Hot water supply control device, hot water supply control system, and hot water supply control method

Abstract

To provide a hot water supply control device capable of reducing a risk of utilization of a power source other than for intended purposes.SOLUTION: A hot water supply control device (1) includes a weather prediction information acquiring section (111), a designation hot water amount determining section (114) for determining a designation hot water amount of the day on the basis of weather prediction information including at least the weather prediction information of the next day or later, and an instruction generating section (116) for generating an additional heating instruction for making an electric hot water supply device perform additional heating operation until a hot water storage amount of the electric hot water supply device becomes the designation hot water amount or more.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a hot water supply control device, a hot water supply control system, and a hot water supply control method. [Background technology]

[0002] Conventionally, electric water heaters (heat pump water heaters or electric hot water heaters) are known that can identify the optimal amount of hot water stored (target amount of hot water) based on a learning function and a two-week history of the amount of hot water used. Electric water heaters use inexpensive late-night electricity supplied from a grid power source during the late-night hours before the hot water is used to heat the hot water stored in the water until it reaches the target amount of hot water.

[0003] For example, Patent Document 1 discloses a hot water supply control device that uses late-night power and surplus power from solar power generation that occurs before the usage time period to store hot water in excess of or up to the required amount. Patent Document 2 discloses a hot water supply control device that calculates a second amount of hot water to be generated using late-night power based on a predicted value of a first amount of hot water to be generated using surplus power from solar power generation.

[0004] Furthermore, with the recent spread of solar power generation in Japan, there is a demand for technology that utilizes surplus solar power generation during the daytime (electricity generated by solar power generation minus electricity consumed by electrical devices).In particular, efforts are being made to use surplus solar power generation during the daytime to operate electric water heaters instead of late-night electricity. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6491494 specification [Patent Document 2] Patent No. 6842887 specification Summary of the Invention [Problem to be solved by the invention]

[0006] However, with such electric water heaters, when there is little solar radiation and little surplus solar power (for example, during rainy weather), there is a risk that they will use electricity from sources other than solar power (for example, commercial electricity) to heat water for an unintended purpose.

[0007] One aspect of the present invention has been made in consideration of the above problems, and an object of the present invention is to determine an appropriate amount of hot water storage. [Means for solving the problem]

[0008] In order to solve the above problems, a hot water control device according to one embodiment of the present invention is a hot water control device that communicates with an electric water heater that uses electricity generated by solar power, and includes a weather forecast information acquisition unit that acquires weather forecast information from outside, a designated hot water volume determination unit that determines a designated hot water volume for the day based on the weather forecast information including weather forecast information for at least the next day and beyond, and an instruction generation unit that generates an additional boiling instruction to cause the electric water heater to perform an additional boiling operation until the amount of hot water stored in the electric water heater becomes equal to or greater than the designated amount.

[0009] In addition, the electric water heater may perform normal heating operation up to a target hot water volume that is set in advance for each day, and the designated hot water volume determination unit may determine the designated hot water volume to be greater than the target hot water volume.

[0010] The instruction generating unit may generate the additional boiling instruction to cause the electric water heater to perform the additional boiling operation during daytime hours.

[0011] In addition, the designated hot water volume determination unit may determine the designated hot water volume for the day based on the predicted amount of solar radiation for at least a specified period from the next day onwards as the weather forecast information, and when the predicted amount of solar radiation corresponding to a first day is less than the predicted amount of solar radiation corresponding to a second day, the designated hot water volume for the first day may be set to be greater than the designated hot water volume for the second day.

[0012] In addition, when the weather forecast information acquisition unit acquires information indicating that a typhoon is approaching as weather forecast information, the designated hot water volume determination unit may determine the designated hot water volume based on the information indicating that a typhoon is approaching.

[0013] The electric water heater may further include a data acquisition unit that acquires hot water usage information indicating a history of the amount of hot water used in the electric water heater from the electric water heater, and the designated hot water volume determination unit may determine the designated amount of hot water based on the hot water usage information.

[0014] The device may further include an output unit that outputs the hot water usage information to the outside, and an input unit that receives designated hot water volume correction information from the outside for correcting the designated hot water volume, and the designated hot water volume determination unit may correct the designated hot water volume based on the designated hot water volume correction information.

[0015] The water heater may further include a data acquisition unit that acquires the amount of stored hot water from the electric water heater, and a start time determination unit that determines the start time of the normal boiling operation based on the amount of stored hot water, the specified amount of hot water, and the weather forecast information.

[0016] In addition, when the amount of stored hot water falls below a lower limit designated hot water amount which is lower than the designated hot water amount, the instruction generation unit may generate an instruction to prevent running out of hot water, which causes the electric water heater to perform an additional boiling operation until the amount of stored hot water is equal to or greater than an upper limit designated hot water amount which is higher than the lower limit designated hot water amount.

[0017] In addition, the hot water control device may be a device on a management server that communicates with multiple electric water heaters via a gateway, and the instruction generation unit may send the additional water boiling instruction for each electric water heater to the gateway, and the gateway may control the operation of each electric water heater in accordance with the additional water boiling instruction.

[0018] In order to solve the above problems, a hot water supply control system according to one embodiment of the present invention comprises the hot water supply control device, the electric water heater, and a gateway that receives instructions from the hot water supply control device and controls the operation of the electric water heater in accordance with the instructions.

[0019] In order to solve the above problems, a hot water supply control method according to one embodiment of the present invention is a hot water supply control method by a hot water supply control device that communicates with an electric water heater that uses electricity generated by solar power, and includes a weather forecast information acquisition step for acquiring weather forecast information from outside, a designated hot water volume determination step for determining a designated hot water volume for the day based on the weather forecast information including weather forecast information for at least the next day onwards, and an instruction generation step for generating an additional boiling instruction to cause the electric water heater to perform an additional boiling operation until the amount of hot water stored in the electric water heater is equal to or greater than the designated amount. Effect of the Invention

[0020] According to one aspect of the present invention, an appropriate amount of hot water storage can be determined. [Brief description of the drawings]

[0021] [Figure 1] 1 is a block diagram showing an example of a configuration of a main part of a hot water supply control system according to a first embodiment. [Diagram 2] 4 is a graph showing an example of a change in the amount of hot water stored in an electric water heater in the above-mentioned hot water supply control system. [Diagram 3] FIG. 11 is a diagram showing an example of operational control of an electric water heater based on weather forecast information. [Figure 4] 11 is a graph showing an example of a change in the amount of hot water stored in an electric water heater when shift control of the start time of a normal water heating operation is not performed. [Diagram 5] 11 is a graph showing an example of a change in the amount of hot water stored in an electric water heater when shift control is performed on the start time of a normal water heating operation. [Figure 6] 4 is a sequence diagram showing a flow of operational control of the electric water heater in the hot water supply control system. FIG. [Figure 7] 10 is a graph showing an example of a change in the amount of hot water stored in an electric water heater in a hot water supply control system according to the second embodiment. [Figure 8] 4 is a sequence diagram showing a flow of operational control of the electric water heater in the hot water supply control system. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] [Embodiment 1] (Overview of hot water supply control system 100) Fig. 1 is a block diagram showing an example of a configuration of a main part of a hot water supply control system 100 according to embodiment 1. As shown in Fig. 1, the hot water supply control system 100 includes a hot water supply control device 1, a gateway 3, and at least one electric hot water heater 5.

[0023] The electric water heater 5 is installed at each consumer facility and includes a heating unit that uses electricity generated by solar power to boil hot water, and a hot water storage tank that stores the generated hot water. The electric water heater 5 also includes a detection unit that detects the amount of hot water stored in the hot water storage tank (amount of stored hot water). The electric water heater 5 also detects the amount of stored hot water used each day at the consumer facility (amount of hot water used) from the change in the amount of stored hot water detected by the detection unit. The electric water heater 5 may be a publicly known type. The at least one electric water heater 5 may include a plurality of electric water heaters 5 with different specifications such as a target amount of hot water.

[0024] The electric water heater 5 sets a target amount of hot water, which is an optimal amount of hot water stored, in advance for each day. For example, the electric water heater 5 uses a learning function to determine the target amount of hot water based on the temperature of the day from the history of the amount of hot water stored (amount of hot water used) used by each consumer over about two weeks. The electric water heater 5 performs a normal boiling operation during daytime, using power generated by solar power generation to boil water up to the above-mentioned target amount of hot water. In the following, the daytime refers to a time period during which solar power generation is possible if it is sunny, and the nighttime refers to a time period during which solar power generation is not possible even if it is sunny. The daytime (and nighttime) may refer to the time from sunrise to sunset (sunset to sunrise), for example. The daytime may vary depending on the season, or may be fixed regardless of the season.

[0025] Furthermore, electric water heater 5 includes a transmission unit that transmits to the outside detected data such as the amount of stored hot water, the target amount of hot water, and hot water usage information indicating the history of the amount of hot water used in electric water heater 5. For example, the detected data detected by electric water heater 5 is collected by a smart meter installed in each consumer facility and transmitted to the outside (gateway 3 in the example of FIG. 1).

[0026] Here, when the amount of sunlight is low and the surplus power of solar power generation is small (for example, during rainy weather), the electric water heater 5 cannot heat up to the target amount of hot water using only the surplus power of solar power generation. Therefore, there is a risk of using an unintended power source to heat the water using power from a power source other than solar power generation (for example, commercial power).

[0027] Furthermore, if the stored hot water volume were to be set to the above-mentioned target volume only through the normal heating operation of the electric water heater 5, there would be a risk that the electric water heater 5 would run out of hot water due to variations in the amount of hot water used from day to day. For example, in a private home, if the amount of hot water used suddenly increases due to visitors, etc., the amount of hot water used may exceed the target amount set by the learning function, resulting in a run-out of hot water (the amount of stored hot water will become 0).

[0028] In order to avoid such a hot water shortage, the electric water heater 5 has a boiling function that boils more water after the normal boiling operation according to user input or the like. However, since the target amount of hot water for the electric water heater 5 varies from day to day, the time when the normal boiling operation ends and the amount of hot water stored by the normal boiling are not determined. Therefore, the user cannot know in advance whether the amount of hot water stored by the normal boiling, which is not known when it will end, will be the amount of hot water expected to be used by the user. In addition, there is also the problem that the amount of hot water supplied per unit time by the boiling function of the electric water heater 5 is typically less than the amount of hot water used per unit time, so boiling more water must be done in advance.

[0029] The inventors have found that the risk of using an unintended power source can be reduced by having a hot water supply control device 1 on a management server that communicates with an electric hot water heater 5 determine a designated amount of hot water based on weather forecast information and output an instruction to set the amount of hot water stored in the electric hot water heater 5 to be equal to or greater than the designated amount. They have also found that the risk of running out of hot water can be reduced by determining the designated amount of hot water while taking into consideration hot water usage information indicating the history of hot water usage in the electric hot water heater 5 of each consumer. The schematic configuration of such a hot water supply control device 1 will be described below with reference to FIG. 1.

[0030] (Schematic configuration of hot water supply control device 1) 1, hot water supply control device 1 includes control device control unit 11, control device communication unit 12, control device storage unit 13, input unit 14, and output unit 15. Hot water supply control device 1 is a management server (e.g., a cloud server) that communicates with electric water heater 5 via gateway 3. Hot water supply control system 100 is a system in which an administrator who operates the management server manages electric water heater 5.

[0031] Control device control unit 11 includes a weather forecast information acquisition unit 111, a data acquisition unit 112, a correction information acquisition unit 113, a designated hot water volume determination unit 114, a start time determination unit 115, and an instruction generation unit 116. Control device control unit 11 controls each unit of hot water supply control device 1 in an integrated manner.

[0032] The control device communication unit 12 receives detection data of the electric water heater 5 from the gateway 3. The control device communication unit 12 also receives various information such as weather forecast information from the outside via an external network. The control device communication unit 12 transmits instructions related to the operation control of the electric water heater 5 to the gateway 3.

[0033] The control device storage unit 13 stores various information handled by the hot water supply control device 1. The control device storage unit 13 stores weather forecast information, detection data of the electric water heater 5 (hot water storage amount, target hot water amount, hot water usage information, etc.), and administrator input information input by an administrator, etc. When the hot water supply control device 1 manages multiple electric water heaters 5, the control device storage unit 13 stores the identifier of each electric water heater 5 in association with the detection data.

[0034] The input unit 14 is a device that receives information input by an administrator (for example, designated hot water volume correction information) from the outside. The output unit 15 is a device that outputs various information handled by the hot water supply control device 1 (for example, hot water usage volume information) to the outside.

[0035] The weather forecast information acquisition unit 111 acquires weather forecast information from an external source. For example, the weather forecast information acquisition unit 111 acquires weather forecast information from a server of the Japan Meteorological Agency or a weather information service company via the control device communication unit 12. The weather forecast information acquisition unit 111 stores the weather forecast information in the control device storage unit 13.

[0036] The data acquisition unit 112 acquires detection data of the electric water heater 5 from the electric water heater 5 via the gateway 3. For example, the data acquisition unit 112 acquires hot water usage information indicating the history of the amount of hot water used in the electric water heater 5 from the electric water heater 5. The data acquisition unit 112 also acquires the amount of hot water stored in the electric water heater 5 from the electric water heater 5 at predetermined intervals (for example, one minute). The data acquisition unit 112 also acquires the operating status of the electric water heater 5 from the electric water heater 5. The data acquisition unit 112 stores the detection data including the hot water usage information and the amount of hot water stored in the electric water heater 5 in the control device memory unit 13.

[0037] The correction information acquisition unit 113 acquires designated hot water volume correction information from an external source. Here, the designated hot water volume correction information is information for correcting the designated hot water volume determined by, for example, an administrator based on hot water volume information. The correction information acquisition unit 113 stores the designated hot water volume correction information in the control device storage unit 13.

[0038] The designated hot water volume determination unit 114 determines the designated hot water volume for the day based on weather forecast information including at least weather forecast information for the following day and thereafter. The designated hot water volume determination unit 114 transmits the determined designated hot water volume to the instruction generation unit 116.

[0039] For example, the designated hot water volume determination unit 114 determines the designated hot water volume for the day based on the predicted amount of solar radiation for at least a specified period from the next day onwards as weather forecast information. The specified period may be one day or more, or may be shorter than one day. Here, when the predicted amount of solar radiation corresponding to the first day (for the specified period from the next day onwards) is less than the predicted amount of solar radiation corresponding to the second day (for the specified period from the next day onwards), the designated hot water volume determination unit 114 determines the designated hot water volume for the first day to be greater than the designated hot water volume for the second day.

[0040] As a result, if the predicted amount of solar radiation for a specified period from the next day onwards is low and the surplus power from solar power generation for the specified period is predicted to be small, the designated amount of hot water for that day can be set to be large, thereby reducing the amount of hot water to be boiled for the specified period from the next day onwards. Therefore, when the amount of solar radiation is low and the surplus power from solar power generation is small, the risk of using an unintended power source to boil water using power from a source other than solar power generation can be reduced. A detailed control example for determining the designated amount of hot water will be described later with reference to Figure 3.

[0041] The designated hot water volume determination unit 114 may determine the designated hot water volume to be greater than the target hot water volume. This allows the hot water storage volume of the electric water heater 5 to be set to a designated hot water volume greater than the target hot water volume in preparation for days when the surplus power from solar power generation is low.

[0042] The designated hot water volume determination unit 114 may also determine the designated hot water volume based on the hot water volume information used. That is, the designated hot water volume determination unit 114 may determine the designated hot water volume by considering the hot water volume information used in addition to the weather forecast information. For example, the hot water volume information used includes information indicating a history of hot water shortage in a specific electric water heater 5. In this case, the designated hot water volume determination unit 114 sets the designated hot water volume to be larger for an electric water heater 5 that has a history of hot water shortage compared to an electric water heater 5 that has no history of hot water shortage. Alternatively, the hot water volume information used may include information indicating the variation in the daily hot water usage. In this case, the designated hot water volume determination unit 114 sets the designated hot water volume to be larger for an electric water heater 5 that has a large daily variation in the hot water usage. This allows the designated hot water volume to be set larger for an electric water heater 5 that is more likely to run out of hot water, thereby reducing the risk of running out of hot water.

[0043] The designated hot water volume determination unit 114 may also determine the designated hot water volume based on the hot water usage volume information by correcting the designated hot water volume based on the designated hot water volume correction information acquired by the correction information acquisition unit 113. For example, the manager determines an increase value of the designated hot water volume based on the hot water usage volume information. The manager inputs the increase value of the designated hot water volume to the input unit 14 as the designated hot water volume correction information. The designated hot water volume determination unit 114 corrects the designated hot water volume by adding the increase value of the designated hot water volume to the designated hot water volume determined based on the weather forecast information. This allows the manager to grasp the variation in the daily hot water usage volume of the electric water heater 5, and when it is determined that the variation is large, to correct the designated hot water volume set for the electric water heater 5. Furthermore, when managing multiple electric water heaters 5, the manager may determine an increase value of the designated hot water volume of the other electric water heaters 5 based on the history of hot water shortages for the designated hot water volume related to the electric water heater 5. It should be noted that instead of the manager deciding the increase value of the designated amount of hot water, the control device control unit 11 may decide the increase value of the designated amount of hot water based on the history of hot water shortages.

[0044] Furthermore, when the weather forecast information acquisition unit 111 acquires information that a typhoon is approaching as weather forecast information, the designated hot water volume determination unit 114 may determine the designated hot water volume based on the information that a typhoon is approaching. For example, the designated hot water volume determination unit 114 determines the designated hot water volume to be the maximum hot water volume that the hot water storage tank can store based on the information that a typhoon is approaching. This allows the electric water heater 5 to secure the maximum hot water volume in preparation for a power outage caused by a typhoon.

[0045] The start time determination unit 115 determines the start time of the normal boiling operation based on the amount of stored hot water, the designated amount of hot water, and weather forecast information. The method of determining the start time by the start time determination unit 115 will be described later with reference to Figs. 4 and 5.

[0046] The instruction generating unit 116 generates an instruction related to the operation control of the electric water heater 5, and outputs the instruction to the gateway 3. For example, the instruction generating unit 116 generates an additional boiling instruction to make the electric water heater 5 perform the additional boiling operation until the amount of hot water stored in the electric water heater 5 becomes equal to or greater than the designated amount of hot water. The instruction generating unit 116 may generate an additional boiling instruction to make the electric water heater 5 perform the additional boiling operation during daytime hours. This allows the electric water heater 5 to perform additional boiling using surplus power from solar power generation during daytime hours, without using commercial power. The instruction generating unit 116 may also generate an instruction to perform shift control to advance the start time of the normal boiling operation set in the electric water heater 5 based on the start time determined by the start time determining unit 115.

[0047] (Gateway 3 schematic configuration) The gateway 3 includes a gateway communication unit 31, a gateway control unit 32, and a gateway storage unit 33. The gateway 3 is a device that controls the operation of the electric water heater 5 in accordance with instructions transmitted from the hot water supply control device 1.

[0048] The gateway communication unit 31 receives instructions related to operational control of the electric water heater 5 transmitted from the hot water supply control device 1. The gateway communication unit 31 transmits a signal based on the instructions to control the operation of the electric water heater 5. The gateway communication unit 31 also receives detection data from the electric water heater 5 and transmits the detection data to the hot water supply control device 1.

[0049] The gateway control unit 32 comprehensively controls each unit of the gateway 3. The gateway storage unit 33 stores various information related to the electric water heater 5.

[0050] (Operation control of electric water heater 5) Fig. 2 is a graph showing an example of changes in the amount of hot water stored in electric water heater 5 in hot water supply control system 100. In the graph of Fig. 2, the vertical axis indicates the amount of hot water stored in electric water heater 5, and the horizontal axis indicates time. Up to time t1, the amount of hot water stored is the remaining amount of hot water A0 from the previous day. From time t1 to t2, normal heating is performed. As a result, at time t2, the amount of hot water stored becomes the target amount of hot water A1.

[0051] After time t2, electric water heater 5 receives a command to reheat water from gateway 3. After that, from time t3 to t4, the first reheating operation is performed. As a result, at time t4, the amount of stored hot water becomes A1+ΔA.

[0052] Here, since the amount of stored hot water A1+ΔA is lower than the designated amount of hot water A2, the electric water heater 5 again receives a command to boil more water from the gateway 3. After that, from time t5 to t6, the electric water heater 5 performs a second boil more water operation. As a result, at time t6, the amount of stored hot water becomes A1+2ΔA.

[0053] Similarly, because the amount of stored hot water A1+2ΔA is lower than the designated amount of hot water A2, electric water heater 5 again receives an instruction to boil more water from gateway 3. After that, from time t7 to t8, electric water heater 5 performs a third boiling operation. As a result, at time t8, the amount of stored hot water becomes A1+3ΔA. Here, because the amount of stored hot water A1+3ΔA is higher than the designated amount of hot water A2, the electric water heater 5 ends its boiling operation.

[0054] In this way, after normal boiling, electric water heater 5 repeats the boiling operation in accordance with the boiling command from gateway 3 until the amount of stored hot water becomes equal to or greater than designated hot water amount A2.

[0055] FIG. 3 is a diagram showing an example of the operation control of the electric water heater 5 based on weather forecast information. In FIG. 3, the amount of power used and the amount of hot water stored in the electric water heater 5 for one week are excerpted and shown. In the example shown in FIG. 3, the weather forecast information includes information that the weather is sunny on Monday, Tuesday, Wednesday, and Sunday, cloudy on Saturday, and rainy on Thursday and Friday. For simplicity, it is assumed here that the amount of hot water used each day is constant, and the electric water heater 5 sets a target amount of hot water equal to the amount of hot water used. The amount of hot water stored that is not used is carried over to the next day.

[0056] In this case, the designated hot water volume determination unit 114 (see FIG. 1) sets a large designated hot water volume from Monday to Wednesday, when the amount of solar radiation is predicted to be high, in preparation for Thursday to Saturday, when the amount of solar radiation is predicted to be low. For example, the designated hot water volume determination unit 114 sets the maximum designated hot water volume that can be boiled with the amount of surplus power from photovoltaic power generation corresponding to the predicted amount of solar radiation from Monday to Wednesday. Also, the designated hot water volume determination unit 114 does not set a designated hot water volume from Thursday to Saturday. This allows the designated hot water volume determination unit 114 to set the amount of hot water stored in the electric water heater 5 to a designated hot water volume that is greater than the target hot water volume (equal to the amount of hot water used) from Monday to Wednesday. In other words, the electric water heater 5 can ensure the amount of hot water used without performing much heating operation from Thursday to Saturday. This reduces the risk of using an unintended power source.

[0057] Due to the specifications of the electric water heater 5 itself, the electric water heater 5 heats at least a specified amount of hot water every day through normal heating operation regardless of the amount of hot water stored (the "amount of hot water stored through normal heating" on Thursdays and Fridays in Figure 3).

[0058] It should be noted that even on Sundays, the weather is sunny and the amount of sunlight is predicted to be high. However, since the amount of sunlight is predicted to be high for a while (a specified period) after Sunday, the designated hot water volume determination unit 114 does not set a designated hot water volume for Sundays. Alternatively, the designated hot water volume determination unit 114 may set a smaller designated hot water volume for Sundays (next day sunny) than for the previous Wednesday (next day rainy) ( A designated hot water volume (which is greater than the target hot water volume) may be set.

[0059] Fig. 4 is a graph showing an example of the change in the amount of hot water stored in electric water heater 5 when shift control of the start time of normal water heating operation is not performed. Fig. 5 is a graph showing an example of the change in the amount of hot water stored in electric water heater 5 when shift control of the start time of normal water heating operation is performed. As shown in Fig. 4, if gateway 3 does not perform shift control, the amount of solar radiation decreases until the additional water heating operation of electric water heater 5 ends (until time t8 in Fig. 4), and there is a possibility that the surplus power of photovoltaic power generation will be less than the power usage P of the additional water heating operation of electric water heater 5. In this case, electric water heater 5 will perform the additional water heating operation using commercial power (due to the use of an unintended power source).

[0060] In order to avoid such unintended use of power sources, start time determination unit 115 (see FIG. 1) determines the start time of the normal boiling operation based on the amount of stored hot water, the designated amount of hot water, and weather forecast information. Also, instruction generation unit 116 (see FIG. 1) generates an instruction to perform shift control to advance the start time of the normal boiling operation set in electric water heater 5 based on the start time determined by start time determination unit 115.

[0061] Specifically, as shown in Fig. 5, the start time determination unit 115 roughly calculates the scheduled end time t8 of the reheating operation from the start time of the normal boiling operation set in the electric water heater 5, the current amount of stored hot water, and the designated amount of hot water. The start time determination unit 115 also predicts a time period during which reheating is possible when the surplus power of photovoltaic power generation is greater than the power usage P of the reheating operation of the electric water heater 5, from weather forecast information. If the scheduled end time t8 of the reheating operation is later than the time period during which reheating is possible, the start time determination unit 115 advances the start time t1 of the normal boiling operation set in the electric water heater 5 by Δt so that the scheduled end time of the reheating operation falls within the time period during which reheating is possible. In other words, the start time determination unit 115 determines the start time of the normal boiling operation to be t1 - Δt. The instruction generation unit 116 generates an instruction to perform shift control to advance the start time of the normal boiling action from t1 to t1-Δt.

[0062] Fig. 6 is a sequence diagram showing the flow of operational control of electric water heater 5 in hot water control system 100. An example of an operation in which hot water control device 1 transmits instructions relating to operational control of electric water heater 5 to gateway 3, and gateway 3 controls the operation of electric water heater 5 in accordance with the instructions transmitted from hot water control device 1 will be described below with reference to Fig. 6.

[0063] 6, first, the weather forecast information acquisition unit 111 acquires weather forecast information from an external source. In addition, the data acquisition unit 112 acquires detection data (information on the amount of hot water stored and the amount of hot water used, etc.) of the electric water heater 5 from the electric water heater 5 via the gateway 3 (weather forecast information acquisition step S1).

[0064] Next, the designated hot water volume determination unit 114 determines the designated hot water volume for the day based on weather forecast information including weather forecast information for at least the next day and thereafter. The designated hot water volume determination unit 114 may determine the designated hot water volume based on hot water usage information. The start time determination unit 115 determines the start time of the normal boiling operation based on the amount of stored hot water, the designated hot water volume, and the weather forecast information. Specifically, if the estimated scheduled end time of the extra boiling operation is later than the time period during which extra boiling is possible, the start time determination unit 115 advances the start time of the normal boiling operation set in the electric water heater 5 by Δt so that the estimated end time of the extra boiling operation falls within the time period during which extra boiling is possible (designated hot water volume determination step S2). If the estimated scheduled end time of the extra boiling operation falls within the time period during which extra boiling is possible, steps S3 and S4 (shift control) described below are omitted.

[0065] Next, the instruction generation unit 116 generates an instruction to perform shift control to advance the start time of the normal water heating operation. The instruction generation unit 116 transmits the instruction to the gateway 3 (S3). The gateway 3 transmits an instruction to the electric water heater 5 to perform shift control to advance the start time of the normal water heating operation set in the electric water heater 5 by Δt (S4).

[0066] Next, the electric water heater 5 starts normal boiling operation at the preset start time of the normal boiling operation (or, if an instruction to perform shift control is received, at a time that is Δt earlier than the preset start time of the normal boiling operation) (S5).

[0067] Next, when the normal boiling operation is completed, the electric water heater 5 transmits a signal to the gateway 3 indicating that the normal boiling operation is completed (S6). The gateway 3 transfers the signal to the hot water supply control device 1.

[0068] Next, the hot water supply control device 1 receives a signal from the gateway 3 indicating that the normal boiling operation has ended (S7). Next, the instruction generating unit 116 generates an additional boiling instruction to cause the electric water heater 5 to perform an additional boiling operation until the amount of hot water stored in the electric water heater 5 reaches or exceeds the designated amount. The instruction generating unit 116 transmits the additional boiling instruction to the gateway 3 (instruction generating step S8).

[0069] Next, in accordance with the reheating instruction received from the hot water supply control device 1, the gateway 3 sends an instruction to the electric water heater 5 to perform a reheating operation using the reheating function of the electric water heater 5 (S9). Next, the electric water heater 5 receives the instruction and starts the reheating operation using the reheating function (S10). Next, when the reheating operation is completed, the electric water heater 5 sends a signal to the gateway 3 indicating that the reheating operation has been completed. At this time, the electric water heater 5 sends the amount of hot water stored after the reheating operation is completed to the gateway 3 (S11).

[0070] Next, the gateway 3 determines whether the amount of stored hot water received from the electric water heater 5 is equal to or greater than the designated amount. If the amount of stored hot water is not equal to or greater than the designated amount (NO in S12), the gateway 3 again sends an instruction to the electric water heater 5 to perform the re-boiling operation (S9). If the amount of stored hot water is equal to or greater than the designated amount (YES in S12), the gateway 3 sends a signal to the hot water supply control device 1 to end the re-boiling operation. This causes the electric water heater 5 to repeat the re-boiling operation until the amount of stored hot water is equal to or greater than the designated amount. When the hot water supply control device 1 receives the signal to end the re-boiling operation from the gateway 3, it ends generating instructions related to the operational control of the electric water heater 5.

[0071] As described above, the hot water supply control device 1 can control the operation of the electric hot water heater 5 so that the amount of hot water stored in the electric hot water heater 5 is equal to or greater than the designated amount of hot water determined based on weather forecast information. Therefore, for example, when the predicted amount of solar radiation for a predetermined period from the next day onwards is low and the surplus power of solar power generation for the predetermined period is predicted to be low, the designated amount of hot water can be set to a large amount to reduce the amount of hot water to be boiled in the predetermined period. Therefore, when the amount of solar radiation is low and the surplus power of solar power generation is low, the risk of using an unintended power source to boil water using power from a power source other than solar power generation can be reduced. Thus, the hot water supply control device 1 can determine an appropriate amount of hot water stored.

[0072] The hot water supply control device 1 can also control the operation of the electric water heater 5 so that the amount of hot water stored in the electric water heater 5 is equal to or greater than a designated amount of hot water that takes into consideration not only weather forecast information but also hot water usage information (variations in the amount of hot water used each day, past records of hot water shortages, etc.). Therefore, the designated amount of hot water can be set higher for electric water heaters 5 that are likely to run out of hot water, reducing the risk of running out of hot water.

[0073] Furthermore, the hot water supply control device 1 is a device on a management server that communicates with the electric water heater 5 via the gateway 3. Therefore, the hot water supply control device 1 can perform the above-mentioned operational control on multiple electric water heaters 5 via the gateway 3. Therefore, the above-mentioned operational control can be performed on multiple electric water heaters 5 without the need to replace the existing electric water heaters 5 installed in each consumer's facility.

[0074] Furthermore, gateway 3 repeatedly transmits an instruction to electric water heater 5 to perform the reheating operation until the amount of stored hot water becomes equal to or greater than the designated amount. Therefore, even when performing the above-described operational control on multiple electric water heaters 5 with different specifications for the reheating function (such as the amount of hot water boiled in one reheating), hot water supply control device 1 can control the operation of multiple electric water heaters 5 so that the amount of stored hot water in each of the multiple electric water heaters 5 becomes equal to or greater than the designated amount.

[0075] [Embodiment 2] Other embodiments of the present invention will be described below. For ease of explanation, the same reference numerals are given to members having the same functions as those described in the above embodiment, and the description thereof will not be repeated.

[0076] 7 is a graph showing an example of a change in the amount of hot water stored in an electric water heater in hot water supply control system 100 according to embodiment 2. In this embodiment, instruction generating unit 116 generates an instruction to prevent running out of hot water, when the amount of hot water stored falls below lower limit designated hot water amount A3 that is lower than the designated hot water amount, to cause electric water heater 5 to perform an operation to boil more hot water until the amount of hot water stored is equal to or greater than upper limit designated hot water amount A4 that is higher than lower limit designated hot water amount A3.

[0077] 7, at time t9, the amount of stored hot water falls below the lower limit designated hot water amount A3, so electric water heater 5 performs the additional boiling operation. As a result, at time t8, the amount of stored hot water becomes equal to or greater than the upper limit designated hot water amount A4, and electric water heater 5 ends the additional boiling operation.

[0078] Fig. 8 is a sequence diagram showing the flow of operational control of an electric water heater in hot water supply control system 100. An operational example in which hot water supply control device 1 transmits an instruction to prevent running out of hot water to gateway 3, and gateway 3 controls the operation of electric water heater 5 in accordance with the instruction to prevent running out of hot water, will be described below with reference to Fig. 8.

[0079] As shown in Fig. 8, first, the data acquisition unit 112 acquires the amount of stored hot water from the electric water heater 5 via the gateway 3 (S21). Next, the instruction generation unit 116 determines whether the amount of stored hot water acquired by the data acquisition unit 112 has fallen below the lower limit designated hot water amount A3. If the amount of stored hot water has not fallen below the lower limit designated hot water amount A3 (NO in S22), the process returns to S21. If the amount of stored hot water has fallen below the lower limit designated hot water amount A3 (YES in S22), the instruction generation unit 116 generates an instruction to prevent hot water from running out. The instruction generation unit 116 sends the instruction to prevent hot water from running out to the gateway 3 (S23).

[0080] Next, in accordance with the hot water shortage prevention instruction received from the hot water supply control device 1, the gateway 3 sends an instruction to the electric water heater 5 to perform a reheating operation using the reheating function of the electric water heater 5 (S24). Next, the electric water heater 5 receives the instruction and starts the reheating operation using the reheating function (S25). Next, when the reheating operation is completed, the electric water heater 5 sends a signal to the gateway 3 indicating that the reheating operation has been completed. At this time, the electric water heater 5 sends the amount of hot water stored after the reheating operation is completed to the gateway 3 (S26).

[0081] Next, the gateway 3 determines whether the amount of stored hot water received from the electric water heater 5 is equal to or greater than the upper limit designated hot water amount A4. If the amount of stored hot water is not equal to or greater than the upper limit designated hot water amount A4 (NO in S27), the gateway 3 again sends an instruction to the electric water heater 5 to perform the re-boiling operation (S9). If the amount of stored hot water is equal to or greater than the upper limit designated hot water amount A4 (YES in S27), the gateway 3 sends a signal to the hot water supply control device 1 to end the re-boiling operation. This causes the electric water heater 5 to repeat the re-boiling operation until the amount of stored hot water reaches the upper limit designated hot water amount A4. When the hot water supply control device 1 receives the signal to end the re-boiling operation from the gateway 3, it ends the generation of instructions related to the operational control of the electric water heater 5.

[0082] As described above, the hot water supply control device 1 can cause the electric water heater 5 to perform the boiling operation when the amount of stored hot water falls below the lower limit designated hot water amount A3. Therefore, the risk of running out of hot water can be reduced even during the nighttime when the boiling operation is not usually performed.

[0083] [Modifications] The functions of the hot water supply control device of the above-mentioned embodiments 1 and 2 may be provided in the electric water heater itself. In this case, the electric water heater may include, for example, each part of the hot water supply control device 1, in particular each part of the control device control unit 11. In this case, the designated hot water volume determined by the control device control unit of the electric water heater becomes the target hot water volume. Such an electric water heater can appropriately store hot water while reducing the risk of using an unintended power source, as described above, based on weather forecast information.

[0084] [Software implementation example] The functions of the hot water control device 1 and gateway 3 (hereinafter referred to as the "device") can be realized by a program for causing a computer to function as the device, and for causing a computer to function as each control block of the device (in particular, each unit included in the control device control unit 11, the control device communication unit 12, the input unit 14, the output unit 15, the gateway communication unit 31, and the gateway control unit 32).

[0085] In this case, the device includes a computer having at least one control device (e.g., a processor) and at least one storage device (e.g., a memory) as hardware for executing the program. The control device and storage device execute the program to realize each function described in each of the above embodiments.

[0086] The program may be non-transitory and may be recorded in one or more computer-readable recording media. The recording media may or may not be included in the device. In the latter case, the program may be provided to the device via any wired or wireless transmission medium.

[0087] In addition, some or all of the functions of each of the control blocks can be realized by a logic circuit. For example, an integrated circuit in which a logic circuit that functions as each of the control blocks is formed is also included in the scope of the present invention. In addition, the functions of each of the control blocks can be realized by, for example, a quantum computer.

[0088] Furthermore, each process described in each of the above embodiments may be executed by AI (Artificial Intelligence). In this case, the AI ​​may be executed by the control device or another device (for example, an edge computer or a cloud server).

[0089] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. [Explanation of symbols]

[0090] 1 Hot water supply control device 3. Gateway 5. Electric water heater 14 Input section 15 Output section 100 Hot water supply control system 111 Weather forecast information acquisition unit 112 Data Acquisition Section 113 Correction information acquisition unit 114 Designated water volume determination unit 115 Start time determination section 116 Instruction generation section A1 Target amount of water A2 Specified hot water amount A3 Minimum designated hot water volume A4 Maximum designated hot water volume

Claims

1. A hot water control device that communicates with an electric hot water heater that uses power generated by solar power generation, a weather forecast information acquisition unit that acquires weather forecast information from an external source; A designated hot water amount determination unit that determines a designated hot water amount for the day based on the weather forecast information including at least weather forecast information for the next day and thereafter; A hot water supply control device comprising: an instruction generating unit that generates an instruction to cause the electric hot water heater to perform an additional boiling operation until the amount of hot water stored in the electric hot water heater becomes equal to or greater than the designated amount of hot water.

2. The electric water heater performs a normal boiling operation up to a target amount of hot water that is set in advance for each day, The hot water supply control device according to claim 1 , wherein the designated hot water volume determination unit determines the designated hot water volume to be greater than the target hot water volume.

3. The hot water supply control device according to claim 1 , wherein the instruction generating unit generates the additional boiling instruction for causing the electric hot water heater to perform the additional boiling operation during daytime hours.

4. The designated hot water volume determination unit determines the designated hot water volume for the day based on the predicted solar radiation amount for at least a predetermined period from the next day onward as the weather forecast information, A hot water supply control device as described in any one of claims 1 to 3, wherein when the predicted solar radiation amount corresponding to a first day is less than the predicted solar radiation amount corresponding to a second day, the designated hot water amount for the first day is set to be greater than the designated hot water amount for the second day.

5. A hot water supply control device as described in any one of claims 1 to 4, wherein when the weather forecast information acquisition unit acquires information indicating that a typhoon is approaching as weather forecast information, the designated hot water volume determination unit determines the designated hot water volume based on the information indicating that a typhoon is approaching.

6. A data acquisition unit that acquires hot water usage information indicating a history of hot water usage in the electric hot water heater from the electric hot water heater, The hot water supply control device according to claim 1 , wherein the designated hot water volume determination unit determines the designated hot water volume based on the hot water usage information.

7. An output unit that outputs the hot water usage information to the outside; An input unit that receives designated hot water volume correction information from the outside for correcting the designated hot water volume, The hot water supply control device according to claim 6 , wherein the designated hot water volume determination unit corrects the designated hot water volume based on the designated hot water volume correction information.

8. A data acquisition unit that acquires the amount of hot water stored from the electric hot water heater; The hot water supply control device according to claim 2 , further comprising a start time determination unit that determines a start time of the normal boiling operation based on the amount of stored hot water, the designated amount of hot water, and the weather forecast information.

9. The hot water control device according to any one of claims 1 to 8, wherein the instruction generating unit generates an instruction to prevent running out of hot water by causing the electric water heater to perform additional boiling operation until the amount of stored hot water is equal to or greater than an upper limit designated hot water amount higher than the lower limit designated hot water amount when the amount of stored hot water falls below a lower limit designated hot water amount which is lower than the designated hot water amount.

10. The hot water supply control device is a device on a management server that communicates with the plurality of electric hot water heaters via a gateway. The instruction generation unit transmits the additional boiling instruction for each electric water heater to the gateway; The hot water supply control device according to claim 1 , wherein the gateway controls the operation of each of the electric hot water heaters in accordance with the additional boiling instruction.

11. A hot water supply control device according to any one of claims 1 to 10, and an electric hot water heater, A hot water supply control system comprising: a gateway that receives instructions from the hot water supply control device and controls the operation of the electric hot water heater in accordance with the instructions.

12. A hot water supply control method by a hot water supply control device that communicates with an electric hot water heater that uses power generated by solar power generation, A weather forecast information acquisition step of acquiring weather forecast information from an external source; A designated hot water amount determination step for determining a designated hot water amount for the day based on the weather forecast information including at least weather forecast information for the next day and thereafter; A hot water supply control method comprising: an instruction generating step of generating an instruction to cause the electric hot water heater to perform an additional boiling operation until the amount of hot water stored in the electric hot water heater becomes equal to or greater than the designated amount of hot water.

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