Stored hot water supply device

Abstract

To provide a storage water heater capable of executing boiling-up by using private power generation electric power and boiling-up by using commercial electric power while reflecting a desire of a user.SOLUTION: A storage water heater includes: a heat pump unit operated by using private power generation electric power generated by a photovoltaic generation system and commercial electric power supplied from a commercial power source; a weather prediction information acquisition section acquiring weather prediction information in a predetermined time zone at a primary determination time and a secondary determination time; an execution determination section determining whether or not boiling-up by using the private power generation electric power is executed in the predetermined time zone by determining whether or not primary prediction power generation amount of the private power generation electric power calculated on the basis of the weather prediction information acquired at the primary determination time is required power generation amount or greater; and an instruction reception section that receives an instruction to execute or cancel the boiling-up in the predetermined time zone if secondary prediction power generation amount of the private power generation electric power calculated on the basis of the weather prediction information acquired at the secondary determination time does not reach the required power generation amount when the execution determination section determines the execution.SELECTED DRAWING: Figure 9

Description

Technical Field

[0001] The present invention relates to a hot water storage type water supply device that boils hot and cold water with electric power generated by a solar power generation system.

Background Art

[0002] Conventionally, a technology for centrally managing the energy used in a house using a HEMS (Home Energy Management System) is known. For example, there is a technology in which a HEMS predicts a time zone with a power generation value at which a boiling operation can be executed so that a hot water storage type water supply device linked to a solar power generation system can efficiently boil hot and cold water with the self-generated power generated by the solar power generation system.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The power generation amount by a solar power generation system varies according to the weather. For example, based on the acquired weather prediction information such as sunny, cloudy, and rainy, the availability of power generation in a predetermined time zone is determined. Therefore, if the weather in a predetermined time zone is as predicted by the weather prediction information, the predicted power generation amount can be obtained, and if the weather prediction information changes, the predicted power generation amount cannot be obtained.

[0005] Here, when self-generated power cannot be obtained, the hot water will be boiled using commercial power supplied from the commercial power source. However, the unit price of the commercial power may vary depending on the time of day. For example, the unit price of the commercial power may be relatively high during the daytime. Due to such circumstances, it is common for users to desire to boil hot water using commercial power during the time periods when the unit price of the power is low, and to boil hot water using self-generated power during other time periods.

[0006] The present invention has been made in consideration of such circumstances, and an object thereof is to provide a hot water storage type water heater that can execute boiling with self-generated power and boiling with commercial power while reflecting the wishes of the user.

Means for Solving the Problems

[0007] In order to solve the above-described problems, the hot water storage type water heater according to the present invention includes a hot water storage tank that stores hot water, a heat pump unit that operates with self-generated power generated by a solar power generation system and commercial power supplied from a commercial power source, and boils the hot water, and a weather prediction information acquisition unit that acquires weather prediction information for a predetermined time period at a primary determination time and a secondary determination time that comes after the primary determination time. , by the weather prediction information acquisition unit The self-generated power calculated based on the acquired weather prediction information of the prediction An execution determination unit that determines whether to execute boiling with the self-generated power that operates the heat pump unit with the self-generated power to boil the hot water in the predetermined time period by determining whether the measured power generation amount is equal to or greater than the required power generation amount. , cause a display means of an external terminal to display an instruction reception screen for receiving An instruction for execution or suspension of boiling in the predetermined time period , and receive the execution or suspension instruction input by the user via the input means of the external terminal And an instruction reception unit that receives the instruction, and is provided with , when the execution determination unit determines to execute the boiling based on the weather prediction information acquired at the primary determination time, the execution determination unit determines whether or not the secondary predicted power generation amount of the self-generated power calculated based on the weather prediction information acquired at the secondary determination time is equal to or greater than the required power generation amount. When the execution determination unit determines that the secondary predicted power generation amount is less than the required power generation amount, the instruction reception unit causes the display means to display the instruction reception screen and receives the execution or suspension instruction.

Effects of the Invention

[0008] In the hot water storage type water heater according to the present invention, boiling with self-generated power and boiling with commercial power can be executed while reflecting the wishes of the user.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Mode for Carrying Out the Invention

[0010] An embodiment of the hot water storage type hot water supply device according to the present invention will be described based on the accompanying drawings.

[0011] FIG. 1 is a system configuration diagram of a hot water supply system 100 including a hot water storage type hot water supply device 1 in this embodiment.

[0012] The hot water supply system 100 includes a distribution board 2, a solar power generation system 3, a server 6, and a hot water storage type hot water supply device 1 (hereinafter simply referred to as "hot water supply device 1").

[0013] The distribution board 2 is installed in a building such as a house (hereinafter simply referred to as "house") together with the solar power generation system 3 and the water heater 1. The distribution board 2 is connected to the commercial power supply 2a and the solar power generation system 3. The distribution board 2 supplies the commercial power supplied from the commercial power supply 2a and the self-generated power generated by the solar power generation system 3 to the water heater 1 used in the house and the electrical load devices in the house such as air conditioners other than the water heater 1 (hereinafter simply referred to as "air conditioner etc. 7" in the following description and FIG. 1).

[0014] The solar power generation system 3 includes a solar power generation panel 4 and an inverter 5. The solar power generation panel 4 is installed on the roof of the house or the like. The inverter 5 converts the generated power of the solar power generation panel 4 into an AC power supply.

[0015] The server 6 is connected to the water heater 1 and the user terminal 9 via the network 8. The server 6 transmits and receives information (details will be described later) necessary for various processes executed by the water heater 1 to the water heater 1 and the user terminal 9. The user terminal 9 is a device that can communicate with the server 6 via the network 8, such as a smartphone, tablet, or personal computer, owned by the user of the water heater 1.

[0016] The water heater 1 includes a hot water storage tank 10, a heat pump unit 19, a circulation circuit 27, a remote control 32, and a control unit 31.

[0017] The hot water storage tank 10 stores hot water to be supplied to hot water supply terminals such as a bathroom and a kitchen. The hot water storage tank 10 includes a water supply pipe 11, a hot water outlet pipe 12, a water supply bypass pipe 13, a hot water supply pipe 15, and a hot water storage temperature sensor 18.

[0018] The water supply pipe 11 is connected to the hot water storage tank 10 at the bottom of the hot water storage tank 10 to supply water to the hot water storage tank 10. The hot water outlet pipe 12 is connected to the hot water storage tank 10 at the top of the hot water storage tank 10 to discharge hot water from the hot water storage tank 10. The water supply bypass pipe 13 is a pipe branched from the water supply pipe 11 and is connected to the hot water outlet pipe 12 via the mixing valve 14. The mixing valve 14 mixes the hot water from the hot water outlet pipe 12 and the water from the water supply bypass pipe 13 so that the temperature reaches the set hot water supply temperature set by the remote control 32.

[0019] The hot water supply pipe 15 supplies the hot water supplied via the mixing valve 14 to the hot water supply terminal. The hot water supply pipe 15 has a hot water supply flow rate sensor 16 and a hot water supply temperature sensor 17. The hot water supply flow rate sensor 16 detects the hot water supply flow rate and outputs a corresponding detection signal to the control unit 31. The hot water supply temperature sensor 17 detects the hot water supply temperature and outputs a corresponding detection signal to the control unit 31.

[0020] The hot water storage temperature sensor 18 detects the temperature of the hot water in the hot water storage tank 10 and outputs a corresponding detection signal to the control unit 31. A plurality of hot water storage temperature sensors 18 are provided on the side surface of the hot water storage tank 10 at different height positions. Each of these plurality of hot water storage temperature sensors 18 outputs a corresponding detection signal to the control unit 31 when, for example, it detects the hot water temperature above a predetermined threshold value set in advance corresponding to the temperature of the hot water in a sufficiently heated state. The control unit 31 detects the amount of hot water (i.e., the hot water storage amount) in the hot water storage tank 10 that is in a state where the hot water is sufficiently heated based on the number of hot water storage temperature sensors 18 that output detection signals.

[0021] The heat pump unit 19 operates with self-generated power and commercial power, exchanges heat with the hot water, and boils the hot water. The heat pump unit 19 has a compressor 20, a water-cooled refrigerant heat exchanger 21, an expansion valve 22, an air heat exchanger 23, a refrigerant pipe 26, and a blower 24.

[0022] The compressor 20 compresses and conveys the refrigerant to high temperature and high pressure. The water-cooled refrigerant heat exchanger 21 performs heat exchange between the high-temperature and high-pressure refrigerant and the water from the hot water storage tank 10. The expansion valve 22 decompresses and expands the refrigerant heat-exchanged in the water-cooled refrigerant heat exchanger 21. The air heat exchanger 23 performs heat exchange between the outside air and the low-pressure refrigerant to evaporate the low-pressure refrigerant. The refrigerant pipe 26 circulates the refrigerant through the compressor 20, the water-cooled refrigerant heat exchanger 21, the expansion valve 22, and the air heat exchanger 23. The blower 24 blows the outside air to the air heat exchanger 23.

[0023] Also, the heat pump unit 19 has a discharge temperature sensor 25 and an outside air temperature sensor 30. The discharge temperature sensor 25 detects the temperature of the refrigerant discharged from the compressor 20 and outputs a corresponding detection signal to the control unit 31. The outside air temperature sensor 30 detects the outside air temperature and outputs a corresponding detection signal to the control unit 31.

[0024] The circulation circuit 27 circulates the hot water in the hot water storage tank 10 between the hot water storage tank 10 and the water-cooled refrigerant heat exchanger 21. The circulation circuit 27 has a heating supply pipe 27a, a heating return pipe 27b, a heating circulation pump 28, and a boiling temperature sensor 29.

[0025] The heating supply pipe 27a connects the lower part of the hot water storage tank 10 and the water-side inlet of the water-cooled refrigerant heat exchanger 21. The heating return pipe 27b connects the water-side outlet of the water-cooled refrigerant heat exchanger 21 and the upper part of the hot water storage tank 10. The heating circulation pump 28 is arranged on the heating supply pipe 27a to circulate the hot water. The boiling temperature sensor 29 is arranged on the heating return pipe 27b and outputs a detection signal to the control unit 31.

[0026] The remote controller 32 has an input unit 33 and a display unit 34. The input unit 33 receives instructions from the user regarding the hot water supply device 1, such as the set temperature of the hot water supplied to the hot water supply terminal. The display unit 34 displays the necessary information to be presented to the user.

[0027] The control unit 31 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), etc., and stores various programs and data necessary for the control of the control unit 31. The control unit 31 controls the operation of the entire water heating device 1 according to various programs. The control unit 31 is connected to the remote control 32 and communicates with the remote control 32 bidirectionally.

[0028] In particular, the control unit 31 has functions for executing a daytime boiling-up determination process and a daytime boiling-up instruction reception process (both described later). Here, FIG. 2 is a functional block diagram of the control unit 31, the remote control 32, and the server 6. In FIG. 2, only the functions necessary for the daytime boiling-up determination process and the daytime boiling-up instruction reception process are illustrated, and the illustration of other functions is omitted. The control unit 31 includes a storage unit 50, a weather prediction information acquisition unit 41, an execution determination unit 42, a mode acquisition unit 43, an instruction reception unit 44, and a boiling-up execution unit 45.

[0029] The storage unit 50 stores the information acquired from the user terminal 9 for the daytime boiling-up determination process, including selection mode information 51, system capacity information 52, boiling-up time zone information 53, in-house power consumption information 54, and region information 55, which will be described later.

[0030] The weather prediction information acquisition unit 41 acquires weather prediction information 61 for a predetermined time zone from the server 6 at a primary determination time and a secondary determination time that comes after the primary determination time. The weather prediction information 61 is the weather defined for each cloud amount, and for example, there are three types: sunny, cloudy, and rainy. Sunny is the weather with the least cloud amount and the highest power generation efficiency of the solar power generation system 3. Cloudy is the weather with more cloud amount than sunny and a lower power generation efficiency of the solar power generation system 3 than sunny. Rainy is the weather in which the solar power generation system 3 does not generate power, or even if it generates power, its power generation efficiency is lower than that of sunny and lower than that of cloudy.

[0031] The specified time period is a time period included in the daytime when the solar power generation system 3 can generate electricity (hereinafter referred to as the "power generation time period"), for example, from 9:00 to 15:00. The weather forecast information acquisition unit 41 acquires weather forecast information 61 for each specified time (for example, every hour) in the power generation time period from the server 6.

[0032] The execution determination unit 42 determines whether to execute boiling using self-generated power at any time during the power generation time period based on the predicted power generation amount of the self-generated power. The predicted power generation amount is calculated based on the weather forecast information 61 acquired by the weather forecast information acquisition unit 41 (described later). Boiling using self-generated power is an operation of operating the heat pump unit 19 with self-generated power at any time during the power generation time period to boil the hot water circulating in the circulation circuit 27. The execution determination unit 42 refers to the selection mode information 51 stored in the storage unit 50 and makes a determination in the selected determination mode.

[0033] The mode acquisition unit 43 acquires information regarding the determination mode selected by the user from the user terminal 9. The mode acquisition unit 43 stores the acquired determination mode in the storage unit 50 as the selection mode information 51. The determination mode is a mode related to the determination of the execution determination unit 42 and is provided for the user to select. The determination mode consists of a standard mode and an aggressive mode.

[0034] The standard mode is a mode in which the execution determination unit 42 is determined to execute boiling using self-generated power during the daytime only when the certainty of obtaining the self-generated power required for boiling is high (for example, when the weather forecast information 61 is sunny). The aggressive mode is a mode in which the execution determination unit 42 is determined to execute daytime boiling even when the certainty of obtaining the self-generated power required for boiling is lower than that assumed in the standard mode (for example, when the weather forecast information 61 is cloudy).

[0035] That is, in the active mode, it is easier for the execution determination unit 42 to determine to execute daytime boiling using the self-generated power than in the standard mode. For example, if the standard mode determines to execute daytime boiling using the self-generated power only when it is sunny, the active mode determines to execute daytime boiling using the self-generated power when it is sunny or cloudy. "Cloudy" has a range of cloud cover, and even for the same "cloudy", it includes cases where the required amount of power can be generated and cases where it cannot. Therefore, when the active mode is selected, even if it is determined to execute daytime boiling using the self-generated power, the certainty of obtaining the generated power is lower than in the standard mode. That is, in a cloudy day with a lot of cloud cover, there is a risk that sufficient self-generated power cannot be secured, and daytime boiling must be performed using commercial power during the day with a relatively high electricity rate per unit in order to boil the required amount of hot and cold water.

[0036] The instruction reception unit 44 performs required displays on the display unit 34 and the user terminal 9, and receives instructions input from the input unit 33 and the user terminal 9 in the daytime boiling instruction reception process described later.

[0037] The boiling execution unit 45 executes boiling of hot and cold water using commercial power or self-generated power at the required timing.

[0038] Next, the details of the daytime boiling determination process executed by the control unit 31 of the water heater 1 in the present embodiment will be described. First, as a premise of the daytime boiling determination process, the problems of the water heater 1 will be described.

[0039] The water heater 1 boils hot and cold water using commercial power or self-generated power. The commercial power is set to have a higher electricity rate per unit during the day (predetermined time zone) than at night (time zone other than the predetermined time zone). Therefore, when the water heater 1 uses commercial power, from the perspective of reducing the user's electricity bill burden, it is preferable to boil hot and cold water at night (night boiling operation) rather than boiling hot and cold water during the day (daytime boiling operation).

[0040] At the same time, when a solar power generation system 3 is installed in a house together with the water heater 1, it is preferable to boil hot water with self-generated power instead of commercial power. Here, the power generation efficiency of the solar power generation system 3 varies according to the sunshine duration and solar radiation amount. Therefore, in order for the water heater 1 to boil hot water with self-generated power, it is necessary for the solar power generation system 3 to obtain the amount of electric power required to boil the amount of hot water needed by the user during the daytime.

[0041] For example, when the HEMS centrally manages the energy used in the house, the water heater 1 can obtain the actual power generation amount of the solar power generation system 3 and the predicted value of the power consumption amount in the house. Therefore, it is possible to judge whether boiling with self-generated power is possible according to the power generation amount. However, in houses where the HEMS is not installed, there is a current situation that it is difficult.

[0042] That is, when it is determined by the water heater 1 that the self-generated power required for daytime boiling can be obtained based on the weather prediction information 61, by reducing the amount of night boiling, the amount of commercial power used can be reduced and the amount of self-generated power used can be increased.

[0043] When the HEMS can grasp the actual power generation amount and the actual power consumption amount consumed by electrical load devices other than the water heater 1, the actual power generation amount and the actual power consumption amount can be used for predicting the surplus power amount available for boiling with self-generated power during the daytime. However, in houses where the HEMS is not installed, since the actual power generation amount cannot be used, the prediction accuracy of the surplus power amount becomes relatively low. Therefore, even when it is decided to execute daytime boiling the next day, there is a possibility that the amount of electric power cannot be actually obtained and boiling will be performed with daytime commercial power with a high electricity rate.

[0044] In order to reliably obtain the excess power generation amount of the solar power generation system 3 used for boiling water in the water supply device 1, it is determined to execute daytime boiling only when clear weather prediction information 61 with high power generation efficiency is obtained. When it is cloudy or rainy, it is preferable to execute boiling of the total amount of hot water required by night boiling and not to perform daytime boiling.

[0045] However, when the system capacity of the solar power generation system 3 is large, since a certain amount of power generation can be expected even on cloudy days, there may be users who wish to actively perform daytime boiling. Therefore, the water supply device 1 executes daytime boiling determination processing in order to execute daytime boiling while reflecting the wishes of each user using the self-generated power.

[0046] FIG. 3 is a flowchart for explaining the daytime boiling determination processing executed by the control unit 31.

[0047] FIG. 4 is a conceptual diagram of the processing executed in the water supply device 1 when it is determined that daytime boiling is impossible in the daytime boiling determination processing.

[0048] FIG. 5 is a conceptual diagram of the processing executed in the water supply device 1 when it is determined that daytime boiling is possible in the daytime boiling determination processing.

[0049] This daytime boiling determination processing is repeatedly executed, for example, while the water supply device 1 is activated.

[0050] In step S1, the weather prediction information acquisition unit 41 determines whether the primary determination time has arrived. The primary determination time is a preset time for acquiring the weather prediction information 61 of the power generation time zone of the next day from the server 6. The primary determination time is, for example, the timing at which, when it is determined in step S4 described later that the total amount of hot water that needs to be boiled can be boiled by night boiling, night boiling can be completed thereafter. Also, from the viewpoint of the accuracy of the weather forecast, the primary determination time is preferably a time (for example, 23:00) as close as possible to the power generation time zone.

[0051] When the weather forecast information acquisition unit 41 determines that the primary determination time has not yet arrived (NO in step S1), it waits until the primary determination time arrives. On the other hand, when the weather forecast information acquisition unit 41 determines that the primary determination time has arrived (YES in step S1), in step S2, it acquires the weather forecast information 61 from the server 6. Here, FIG. 6 is an explanatory diagram conceptually showing the information necessary for executing the daytime boiling-up determination process when the standard mode is selected. FIG. 7 is an explanatory diagram conceptually showing the information necessary for executing the daytime boiling-up determination process when the aggressive mode is selected. In FIG. 6, the weather forecast information 61 acquired at the primary determination time and the weather forecast information 61 acquired at the secondary determination time are shown. In FIG. 7, the weather forecast information 61 acquired at the primary determination time is shown.

[0052] The weather forecast information acquisition unit 41 acquires the corresponding regional weather forecast information 61 from the server 6 based on the regional information 55 regarding the region where the water heater 1 is installed. Here, FIG. 8 is a diagram showing an example of a display screen when receiving information necessary for performing the daytime boiling-up determination process from the user on the user terminal 9.

[0053] The user terminal 9 can be used, for example, by downloading and installing an application program (app) specifically created and provided by the water heater 1 from a predetermined server. The user terminal 9 transmits instructions for operating the water heater 1 to the water heater 1 via this app, or receives and views the current usage status and past usage history of the water heater 1. The control unit 31 provides the necessary information required for these processes to the user terminal 9, or executes the instructions acquired from the user terminal 9 on the water heater 1. In the present embodiment, as an initial setting for executing the daytime boiling-up determination process, the control unit 31 receives the necessary information from the user terminal 9 on the display screen 9a of FIG. 8.

[0054] The regional information 55 is acquired by the control unit 31 by receiving information regarding prefectures and municipalities from the user terminal 9 via the application. The storage unit 50 stores the acquired regional information 55.

[0055] The server 6 preliminarily holds meteorological prediction information 61 at a plurality of locations across the country provided by, for example, a vendor that provides meteorological information. Alternatively, when the hot water supply device 1 requests the meteorological prediction information 61, the server 6 acquires the meteorological prediction information 61 from a predetermined data server. The meteorological prediction information acquisition unit 41 requests and acquires the corresponding meteorological prediction information 61 from the server 6 based on the regional information 55. The meteorological prediction information acquisition unit 41 acquires the meteorological prediction information 61 every hour during the power generation time period from 9:00 to 15:00, as shown in FIGS. 6 and 7, for example. In FIGS. 6 and 7, the meteorological prediction information 61 at the time "9:00" indicates the meteorological prediction information for one hour from 9:00 to 10:00.

[0056] In step S3, the execution determination unit 42 determines whether to execute daytime boiling using self-generated power to operate the heat pump unit 19 to boil hot and cold water during the power generation time period. That is, the execution determination unit 42 determines whether the predicted power generation amount (primary predicted power generation amount) of the self-generated power calculated based on the meteorological prediction information 61 acquired at the primary determination time is equal to or greater than the required power generation amount, thereby determining whether to execute boiling using self-generated power instead of commercial power during the power generation time period.

[0057] Specifically, the execution determination unit 42 calculates the predicted power generation amount based on the content of the obtained meteorological prediction information 61, that is, the power generation rates assigned to sunny, cloudy, and rainy weather respectively. Further, the execution determination unit 42 compares the surplus power amount obtained by subtracting the power consumption amount (hereinafter simply referred to as "indoor power consumption amount") consumed by the air conditioner etc. 7 from the predicted power generation amount with the power consumption amount consumed when the heat pump unit 19 boils hot and cold water. The execution determination unit 42 compares with the amount consumed by the heat pump unit 19 (hereinafter simply referred to as heat pump power consumption amount), and when the surplus power amount is greater than the heat pump power consumption amount, determines to execute boiling using self-generated power.

[0058] As described above, the determination mode is set by the user when the mode acquisition unit 43 receives a selection via the user terminal 9. On the display screen 9a of the user terminal 9 in FIG. 8, the setting of the determination mode is accepted by the selection of the "Aggressive" button or the "Standard" button. The mode acquisition unit 43 stores the information regarding the determination mode received from the user as selection mode information 51.

[0059] When the standard mode is selected, the execution determination unit 42 sets the power generation rate to 0.6 if the weather forecast information 61 is sunny. Also, when it is cloudy or rainy, the power generation rate is set to 0. When the aggressive mode is selected, the power generation rate is set to 0.6 if the weather forecast information 61 is sunny. Also, when it is cloudy, the power generation rate is set to 0.4. Also, when it is rainy, the power generation rate is set to 0.

[0060] The power generation rate is set so that when the aggressive mode is selected, the power generation rate is higher when it is cloudy than when the standard mode is selected. That is, the execution determination unit 42 makes the method for calculating the predicted power generation amount different between when the standard mode is selected and when the aggressive mode is selected. Thereby, when the aggressive mode is selected by the user, it becomes easier to determine that boiling is executed by the self-generated power than when the standard mode is selected.

[0061] The predicted power generation amount uses a value obtained by multiplying the system capacity of the solar power generation system 3 by the power generation rate assigned to the obtained weather forecast information 61. The system capacity is the power generation amount per unit time (per hour) of the solar power generation system 3 and represents the power generation ability, and is a value unique to the solar power generation system 3. As shown in FIG. 8, the control unit 31 receives the system capacity from the user terminal 9 on the display screen 9a of the application and stores it in the storage unit 50 as system capacity information 52.

[0062] When the execution determination unit 42 obtains weather prediction information 61 as shown in FIG. 6, for example, in a state where the standard mode is selected, it calculates the predicted power generation amount per hour by multiplying the system capacity by the power generation rate respectively.

[0063] The power consumption amount in the house is, for example, the average value of the power consumption amount in the house per unit time (per hour), and is a value set by the user. The control unit 31 stores the power consumption amount in the house received from the user terminal 9 via the display screen 9a in the storage unit 50 as the in-house power consumption information 54.

[0064] The execution determination unit 42 calculates the surplus power amount by subtracting the in-house power consumption amount from the predicted power generation amount. That is, the surplus power amount is defined as system capacity × power generation rate - in-house power consumption amount.

[0065] The power consumption amount of the heat pump is a value obtained by multiplying the power consumption amount that the heat pump unit 19 consumes when boiling up by a coefficient with a slight addition, which is set in advance and held by the control unit 31. The power consumption amount of the heat pump is a value that can vary depending on seasons, days of the week, etc. For example, the power consumption amount of the heat pump is set to a value obtained by multiplying 1 kW by a coefficient of 1.2 during normal times. Also, in winter when the usage frequency of the heat pump unit 19 is high, it is set to a value obtained by multiplying 1.5 kW by a coefficient of 1.2.

[0066] In step S4, the execution determination unit 42 determines whether it is possible to boil water during the day with the surplus power amount of the self-generated power by determining whether the calculated surplus power amount is greater than the power consumption amount of the heat pump. The execution determination unit 42 determines that it is possible to boil water during the day when the surplus power amount is continuously greater than the power consumption amount of the heat pump for the time required for boiling (for example, 3 hours). For example, in the examples of FIGS. 6 and 7, in any determination mode, the surplus power amount is continuously greater than the power consumption amount of the heat pump for 3 hours and the operation determination is ○, so the execution determination unit 42 determines that it is possible to boil water during the day.

[0067] When the execution determination unit 42 determines that daytime boiling is impossible (NO in step S4), in step S5, it executes night boiling to boil the entire amount of hot water that needs to be boiled (see FIG. 4). That is, since the required sunshine duration and solar radiation amount cannot be obtained during the daytime of the next day and daytime boiling cannot be performed, or since the surplus power amount is equal to or less than the power consumption amount of the heat pump, the entire amount of hot water is boiled with commercial power at night when the electricity rate unit price is low. After that, the control unit 31 returns to step S1 and repeats the subsequent processing.

[0068] On the other hand, when the execution determination unit 42 determines that daytime boiling is possible (YES in step S4), in step S6, it determines the start time of daytime boiling. The execution determination unit 42 sets the earliest time zone among the time zones that can be continuously obtained for the time required for boiling as the start time of daytime boiling. This is because it can be said that the meteorological prediction information 61 at a time close to the timing when the meteorological prediction information 61 is acquired has a high accuracy. For example, in the examples of FIGS. 5 to 7, the earliest 9 o'clock among the time zones where daytime boiling can be continuously executed for 3 hours is determined as the start time.

[0069] Also, the execution determination unit 42 may accept from the user the setting of the time zone for executing daytime boiling. On the display screen 9a of the user terminal 9 in FIG. 8, the setting of the time zone is accepted by selecting the "earlier", "standard", or "later" button. The control unit 31 stores the information regarding the boiling time zone received from the user terminal 9 in the storage unit 50 as the boiling time zone information 53. The peak of the power generation of the solar power generation system 3 varies for each user according to the installation angle of the solar power generation panel 4 and the like. For this reason, the water heater 1 allows the user to select the time zone for executing daytime boiling with self-generated power, and executes boiling according to the environment of each user.

[0070] In step S7, the boiling-up execution unit 45 executes night boiling-up using commercial power for a part of the amount of hot water that needs to be boiled up (see FIG. 5). That is, since it is predicted that the required sunshine duration and solar radiation amount can be obtained during the daytime of the next day, at night when the electricity rate per unit is low, a part of the hot water that needs to be boiled up (for example, 20 to 60% of the total amount) is boiled up using commercial power.

[0071] In step S8, the weather prediction information acquisition unit 41 determines whether the secondary determination time has arrived. The secondary determination time is a preset time (for example, 7 o'clock) at which the weather prediction information 61 for the power generation time zone on the day when daytime boiling-up is to be executed is acquired from the server 6. The secondary determination time is a time before the start time of the daytime boiling-up executed in step S13 described later.

[0072] When the weather prediction information acquisition unit 41 determines that the secondary determination time has not arrived yet (NO in step S8), it waits until the secondary determination time arrives. On the other hand, when the weather prediction information acquisition unit 41 determines that the secondary determination time has arrived (YES in step S8), in step S9, it acquires the weather prediction information 61 from the server 6 in the same manner as in step S2.

[0073] The weather prediction information acquisition unit 41 acquires the weather prediction information 61 every hour for the power generation time zone from 9 o'clock to 15 o'clock, for example, as shown in FIG. 6.

[0074] In step S10, the execution determination unit 42 determines whether there is a change in the weather prediction information 61 acquired at the primary determination time with respect to the weather prediction information 61 acquired at the secondary determination time. When the execution determination unit 42 determines that there is a change (YES in step S10), in step S11, it determines the start time of the daytime boiling-up based on the changed weather prediction information 61 acquired at the secondary determination time. The execution determination unit 42 sets the earliest time zone among the time zones when the time required for boiling-up can be continuously obtained as the start time of the daytime boiling-up. Also, the execution determination unit 42 may determine the start time so that the daytime boiling-up is executed in the time zone where the total surplus power amount for three consecutive hours is the largest.

[0075] For example, in the example of FIG. 6, since the weather forecast information 61 from 10:00 to 11:00 changed from sunny to cloudy, the surplus power amount became smaller than the heat pump power consumption amount, and the operation determination was changed to ×. Therefore, the execution determination unit 42 determines that it is impossible to perform daytime heating starting at 9:00. The execution determination unit 42 determines 11:00, which is a time when daytime heating can be continuously executed for 3 hours, as the start time. In step S11, when the surplus power amount is smaller than the heat pump power consumption amount and there is no time when the time required for heating can be continuously obtained, the control unit 31 proceeds to the daytime heating instruction reception process of FIG. 9, which will be described later.

[0076] When it is determined that there is no change in the weather forecast information 61 (NO in step S10), and after step S11, in step S12, the control unit 31 determines whether the start time determined in the start time determination step S6 or S11 has arrived. When the control unit 31 determines that the start time has not yet arrived (NO in step S12), it waits until the start time arrives. On the other hand, when it is determined that the start time has arrived (YES in step S12), in step S13, the heating execution unit 45 heats the remaining amount of hot and cold water that needs to be heated with the power generated by the solar power generation system (see FIG. 5). After that, the control unit 31 returns to step S1 and repeats the subsequent processing.

[0077] In the daytime heating determination process as described above, by acquiring the required information obtained from the user and the weather forecast information 61, the cooperation between the solar power generation system 3 and the water heater 1 can be easily realized. Therefore, the water heater 1 can use the power generated by the solar power generation system 3 for heating while reflecting the wishes of each user.

[0078] Here, even though it is determined that daytime boiling is possible based on the weather prediction information 61 obtained at the primary determination time (YES in step S4), the weather prediction information 61 obtained at the secondary determination time may change (YES in step S10), and there may be a case where it is difficult to perform daytime boiling with the power generated by the home power generation. For example, even though the weather prediction information 61 obtained at the primary determination time is sunny, the weather prediction information 61 obtained at the secondary determination time may turn to rain. In this case, the primary predicted power generation amount of the home power generation calculated at the primary determination time is larger than the required power generation amount (excess power amount > heat pump power consumption), but there may also be a case where the secondary predicted power generation amount of the home power generation calculated at the secondary determination time is less than the required power generation amount. In this case, since the remaining amount of hot water that needs to be boiled and assigned to daytime boiling cannot be boiled by the home power generation, there is a risk of insufficient hot water storage. Therefore, by performing daytime boiling with commercial power, the remaining amount of hot water required can be obtained. However, as described above, since the electricity price per unit is high during the day, the economic burden on the user becomes larger compared to at night. That is, there is a risk that the user has to perform daytime boiling using commercial power with a relatively high electricity price per unit.

[0079] Therefore, when it is determined at the primary determination time that daytime boiling is to be executed with the power generated by the home power generation, if the secondary predicted power generation amount calculated at the secondary determination time is less than the required power generation amount, the hot water supply device 1 in the present embodiment is configured to determine whether to execute daytime boiling by reflecting the user's judgment.

[0080] FIG. 9 is a flowchart for explaining the daytime boiling instruction reception process executed by the control unit 31.

[0081] The daytime boiling start instruction reception process may be started when the secondary predicted power generation amount is calculated based on the weather prediction information 61 obtained at the secondary determination time and is less than the required power generation amount, or simply when the weather prediction information 61 at the secondary determination time changes to a content where the power generation efficiency is lower than that of the weather prediction information 61 at the primary determination time. For example, the daytime boiling start instruction reception process may be started when the time during which the surplus power generation amount is equal to or greater than the heat pump power consumption amount in step S11 of FIG. 3 cannot be continuously obtained for the time required for boiling (for example, 3 hours), or when it was sunny or cloudy at the primary determination time but changes to cloudy or rainy at the secondary determination time.

[0082] In step S21, the instruction reception unit 44 of the control unit 31 displays an instruction reception screen for receiving an instruction to execute or cancel boiling during the power generation time zone on the display unit 34 of the remote controller 32. Alternatively, the instruction reception unit 44 displays it on the user terminal 9 via an application. The instruction reception screen is composed of information for allowing selection, for example, of whether to execute or cancel daytime boiling. At this time, when the instruction reception unit 44 executes daytime boiling, it notifies the user that the power generation amount is insufficient for self-power generation and there is a possibility of executing daytime boiling using commercial power, and accordingly, the electricity bill will increase. The instruction reception unit 44 gives a notice to the user, for example, "The weather forecast has changed. Operating the boiler during the day may increase the electricity bill. Do you want to continue the boiler operation?" The remote controller 32 and the user terminal 9 output the instruction received via the input unit 33 or the like to the control unit 31.

[0083] In step S22, the instruction reception unit 44 determines whether it has received an instruction to cancel the daytime boiling. If it is determined that the instruction reception unit 44 has received an instruction to cancel (YES in step S22), in step S23, the control unit 31 displays, on the display unit 34 or the user terminal 9, that the scheduled boiling will not be performed and the stored hot water volume will decrease due to the cancellation of the daytime boiling. Further, the control unit 31 displays that the stored hot water volume is decreasing, issues a reminder to promote water conservation, and prompts the user to manually increase the stored hot water volume (add to the stored hot water volume). The control unit 31 notifies the user, for example, with a message such as "The stored hot water volume is less than usual. Please add hot water when the stored hot water volume is insufficient."

[0084] In step S24, based on the user's instruction, the boiling execution unit 45 cancels the scheduled daytime boiling.

[0085] On the other hand, if it is determined that the instruction reception unit 44 has not received an instruction to cancel (NO in step S22), in step S25, the boiling execution unit 45 performs the daytime boiling as scheduled. The case where the instruction reception unit 44 has not received an instruction to cancel includes the case where it has received an instruction to execute and the case where the user has not noticed the notification and thus has not received any instruction to execute or cancel. That is, when no user instruction is obtained and the user's preference cannot be grasped, the instruction received on the setting screen of FIG. 8 described above is prioritized and the daytime boiling is executed. The boiling execution unit 45 executes the boiling using the self-generated power. If the required self-generated power cannot be obtained, the boiling is executed using commercial power. Alternatively, when the weather is rainy or the like, the boiling execution unit 45 may not perform the boiling using the self-generated power and only execute the boiling using commercial power.

[0086] After steps S24 and S25, the process ends.

[0087] By executing such a daytime heating instruction reception process, the water heater 1 in this embodiment enables the control unit 31 to automatically determine whether or not to execute daytime heating based on the weather prediction information 61. At the same time, when there is a possibility that commercial power is used for daytime heating, the user can be made to determine whether or not to execute daytime heating even using commercial power. That is, when, despite the user desiring daytime heating expecting heating by self-generated power, there is a possibility that daytime heating using commercial power, which is relatively more economically burdensome, is executed against the user's will, the presence or absence of execution can be determined by the user's judgment. For this reason, the water heater 1 can execute heating by self-generated power and heating by commercial power while reflecting the user's wishes.

[0088] Also, when receiving an instruction to execute or cancel daytime heating, the water heater 1 notifies the user that the electricity cost may increase, so that the user can appropriately determine whether to execute or cancel according to the situation. Further, when receiving an instruction to cancel daytime heating, the water heater 1 notifies the user that the stored hot water amount is decreasing, so that the user can be made aware of that fact, and the user can be prompted to execute hot water replenishment or water conservation as appropriate.

[0089] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and its equivalent scope.

[0090] For example, in the boiling determination step S3 of the daytime heating determination process, an example was described in which the determination conditions are made different between the standard mode and the aggressive mode, but it is not necessary to have a plurality of modes, and determination may be made under certain conditions.

[0091] Also, an example of executing the daytime boiling-up determination process of FIG. 3 and the daytime boiling-up instruction reception process of FIG. 9 was described using an example where the water heater 1 is not connected to the HEMS. However, the same processes can be executed even when the water heater 1 is connected to the HEMS.

[0092] The server 6 acquired and stored the information necessary for the daytime boiling-up determination process from the user, but the control unit 31 may directly acquire it from the user.

Explanation of Signs

[0093] 1 Storage-type water heater (water heater) 3 Photovoltaic power generation system 6 Server 7 Air conditioner, etc. 8 Network 9 User terminal 10 Hot water storage tank 19 Heat pump unit 27 Circulation circuit 31 Control unit 32 Remote control 33 Input unit 34 Display unit 41 Weather prediction information acquisition unit 42 Execution determination unit 43 Mode acquisition unit 44 Instruction reception unit 45 Boiling-up execution unit 50 Storage unit 51 Selection mode information 52 System capacity information 53 Boiling-up time zone information 54 Indoor power consumption information 55 Region information 61 Weather prediction information 100 Hot water supply system

Claims

1. A hot water storage tank for storing hot water, A heat pump unit that operates with self-generated power generated by a solar power generation system and commercial power supplied from a commercial power source, and boils the hot water, A weather prediction information acquisition unit that acquires weather prediction information for a predetermined time period at a primary determination time and a secondary determination time that comes after the primary determination time, By determining whether the predicted power generation amount of the self-generated power calculated based on the weather prediction information acquired by the weather prediction information acquisition unit is equal to or greater than the required power generation amount, it is determined whether to execute boiling with the self-generated power to boil the hot water with the heat pump unit during the predetermined time period. An execution determination unit, An instruction reception unit that displays an instruction reception screen for receiving an instruction to execute or cancel boiling in the predetermined time period on a display means of an external terminal, and receives the execution or cancellation instruction input by a user via an input means of the external terminal, Comprising, When the execution determination unit determines to execute the boiling based on the weather prediction information acquired at the primary determination time, the secondary predicted power generation amount of the self-generated power calculated based on the weather prediction information acquired at the secondary determination time is determined whether it is equal to or greater than the required power generation amount, When the instruction reception unit determines that the secondary predicted power generation amount is less than the required power generation amount by the execution determination unit, the instruction reception screen is displayed on the display means, and the execution or cancellation instruction is received A hot water supply device with a hot water storage type, characterized in that.

2. When the instruction reception unit receives an instruction to execute, or when it does not receive any instruction to execute or cancel, boiling with the self-generated power is executed in the predetermined time period, and when the required self-generated power cannot be obtained, boiling with the commercial power is executed. The hot water supply device with a hot water storage type according to claim 1, further comprising a boiling execution unit.

3. The hot water supply device with a hot water storage type according to claim 1 or 2, wherein the predetermined time period is a time period when the unit price of the commercial power is higher than that in a time period other than the predetermined time period.

4. The hot water supply device with a hot water storage type according to claim 3, wherein the instruction reception unit notifies that the power charge of the commercial power will increase when boiling in the predetermined time period, and receives the execution or cancellation instruction.

5. When the instruction receiving unit receives the stop instruction, the hot water storage type water supply device according to any one of claims 1 to 4 gives a notice indicating that the amount of stored hot water in the hot water storage tank is decreasing or gives a notice prompting the replenishment of the stored hot water amount.

6. The instruction receiving unit receives an instruction to execute or stop the boiling in the predetermined time period when the weather prediction information acquired at the first determination time is sunny or cloudy and the weather prediction information acquired at the second determination time is rainy. The hot water storage type water supply device according to any one of claims 1 to 5.

Images