JP2019173975A - Hot water storage and supply device - Google Patents

Abstract

To provide a hot water storage and supply device capable of improving a COP of a heat pump heat source machine when performing hot water storage operation in consideration of residual hot water.SOLUTION: A hot water storage and supply device (1): predicts hot water use amount in the future by learning and storing usage of hot water; and preliminarily stores a heat quantity corresponding to the predicted hot water use amount in a hot water storage tank (4) by activating a heat pump heat source machine (3) before hot water is actually used. The hot water storage and supply device: has residual temperature estimation means which estimates a temperature of residual hot water inside the hot water storage tank (4) in consideration of a temperature reduction due to heat radiation until next hot water storage operation; and, when estimating that the temperature of residual hot water becomes a reheat requiring temperature requiring an auxiliary heat source machine to reheat the hot water at the time of the next hot water storage operation, performs homogenizing operation to homogenize the temperature of the hot water inside the hot water storage tank.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a hot water storage and hot water supply apparatus, and more particularly to a technique for effectively using residual hot water remaining in a hot water storage tank due to a prediction error when hot water usage estimated by learning control is stored.

  Conventionally, a heat pump heat source device in which a compressor, a condensation heat exchanger, an expansion means, and an evaporation heat exchanger are connected by a refrigerant circuit, and a hot water storage tank for storing hot water heated by the heat pump heat source device, A hot water storage and hot water supply apparatus having a circulation pump that circulates hot water between the hot water storage tank and the heat pump heat source device and an auxiliary heat source device that reheats when the hot water temperature of the hot water storage tank decreases is widely used. Has been.

  In this type of hot water storage hot water supply device, the future hot water usage is predicted by learning and storing the hot water usage, and the heat pump heat source device is driven before the hot water usage to calculate the amount of heat corresponding to the predicted hot water usage. Storage in a hot water storage tank is also widely performed.

  Here, if the actual amount of hot water used is less than the predicted amount of hot water used, residual hot water may remain in the hot water storage tank after the end of the daily hot water use. In this case, the first hot water storage operation in the next morning At this time, it is desirable to perform the hot water storage operation in consideration of the residual hot water. However, since the temperature of the residual hot water decreases due to heat dissipation, it does not always maintain a temperature higher than the reheating required temperature that requires reheating by the auxiliary heat source machine when supplying hot water the next day. The temperature during hot water storage operation on the next day varies depending on the temperature. Therefore, it is a difficult problem how to take advantage of the residual hot water during the hot water storage operation on the next day and to perform the hot water storage operation.

  In the hot water storage hot water supply system of Patent Document 1, when there are a high temperature layer, a medium temperature layer above the reheating effective temperature, and a low temperature layer in the hot water storage tank, the high temperature layer and the medium temperature layer are mixed together. The temperature of the upper part in the hot water storage tank is lowered to improve the resistance to reheating hot water.

Japanese Patent No. 5454534

  As described above, when residual hot water remains in the hot water storage tank, the temperature of the residual hot water decreases by heat radiation until the next morning, and becomes hot water having a temperature lower than the hot water supply set temperature. When heating the medium temperature water with a heat pump heat source machine, there is a problem that the COP of the heat pump heat source machine is lowered.

  The objective of this invention is providing the hot water storage hot-water supply apparatus which can improve COP of the heat pump heat source machine in the case of performing the hot water storage operation which considered the residual hot water.

  The hot water storage hot water supply apparatus according to claim 1 stores a heat pump heat source device in which a compressor, a condensation heat exchanger, an expansion means, and an evaporation heat exchanger are connected by a refrigerant circuit, and hot water heated by the heat pump heat source device. A hot water storage tank, a circulation pump for circulating hot water between the hot water storage tank and the heat pump heat source device, and an auxiliary heat source device for reheating and discharging hot water when the hot water temperature of the hot water storage tank decreases. A hot water storage hot water storage device that predicts the future hot water usage by learning and storing the hot water usage, and drives the heat pump heat source device before using the hot water to store the amount of heat equivalent to the predicted hot water usage. In the hot water storage and hot water storage device stored in the hot water storage device, residual temperature estimation means for estimating a temperature when the temperature of the residual hot water in the hot water storage tank decreases due to heat radiation until the next hot water storage operation is provided. If the residual hot water temperature estimated by the residual temperature estimating means becomes a temperature that needs to be reheated by the auxiliary heat source machine during the next hot water storage operation, a specific operation for equalizing the hot water temperature in the hot water storage tank is performed. It is characterized by doing.

  According to the above configuration, the residual temperature estimating means for estimating the temperature of the remaining hot water in the hot water storage tank at the next hot water storage operation is provided, and the residual hot water temperature estimated by the residual temperature estimating means is the auxiliary heat source at the next hot water storage operation. When the temperature reaches the temperature that requires reheating by the machine, the hot water temperature in the hot water storage tank is made uniform, so that the hot water temperature in the hot water storage tank can be lowered uniformly. It is possible to prevent the COP of the heat pump heat source machine from decreasing during the next hot water storage operation.

According to a second aspect of the present invention, there is provided the hot water storage and hot water supply apparatus according to the first aspect of the invention, wherein the equalization process is performed by driving the circulation pump and stirring the hot water storage tank without driving the heat pump heat source device. Yes.
According to said structure, the inside of a hot water storage tank can be stirred using a circulation pump.

  According to a third aspect of the present invention, in the first or second aspect of the invention, when the residual hot water is not heated by the heat pump heat source device during the next hot water storage operation, the residual hot water temperature estimated by the residual temperature estimating means is The homogenization process is not performed even at a temperature that requires reheating by the auxiliary heat source machine during the next hot water storage operation.

  According to the above configuration, for example, when the amount of residual hot water is small, the residual hot water is not heated by the heat pump heat source device at the next hot water storage operation, so that the residual hot water temperature is reheated by the auxiliary heat source device at the next hot water storage operation. Even at a necessary temperature, it is advantageous not to perform the homogenization treatment.

According to a fourth aspect of the present invention, there is provided the hot water storage hot water supply apparatus according to any one of the first to third aspects, wherein the equalization process is performed immediately before the start of the next hot water storage operation.
According to said structure, the said homogenization process can be performed immediately before the next hot water storage driving | operation start, and the uniform state in the hot water storage tank at the time of hot water storage can be maintained.

  As described above, the present invention has various effects.

1 is an overall configuration diagram of a hot water storage and hot water supply apparatus according to an embodiment of the present invention. It is a flowchart of hot water supply equipment usage data acquisition control. It is a flowchart of hot water storage operation control. It is a flowchart of the equalization process at the time of residual hot water generation | occurrence | production in a hot water storage tank. It is a time chart of predicted hot water supply usage and hot water storage operation hot water. It is a time chart which shows the waiting time until the next hot water storage driving | operation at the time of residual hot water generation | occurrence | production in a hot water storage tank.

  Hereinafter, modes for carrying out the present invention will be described based on examples.

Initially, the whole structure of the heat pump hot-water supply apparatus 1 is demonstrated based on FIG.
The heat pump hot water supply apparatus 1 includes a hot water storage hot water supply unit 2 and a heat pump heat source unit 3, and the hot water storage hot water supply unit 2 includes a hot water storage tank 4, a gas combustion type auxiliary heat source device 5, and other devices (pipes, valves, temperature sensors). Etc.) and an exterior case 2a covering the hot water storage hot water supply unit 2. The hot water storage hot water supply unit 2 stores hot water heated by driving the heat pump heat source device 3 in a hot water storage tank 4, and uses the stored hot water for hot water supply or filling of a bathtub 6. Moreover, the hot water taken out from the hot water storage tank 4 can be heated by the auxiliary heat source device 5 as needed, and can be used for hot water supply, bath bathing, and the like.

  A hot water supply passage 7 for discharging hot water stored in the hot water storage tank 4 is connected to the upper part of the hot water storage tank 4. A water supply passage 8 for supplying hot water from the hot water source to the hot water storage tank 4 is connected to the lower part of the hot water storage tank 4. A bypass passage 9 branched from the water supply passage 8 is connected to the hot water passage 7, and a hot water / water mixing valve 10 capable of adjusting a mixing ratio for mixing the hot water in the hot water passage 7 and the clean water of the bypass passage 9 is provided at this connection portion. Has been. A hot water supply passage 11 is connected to the hot water mixing valve 10, and hot water mixed by the hot water mixing valve 10 can flow through the hot water supply passage 11 and supply hot water to a hot water tap or the like not shown in the figure. It is possible to fill the bathtub 6 with a hot water passage 13 connected to the memorial passage 12. The hot water filling passage 13 is provided with an open / close valve 13a for hot water filling.

  A hot water supply passage 16 for supplying hot water to the heat pump heat source unit 3 is connected to the lower part of the hot water storage tank 4, and a return side hot water passage 17 for supplying hot water heated by the heat pump heat source device 3 to the hot water storage tank 4 is connected to the hot water storage tank. 4, a circulation heating passage 15 is formed between the hot water storage tank 4 and the heat pump heat source unit 3 so that hot water can circulate.

  An incoming water temperature sensor 18, a circulation pump 19, and a switching valve 20 are connected to the outgoing hot water passage 16 to detect the incoming temperature of hot water entering the heat pump heat source unit 3 from the hot water storage tank 4. A heating temperature sensor 21 that detects the temperature of hot water heated by the heat pump heat source unit 3 is connected to the return side hot water passage 17, and a bypass passage 22 that connects the outgoing side hot water passage 16 and the return side hot water passage 17 is provided. The switching valve 20 is connected to the connecting portion between the outgoing hot water passage 16 and the bypass passage 22. When the heating temperature is low, such as immediately after the heat pump heat source unit 3 is started, the hot water heated by the heat pump heat source unit 3 by switching the switching valve 20 can be sent again to the heat pump heat source unit 3 to be reheated.

  On the outer periphery of the hot water storage tank 4, a plurality of hot water storage temperature sensors 4 a to 4 d that detect the temperature of the stored hot water are provided at predetermined intervals in the vertical direction. These hot water storage temperature sensors 4a to 4d and the hot water storage tank 4 are covered with a heat insulating material (not shown). Connected to the hot water passage 7 is a hot water temperature sensor 7 a for detecting the hot water temperature of hot water supplied to the hot water mixing valve 10. A water supply temperature sensor 8 a for detecting the temperature of the clean water supplied from the clean water source is connected to the feed water passage 8. A flow meter 11b for detecting the flow rate of hot water to be supplied and a hot water supply temperature sensor 11a for detecting the hot water temperature are connected to the downstream side of the hot water / water mixing valve 10 in the hot water supply passage 11.

An auxiliary heating passage 23 for heating hot water in the hot water storage tank 4 with the auxiliary heat source unit 5 is branched from the hot water passage 7 and connected to the auxiliary heat source unit 5. An auxiliary hot water passage 24 for discharging hot water heated by the auxiliary heat source unit 5 is connected to the hot water passage 7 on the downstream side of the branching portion of the auxiliary heating passage 23 via an adjustment valve 25. The auxiliary hot water passage 24 is provided with a temperature sensor 24a.
The adjustment valve 25 adjusts the flow rate of hot water supplied to the hot water passage 7 through the auxiliary hot water passage 24. The auxiliary heating passage 23 is provided with a three-way valve 26 and a pump 27 for sending hot water to the auxiliary heat source unit 5.

  A heat exchange passage 28 branched from the auxiliary hot water passage 24 is connected to the three-way valve 26. The three-way valve 26 is switched so that hot water in the hot water storage tank 4 or hot water in the heat exchange passage 28 can be supplied to the auxiliary heat source unit 5. A heat exchanger 29, an on-off valve 30, and a temperature sensor 28a are interposed in the heat exchange passage 28. The heat exchanger 29 is used for a chasing operation in which hot water in the bathtub 6 flowing through the chasing passage 12 is heated by heat exchange with hot water heated by the auxiliary heat source unit 5 by the operation of the chasing pump 31.

  Connected to the water supply passage 8 are a check valve 32 and a branch passage portion 33 branched from the water supply passage 8 and connected to the heat exchange passage 28. A check valve 34 is interposed in the bypass passage 9, and a high temperature hot water avoidance electromagnetic valve 36 is interposed in the high temperature hot water avoidance passage 35 branched from the bypass passage 9 and connected to the hot water supply passage 11. The various devices (pumps, valves, sensors) described above are electrically connected to the control unit 43 and controlled by the control unit 43.

  The heat pump heat source unit 3 includes a heat pump circuit in which a compressor 37, a condensation heat exchanger 38, an expansion valve 39, and an evaporating heat exchanger 40 are connected by a refrigerant pipe 41. The heat pump heat source unit 3 compresses the refrigerant sealed in the refrigerant pipe 41 with the compressor 37 to raise the temperature, and drives the circulation pump 19 to heat the hot water flowing through the circulation heating circuit 15 at a high temperature in the condensation heat exchanger 38. It heats by heat exchange with the refrigerant. The refrigerant after the heat exchange expands at the expansion valve 39 and becomes cooler than the outside air, absorbs heat from the outside air in the evaporating heat exchanger 40, and is then introduced into the compressor 37 again.

  The evaporative heat exchanger 40 includes an outside air temperature sensor 40a for detecting the outside air temperature and a blower 40b. The heat pump heat source unit 3 includes an auxiliary control unit 42 that controls the compressor 37, the expansion valve 39, the blower 40b, and the like. The auxiliary control unit 42 is communicably connected to the control unit 43 and controls the heat pump heat source unit 3 in accordance with instructions from the control unit 43 and the like. The outside air temperature detected by the outside air temperature sensor 40 a is transmitted to the control unit 43 via the auxiliary control unit 42.

Next, various controls employed in the hot water storage hot water supply apparatus 1 will be described.
In this hot water storage and hot water supply apparatus 1, a future hot water supply usage is predicted by learning and storing a hot water usage, and the heat pump heat source unit 3 is driven before the hot water use to store the amount of heat corresponding to the predicted hot water usage. Store in tank. In addition, the flowchart demonstrated below is stored in the control part 43, and the code | symbol Si (i = 1, 2, ...) in a flowchart shows each step.

This learning memory (hot water supply usage data acquisition control) will be described with reference to FIGS. 2, 3, and 5.
In FIG. 2, the hot water use amount data acquisition control is a control that is always executed while the hot water storage hot water supply device 1 is in operation. When this hot water use amount data acquisition control is started, various signals are read from the sensors in S1, and then in S2, the data on the hot water use amount every 60 minutes is calculated in time series.
Note that the amount of hot water used is calculated through calorific value calculation using detection data of the temperature sensors 24a, 7a, 11a, 28a and the flow meter 11b. Next, in S3, the hot water usage amount for every 60 minutes is stored in a predetermined memory in association with the year, month, day of the week, and time zone, and the above S1 to S3 are repeatedly executed.

Next, hot water storage operation control will be described with reference to FIGS.
When this hot water storage operation control is started, in S10, hot water usage data for one day of the corresponding day of the week is read from the memory, and in S11, based on the hot water usage data read in S10, The estimated hot water usage every 60 minutes is calculated for one day by time zone. For example, as shown in FIG. 5, a predicted hot water supply usage amount similar to the hot water supply usage amount is calculated.

  Next, in S12, a hot water storage operation schedule for every 60 minutes for one day is created based on the predicted hot water supply usage every 60 minutes. This is a hot water storage operation schedule for storing the predicted hot water usage every 60 minutes immediately before hot water supply (for example, one hour ahead).

  For example, as shown in FIG. 5, a hot water storage hot water amount schedule in which the predicted hot water supply usage amount is advanced by one hour is calculated. Next, in S13, based on the hot water storage operation schedule, it is determined whether or not it is the hot water storage operation timing. If the determination is Yes, the hot water storage operation based on the hot water storage operation schedule is executed in S14. Next, in S15, it is determined whether or not the time is 24:00. If the determination is No, S13 to S15 are repeated, and if the determination in S15 is Yes, the control ends. Note that the hot water storage operation control from 0 o'clock the next day may be started without terminating the control at 24:00.

Next, the equalization process performed when the remaining hot water is generated in the hot water storage tank 4 at the end of hot water supply on each day (for example, 24:00) will be described with reference to FIG.
This equalization process estimates the temperature when the temperature of the remaining hot water in the hot water storage tank 4 is lowered due to heat radiation until the next hot water storage operation, and this estimated residual hot water temperature is determined by the auxiliary fuel during the next hot water storage operation. When the temperature needs to be reheated, the hot water temperature in the hot water storage tank 4 is made uniform.

  When this control is started, it is determined in S20 whether or not there is residual hot water in the hot water storage tank at the time of 24:00 (at the end of hot water supply for each day). This determination is made based on detection signals from the temperature sensors 4 a to 4 d of the hot water storage tank 4. If the determination in S20 is No, the control is terminated. If the determination in S20 is Yes, the remaining hot water temperature Tr is detected in S21 based on the detection signals of the temperature sensors 4a to 4d of the hot water storage tank 4.

Next, in S22, the standby time until the first hot water storage operation of the next morning is calculated, and the remaining hot water temperature Ty of the next morning is estimated and calculated based on the standby time and the heat dissipation characteristics set in the hot water storage tank 4. . FIG. 6 is a time chart showing the standby time and the first hot water storage operation in the next morning.
Note that step S22 and the control unit 43 correspond to the residual temperature estimating means.

  Next, in S23, it is determined whether or not the residual hot water temperature Ty is equal to or lower than a reheating required temperature (for example, 36 ° C. or less) that requires reheating by the auxiliary heat source unit 5. If the determination is Yes, in S24 Drives the pump 19 and circulates hot water in the hot water storage tank 4 through the circulation heating passage 15 to stir the hot water in the hot water storage tank 4 to make the hot water temperature uniform (this makes the hot water temperature uniform) Processing). In addition, this equalization process is performed, for example, for the time of circulating about half of the total amount of hot water in the hot water storage tank 4 to the circulation heating passage 15.

  As described above, when the hot water in the hot water storage tank 4 is agitated and the temperature thereof is made uniform to lower the temperature, the COP of the heat pump heat source device 3 is operated when the heat pump heat source device 3 is operated and the hot water storage operation is performed the next morning. Can be increased.

  That is, if there is residual hot water in the upper part of the hot water storage tank 4 and if it is not stirred, the low temperature hot water in the lower part of the hot water storage tank 4 can be supplied to the heat pump heat source unit 3 at the time of hot water storage operation the next morning, so the COP is kept high. However, when the medium temperature residual hot water is supplied to the heat pump heat source unit 3 after that, the COP of the heat pump heat source unit 3 is remarkably lowered, and the COP of the heat pump heat source unit 3 is lowered as a whole. It is more advantageous to perform the homogenization process.

  Next, in S25, it is determined whether or not the outside temperature detected by the temperature sensor 40a is equal to or lower than a set temperature Ts (for example, 0 ° C.). If the determination is No, the control is terminated, and the determination in S25 is Yes. In this case, a freeze prevention operation is performed in which the hot water in the hot water storage tank 4 is intermittently circulated through the circulation heating passage 15 to prevent the piping of the heating passage 15 from freezing. Next, in S27, it is determined whether or not the first hot water supply operation in the next morning has been completed. If the determination is No, the process returns to S25 and repeats S25 to S27. When the determination in S27 becomes Yes, this control ends.

  On the other hand, when the remaining hot water temperature Ty in the next morning is higher than the reheating required temperature and the determination in S23 is No, it is determined in S28 whether or not the outside air temperature is equal to or lower than the set temperature Ts. If the determination is No, the control is performed. When the determination is YES in S28, the switching valve 20 is switched so that the outgoing hot water passage 16 and the bypass passage 22 communicate with each other, the heat pump heat source unit 3 and the pump 19 are intermittently driven, and the hot hot water is heated. The freeze prevention operation is performed in which the heat is circulated through the condensation heat exchanger 38, the return side hot water passage 17, the bypass passage 22, and the forward side hot water passage 16. Next, in S30, it is determined whether or not the first hot water supply operation in the next morning is completed. If the determination is No, the process returns to S28 and repeats S28 to S30. When the determination in S30 is Yes, this control is ended.

The operation and effect of the hot water storage hot water supply apparatus 1 will be described.
As shown in FIG. 4, when the temperature of the remaining hot water in the hot water storage tank 4 at the next hot water storage operation is estimated, and the estimated residual hot water temperature Ty becomes the reheating required temperature at the next hot water storage operation, the hot water storage tank In order to carry out a homogenization process to make the temperature of the hot water in 4 uniform, the temperature of the hot water in the hot water storage tank is uniformly reduced to prevent the COP of the heat pump heat source unit 3 from being lowered during the next hot water storage operation. Can do. In addition, the said equalization process is performed by driving the circulation pump 19 in the state which does not drive the heat pump heat-source apparatus 3, and stirring the hot water storage tank 4. FIG.

  In addition, as shown in S26 of FIG. 4, when the outside air temperature is low, in order to perform the freeze prevention operation for preventing the pipe from freezing by circulating the medium temperature water at a uniform temperature in the hot water storage tank 4, It is not necessary to operate the heat pump heat source unit 3 to prevent freezing, thus saving energy.

Further, if the residual hot water temperature Ty does not reach the reheating required temperature during the next hot water storage operation, the temperature stratification in the hot water storage tank 4 can be maintained by omitting the equalization process.
In this case, as described in S29, the heat pump heat source unit 3 is intermittently driven and the freeze prevention operation is performed such that hot water is circulated using the bypass passage 22, so that the temperature stratification in the hot water storage tank 4 is maintained. can do.

Next, an example in which the embodiment is partially changed will be described.
1] In the homogenization process of FIG. 4, the step of S24 was executed immediately after 24:00 because of the freeze prevention operation. However, when several hours elapse after the execution of the specific operation, the high temperature water moves upward, the low temperature water moves downward, and the hot water temperature becomes uneven.
Therefore, at the time immediately before the start of the first hot water storage operation in the next morning, the same step as S24 may be repeated to make the hot water temperature in the hot water storage tank 4 uniform.

  2] As a condition for executing S24, S24 is executed only when the amount of residual hot water is not less than a predetermined amount (for example, 1/3 of the volume of the hot water storage tank 4), and the amount of residual hot water is not more than the predetermined amount. In this case, the equalization process is not executed even if the determination in S23 is Yes.

  That is, when the amount of residual hot water is equal to or less than a predetermined amount, the residual hot water is not reheated by the heat pump heat source unit 3 during the next hot water storage operation. That is, even if the hot water temperature in the hot water storage tank 4 is made uniform by the homogenization process, the temperature drop due to the homogenization is small, and the effect of preventing the COP reduction of the heat pump heat source unit 3 cannot be expected so much. It is assumed that no processing is executed.

3] When a stirring means (for example, a stirring blade rotated by a motor) capable of stirring hot water in the hot water storage tank 4 is provided, the specific operation can be performed by driving the stirring means.
4] In addition, the present invention can be implemented by partially modifying the embodiment without departing from the gist of the present invention, and the present invention includes such a modified form.

DESCRIPTION OF SYMBOLS 1 Hot water storage hot water supply apparatus 2 Hot water storage hot water supply unit 3 Heat pump heat source machine 4 Hot water storage tank 5 Auxiliary heat source machine 15 Circulation heating passage 19 Circulation pump 37 Compressor 38 Condensing heat exchanger 39 Expansion means 40 Evaporation heat exchanger 43 Control part

Claims (4)

A heat pump heat source device in which a compressor, a condensation heat exchanger, an expansion means, and an evaporative heat exchanger are connected by a refrigerant circuit, a hot water storage tank for storing hot water heated by the heat pump heat source device, and this hot water storage A hot water storage and hot water supply apparatus comprising a circulation pump for circulating hot water between a tank and a heat pump heat source device, and an auxiliary heat source device for reheating and discharging hot water when the hot water temperature of the hot water storage tank decreases. In the hot water storage hot water supply device that predicts the amount of hot water used in the future by learning and storing the usage status of the hot water, and driving the heat pump heat source machine before using the hot water to store the amount of heat corresponding to the predicted hot water usage in the hot water storage tank,
A residual temperature estimating means for estimating a temperature when the temperature of the residual hot water in the hot water storage tank decreases due to heat radiation until the next hot water storage operation,
When the residual hot water temperature estimated by the residual temperature estimating means becomes a temperature that needs to be reheated by the auxiliary heat source device during the next hot water storage operation, a homogenization process is performed to equalize the hot water temperature in the hot water storage tank. A hot water storage hot water supply device characterized by that.   The hot water storage hot water supply apparatus according to claim 1, wherein the homogenization processing is performed by driving the circulation pump and stirring the hot water storage tank without driving the heat pump heat source device.   If the residual hot water is not heated by the heat pump heat source device during the next hot water storage operation, the residual hot water temperature estimated by the residual temperature estimating means is a temperature that requires reheating by the auxiliary heat source device during the next hot water storage operation. The hot water storage and hot water supply apparatus according to claim 1 or 2, wherein the equalization process is not performed.   The hot water storage hot water supply apparatus according to any one of claims 1 to 3, wherein the equalization process is performed immediately before the start of the next hot water storage operation.