Hot water supply equipment

Abstract

To provide a water heater capable of improving energy saving performance by finishing boiling-up in accordance with an actual boiling-up state when a daytime set operation time is longer than a daytime operation time.SOLUTION: In a water heater, a control device 30 calculates a daytime operation time in a daytime time zone mode 31A from a total boiling-up hot water amount of one day determined on the basis of a use history, compares a daytime set operation time set by operation means 40 with the calculated daytime operation time, performs a boiling-up operation in the daytime set operation time in the daytime time zone mode 31A when the daytime set operation time is shorter than the daytime operation time, starts the boiling-up operation at a time set by the operation means 40 in the daytime time zone mode 31A when the daytime set operation time is longer than the daytime operation time, and finishes the boiling-up operation when a detection temperature detected by residual hot water temperature detection means 18a or inflow water temperature detection means 18c reaches a set temperature.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a hot water supply apparatus having a boiling operation mode. [Background technology]

[0002] Patent Document 1 discloses a water heating apparatus that includes a hot water storage tank, a heating device that heats the hot water in the hot water storage tank, and a control device, the control device having 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 heating device performs boiling operation during daytime hours using electricity generated by other equipment, and that can perform boiling operation taking into account not only the amount of hot water used but also the balance of electricity demand. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-189347 A Summary of the Invention [Problem to be solved by the invention]

[0004] According to Patent Document 1, the amount of hot water to be boiled in the nighttime mode is determined by subtracting the amount of hot water set in the daytime mode. If the amount of hot water set in the daytime mode is set to be more than the amount of hot water actually used by the user, the amount of hot water to be boiled in the daytime mode is set to be less than the amount of hot water determined based on the history of hot water usage, rather than the set amount, so that the minimum amount of hot water required at night is boiled, and the system can respond to some sudden hot water usage by the user from morning to daytime without running out of hot water. In the daytime mode, the amount of water boiled is determined based on the history of hot water usage, but if the water is boiled during daytime operating hours calculated from the total amount of hot water boiled in a day, there are cases where the water is boiled more than necessary.

[0005] Therefore, an object of the present invention is to provide a hot water supply device that can improve energy-saving performance by terminating heating based on the actual heating state when the daytime set operating time is longer than the daytime operating time. [Means for solving the problem]

[0006] The hot water supply device of the present invention described in claim 1 includes a hot water storage tank 10, a heating device 20 for heating hot water in the hot water storage tank 10, a control device 30, a remaining hot water temperature detection means 18a for detecting a temperature of remaining hot water in the hot water storage tank 10, and an inlet water temperature detection means 18c for detecting a temperature of the hot water introduced into the heating device 20 from a bottom of the hot water storage tank 10. 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, and the boiling operation mode 31 includes a daytime time zone mode 31A in which a boiling operation is performed during daytime hours. and a nighttime mode that runs the heating operation during nighttime hours. 31B and and an operation means 40 for allowing a user to set at least one of a daytime operation start time, a daytime operation end time, or a daytime operation execution time during which the daytime time slot mode 31A is executed; The daytime time zone and the nighttime time zone are set in advance or are changed by operation of the operation means 40, setting conditions are restricted so that the daytime set operation time cannot be set to less than the preset minimum operation time, and when the user sets only the daytime operation start time by the operation means 40, the daytime operation end time is set according to the minimum operation time, when the user sets only the daytime operation end time, the daytime operation start time is set according to the minimum operation time, and when the user sets only the daytime operation execution time, the start time of the daytime time zone is set as the daytime operation start time on condition that it is equal to or greater than the minimum operation time, The control device 30 includes: The amount of hot water used in one day is stored as a usage history in the hot water usage storage means 33A, the minimum amount of hot water to be boiled in the nighttime mode 31B is determined, the set amount of hot water to be boiled is calculated based on the set daytime operation time, and the total amount of hot water of the minimum amount of hot water to be boiled and the set amount of hot water to be boiled is calculated as follows: Total amount of water boiled per day determined based on usage history If it is more than this, Calculate the daytime driving time in the daytime time zone mode 31A. , established Determined The above The daytime set operation time is compared with the calculated daytime operation time, and if the daytime set operation time is shorter than the daytime operation time, the heating operation is performed at the daytime set operation time in the daytime time zone mode 31A, and if the daytime set operation time is longer than the daytime operation time, the heating operation is performed at the daytime set operation time in the daytime time zone mode 31A. , established Determined Daytime operation started The boiling operation is started at a certain time, and when the temperature detected by the remaining hot water temperature detection means 18a or the inlet water temperature detection means 18c reaches a set temperature, the boiling operation is terminated. The water heating apparatus of the present invention described in claim 2 is characterized in that, in the water heating apparatus described in claim 1, the control device 30 sets the boiling level from the total amount of water to be boiled, and changes the set temperature in accordance with the boiling level. The water heating apparatus of the present invention described in claim 3 is characterized in that, in the water heating apparatus described in claim 2, it is provided with a boiling temperature detection means 18d for detecting the boiling temperature of the hot water heated by the heating device 20, and the control device 30 controls the heating device 20 so that the boiling temperature becomes a boiling set temperature, and changes the boiling set temperature according to the boiling level. The hot water supply device of the present invention as set forth in claim 4 is the hot water supply device as set forth in any one of claims 1 to 3. ,before The daytime boiling water volume in the daytime time zone mode 31A is set to a predetermined ratio or more to the total boiling water volume. Effect of the Invention

[0007] According to the present invention, when the daytime set operation time is longer than the daytime operation time, instead of terminating the heating operation at the calculated daytime operation time, the heating operation is terminated when the detected temperature detected by the remaining hot water temperature detection means or the inlet water temperature detection means reaches the set temperature, thereby eliminating unnecessary heating and improving energy-saving performance. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a block diagram of a water heater according to an embodiment of the present invention; [Diagram 2] Operational diagram of the hot water supply device [Diagram 3] Control flow diagram of the hot water supply device [Figure 4] A diagram showing an example of the boiling temperature setting and boiling end conditions when the boiling level is set based on the total amount of boiled water (amount of water used) DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] In the hot water supply device according to the first embodiment of the present invention, the boiling operation mode is a daytime mode in which the boiling operation is performed during daytime hours. and a nighttime mode in which heating operation is performed during the nighttime hours. and an operation means for allowing a user to set at least one of a daytime operation start time, a daytime operation end time, or a daytime operation execution time during which the daytime time zone mode is executed; The daytime time zone and the nighttime time zone are set in advance or are changed by operation with the operation means, the setting conditions for the daytime set operation time are restricted so that it cannot be set to less than the preset minimum operation time, when the user sets only the daytime operation start time with the operation means, the daytime operation end time is set according to the minimum operation time, when the user sets only the daytime operation end time, the daytime operation start time is set according to the minimum operation time, and when the user sets only the daytime operation execution time, the start time of the daytime time zone is set as the daytime operation start time on condition that it is equal to or greater than the minimum operation time, The control device includes: The amount of hot water used in one day is stored in the hot water usage storage means as a usage history, the minimum amount of hot water to be boiled in the nighttime mode is determined, the set amount of hot water to be boiled is calculated based on the set daytime operation time, and the total amount of hot water of the minimum amount of hot water to be boiled and the set amount of hot water to be boiled is calculated as follows: Total amount of water boiled per day determined based on usage history If it is more than this, Calculate the daytime driving time in daytime mode. , established The daytime set operation time is compared with the calculated daytime operation time, and if the daytime set operation time is shorter than the daytime operation time, the heating operation is performed at the daytime set operation time in the daytime time zone mode. If the daytime set operation time is longer than the daytime operation time, the heating operation is performed at the daytime set operation time in the daytime time zone mode. , established Determined Daytime operation begins The boiling operation is started at the specified time and terminated when the temperature detected by the remaining hot water temperature detection means or the inlet water temperature detection means reaches the set temperature. According to this embodiment, when the daytime set operation time is longer than the daytime operation time, the boiling operation is not terminated at the calculated daytime operation time, but when the temperature detected by the remaining hot water temperature detection means or the inlet water temperature detection means reaches the set temperature, thereby eliminating unnecessary boiling and improving energy saving performance.

[0010] In the second embodiment of the present invention, in the hot water supply device according to the first embodiment, the control device sets the boiling level from the total amount of hot water to be boiled, and changes the set temperature according to the boiling level. According to this embodiment, by changing the set temperature according to the boiling level, energy saving performance is further improved.

[0011] The third embodiment of the present invention is a hot water supply device according to the second embodiment, further comprising a boiling temperature detection means for detecting the boiling temperature of the hot water heated by the heating device, and a control device controls the heating device so that the boiling temperature becomes a boiling set temperature, and changes the boiling set temperature according to the boiling level. According to this embodiment, by changing the boiling set temperature according to the boiling level, energy saving performance is further improved.

[0012] A fourth embodiment of the present invention is a water heater according to any one of the first to third embodiments. ,noon The amount of hot water heated during the daytime in the intermittent mode is set to a predetermined ratio or more of the total amount of hot water to be heated. According to this embodiment, it is possible to reliably heat up during the daytime. Compared to the nighttime, there is less heat radiation during the daytime, so the heat retention is high, and the outdoor temperature is high, so the COP of the heat pump unit is improved, leading to improved energy-saving performance. EXAMPLES

[0013] An embodiment of the present invention will now be described with reference to the drawings. FIG. 1 is a configuration diagram of a hot water supply device according to this embodiment. The hot water supply system of this embodiment comprises a hot water storage tank 10, a heating device 20 for heating the hot water in the hot water storage tank 10, a control device 30 for controlling the heating device 20, and an operating means 40 by which a user can set the setting conditions of the control device 30.

[0014] The hot water in the hot water storage tank 10 is drawn from the bottom of the hot water storage tank 10 and passed through the boiling pipe 11 to the heating device 20, where it is heated to a high temperature and then introduced from the top of the hot water storage tank 10 and stored in the hot water storage tank 10. When the hot water tap 12 is opened, the hot water in the hot water storage tank 10 that has been heated to a high temperature is mixed with water supplied from the water supply pipe 14 by the mixing valve 13 to a predetermined temperature and is supplied from the hot water tap 12. When hot water is supplied from the hot water tap 12, any shortage in the hot water storage tank 10 is made by supplying it from a water supply pipe 14 connected to the bottom of the hot water storage tank 10, so that the hot water storage tank 10 is always filled with hot water. The boiling pipe 11 leading from the hot water storage tank 10 to the heating device 20 has a circulation pump 16, and by operating the circulation pump 16, 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. The boiling pipe 11 guides the hot water at the bottom of the hot water storage tank 10 to the heating device 20, and guides the hot water heated by the heating device 20 to the top of the hot water storage tank 10. In this way, by drawing out the hot water from the bottom of the hot water storage tank 10 and directing the heated hot water to the top of the hot water storage tank 10, a mixed layer is formed between the high temperature layer and the low temperature layer inside the hot water storage tank 10.

[0015] The hot water supply pipe 15 extending from the hot water storage tank 10 to the hot water tap 12 is provided with a hot water supply flow rate detection means 17 for detecting the amount of hot water supplied to the hot water tap 12 . A residual hot water temperature detection means 18a is provided in the middle lower part of the hot water storage tank 10, a supply water temperature detection means 18b is provided in the water supply pipe 14 that supplies water to the lower part of the hot water storage tank 10 or in the lower part of the hot water storage tank 10, an inlet water temperature detection means 18c is provided in the boiling pipe 11 from the hot water storage tank 10 to the circulation pump 16, and a boiling temperature detection means 18d is provided in the boiling pipe 11 from the heating device 20 to the top of the hot water storage tank 10. The remaining hot water temperature detection means 18a detects the temperature of the remaining hot water according to the amount of hot water used, and is disposed at the position of the mixed layer that is formed when the amount of hot water used is stored.

[0016] A heat pump device composed of a compressor, a radiator, a pressure reducer, and an evaporator is suitable for the heating device 20. When a heat pump device is used as the heating device 20, heat dissipated by the radiator is used as a heat source. By using the heating device 20 as a heat pump device, electric power can be used effectively.

[0017] 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 has a daytime time zone mode 31A in which the boiling operation is performed during daytime hours, and a nighttime time zone mode 31B in which the boiling operation is performed during nighttime hours. The control device 30 has a timer means 32. The timer means 32 measures time, and can determine the date and time. Therefore, the daytime period and the nighttime period are determined by the timer means 32. The daytime period and the nighttime period may be set in advance, or may be changed by operation of the operation means 40. For example, the daytime period is set from 9:00 to 16:00, and the nighttime period is set from 23:00 to 6:00.

[0018] The control device 30 has a hot water usage amount storage means 33A, a water supply temperature storage means 33B, and a setting condition storage means 33C. The hot water usage storage means 33A stores the amount of hot water detected by the hot water supply flow rate detection means 17 together with the time measured by the timer means 32. The hot water usage storage means 33A stores the amount of hot water by time period for a specified period such as one day, one week, one month, and one year as a hot water usage history. The supply water temperature storage means 33B stores the supply water temperature detected by the supply water temperature detection means 18b together with the time kept by the timer means 32. The supply water temperature storage means 33B stores the supply water temperature by time zone for a predetermined period such as one day, one week, one month, and one year. Furthermore, by operating the circulation pump 16 during the nighttime hours when the heat quantity of the hot water in the hot water storage tank 10 is estimated to be at its lowest by the control device 30, and after operating the circulation pump 16, the hot water temperature is detected by the remaining hot water temperature detection means 18a, the supply water temperature detection means 18b, and the inlet water temperature detection means 18c, so that the supply water temperature can be detected without being affected by the hot water in the hot water storage tank 10.Furthermore, by operating the circulation pump 16 during the nighttime hours when the heat quantity of the hot water in the hot water storage tank 10 is estimated to be at its lowest, the supply water temperature can be detected without being affected by the hot water in the hot water storage tank 10.

[0019] The set condition storage means 33C stores at least one of the set conditions of the daytime operation start time, the daytime operation end time, and the daytime operation execution time, for which the daytime time slot mode 31A is executed. These set conditions are set by the operation means 40. The operation means 40 restricts the setting conditions so that the daytime set operation time cannot be set to less than the preset minimum operation time. For example, if the control device 30 has preset the minimum operation time to four hours, the user can set the daytime operation execution time to four hours or more, but the user cannot set it to less than four hours. The same applies to the daytime operation start time and daytime operation end time; if the daytime operation start time is set to 9:00, the user cannot set the daytime operation execution time to a time less than four hours, for example, the daytime operation end time to 12:00. If the daytime operation start time is set to 9:00, the user can set the daytime operation end time to a time after 13:00. It is preferable that the operation means 40 allows the user to set the daytime operation start time and daytime operation end time. However, if the user sets only the daytime operation start time, the daytime operation end time may be set based on the minimum operation time, and if the user sets only the daytime operation end time, the daytime operation start time may be set based on the minimum operation time.

[0020] The control device 30 has a total boiled water volume calculation means 34A that calculates the total volume of boiled water in a day, a minimum boiled water volume determination means 34B that determines the minimum volume of boiled water to be boiled in the nighttime time zone mode 31B, a set boiled water volume calculation means 34C that calculates the set boiled water volume for the daytime set operating hours set by the operation means 40, and a boiled water volume comparison means 34D that compares the total volume of boiled water in a day with the set boiled water volume and the minimum boiled water volume. The total amount of boiled hot water calculation means 34A calculates the total amount of boiled hot water for one day based on the hot water usage history stored in the hot water usage storage means 33A. The minimum amount of hot water to be boiled by the means 34B for determining the amount of hot water to be boiled is determined by the water supply temperature stored in the water supply temperature storage means 33B. The water supply temperature here can be the water supply temperature at the time of detection, but it may also be the minimum temperature, maximum temperature, or average temperature over the past seven days. Using the minimum temperature over a specified period of time in the past can prevent hot water from running out. The minimum amount of hot water to be boiled can also be determined by the outside air temperature and the amount of hot water used (calorie) in addition to the water supply temperature. The minimum amount of hot water to be boiled can also be determined by dividing it into a minimum amount of hot water to be boiled for summer, a minimum amount of hot water to be boiled for winter, and a minimum amount of hot water to be boiled for intermediate periods. The set amount of hot water to be heated calculation means 34C calculates the set amount of hot water to be heated based on the set daytime operation time stored in the set condition storage means 33C. The boiled water volume comparison means 34D uses the total boiled water volume for the day calculated by the total boiled water volume calculation means 34A, the minimum boiled water volume determined by the minimum boiled water volume determination means 34B, and the set boiled water volume calculated by the set boiled water volume calculation means 34C.

[0021] In the hot water volume comparison means 34D, if the total volume of the set hot water volume and the minimum hot water volume is equal to or greater than the total hot water volume for the day, the daytime operation time calculation means 35A calculates the daytime operation time in the daytime time zone mode 31A so that the total volume is the total hot water volume. The daytime driving time comparison means 35B compares the daytime driving time calculated in the daytime time zone mode 31A with the set daytime driving time stored in the set condition storage means 33C. In the daytime operation time comparison means 35B, if the daytime set operation time is shorter than the daytime operation time, the daytime operation end time determination means 35C determines the daytime operation end time stored in the set condition storage means 33C as the operation end time, and in the daytime time zone mode 31A, heating operation is performed at the daytime set operation time. If the daytime operation time comparison means 35B determines that the daytime set operation time is longer than the daytime operation time, the daytime time zone mode 31A starts boiling operation at the time set by the operation means 40, and ends the daytime boiling operation by the daytime operation end determination means 35D.

[0022] The daytime operation end decision means 35D decides to end the boiling operation when the temperature detected by the remaining hot water temperature detection means 18a or the inlet water temperature detection means 18c reaches the set temperature. It is preferable to set the conditions for deciding to end operation as follows: the temperature detected by the remaining hot water temperature detection means 18a reaches the set remaining hot water temperature, and the temperature detected by the inlet water temperature detection means 18c reaches the set inlet water temperature. Furthermore, as described below, it is preferable to set the boiling level based on the total amount of water to be boiled, and to change the set temperature according to the boiling level. Moreover, it is preferable that the control device 30 controls the heating device 20 so that the boiling temperature detected by the boiling temperature detection means 18d becomes the boiling set temperature, and changes the boiling set temperature according to the boiling level. In addition, if the total amount of hot water is equal to or greater than the total amount of hot water to be boiled in a day, the daytime operation time in daytime time zone mode 31A can be made shorter than the daytime operation time setting to prevent boiling more than necessary.

[0023] In the boiling water volume comparison means 34D, if the total volume of the set boiling water volume and the minimum boiling water volume is less than the total boiling water volume, the night operation time calculation means 36A calculates the night operation time in the night time zone mode 31B so that the total volume of hot water becomes the total boiling water volume. In the nighttime operation time calculation means 36A, if the total amount of hot water is less than the total amount of hot water to be boiled, the nighttime operation time in the nighttime time zone mode 31B is lengthened to eliminate the insufficient boiling. In the control device 30, the night time zone mode 31B is set to end operation at a preset night operation end time, and when the night operation time calculation means 36A calculates the night operation time, the night operation start time determination means 36B determines the night operation start time in the night time zone mode 31B. In this way, in nighttime mode 31B, by setting the nighttime operation end time to a fixed time, hot water shortages can be prevented even for users who use a lot of hot water in the morning. In daytime mode 31A, operation starts from the set daytime operation start time, making it possible to heat water during the necessary daytime hours.

[0024] FIG. 2 is an explanatory diagram of the operation of the hot 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.

[0025] Fig. 2(a) shows an example of hot water usage. For example, as shown in Fig. 2(a), hot water is used from 18:00 to 22:00, 7:00, and 12:00. FIG. 2( b ) shows the state of hot water in the hot water storage tank 10 . 2(c) and 2(d) show the operation time periods of the heating device 20. At 11:00 p.m., which is the start time of the nighttime period set by the control device 30, the circulation pump 16 is operated and the water supply temperature is detected. The minimum water supply amount determination means 34B then determines the minimum water supply amount based on the detected water supply temperature. Note that it is preferable to use the water supply temperature detected during a certain period of time in the past as the water supply temperature. In this manner, in this embodiment, the amount of hot water required to be used from 6:00 to 9:00 is determined based on the water supply temperature, which varies with the season. This makes it possible to set the minimum amount of hot water to be boiled in nighttime mode 31B to the optimal minimum amount required throughout the year, and to efficiently boil hot water in daytime mode 31A without running out of hot water.

[0026] Furthermore, at 11pm, which is the start time of the nighttime period, the control device 30 calculates the total amount of boiled hot water for the day using the total amount of boiled hot water calculation means 34A. Operation state A shown in FIG. 2(c) shows a case where the total amount of hot water boiled up including the set amount of hot water boiled up during the daytime operation hours and the minimum amount of hot water boiled up is equal to or greater than the total amount of hot water boiled up in one day. An operating state A is a case where the user sets the daytime operating hours from 9:00 to 16:00. If the total amount of hot water boiled during the daytime set operating time and the minimum amount of hot water boiled is equal to or greater than the total amount of hot water boiled in a day, the control device 30 calculates the daytime operating time in the daytime time zone mode 31A so that the total amount of hot water boiled is the total amount of hot water boiled. Figure 2(c) shows a case where the calculated daytime operation time is 4 hours. Since the daytime operation start time is 9:00, if heating operation is performed during the daytime operation time, the scheduled end time of daytime operation is 13:00.

[0027] In this embodiment, as shown in Figure 2(c), when the daytime set operation time is longer than the daytime operation time, the end time of the boiling operation is not set to 13:00, but the boiling operation is ended when the detected temperature detected by the remaining hot water temperature detection means 18a reaches the set remaining hot water temperature and the detected temperature detected by the inlet water temperature detection means 18c reaches the set inlet water temperature, so that the boiling operation can be ended at, for example, 12:40. In the nighttime mode 31B, the determined minimum amount of hot water is boiled. Since the control device 30 is set to end operation at 6:00, which is the preset nighttime operation end time, the nighttime operation start time is determined by the determined minimum amount of hot water. As a result, as shown in operating state A in Figure 2 (c), during the nighttime hours, boiling operation is performed in nighttime time zone mode 31B so as to end at 6:00, and during the daytime hours, boiling operation is performed in daytime time zone mode 31A from 9:00 to 13:00.

[0028] 2(d) shows a case where the total amount of hot water boiled during the daytime set operation time and the minimum amount of hot water boiled is less than the total amount of hot water boiled in one day. In other words, when the daytime set operation time is shorter than the daytime operation time, the daytime time zone mode 31A performs boiling operation during the daytime set operation time. An operating state B is a case where the user sets the daytime operating hours from 12:00 to 16:00. If the total amount of hot water boiled during the daytime set operating time and the minimum amount of hot water boiled is less than the total amount of hot water boiled for the day, the control device 30 calculates the nighttime operating time in the nighttime mode 31B so that the total amount of hot water boiled becomes the total amount of hot water boiled. In the nighttime time zone mode 31B, water is boiled for the calculated nighttime operation time. Since the control device 30 is set to end operation at 6:00, which is the preset nighttime operation end time, the nighttime operation start time is determined by the calculated nighttime operation time. In the nighttime time zone mode 31B, the amount of hot water to be boiled at night is boiled during the calculated nighttime operation time, and in the daytime time zone mode 31A, the set amount of hot water to be boiled is boiled. As a result, as shown in operating state B in Figure 2 (d), during the nighttime hours, boiling operation is performed in nighttime time zone mode 31B so as to end at 6:00, and during the daytime hours, boiling operation is performed in daytime time zone mode 31A from 12:00 to 16:00.

[0029] FIG. 3 is a control flow diagram of the hot water supply device according to this embodiment. The control device 30 calculates the total amount of hot water to be boiled in one day using the hot water usage history data (S1), and determines the minimum amount of hot water to be boiled in the nighttime mode 31B using the water supply temperature data (S2). Furthermore, the control device 30 calculates the set amount of hot water to be heated for the set operation time based on the set operation time in the daytime time zone mode 31A (S3). Then, the control device 30 compares the total amount of hot water to be boiled for one day calculated in S1 with the minimum amount of hot water to be boiled determined in S2 and the set amount of hot water to be boiled calculated in S3 (S4).

[0030] If the total amount of hot water is equal to or greater than the total amount of hot water boiled in one day (Yes in S4), the daytime operation time in daytime mode 31A is calculated so that the total amount of hot water is equal to the total amount of hot water boiled (S5). The daytime operating time calculated in the daytime time zone mode 31A is compared with the daytime set operating time stored in the set condition storage means 33C by the daytime operating time comparison means 35B (S6). If the daytime operation set time is shorter than the daytime operation time (Yes in S6), the daytime operation end time determination means 35C determines the daytime operation end time stored in the set condition storage means 33C as the daytime operation end time in the daytime time zone mode 31A (S7). If the daytime operation time setting is longer than the daytime operation time (No in S6), the daytime operation end determination means 35D determines the end of operation based on the detected temperature (S9).

[0031] If the total amount of hot water is less than the total amount of hot water boiled in one day (No in S4), the night operation time in night time mode 31B is calculated so that the total amount of hot water becomes the total amount of hot water boiled (S8).

[0032] When the daytime operation end time in the daytime time zone mode 31A is determined in S7 or the end of operation is judged based on the detected temperature in S9, and then the nighttime operation time in the nighttime time zone mode 31B is calculated in S8, the nighttime operation start time in the nighttime time zone mode 31B is determined (S10). In S10, when the daytime operation end time in daytime time zone mode 31A is determined by S7, the nighttime operation start time is determined using the minimum amount of hot water to be heated determined by S2, and when the nighttime operation time in nighttime time zone mode 31B is calculated by S8, the nighttime operation start time is determined using this nighttime operation time. Then, at the night-time operation start time determined in S10, the control device 30 starts the operation of the heating device 20, and performs boiling in the night-time mode 31B until the preset night-time operation end time arrives (S11). In addition, when the daytime operation start time set by the operating means 40 arrives, the control device 30 starts operation of the heating device 20 and performs boiling in the daytime time zone mode 31A until the daytime operation end time determined by S7 or the detected temperature detected by the remaining hot water temperature detection means 18a or the inlet water temperature detection means 18c reaches the set temperature (S12).

[0033] Here, the amount of hot water to be boiled in the daytime time zone mode 31A in S12 is set to a predetermined ratio or more of the total amount of hot water to be boiled in a day determined in S1. The predetermined ratio is preferably 50% or more, and by setting the predetermined ratio to 50% or more, daytime boiling can be ensured. In the daytime, less heat is released compared to the nighttime, so heat retention is high, and the tank efficiency is better than before because the hot water is boiled just before use. Furthermore, when a heat pump device is used as the heating device 20, boiling can be performed more efficiently in the daytime compared to the nighttime, because the outside air temperature is higher. Furthermore, in order to ensure that the daytime volume of hot water boiled in daytime time zone mode 31A is at least a predetermined ratio to the total volume of hot water boiled in one day determined in S1, it is preferable that the operating means 40 restricts the daytime set operating time so that it cannot be set to less than a preset minimum operating time. By ensuring a daytime boiling time that is at least the minimum operating time, it is possible to achieve an optimal ratio between the operations of daytime time zone mode 31A and nighttime time zone mode 31B.

[0034] FIG. 4 is a diagram showing an example of the set boiling temperature and boil-off conditions when the boiling level is set based on the total amount of boiled hot water (amount of hot water used). In Figure 4, the boiling level is set to six levels depending on the total amount of water boiled (amount of water used). In FIG. 4, "inlet water Th" is the set inlet water temperature, and "remaining hot water Th" is the set remaining hot water temperature. For example, at boiling level 1, the boiling stop condition (the condition for determining whether to end operation) is that the detected temperature detected by the remaining hot water temperature detection means 18a reaches the set remaining hot water temperature of 50°C and the detected temperature detected by the inlet water temperature detection means 18c reaches the set inlet water temperature of 45°C, while at boiling level 6, the boiling stop condition (the condition for determining whether to end operation) is that the detected temperature detected by the remaining hot water temperature detection means 18a reaches the set remaining hot water temperature of 60°C and the detected temperature detected by the inlet water temperature detection means 18c reaches the set inlet water temperature of 60°C. 4, the boiling temperature setting is changed according to the boiling level. For example, at boiling level 1, the heating means 20 is controlled so that the boiling temperature detected by the boiling temperature detection means 18d becomes the boiling temperature setting of 65°C, and at boiling level 6, the heating means 20 is controlled so that the boiling temperature detected by the boiling temperature detection means 18d becomes the boiling temperature setting of 90°C. The boiling temperature can also be changed by controlling the flow rate of the circulation pump 16 while controlling the heating means 20. In this way, by setting the boiling level based on the total amount of water to be boiled and changing the set temperature according to the boiling level, energy saving performance is further improved. In addition, energy saving performance can be further improved by changing the boiling temperature setting depending on the boiling level.

[0035] As described above, in this embodiment, the daytime operation time in daytime time zone mode 31A is calculated from the total amount of hot water to be heated in a day determined based on the usage history, and the calculated daytime operation time is compared with the daytime set operation time set by the operation means 40. If the daytime set operation time is shorter than the daytime operation time, the daytime time zone mode 31A performs the heating operation at the daytime set operation time, and if the daytime set operation time is longer than the daytime operation time, the daytime time zone mode 31A starts the heating operation at the time set by the operation means 40, and ends the heating operation when the temperature detected by the remaining hot water temperature detection means 18a or the inlet water temperature detection means 18c reaches the set temperature. Therefore, if the daytime set operation time is longer than the daytime operation time, the heating operation is not ended at the calculated daytime operation time, but is ended when the temperature detected by the remaining hot water temperature detection means 18a or the inlet water temperature detection means 18c reaches the set temperature, thereby eliminating unnecessary heating and improving energy saving performance. [Industrial Applicability]

[0036] According to the present invention, operation in daytime mode can be performed effectively and efficiently. [Explanation of symbols]

[0037] 10 Hot water tank 11 Boiling piping 12 Hot water tap 13 Mixing valve 14 Water supply piping 15 Hot water piping 16 Circulation pump 17 Hot water flow rate detection means 18a Remaining water temperature detection means 18b Supply water temperature detection means 18c Inlet water temperature detection means 18d Boiling temperature detection means 20 Heating device 30 Control device 31 Boiling operation mode 31A Daytime mode 31B Nighttime mode 32 Timer means 33A Storage means for amount of hot water used 33B Supply water temperature storage means 33C Setting condition storage means 34A Total boiling water volume calculation method 34B Means for determining minimum amount of boiled water 34C Set boiling water volume calculation method 34D Means for comparing boiling water volume 35B Daytime driving time comparison means 35C Means for determining daytime operation end time 35D Means for determining the end of daytime operation 36A Nighttime driving time calculation means 36B Means for determining nighttime operation start time 40 Operating means

Claims

1. a hot water storage tank, a heating device for heating the hot water in the hot water storage tank, a control device, a residual hot water temperature detection means for detecting the temperature of the residual hot water in the hot water storage tank, and an inlet water temperature detection means for detecting the temperature of the hot water introduced into the heating device from the bottom of the hot water storage tank; Equipped with The control device includes: The heating device has a boiling operation mode in which the hot water in the hot water storage tank is heated, The boiling operation mode is A daytime mode in which heating operation is performed during daytime hours; A nighttime mode that performs heating operation during nighttime hours. and an operation means for allowing a user to set at least one of a daytime operation start time, a daytime operation end time, or a daytime operation execution time during which the daytime time zone mode is executed; The daytime period and the nighttime period are set in advance or are changed by an operation of the operation means, The daytime operation time is restricted so that it cannot be set below the minimum operation time set in advance. by the operation means, when the user sets only the daytime driving start time, the daytime driving end time is set according to the minimum driving time, when the user sets only the daytime driving end time, the daytime driving start time is set according to the minimum driving time, and when the user sets only the daytime driving execution time, the start time of the daytime time zone is set as the daytime driving start time on condition that it is equal to or greater than the minimum driving time, The control device includes: The amount of hot water used in one day is stored in a hot water usage storage means as a usage history. determining a minimum amount of water to be boiled in the nighttime mode; Calculate the set amount of hot water to be heated based on the set daytime operation time, If the total amount of hot water of the minimum amount of hot water to be heated and the set amount of hot water to be heated is equal to or greater than the total amount of hot water to be heated in one day determined based on the usage history, calculate the daytime operation time in the daytime time zone mode, A comparison is made between the set daytime set operating time and the calculated daytime operating time, When the daytime set operation time is shorter than the daytime operation time, the heating operation is performed for the daytime set operation time in the daytime time zone mode, When the daytime set operation time is longer than the daytime operation time, in the daytime time zone mode, the boiling operation is started at the set daytime operation start time, and the boiling operation is ended when the temperature detected by the remaining hot water temperature detection means or the inlet water temperature detection means reaches the set temperature. A water heating apparatus comprising:

2. The control device includes: A boiling level is set based on the total amount of boiled water, The set temperature is changed according to the boiling level. The water heater according to claim 1 .

3. A boiling temperature detection means is provided for detecting the boiling temperature of the hot water heated by the heating device, The control device includes: Controlling the heating device so that the boiling temperature becomes a boiling set temperature; The boiling temperature setting is changed according to the boiling level.

3. The water heater according to claim 2.

4. The amount of hot water boiled during the daytime period mode is set to a predetermined ratio or more to the total amount of hot water boiled. The hot water supply device according to any one of claims 1 to 3.

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