply and heating device, but the operation planning device may be set up inside the hot water supply and heating device or inside the power distribution device. The operation plan function of the operation planning device may also be a part of the hot water supply device or the power distribution device instead.
Moreover, the reverse power threshold value is calculated by the operation planning means and the hot water supply and heating device is controlled according to the amount of reverse power using the operation control means, but the hot water supply and heating device may be operated by setting a timer for a predetermined time period calculated to minimize reverse power, such as from 11:00 through 13:00.
Moreover, the operation planning device performs the operation planning process once a day at 00:00, but the process may be performed more than one time a day and at an arbitrary time such as 02:00 or 06:00 instead of 00:00. In this case, the end of the reverse flow standby time period (24:00 in the embodiment examples) is also adjusted accordingly. In other words, after the completion of the reverse flow standby time period, which is a time period delimited by the reverse flow standby start time (17:00 in the embodiment) and a predetermined assumed time radiator unit (the hot water supply device) will stop radiating heat, the operation planning device may design an operation plan for the next day.
Moreover, the unit time for the load information and prediction information used in the processing by the operation planning device is one hour, but an arbitrary unit time, such as 15 minutes or one minute, may be used for the information.
Moreover, an average of past values from the same time and day of week is used for the prediction values used by the load prediction means, but prediction using a neural network or another technique may also be used.
Hereinbefore, the embodiment of the present invention was described with reference to the drawings, but the present invention is not limited to the embodiment shown in the drawings. It is acceptable to add variations to or modify the embodiment depicted in the drawings within the scope of the invention or an equal scope.
INDUSTRIAL APPLICABILITY
The operation planning device according to the present invention is useful in contributing to the stabilization of the power grid when a hot water supply system or a hot water supply and heating system, for example, is in operation.
REFERENCE SIGNS LIST


    301 storage means
    302 load prediction means
    303 operation planning means
    304 operation control means
    900 heat pump hot water supply and heating device
    901 heat pump
    901a heat pump unit
    902 heat exchanger
    903 hot water supply device
    903a hot water supply tank
    903h hot water supply heater
    904 heating device
    904a heating circuit
    905 power distribution device
    906 first electric load
    907 power meter
    908 energy supplier
    909 server
    910 operation planning device
    911 photovoltaic device
    1001 hot water supply and heating control device
    1010 three-way valve
    1101 remote control
    9000 heat pump hot water supply and heating system

## Claims

1. An operation planning method performed in a system including a power generation device, a first electric load which operates using power generated by the power generation device, and a second electric load which generates heat using power generated by the power generation device, the second electric load including a heat generation unit which generates heat using power generated by the power generation device, a heat storage unit which stores heat generated by the heat generation unit, a first radiator unit which radiates heat stored in the heat storage unit, and a second radiator unit which directly radiates heat generated by the heat generation unit, said operation planning method being performed to design an operation plan for the second electric load, and said operation planning method comprising:
predicting, for individual unit time periods, an amount of power to be generated by the power generation device, a first amount of power to be consumed by the first electric load, and a second amount of power to be consumed by the heat generation unit to generate heat to be radiated by the second radiator unit; and
designing the operation plan for the second electric load to cause the second electric load to operate during an operation period which includes, among the unit time periods, a unit time period in which an amount of reverse power is the largest, the reverse power being calculated by subtracting the first amount of power to be consumed and the second amount of power to be consumed from the amount of power to be generated.

2. The operation planning method according to claim 1,
wherein the power generation device is a photovoltaic device,
in the predicting, an amount of heat to be radiated in reverse flow standby by the first radiator unit during a reverse flow standby time period is further predicted, the reverse flow standby time period being a time period in which the amount of power to be consumed exceeds the amount of power to be generated, and
in the designing, an operation plan for the heat generation unit to operate during the operation period is designed such that an amount of heat is stored in the heat storage unit, the amount of heat corresponding to the amount of heat to be radiated in reverse flow standby as predicted in the predicting.

3. The operation planning method according to claim 2,
wherein in the designing, the operation plan is designed for the operation period which is determined by selecting one or more of the unit time periods in descending order of the amount of reverse power until a total amount of time of the one or more selected unit time periods exceeds an amount of time required for the heat generation unit to generate the amount of heat corresponding to the amount of heat to be radiated in reverse flow standby.

4. The operation planning method according to claim 3,
wherein in the designing,
a reverse power threshold value is set to be the amount of reverse power with the lowest value among the one or more selected unit time periods, and
the operation plan is designed such that operation of the heat generation unit is started at a point in time at which the reverse power, as actually measured, becomes equal to or exceeds the reverse power threshold value during the operation period.

5. The operation planning method according to claim 4,
wherein in the designing, the operation plan is further designed such that operation of the heat generation unit is stopped at a point in time at which the amount of heat corresponding to the amount of heat to be radiated in reverse flow standby is generated during the operation period.

6. The operation planning method according to claim 2,
wherein the heat storage unit includes a thermal storage medium whose temperature varies according to the amount of heat stored,
the heat generation unit includes a heat pump capable of heating the thermal storage medium to a first temperature, and a heater capable of heating of the thermal storage medium beyond the first temperature, and
in the designing, with respect to the amount of heat corresponding to the amount of heat to be radiated in reverse flow standby, the operation plan is designed to cause the heat pump to generate an amount of heat until the thermal storage medium reaches the first temperature, and to cause the heater to generate an amount of heat after the thermal storage medium reaches the first temperature.

7. The operation planning method according to claim 2,
wherein in the predicting, the amount of heat to be radiated by the radiator unit during the reverse flow standby time period is predicted as the amount of heat to be radiated in reverse flow standby, the reverse flow standby time period being a time period delimited by a reverse flow standby start time and a predetermined assumed time at which the radiator unit will stop radiating heat, and the reverse flow standby start time being a time when the amount of reverse power changes from a positive value to a non-positive value.

8. An operation method performed by a heat pump hot water supply and heating system including a photovoltaic device and a heat pump hot water supply and heating device,
the heat pump hot water supply and heating device including:
a heat pump which generates heat using power generated by the photovoltaic device;
a hot water supply tank which stores hot water heated using heat generated by the heat pump; and
a heating device which heats a space using heat generated by the heat pump,
the system including an operation planning device, and
the operation method comprising control of the system by the operation planning device, the control including:
predicting an amount of power to be generated by the power generation device, a first amount of power to be consumed by an electric load, and a second amount of power to be consumed by the heat pump to generate heat to be radiated by the heating device;
calculating an amount of reverse power by subtracting the first amount of power to be consumed and the second amount of power to be consumed from the amount of power to be generated;
predicting an amount of heat required in a reverse flow standby time period during which the amount of reverse power is zero; and
designing an operation plan which causes the heat pump hot water supply and heating device to operate to store the predicted amount of heat during an operation period which includes a time period in which the amount of reverse power is the largest.

9. The operation method performed by the heat pump hot water supply and heating system according to claim 8,
wherein in the designing,
a heat storage target temperature to store the predicted amount of heat is determined and a reverse power threshold value is set to the amount of reverse power with the lowest value among the operation periods.

10. The operation method performed by the heat pump hot water supply and heating system according to claim 9,
the controlling further comprising performing control based on the heat storage target temperature and the reverse power threshold value determined and set in the designing,
wherein in the controlling, operation of the heat pump hot water supply and heating device is started at a point in time at which the reverse power as measured reaches or exceeds the reverse power threshold value during the operation period, and
operation of the heat pump hot water supply and heating device is stopped at a point in time at which the predicted amount of heat is generated during the operation period.

11. The operation method performed by the heat pump hot water supply and heating system according to claim 10,
wherein in the designing, the heat storage target temperature for storing the predicted amount of heat in a hot water supply tank is determined, and
a thermal storage medium inside the hot water supply tank is heated to a first temperature with a heat pump included in the heat pump hot water supply and heating device, then the thermal storage medium is heated to a second temperature which is higher than the first temperature with a heater installed in the hot water supply tank.

12. The operation method performed by the heat pump hot water supply and heating system according to claim 10,
wherein the heat pump hot water supply and heating device includes a hot water supply and heating control device, and
the hot water supply and heating control device is set up to receive operation information for the heat pump hot water supply and heating device from a remote control as well as from the operation planning device, and
when operation information is received from the operation planning device and from the remote control, the hot water supply and heating control device gives the operation information from the operation planning device priority over the operation information from the remote control, and controls the heat pump hot water supply and heating device based on the operation information from the operation planning device.

13. The operation method performed by the heat pump hot water supply and heating system according to claim 12,
wherein the operation information is an operation mode for the heat pump hot water supply and heating device, and a hot water supply temperature setting for the hot water supply tank.

14. The operation method performed by the heat pump hot water supply and heating system according to claim 11,
wherein the heat pump hot water supply and heating device further includes a heat exchanger which facilitates heat exchange between a refrigerant in the heat pump and the thermal storage medium, and a switching device which switches supply of the thermal storage medium supplied from the heat exchanger to one of the hot water supply tank and the heating device, and

in the controlling, when the switching device is switched to the heating device and the temperature of the thermal storage medium is below the first temperature at a point in time at which operation of the heat pump hot water supply and heating device starts, the switching device switches to the hot water supply tank.