JP2024034063A - Hot water storage type water heater - Google Patents

Abstract

To provide a storage-type hot water supply device capable of making compatible of performing a sterilizing operation and saving energy consumption without disturbing use of hot water.SOLUTION: A hot water storage type water heater (1) which includes a heat source machine (4), a hot water storage tank (2), and a control portion (18) controlling a hot water storage operation for storing hot water/water heated by the heat source machine (4) in the hot water storage tank (2) and in which the control portion (18) controls a hot water storage operation on the basis of prediction of hot water supply based on hot water use history, is constituted so that the control portion (18) prohibits supply and use of hot water in the hot water storage tank (2) and execute a sterilizing operation for sterilizing the hot water/water in the hot water storage tank (2) in a case when a predetermined condition for the sterilizing operation is established. In a case when the difference between sterilizing operation condition establishment schedule date (Tc) and hot water storage operation start schedule date (Tb) based on hot water supply prediction is a specified time (Δt) or less, the sterilizing operation is started when the hot water/water in the hot water storage tank is not completely replaced until the date (Te) advanced by the difference (Δt) between the sterilizing operation schedule time necessary for the sterilizing operation and the hot water storage operation schedule time necessary for the hot water storage operation, from the hot water storage operation start schedule date (Tb).SELECTED DRAWING: Figure 4

Description

The present invention relates to a hot water storage water supply device that uses hot water heated by a main heat source device and stored in a hot water storage tank for hot water supply.

BACKGROUND ART Conventionally, hot water storage water supply devices have been widely used, which store hot water heated by a heat pump type heat source device as a main heat source device with high heating operation efficiency in a hot water storage tank, and use the hot water in the hot water storage tank for hot water supply. A hot water storage water heater has a main heat source device, a hot water storage unit equipped with a hot water storage tank, and an auxiliary heat source device, such as a combustion type, which has a heating capacity greater than the main heat source device, and there is no hot water in the hot water storage tank at a temperature that can be used to supply hot water. In some cases, the hot water is heated by an auxiliary heat source and adjusted to the hot water supply set temperature.

The hot water storage tank has a capacity that can store hot water equivalent to the amount of heat used for hot water supply at peak times when the amount of hot water used in a general household is the highest, for example. Since the same amount of tap water is supplied to the hot water storage tank as the hot water output, the entire amount of hot water in the hot water storage tank is often replaced in about one to two days.

However, when the user of the hot water storage and water supply device is away for several days, for example due to travel, the hot water in the hot water storage tank remains for a long time without being replaced. Furthermore, if the amount of hot water used by the user is small, it may take several days for the hot water tank to be completely replaced. If the heated hot water remains in the hot water storage tank and remains at a temperature suitable for breeding bacteria such as Legionella bacteria for a long time, the concentration of bacteria in this hot water may have a negative impact on the human body. There is a possibility that the concentration will reach a certain level.

Therefore, when preset sterilization operation conditions are met, the hot water storage and water supply device performs a sterilization operation by prohibiting hot water from being discharged from the hot water storage tank for hot water supply use, and prohibits hot water from being discharged from the hot water storage tank after the sterilization operation is completed. It is configured to be released. The sterilization operation condition is, for example, that the hot water in the hot water storage tank is not completely replaced for a predetermined period of time or more.

In the sterilization operation, hot water heated to a high temperature by the main heat source device is kept in a hot water storage tank for a certain period of time to sterilize the hot water. During the sterilization operation, hot water heated by the auxiliary heat source can be used for hot water supply, but after this hot water supply is used, the hot water from the sterilization operation is stored in the hot water storage tank, and this high-temperature hot water is is difficult to use effectively. Therefore, for example, Patent Document 1 discloses that in a hot water storage and water heater that stores hot water heated using the exhaust heat of a gas engine for power generation, the system learns the time period when the amount of hot water usage increases, and It is described that sterilization (sterilization) operations are performed.

Furthermore, Patent Document 2 describes a hot water storage water supply device that stores hot water heated using exhaust heat of a fuel cell power generation device, which predicts hot water usage for each time period based on the learned hot water usage amount, and It is stated that it is determined whether the user is at home or not based on the amount of electricity used in There is.

Patent No. 3935416 Patent No. 6551062

A hot water storage water heater equipped with a heat pump type main heat source device predicts the future hot water usage time and usage amount based on the learned hot water usage history, and supplies the amount of heat equivalent to the usage amount to the hot water storage tank before the predicted time. Store hot water in This makes it possible to reduce the heat radiation loss of the stored hot water, store the necessary amount of hot water, prevent the stored hot water from being wasted without being used, and save energy consumption. However, if the hot water storage operation is started several hours before the sterilization operation conditions are met, the sterilization operation conditions will be met and the sterilization operation will start during the hot water storage operation or during the time period when the stored hot water is used for hot water supply. There is a risk that the stored hot water cannot be used for hot water supply and is wasted. Furthermore, since hot water is supplied by the auxiliary heat source device during the sterilization operation, there is a possibility that the hot water in the hot water storage tank will not be used for hot water supply after the sterilization operation.

Therefore, as in Patent Documents 1 and 2, it is being considered to start the sterilization operation earlier than the hot water supply period. However, heat pump type main heat source equipment is not a heat source equipment that uses the waste heat from power generation to heat hot water, so the sterilization operation, which consumes a large amount of energy, can be performed earlier than when hot water is used. It's not entirely desirable. For example, by using the hot water stored in the hot water storage operation before the sterilization operation conditions are satisfied, the entire amount of hot water in the hot water storage tank may be replaced, and the sterilization operation and hot water supply by the auxiliary heat source device may be avoided.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a hot water storage and water supply device that can perform a sterilization operation without interfering with the use of hot water and save energy consumption.

The hot water storage and hot water supply device of the invention according to claim 1 includes a heat source device, a hot water storage tank, and a control unit that controls a hot water storage operation for storing hot water heated by the heat source device in the hot water storage tank, and the control unit controls the hot water supply use. In the hot water storage and hot water supply device that controls the hot water storage operation based on a hot water supply prediction predicted based on history, the control unit prohibits the use of hot water in the hot water storage tank for hot water supply when a preset sterilization operation condition is satisfied. and executes a sterilization operation to sterilize hot water in the hot water storage tank, and the difference between the scheduled date and time when the sterilization operation condition is satisfied and the scheduled start date and time of the hot water storage operation based on the hot water supply prediction is less than or equal to a specified time. In this case, the hot water in the hot water storage tank is not completely replaced by the date and time that is earlier than the scheduled start date and time of the hot water storage operation by the difference between the scheduled sterilization time required for the sterilization operation and the scheduled hot water storage operation time required for the hot water storage operation. It is characterized in that the sterilization operation is started when the sterilization occurs.

According to the above configuration, the hot water storage and hot water supply apparatus is configured such that the control unit controls the hot water storage operation based on the hot water supply prediction, and performs the sterilization operation when the sterilization operation condition is satisfied. If the difference between the scheduled date and time when the sterilization operation conditions are satisfied and the scheduled start date and time of hot water storage operation is less than the specified time, set the date and time that is earlier than the scheduled start date and time of hot water storage operation by the difference between the scheduled sterilization operation time and the scheduled hot water storage operation time. do. If the hot water in the hot water storage tank has not been completely replaced by the earlier date and time, the sterilization operation is started. By advancing the start of the sterilization operation in this manner, the sterilization operation can be completed at the scheduled end date of the hot water storage operation, so the sterilization operation can be performed without interfering with hot water supply. In addition, since the high-temperature hot water after sterilization is completed can be used for hot water supply, energy consumption can be saved by avoiding hot water storage operation before sterilization conditions are met and hot water supply by an auxiliary heat source device during sterilization. .

The hot water storage and hot water supply device according to the second aspect of the invention is characterized in that the prescribed time is variable in the first aspect of the invention.
According to the above configuration, since the specified time is variable, for example, when it is desired to use safe hot water after the sterilization operation, the specified time can be set longer, and the date and time of the sterilization operation can be advanced to make it easier to perform. Further, in order to reduce the chances of sterilization operations, for example, when it is desired to reduce the waste of unused hot water, it is possible to set the specified time short to reduce the chances of advancing the date and time of sterilization operations.

The hot water storage and hot water supply apparatus according to the invention according to claim 3 is characterized in that, in the invention according to claim 1, the control section sets the prescribed time to be longer as the target hot water storage heat amount of the hot water storage operation is larger.
According to the above configuration, the larger the target hot water storage heat value is, the longer the specified time is, so the opportunities and amount of use for hot water in the hot water storage tank after the sterilization operation performed at an earlier date and time for hot water supply increases. Therefore, the larger the target hot water storage heat value is, the smaller the increase in energy consumption due to sterilization operation from the planned energy consumption of hot water storage operation becomes, so that energy consumption can be saved.

According to the hot water storage and hot water supply device of the present invention, it is possible to perform a sterilization operation without interfering with the use of hot water supply and to save energy consumption.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram of a hot water storage and hot water supply device according to an embodiment of the present invention. It is a flowchart of hot water storage operation control. It is a flowchart of sterilization operation control. FIG. 3 is a diagram showing an example of accelerating the start of a sterilization operation. FIG. 7 is a diagram showing another example of accelerating the start of sterilization operation.

EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing this invention is demonstrated based on an Example.

First, the configuration of a hot water storage and hot water supply apparatus 1 of the present invention will be explained based on FIG. 1.
The hot water storage and hot water supply device 1 includes a hot water storage unit 3 including a hot water storage tank 2, a heat pump type main heat source device 4 (heat source device), and, for example, a combustion type auxiliary heat source device 5. This hot water storage and hot water supply device 1 performs a hot water storage operation in which hot water heated to a predetermined target hot water storage temperature by a main heat source device 4 is stored in a hot water storage tank 2 . The auxiliary heat source device 5 heats the hot water discharged from the hot water storage unit 3 according to its temperature or supplies hot water to the hot water tap 6 without heating.

Next, the hot water storage unit 3 will be explained.
A main heat source machine going passage 8 equipped with a pump 7 is connected to the lower part of the hot water storage tank 2 in order to supply hot water from the hot water storage tank 2 to the main heat source machine 4 . A main heat source return passage 9 for storing hot water heated by the main heat source device 4 in the hot water storage tank 2 is connected to the upper part of the hot water storage tank 2 . A switching valve 10 for switching the hot water flow path is disposed in the middle of the main heat source machine return passage 9, and a return branch passage 9a branched from the main heat source machine return passage 9 at this switching valve 10 is connected to the main heat source machine return passage 9. It is connected to a portion of the passage 8 upstream of the pump 7.

A return temperature sensor 9b that detects the temperature of hot water heated by the main heat source device 4 is disposed upstream of the switching valve 10 in the main heat source device return passage 9. For example, if the temperature detected by the return temperature sensor 9b immediately after starting the main heat source device 4 is lower than the target hot water storage temperature, the switching valve 10 is switched from the hot water storage tank 2 side to the return branch passage 9a side to ensure sufficient heating. The hot water can be circulated without returning to the hot water storage tank 2 until it reaches the desired temperature.

A water supply passage 11 for supplying clean water is connected to the bottom of the hot water storage tank 2, as indicated by an arrow CW. A hot water supply passage 12 for discharging hot water from the hot water storage tank 2 from the hot water storage unit 3 is connected to the top of the hot water storage tank 2 . A mixing valve 14 is disposed in the middle of the tapping passage 12. A water supply branch passage 11a branched from the middle of the water supply passage 11 is connected to the mixing valve 14. Then, the hot water from the hot water storage tank 2 and the clean water from the water supply branch passage 11a are mixed by the mixing valve 14 and the hot water is discharged. Note that, instead of the mixing valve 14, the hot water mixing section may be configured with a flow rate adjusting valve that adjusts the flow rate on the hot water storage tank 2 side and a flow rate adjusting valve that adjusts the flow rate on the water supply branch passage 11a side.

A plurality of hot water temperature sensors 2a to 2d are arranged in the hot water storage tank 2 at predetermined intervals in the height direction, and measure the temperature of hot water stored in the hot water storage tank 2 and the amount of hot water stored at that temperature. Can be detected. In order to prevent the temperature of the stored hot water from decreasing, a heat insulating material (not shown) is provided to cover the hot water temperature sensors 2a to 2d and the hot water storage tank 2.

A water supply temperature sensor 11b is disposed in the water supply passage 11 to detect the temperature of the clean water (water supply temperature) supplied from the water supply passage 11. The hot water outlet passage 12 includes a hot water outlet flow rate sensor 12 a that detects the flow rate of hot water coming from the hot water storage unit 3 , a hot water tank outlet temperature sensor 12 b that detects the temperature of hot water dispensed from the hot water storage tank 2 , and a hot water outlet temperature sensor 12 b that detects the temperature of hot water dispensed from the hot water storage tank 2 . A hot water temperature sensor 12c is provided to detect the hot water temperature. A hot water tapping avoidance passage 31 is branched from the water supply branch passage 11a and connected to the downstream side of the mixing valve 14 of the hot water tapping passage 12. The high temperature hot water supply avoidance passage 31 is equipped with a high temperature hot water supply avoidance valve 32, and when the temperature detected by the hot water supply temperature sensor 12c is high and dangerous, the high temperature hot water supply avoidance valve 32 is opened to mix tap water and prevent hot water from being discharged from the hot water storage unit 3. lower the temperature.

The hot water outlet passage 12 of the hot water storage unit 3 and the water supply port 5a of the auxiliary heat source device 5 are connected by a hot water passage 15. A hot water passage 16 connected to a hot water tap 6 is connected to the hot water inlet 5b of the auxiliary heat source device 5. Hot water discharged from the hot water storage unit 3 is supplied to the hot water tap 6 via the auxiliary heat source device 5, and hot water is supplied from the hot water tap 6 as shown by arrow HW.

The auxiliary heat source device 5 performs a heating operation of heating the hot water discharged from the hot water storage unit 3 by using combustion heat when hot water cannot be supplied at the hot water set temperature with the temperature of the hot water stored in the hot water storage tank 2. The auxiliary heat source device 5 adjusts the heating capacity of the heating operation to supply hot water adjusted to the hot water supply set temperature.

In hot water storage operation, the main heat source device 4 and pump 7 are driven to circulate hot water between the hot water storage tank 2 and the main heat source device 4, and the hot water heated to the target hot water storage temperature by the main heat source device 4 is pumped from the top of the hot water storage tank 2. Store hot water. The hot water storage unit 3 includes a hot water storage unit control section 18 (control section) that controls the hot water storage operation, adjusts the temperature of the hot water stored in the hot water storage operation, and controls the hot water dispensed from the hot water storage unit 3.

The hot water storage unit control unit 18 stores hot water supply information including the date and time of hot water use, the amount of heat used in hot water supply, the set temperature for hot water supply, etc. as a history of hot water supply use, and predicts the amount of heat used in future hot water supply and the date and time to start hot water supply based on the history of hot water supply use. It has a hot water supply prediction function. The hot water storage unit control unit 18 also has a function of calculating the amount of hot water output from the hot water storage tank 2 based on the mixing ratio of the hot water output flow rate sensor 12a and the mixing valve 14, for example, and acquiring the date and time when the entire amount of hot water in the hot water storage tank 2 is replaced. has.

An operation terminal 19 is connected to the hot water storage unit control section 18 and the auxiliary heat source device 5, and is used by the user to set, for example, a hot water supply temperature setting. Note that a plurality of operation terminals 19 may be connected, and the operation terminal 19 corresponding to the hot water storage unit 3 is connected to the hot water storage unit control section 18, and the operation terminal corresponding to the auxiliary heat source device 5 is connected to the auxiliary heat source device 5. may have been done.

Next, the hot water storage operation control performed by the hot water storage unit control section 18 of the hot water storage and hot water supply apparatus 1 will be explained based on the flowchart of FIG. 2. Si (i=1, 2, . . . ) in the figure represents a step.

When the hot water storage operation control is started, in S1, the current stored hot water heat amount (temperature and amount of hot water) of the hot water storage tank 2 is acquired, and the process proceeds to S2. Then, in S2, the future amount of heat used for hot water supply and the date and time Ta of starting hot water supply use are predicted based on the hot water usage history, and the process proceeds to S3.

Next, in S3, based on the hot water storage calorie in the hot water storage tank 2 in S1 and the hot water supply usage prediction in S2, hot water storage operation is started so that the required amount of heat (target hot water storage calorie) is completed by the hot water supply use start date and time Ta. The scheduled date and time (scheduled date and time Tb for starting hot water storage operation) is set, and the process proceeds to S4. At this time, the target hot water storage temperature and target hot water storage amount are set, for example, so that the operating efficiency of the main heat source device 4 becomes high and energy consumption can be saved. Then, in S4, it is determined whether the scheduled hot water storage operation start date and time Tb set in S3 has arrived. If the determination in S4 is No, the process returns to S4. If the determination in S4 is Yes, the process advances to S5, where hot water storage operation is executed and the process returns to prepare for the next hot water storage operation.

For example, when the user of the hot water storage and water supply device 1 is away for a long time due to travel, etc., the hot water in the hot water storage tank 2 remains for a long time without being used for hot water supply. If there is still hot water stored in the hot water storage operation, it will remain for a long time at a temperature where bacteria such as Legionella bacteria can easily breed. Therefore, when hot water remains in the hot water storage tank 2 for a long time, the hot water storage water supply device 1 performs a sterilization operation to prevent the concentration of bacteria in the hot water in the hot water storage tank 2 from reaching a concentration that would affect the human body. conduct. This sterilization operation is started on the assumption that the sterilization operation condition is satisfied that the hot water in the hot water storage tank 2 has not been completely replaced within a preset replacement time. The replacement time is set to, for example, 100 hours (100h).

In the sterilization operation, the hot water storage unit control unit 18 prohibits hot water from being discharged from the hot water storage tank 2 for hot water supply, fills the hot water storage tank 2 with hot water heated by the main heat source device 4 to a temperature that kills bacteria, and maintains this state. Maintain for a certain period of time. During the sterilization operation, the hot water storage tank 2 is filled with hot water of, for example, 65° C. or higher. This temperature is equal to or higher than the maximum temperature that can be set as the target hot water storage temperature, and consumes a large amount of energy.

During the sterilization operation, clean water supplied via the hot water storage unit 3 can be heated by the auxiliary heat source device 5 to supply hot water. However, after hot water is supplied by the auxiliary heat source device 5 during the sterilization operation, the hot water in the hot water storage tank 2 after the completion of the sterilization operation may not be used for hot water supply and may be wasted. Therefore, this hot water storage and hot water supply device 1 adjusts the timing of starting the sterilization operation so that the high temperature hot water in the hot water storage tank 2 after the completion of the sterilization operation can be used effectively. This sterilization operation control will be explained based on the flowchart of FIG. 3.

When the sterilization operation control is started, in S11, the date and time T0 when the entire amount of hot water in the hot water storage tank 2 was replaced last and the scheduled date and time Tb for starting the hot water storage operation set by the hot water storage operation control are acquired, and the process proceeds to S12. Then, in S12, a scheduled date and time for the sterilization operation condition to be met (scheduled date and time for the sterilization operation condition to be met) that is after the replacement time from the date and time T0 when the total quantity is replaced is set, and the process proceeds to S13.

Next, in S13, the difference Δt between the scheduled date and time Tb of starting the hot water storage operation in S11 and the scheduled date and time Tc of satisfaction of the sterilization operation conditions in S12 is calculated, and the process proceeds to S14. Then, in S14, it is determined whether this Δt is less than or equal to the specified time t. This prescribed time t is variable and is set by the hot water storage unit control section 18, but can also be set by the user from the operating terminal 19.

Here, the specified time t starts from the scheduled date and time Tb for starting the hot water storage operation, with a lower limit of 2 hours as the time during which the stored hot water can be used for hot water supply, for example, and an upper limit of 5 hours, so that the sterilization operation does not start immediately after the hot water storage operation ends. It is set to be proportional to the target hot water storage heat amount for the hot water storage operation. Further, the prescribed time t may be set to be proportional to the time required to store hot water of the target hot water storage heat amount (scheduled hot water storage operation time). Note that when hot water is stored with the maximum heat amount that can be stored in the hot water storage tank 2 as the target hot water storage heat amount, the scheduled hot water storage operation time is, for example, 3 hours, and the time required for the sterilization operation (scheduled sterilization operation time) is, for example, 5 hours.

If the determination in S14 is Yes, the process proceeds to S15, where the difference ΔT between the scheduled hot water storage operation time and the scheduled sterilization operation time is calculated, and the process proceeds to S16. Then, in S16, the date and time before the scheduled hot water storage operation start date and time Tb by the difference ΔT between the scheduled hot water storage operation time and the scheduled sterilization operation time is set as the scheduled sterilization operation start date and time Te, and the process proceeds to S17.

For example, as shown in the upper part of FIG. 4, when the scheduled hot water storage operation time is 3 hours and the specified time t is 5 hours, the difference Δt between the scheduled date and time Tc when the sterilization operation condition is satisfied and the scheduled date and time Tb to start the hot water storage operation is smaller than the specified time t. , ΔT=2h are calculated. Then, as shown in the lower part of FIG. 4, a date and time ΔT before the scheduled hot water storage operation start date and time Tb is set as the scheduled sterilization operation start date and time Te. Thereby, it becomes possible to start the sterilization operation before the scheduled date and time Tb to start hot water storage operation and the scheduled date and time Tc to satisfy the sterilization operation conditions, and to finish the sterilization operation at the date and time Ta when hot water supply use starts.

For example, as shown in the upper part of FIG. 5, when the scheduled hot water storage operation time is 1 hour and the specified time t is 3 hours, the difference Δt between the scheduled date and time Tc when the sterilization operation condition is met and the scheduled date and time Tb to start the hot water storage operation is equal to the specified time t. Therefore, ΔT=4h is calculated. Then, as shown by the arrow, a date and time ΔT before the scheduled hot water storage operation start date and time Tb is set as the scheduled sterilization operation start date and time Te. Thereby, it becomes possible to start the sterilization operation before the scheduled date and time Tb to start hot water storage operation and the scheduled date and time Tc to satisfy the sterilization operation conditions, and to finish the sterilization operation at the date and time Ta when hot water supply use starts.

The longer the variable predetermined time t is set, the more opportunities for sterilization operations with an earlier start date and time are expected to increase. It is possible to set the time to a long time to advance the date and time of the sterilization operation so that it is more likely to be performed. Further, for example, when it is desired to reduce the number of sterilization operations, it is possible to set the specified time t short to reduce the opportunity to advance the date and time of the sterilization operation.

Next, in S17 of FIG. 3, it is determined whether the entire amount of hot water in the hot water storage tank 2 has been replaced. If the determination in S17 is Yes, the date and time T0 when the entire amount of hot water in the hot water storage tank 2 was last replaced has changed, so the process returns and sterilization operation control is started in preparation for the sterilization operation when the next replacement time has elapsed. If the determination in S17 is No, the process advances to S18, and in S18 it is determined whether the scheduled sterilization operation start date and time Te has arrived. If the determination in S18 is No, the process returns to S17. If the determination in S18 is Yes, the process advances to S21.

On the other hand, if the determination in S14 is No, the process advances to S19, and in S19 it is determined whether the entire amount of hot water in the hot water storage tank 17 has been replaced. If the determination in S19 is Yes, the process returns and the sterilization operation control is started in preparation for the sterilization operation when the next replacement time has elapsed. If the determination in S19 is No, the process advances to S20, and in S20 it is determined whether the scheduled date and time Tc for satisfying the sterilization operation conditions has arrived. If the determination in S20 is No, the process returns to S19. If the determination in S20 is Yes, the process advances to S21.

Next, in S21, discharging hot water from the hot water storage tank 2 for use in hot water supply is prohibited, and a sterilization operation is started. At this time, the main heat source device 4 and pump 7 are driven to circulate hot water between the hot water storage tank 2 and the main heat source device 4, and the hot water heated by the main heat source device 4 to a temperature that kills bacteria is stored in the hot water storage tank 2. do.

When the state in which the hot water storage tank 2 is filled with hot water is maintained for a certain period of time and the scheduled sterilization operation time has elapsed, the sterilization operation is ended in S22, the prohibition of hot water discharge from the hot water storage tank 2 is canceled, and the process proceeds to S23. As a result, the sterilization operation is completed at the hot water supply usage start date and time Ta, and the high temperature hot water in the hot water storage tank 2 after the sterilization operation can be used for hot water supply from the hot water supply usage start date and time Ta. Therefore, the sterilization operation can be performed without interfering with the use of hot water supply, and the high temperature hot water after the sterilization operation can be used for hot water supply so that it is not wasted.

Next, in S23, the date and time when the sterilization operation ended is set as the date and time T0 when the entire amount of hot water in the hot water storage tank 2 was replaced last, and the process returns, and sterilization operation control is started in preparation for the sterilization operation when the next replacement time has elapsed. do. As in the case where the entire amount of hot water in the hot water storage tank 2 is replaced, the concentration of bacteria that can proliferate in the hot water storage tank 2 decreases due to the sterilization operation, so the date and time of the end of the sterilization operation is used as the starting point for the passage of the next replacement time.

The functions and effects of the hot water storage and hot water supply device 1 described above will be explained.
The hot water storage and hot water supply apparatus 1 is configured such that the hot water storage unit control section 18 controls the hot water storage operation based on the hot water supply prediction, and performs the sterilization operation when the sterilization operation conditions are satisfied. If the difference between the scheduled date and time Tc when sterilization operation conditions are satisfied and the scheduled date and time Tb to start hot water storage operation is less than the specified time t, the sterilization operation is advanced by the difference ΔT between the scheduled sterilization operation time and the scheduled hot water storage operation time from the scheduled date and time Tb to start hot water storage operation. Set the scheduled start date and time Te. If the hot water in the hot water storage tank 2 has not been completely replaced by the scheduled sterilization start date and time Te, the sterilization is started. By advancing the start of the sterilization operation in this way, the sterilization operation can be completed at the scheduled end date and time of the hot water storage operation (hot water supply use start date and time Ta), so the sterilization operation can be performed without interfering with the use of hot water supply. be able to. In addition, since the high temperature hot water after the sterilization operation can be used for hot water supply, energy consumption can be saved by avoiding the hot water storage operation before the sterilization operation conditions are established and the hot water supply by the auxiliary heat source device 5 during the sterilization operation. can.

At this time, since the prescribed time t is variable, for example, if it is desired to use safe hot water after sterilization, the prescribed time t can be set longer to bring the date and time of the sterilization earlier and make it easier to perform it. Furthermore, in order to reduce the chances of sterilization, for example, when it is desired to reduce the waste of unused high-temperature hot water, it is possible to set the specified time t short to reduce the chances of advancing the date and time of sterilization.

In addition, when a configuration is configured such that the larger the target hot water storage heat value is, the longer the specified time t is set, the larger the target hot water storage heat value is, the more opportunities and usage amount of high temperature hot water in the hot water storage tank 2 after sterilization operation will be used for hot water supply. . Therefore, the larger the target hot water storage heat value is, the smaller the increase in energy consumption due to sterilization operation from the planned energy consumption of hot water storage operation becomes, so that energy consumption can be saved.

The above method also applies to a hot water storage water supply device configured to supply hot water directly from the hot water storage unit when there is hot water at a temperature that can be supplied in the hot water storage tank, and to supply hot water from the auxiliary heat source device when there is no hot water that can be supplied in the hot water storage tank. Sterilizing operations can be applied. In addition, those skilled in the art can implement various modifications to the embodiments described above without departing from the spirit of the present invention, and the present invention includes such modifications.

1: Hot water storage water supply device 2: Hot water storage tanks 2a to 2d: Hot water storage temperature sensor 3: Hot water storage unit 4: Main heat source machine (heat source machine)
5: Auxiliary heat source unit 5a: Water inlet 5b: Hot water supply port 6: Hot water tap 7: Pump 8: Main heat source unit going passage 9: Main heat source unit return passage 9a: Return branch passage 10: Switching valve 11: Water supply passage 11a: Water supply Branch passage 11b: Water supply temperature sensor 12: Hot water outlet passage 12a: Hot water outlet flow rate sensor 12b: Hot water storage tank outlet temperature sensor 12c: Outlet hot water temperature sensor 14: Mixing valves 15, 16: Hot water passage 18: Hot water storage unit control section (control section)
19: Operation terminal

Claims (3)

A heat source device, a hot water storage tank, and a control section for controlling a hot water storage operation for storing hot water heated by the heat source device in the hot water storage tank, the control section based on a hot water supply prediction predicted based on a hot water usage history. In the hot water storage and hot water supply device that controls the hot water storage operation,
The control unit is configured to perform a sterilization operation of prohibiting hot water supply in the hot water storage tank and sterilizing the hot water in the hot water storage tank when a preset sterilization operation condition is satisfied;
If the difference between the scheduled date and time when the sterilization operation condition is satisfied and the scheduled start date and time of the hot water storage operation based on the hot water supply prediction is less than a specified time, the sterilization operation required for the sterilization operation starts from the scheduled start date and time of the hot water storage operation. The hot water storage and hot water supply device is characterized in that the sterilization operation is started when the hot water in the hot water storage tank has not been completely replaced by a date and time advanced by the difference between the scheduled time and the scheduled hot water storage operation time required for the hot water storage operation. The hot water storage and hot water supply device according to claim 1, wherein the specified time is variable. The hot water storage and hot water supply apparatus according to claim 1, wherein the control unit sets the prescribed time to be longer as the target hot water storage heat amount of the hot water storage operation is larger.

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