Hot water supply device

Abstract

To provide a water heater capable of improving boiling-up efficiency when performing a boiling-up operation in a daytime zone and a night time zone.SOLUTION: A water heater includes, as stored hot water temperature detecting means 18a detecting temperatures of hot water in the hot water storing tank 10: a first stored hot water temperature detecting means 18ad detecting a lower part hot water temperature in a hot water storing tank 10; and a second stored hot water temperature detecting means 18au detecting an upper part hot water temperature at a position higher than the first stored hot water detecting means 18ad. A control device 30 detects the lower part hot water temperature by the first stored hot water temperature detecting means 18ad in a daytime zone mode 31A, and meanwhile, detects the upper part hot water temperature by the second stored hot water temperature detecting means 18au in a night time zone mode 31B, and finishes a boiling-up operation in the daytime zone mode 31A in a state where the lower part hot water temperature detected by the first stored hot water temperature detecting means 18ad is higher than the upper part hot water temperature detected by the second store hot water temperature detecting means 18au, at the time when the boiling-up operation finishes in the night time zone mode 31B.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a water supply device having a boiling operation mode. [Background Art]

[0002] Patent Document 1 proposes to prevent a decrease in heating efficiency by controlling the daytime heating operation stop temperature to be lower than the nighttime heating operation stop temperature. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent No. 3867547 [Summary of the Invention] [Problems to be Solved by the Invention]

[0004] Recently, a water supply device has been proposed that actively uses the power generated by home power generation during the daytime in cooperation with a solar power generation system to boil the hot water in a hot water storage tank. In such a water supply device, the boiling time during the daytime is longer compared to a conventional water supply device (where boiling at night is the main operation). In such a water supply device that mainly boils water during the daytime, with the control method described in Patent Document 1, the boiling time during the daytime becomes shorter, and the original purpose of actively utilizing daytime power is hindered. Also, the boiling efficiency may conversely decrease. This is because the boiling time during the high-heating-efficiency daytime is shortened, and the heat dissipation loss from the time of boiling until the user uses it increases.

[0005] Therefore, an object of the present invention is to provide a water supply device that can improve the boiling efficiency when performing the boiling operation in the daytime and nighttime time zones. [Means for Solving the Problems]

[0006] The water heating device of the present invention according to claim 1 includes a hot water storage tank 10, a heating device 20 for heating the hot water in the hot water storage tank 10, and a control device 30. The control device 30 has a boiling operation mode 31 in which the heating device 20 heats the hot water in the hot water storage tank 10. The boiling operation mode 31 includes a daytime mode 31A for performing the boiling operation during the daytime time period and a nighttime mode 31B for performing the boiling operation during the nighttime time period. The water heating device is configured such that the amount of hot water boiled during the daytime mode 31A is 50% or more of the total amount of hot water boiled in a day. As the hot water storage temperature detection means 18a for detecting the temperature of the warm water in the hot water storage tank 10, it has a first hot water storage temperature detection means 18ad for detecting the lower hot water temperature of the hot water storage tank 10 and a second hot water storage temperature detection means 18au for detecting the upper hot water temperature at a position higher than the first hot water storage temperature detection means 18ad. The control device 30 detects the lower hot water temperature by the first hot water storage temperature detection means 18ad in the daytime mode 31A, detects the upper hot water temperature by the second hot water storage temperature detection means 18au in the nighttime mode 31B, and ends the boiling operation in the daytime mode 31A in a state where the lower hot water temperature detected by the first hot water storage temperature detection means 18ad is higher than the upper hot water temperature detected by the second hot water storage temperature detection means 18au at the end of the boiling operation in the nighttime mode 31B. The water heating device of the present invention according to claim 2 is the water heating device according to claim 1, characterized in that when the lower hot water temperature detected by the first hot water storage temperature detection means 18ad reaches the daytime boiling end temperature, the boiling operation in the daytime mode 31A is ended. The water heating device of the present invention according to claim 3 is the water heating device according to claim 1 or claim 2, characterized in that when the upper hot water temperature detected by the second hot water storage temperature detection means 18au reaches the nighttime boiling end temperature, the boiling operation in the nighttime mode 31B is ended. The water heating device of the present invention according to claim 4 is the water heating device according to any one of claims 1 to 3, and is provided with an operating means 40 by which a user can set at least one of a daytime operation start time, a daytime operation end time, or a daytime operation execution time at which the daytime time zone mode 31A is executed. The operating means 40 is characterized in that it is not possible to set a daytime set operation time to be less than a preset minimum operation time. The water heating device of the present invention according to claim 5 is the water heating device according to any one of claims 1 to 4, and is characterized in that electric power obtained by a photovoltaic power generation device 50 is used in the daytime time zone mode.

Advantages of the Invention

[0007] According to the present invention, by making the lower hot water temperature of the hot water storage tank at the end of the boiling operation in the daytime time zone mode higher than the upper hot water temperature of the hot water storage tank at the end of the boiling operation in the nighttime time zone mode, it is possible to boil more hot water in the daytime time zone, where the outside air temperature is high and the time until the main hot water usage time zone is short, than in the nighttime time zone. By boiling more hot water in the daytime time zone, where the outside air temperature is higher than in the nighttime time zone, the heating efficiency is good, and since the time until evening, which is the main usage time zone, is short, the heat dissipation loss is small, so efficient boiling can be performed.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Modes for Carrying Out the Invention

[0009] The water heater according to the first embodiment of the present invention has, as a hot water storage temperature detection means for detecting the temperature of the hot water in the hot water storage tank, a first hot water storage temperature detection means for detecting the lower hot water temperature of the hot water storage tank and a second hot water storage temperature detection means for detecting the upper hot water temperature at a position higher than the first hot water storage temperature detection means. The control device detects the lower hot water temperature by the first hot water storage temperature detection means in the daytime mode, detects the upper hot water temperature by the second hot water storage temperature detection means in the nighttime mode, and ends the heating operation in the daytime mode when the lower hot water temperature detected by the first hot water storage temperature detection means is higher than the upper hot water temperature detected by the second hot water storage temperature detection means at the end of the heating operation in the nighttime mode. According to the present embodiment, by making the lower hot water temperature of the hot water storage tank at the end of the heating operation in the daytime mode higher than the upper hot water temperature of the hot water storage tank at the end of the heating operation in the nighttime mode, it is possible to boil more hot water in the daytime when the outside air temperature is high and the time until the main hot water usage time zone is short than in the nighttime mode. By boiling more hot water in the daytime when the outside air temperature is higher than in the nighttime mode, the heating efficiency is good, and since the time until evening, which is the main usage time zone, is short, the heat dissipation loss is small, and efficient boiling can be performed.

[0010] The second embodiment of the present invention is the water heater according to the first embodiment, and when the lower hot water temperature detected by the first hot water storage temperature detection means reaches the daytime heating end temperature, the heating operation in the daytime mode is ended. According to the present embodiment, it is possible to end the heating operation in the daytime mode with a higher lower hot water temperature than the upper hot water temperature at the end of the heating operation in the nighttime mode.

[0011] The third embodiment of the present invention is the water heater according to the first or second embodiment, and when the upper hot water temperature detected by the second hot water storage temperature detection means reaches the nighttime heating end temperature, the heating operation in the nighttime mode is ended. According to the present embodiment, it is possible to control the upper hot water temperature of the hot water storage tank at the end of the heating operation in the nighttime mode.

[0012] According to the fourth embodiment of the present invention, in the water supply device according to any one of the first to third embodiments, among the daytime operation start time, the daytime operation end time, or the daytime operation execution time when the daytime time zone mode is executed, at least any one of them is provided with an operation means that can be set by the user, and the operation means cannot set the daytime set operation time to be less than a preset minimum operation time. According to this embodiment, by ensuring a boiling-up time during the daytime that is equal to or longer than the minimum operation time, the operations in the daytime time zone mode and the nighttime time zone mode can be set to an optimal ratio.

[0013] According to the fifth embodiment of the present invention, in the water supply device according to any one of the first to fourth embodiments, the daytime time zone mode uses the electric power obtained by the solar power generation device. According to this embodiment, in the boiling-up during the daytime time zone, the electric power obtained by the solar power generation device can be effectively utilized.

Example

[0014] Hereinafter, an example of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of the water supply device according to this example. The water supply device according to this example includes a hot water storage tank 10, a heating device 20 for heating the hot water in the hot water storage tank 10, a control device 30 for controlling the heating device 20, and an operation means 40 by which a user can set the setting conditions of the control device 30.

[0015] The hot water in the hot water storage tank 10 is led out from the bottom of the hot water storage tank 10, passed through the boiling-up pipe 11 to the heating device 20, boiled up to a high temperature by the heating device 20, and then introduced from the upper part of the hot water storage tank 10 and stored in the hot water storage tank 10. When the hot water faucet 12 is opened, the hot water in the hot water storage tank 10 that has been boiled up to a high temperature is mixed with the water supply from the water supply pipe 14 by the mixing valve 13 to a predetermined temperature and supplied as hot water from the hot water faucet 12. The hot water that is insufficient in the hot water storage tank 10 when hot water is supplied from the hot water faucet 12 is supplied from the water supply pipe 14 connected to the bottom of the hot water storage tank 10, and the hot water storage tank 10 is always filled with hot water. The boiling-up pipe 11 leading from the hot water storage tank 10 to the heating device 20 has a circulation pump 16. When the circulation pump 16 operates, the hot water in the hot water storage tank 10 is passed through the heating device 20 and stored in the hot water storage tank 10.

[0016] The hot water supply pipe 15 leading from the hot water storage tank 10 to the hot water tap 12 is provided with a hot water flow rate detection means 17 for detecting the amount of hot water supplied to the hot water tap 12. The hot water storage tank 10 is provided with a hot water storage temperature detection means 18a, the water supply pipe 14 for supplying water to the lower part of the hot water storage tank 10 is provided with a water supply temperature detection means 18b, and the boiling-up pipe 11 leading from the hot water storage tank 10 to the circulation pump 16 is provided with a water supply temperature detection means 18c. The hot water storage temperature detection means 18a has a first hot water storage temperature detection means 18ad for detecting the temperature of the warm water in the hot water storage tank 10, at least detecting the temperature of the lower hot water in the hot water storage tank 10, and a second hot water storage temperature detection means 18au for detecting the temperature of the upper hot water at a position higher than the first hot water storage temperature detection means 18ad. At least any one of the first hot water storage temperature detection means 18ad, the water supply temperature detection means 18b, and the water supply temperature detection means 18c can be used for detecting the water supply temperature.

[0017] A heat pump device composed of a compressor, a radiator, a decompressor, and an evaporator is suitable for the heating device 20. When the heat pump device is used as the heating device 20, the heat dissipation in the radiator is used as a heat source. By using the heat pump device as the heating device 20, electric power can be effectively utilized. Further, the hot water supply device according to the present embodiment preferably receives power supply from the solar power generation device 50, and the power obtained by the solar power generation device 50 can be used in the daytime time zone mode 31A. By cooperating with the solar power generation device 50, in the boiling-up during the daytime time zone, the power obtained by the solar power generation device 50 can be effectively utilized.

[0018] The control device 30 has a boiling operation mode 31. In the boiling operation mode 31, the heating device 20 heats the hot water in the hot water storage tank 10. As the boiling operation mode 31, it has a daytime zone mode 31A that executes the boiling operation during the daytime zone and a nighttime zone mode 31B that executes the boiling operation during the nighttime zone. The control device 30 has a timer means 32. The timer means 32 measures time, and the year, month, day, and time can be determined by the timer means 32. Therefore, the daytime zone and the nighttime zone are determined by the timer means 32. The daytime zone and the nighttime zone may be set in advance or may be changed by an operation on the operation means 40. For example, the daytime zone is set from 9:00 to 16:00, and the nighttime zone is set from 23:00 to 6:00.

[0019] The control device 30 has a used hot water amount storage means 33A, a feed water temperature storage means 33B, and a set condition storage means 33C. The used hot water amount storage means 33A stores the hot water amount detected by the hot water supply flow rate detection means 17 together with the time measured by the timer means 32. The used hot water amount storage means 33A stores the hot water amount for each time zone in a predetermined period such as one day, one week, one month, and one year as a used hot water amount history. The feed water temperature storage means 33B stores the feed water temperature detected by the feed water temperature detection means 18b or the feed water temperature detection means 18c together with the time measured by the timer means 32. The feed water temperature storage means 33B stores the feed water temperature for each time zone in a predetermined period such as one day, one week, one month, and one year. In the control device 30, the circulation pump 16 is operated during the nighttime period when the amount of heat of the hot water in the hot water storage tank 10 is estimated to be minimized, and the detection of the feed water temperature by the feed water temperature detection means 18c is performed after the circulation pump 16 is operated. In this way, by operating the circulation pump 16, the feed water temperature can be detected without being affected by the hot water in the hot water storage tank 10 or the outside air temperature. Further, by operating the circulation pump 16 during the nighttime period when the amount of heat of the hot water in the hot water storage tank 10 is estimated to be minimized, the feed water temperature can be detected without being affected by the hot water in the hot water storage tank 10 or the outside air temperature even if the operation time of the circulation pump 16 is shortened. When hot water is being supplied from the hot water tap 12, the feed water temperature detection means 18b can detect the feed water temperature without being affected by the hot water in the hot water storage tank 10 or the outside air temperature.

[0020] The setting condition storage means 33C stores at least one of the setting conditions among the start time of daytime operation, the end time of daytime operation, or the daytime operation execution time when the daytime period mode 31A is executed. These setting conditions are set by the operation means 40. The operation means 40 restricts the setting conditions so that the setting of the daytime set operation time to be less than the preset minimum operation time cannot be performed. For example, in the control device 30, when the minimum operation time is preset to 4 hours, the user can set the daytime operation execution time to 4 hours or more, but the control device 30 does not accept the user setting it to less than 4 hours. The same applies to the start time of daytime operation and the end time of daytime operation. For example, when the start time of daytime operation is set to 9 o'clock, the control device 30 does not accept setting the end time of daytime operation to 12 o'clock when the daytime operation execution time is less than 4 hours. When the start time of daytime operation is set to 9 o'clock, the user can set the end time of daytime operation to a time after 13 o'clock.

[0021] The minimum operation time is set so that the boiling operation in the daytime period mode 31A ends in a state where the lower hot water temperature detected by the first hot water storage temperature detection means 18ad is higher than the upper hot water temperature detected by the second hot water storage temperature detection means 18au at the end of the boiling operation in the nighttime period mode 31B. In addition, the minimum operation time shall be such that the daytime boiling-up hot water volume boiled up in the daytime time zone mode 31A is 50% or more of the total daily boiling-up hot water volume. By setting the daytime boiling-up hot water volume to 50% or more of the total daily boiling-up hot water volume, it is possible to ensure daytime boiling-up. Compared with nighttime, in the daytime, the outside air temperature is high, heat dissipation is small, so the heat preservation property is high, and since the time until evening, which is the main usage time zone, is short, heat dissipation loss is small, thus efficient boiling-up can be performed. Furthermore, when the heat pump device is used as the heating device 20, in the daytime compared with nighttime, since the outside air temperature is high, boiling-up can be performed efficiently.

[0022] The control device 30 includes a total boiling-up hot water volume calculating means 34A for calculating the total daily boiling-up hot water volume, a set boiling-up hot water volume calculating means 34C for calculating the set boiling-up hot water volume at the daytime set operation time set by the operation means 40, and a boiling-up hot water volume comparing means 34D for comparing the set boiling-up hot water volume with the total daily boiling-up hot water volume. The total boiling-up hot water volume calculating means 34A calculates the total daily boiling-up hot water volume based on the hot water usage history stored in the hot water usage storage means 33A.

[0023] The set boiling-up hot water volume calculating means 34C calculates the set boiling-up hot water volume based on the daytime set operation time stored in the set condition storage means 33C. It is preferable to determine the set boiling-up hot water volume using the feed water temperature stored in the feed water temperature storage means 33B. This is because even if the length of the daytime set operation time is the same, the set boiling-up hot water volume varies depending on the feed water temperature. The feed water temperature here can be the feed water temperature at the detection time point, but for example, the minimum temperature, maximum temperature, or average temperature in the past 7 days may also be used. By using the minimum temperature in the past predetermined period, the occurrence of running out of hot water can be prevented. The outside air temperature can also be used together with the feed water temperature. In addition, the feed water temperature can also be divided into a summer feed water temperature, a winter feed water temperature, and an intermediate season feed water temperature for use.

[0024] In the boiling water volume comparison means 34D, the total boiling water volume for one day calculated by the total boiling water volume calculation means 34A is compared with the set boiling water volume calculated by the set boiling water volume calculation means 34C. In the boiling water volume comparison means 34D, if the set boiling water volume is equal to or greater than the total boiling water volume for one day, the daytime operation end time determination means 35B determines the daytime operation end time in the daytime time zone mode 31A.

[0025] In the daytime operation end time determination means 35B, when the lower hot water temperature of the hot water storage tank 10 detected by the first hot water storage temperature detection means 18ad becomes the daytime boiling end temperature that is higher than the upper hot water temperature of the hot water storage tank 10 detected by the second hot water storage temperature detection means 18au at the end of the boiling operation in the nighttime time zone mode 31B, the boiling operation in the daytime time zone mode 31A is terminated. Here, as the upper hot water temperature of the hot water storage tank 10 at the end of the boiling operation in the nighttime time zone mode 31B, the temperature at the end of the immediately preceding nighttime time zone mode 31B can be used. However, for example, the minimum temperature, the maximum temperature, or the average temperature of the past seven days may be used as the daytime boiling end temperature. Further, the upper hot water temperature of the hot water storage tank 10 at the end of the boiling operation in the nighttime time zone mode 31B may be classified into the upper hot water temperature for summer, the upper hot water temperature for winter, and the upper hot water temperature for the intermediate period, and the daytime boiling end temperature may be changed.

[0026] In the boiling water volume comparison means 34D, if the set boiling water volume is less than the total boiling water volume, the nighttime operation time calculation means 36A calculates the nighttime operation time in the nighttime time zone mode 31B so as to satisfy the total boiling water volume. If the set boiling water volume is less than the total boiling water volume, the shortage of boiling can be eliminated by increasing the nighttime operation time in the nighttime time zone mode 31B. In the control device 30, the operation is started so that the operation can be performed for the nighttime operation time calculated by the nighttime operation time calculation means 36A, and the control device 30 determines the end time of the nighttime operation in the nighttime time zone mode 31B by the nighttime operation end time determination means 36B. In the nighttime operation end time determination means 36B, when the upper hot water temperature of the hot water storage tank 10 detected by the second hot water temperature detection means 18au reaches the nighttime boiling end temperature, the boiling operation in the nighttime time zone mode 31B is terminated. The nighttime boiling end temperature is set to a temperature lower than the daytime boiling end temperature. Note that in the nighttime operation end time determination means 36B, the nighttime operation time may be set so that the upper hot water temperature of the hot water storage tank 10 detected by the second hot water temperature detection means 18au at the end of the boiling operation in the nighttime time zone mode 31B becomes the nighttime boiling end temperature.

[0027] As described above, in the daytime time zone mode 31A, the control device 30 detects the lower hot water temperature of the hot water storage tank 10 by the first hot water temperature detection means 18ad, and in the nighttime time zone mode 31B, the control device 30 detects the upper hot water temperature by the second hot water temperature detection means 18au. By ending the boiling operation in the daytime time zone mode 31A in a state where the lower hot water temperature of the hot water storage tank 10 detected by the first hot water temperature detection means 18ad is higher than the upper hot water temperature of the hot water storage tank 10 detected by the second hot water temperature detection means 18au at the end of the boiling operation in the nighttime time zone mode 31B, more hot water can be boiled in the daytime time zone where the outside air temperature is high and the time until the main hot water usage time zone is short than in the nighttime time zone. By boiling more hot water in the daytime time zone where the outside air temperature is higher than in the nighttime time zone, the heating efficiency is good, and since the time until evening, which is the main usage time zone, is short, the heat dissipation loss is small, so efficient boiling can be performed.

[0028] In the present embodiment, by determining the end of the boiling operation in the daytime time zone mode 31A based on the lower hot water temperature detected by the first hot water temperature detection means 18ad, the boiling operation in the daytime time zone mode 31A can be ended in a state where the lower hot water temperature is higher than the upper hot water temperature at the end of the boiling operation in the nighttime time zone mode 31B. Also, by determining the end of the boiling operation in the nighttime mode 31B based on the upper hot water temperature detected by the second hot water storage temperature detection means 18au, the upper hot water temperature at the end of the boiling operation in the nighttime mode 31B can be controlled.

[0029] FIG. 2 is an operation explanatory diagram of the water supply device according to this embodiment. In this embodiment, the control device 30 sets the daytime period from 9:00 to 16:00 and the nighttime period from 23:00 to 6:00, and sets the minimum operation time in the daytime period to 4 hours.

[0030] FIG. 2(a) shows an example of using hot water. For example, as shown in FIG. 2(a), hot water is used from 18:00 to 22:00, at 7:00, and at 12:00. FIG. 2(b) shows the state of hot water in the hot water storage tank 10. FIGS. 2(c) and 2(d) show the operation time zones of the heating device 20.

[0031] When it reaches 23:00, which is the start time of the nighttime period, the control device 30 calculates the total boiling hot water amount for one day by the total boiling hot water amount calculation means 34A. The operation state A shown in FIG. 2(c) indicates the case where the set boiling hot water amount during the daytime set operation time is equal to or more than the total boiling hot water amount for one day. The operation state A is the case where the user sets the daytime set operation time from 9:00 to 16:00. If the set boiling hot water amount during the daytime set operation time is equal to or more than the total boiling hot water amount for one day, the control device 30 starts the operation at 9:00, which is the start time of the daytime operation, and ends the daytime time zone mode 31A at the daytime operation end time determined by the daytime operation end time determination means 35B.

[0032] The operation state B shown in FIG. 2(d) indicates the case where the set boiling hot water amount during the daytime set operation time is less than the total boiling hot water amount for one day. The operation state B is the case where the user sets the daytime set operation time from 12:00 to 16:00. If the set boiling-up hot water amount during the daytime set operation time is less than the total boiling-up hot water amount for one day, the control device 30 calculates the nighttime operation time in the nighttime time zone mode 31B so that it becomes the total boiling-up hot water amount. In the nighttime time zone mode 31B, boiling-up is performed for the calculated nighttime operation time, or when the upper hot water temperature of the hot water storage tank 10 detected by the second hot water storage temperature detection means 18au reaches the nighttime boiling-up end temperature, the boiling-up operation is terminated.

[0033] Figure 3 is a control flowchart of the hot water supply device according to this embodiment. In the control device 30, the total boiling-up hot water amount for one day is calculated using the used hot water amount history data (S1), and the set boiling-up hot water amount at the set operation time is calculated based on the set operation time in the daytime time zone mode 31A (S2). Then, in the control device 30, the set boiling-up hot water amount calculated in S2 and the total boiling-up hot water amount for one day calculated in S1 are compared (S3). If the calculated set boiling-up hot water amount is greater than or equal to the total boiling-up hot water amount for one day (Yes in S3), the operation is started from the daytime operation start time set by the operation means 40 (S4). If the lower hot water temperature of the hot water storage tank 10 detected by the first hot water storage temperature detection means 18ad is less than the daytime boiling-up end temperature (No in S5), the daytime operation is continued. When the lower hot water temperature of the hot water storage tank 10 detected by the first hot water storage temperature detection means 18ad reaches the daytime boiling-up end temperature (Yes in S5), the daytime operation in the daytime time zone mode 31A is terminated (S6). If the calculated set boiling-up hot water amount is less than the total boiling-up hot water amount for one day (No in S3), the nighttime operation time in the nighttime time zone mode 31B is calculated so that it becomes the total boiling-up hot water amount (S7).

[0034] When the daytime operation start time set by the operation means 40 arrives, the daytime operation in the daytime time zone mode 31A is performed until the set daytime operation end time (S8). Also, when it becomes the nighttime period, nighttime operation is started so that it can be operated for the nighttime operation time calculated by the nighttime operation time calculating means 36A (S9). If the upper hot water temperature of the hot water storage tank 10 detected by the second hot water storage temperature detecting means 18au is less than the nighttime boiling end temperature (No in S10), the nighttime operation is continued. When the upper hot water temperature of the hot water storage tank 10 detected by the second hot water storage temperature detecting means 18au becomes equal to or higher than the nighttime boiling end temperature (Yes in S10), the nighttime operation in the nighttime period mode 31B is terminated (S11).

[0035] In addition, in order to make the daytime boiling hot water amount boiled in the daytime period mode 31A be equal to or more than a predetermined ratio with respect to the total boiling hot water amount for one day determined in S1, it is preferable that the operation means 40 restricts so that the daytime set operation time cannot be set to be less than the preset minimum operation time. By ensuring the daytime boiling time of the minimum operation time or more, the operations in the daytime period mode 31A and the nighttime period mode 31B can be made to an optimal ratio.

Industrial Applicability

[0036] According to the present invention, efficient operation in the daytime period mode can be effectively performed.

Explanation of Signs

[0037] 10 Hot water storage tank 11 Boiling up pipe 12 Hot water supply faucet 13 Mixing valve 14 Water supply pipe 15 Hot water supply pipe 16 Circulation pump 17 Hot water supply flow rate detecting means 18a Hot water storage temperature detecting means 18ad First hot water storage temperature detecting means 18au Second hot water storage temperature detecting means 18b, 18c Water supply temperature detecting means 20 Heating device 30 Control device 31 Boiling up operation mode 31A Daytime period mode 31B Nighttime mode 32 Timer means 33A Used hot water amount memory means 33B Feed water temperature memory means 33C Set condition memory means 34A Total heated hot water amount calculation means 34C Set heated hot water amount calculation means 34D Heated hot water amount comparison means 35B Daytime operation end time determination means 36A Nighttime operation time calculation means 36B Nighttime operation end time determination means 40 Operation means 50 Photovoltaic power generation device

Claims

1. A hot water supply device comprising a hot water storage tank, a heating device for heating the hot water in the hot water storage tank, and a control device, wherein the control device has a boiling operation mode in which the heating device heats the hot water in the hot water storage tank, and the boiling operation mode includes a daytime mode in which the boiling operation is executed during the daytime, and a nighttime mode in which the boiling operation is executed during the nighttime, and the hot water supply device is configured such that the amount of hot water boiled during the daytime in the daytime mode is 50% or more of the total amount of hot water boiled in a day, and has a hot water storage temperature detection means for detecting the temperature of the hot water in the hot water storage tank, including a first hot water storage temperature detection means for detecting the temperature of the lower hot water in the hot water storage tank, and a second hot water storage temperature detection means for detecting the temperature of the upper hot water at a position higher than the first hot water storage temperature detection means, wherein the control device detects the temperature of the lower hot water by the first hot water storage temperature detection means in the daytime mode, detects the temperature of the upper hot water by the second hot water storage temperature detection means in the nighttime mode, and ends the boiling operation in the daytime mode when the temperature of the lower hot water detected by the first hot water storage temperature detection means is higher than the temperature of the upper hot water detected by the second hot water storage temperature detection means at the end of the boiling operation in the nighttime mode. The hot water supply device is characterized by the above.

2. When the temperature of the lower hot water detected by the first hot water storage temperature detection means reaches the daytime boiling end temperature, the boiling operation in the daytime mode is ended. The hot water supply device according to claim 1, characterized by the above.

3. When the temperature of the upper hot water detected by the second hot water storage temperature detection means reaches the nighttime boiling end temperature, the boiling operation in the nighttime mode is ended. The hot water supply device according to claim 1 or claim 2, characterized by the above.

4. The hot water supply device according to any one of claims 1 to 3 is provided with an operation means by which a user can set at least one of a daytime operation start time, a daytime operation end time, or a daytime operation execution time when the daytime mode is executed, and the operation means is configured such that a setting in which the set daytime operation time is less than a preset minimum operation time cannot be made. The hot water supply device is characterized by the above.

5. The hot water supply device according to any one of claims 1 to 4 uses electric power obtained by a solar power generation device in the daytime mode. The hot water supply device is characterized by the above. ​ ​

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