JP5904010B2 - Control method for hot water storage hot water supply system - Google Patents

Description

  The present invention relates to a method for controlling a hot water storage hot water supply apparatus, and stores high temperature water heated by using an external heat source device in a hot water storage tank to store heat, while low temperature water is extracted from the top of the hot water storage tank when hot water is used. For hot water storage water heaters that adjust the temperature to the set hot water temperature by mixing the hot water supply, and when hot water is used again while waiting for re-hot water after the end of the previous hot water use, The present invention relates to a control method for allowing hot water to be supplied at a stable temperature at the set hot water supply temperature from the beginning of the start.

  Conventionally, as a method for controlling a hot water storage and hot water supply apparatus, a method using a heat pump as an external heat source is known (see, for example, Patent Documents 1 and 2). In the hot water storage hot water supply apparatus described in Patent Document 1, high temperature water (hot water) heated by a heat pump is stored in a hot water storage tank for heating operation control (hot water storage operation control), and high temperature water is supplied from the top of the hot water storage tank. Hot water supply operation control for taking out and supplying hot water is performed separately and independently. That is, the heat storage control that heats the low temperature water taken out from the bottom of the hot water tank to the high temperature hot water by circulating to the condensation heat exchanger of the heat pump and returns to the top of the hot water tank, and takes out from the top of the hot water tank The hot water supply control in which the hot water is mixed with a predetermined mixing ratio to adjust the temperature to the set hot water supply temperature and hot water is supplied to the hot water supply destination is independent of each other. Moreover, in the hot water storage hot water supply apparatus described in Patent Document 2, when the heating operation control and the hot water supply operation control are simultaneously performed, the target hot water temperature for heating by the heat pump is set as the target hot water storage temperature when the heating operation control is performed independently. It has been proposed that the COP is so high that the occurrence of hot water can be suppressed.

Japanese Patent No. 3968631 JP 2006-78041 A

  However, in the control method of the conventional hot water storage and hot water supply apparatus, in the hot water standby state after the hot water supply operation control based on the previous hot water supply use is completed (the state in which it waits until the use of the hot water supply again), If the current hot water use occurs while the heating operation control has been continuously performed from before, the hot water temperature may be temporarily destabilized at the beginning of the hot water operation control. It is done.

  That is, the heating operation control is continuously performed for a certain period of time (for example, several hours) until the inside of the hot water tank is filled with high-temperature water having the target hot water storage temperature, while the use of hot water is relatively short (for example, several minutes). In many cases, the use of hot water supply is repeated at relatively short intervals during the execution of one heating operation control. For example, when the heating operation control is continued at a target hot water storage temperature of 65 ° C., high temperature water of 65 ° C. is returned from the heat pump to the top of the hot water storage tank and stored. At this time, when hot water is used, the hot water (hot water) of 65 ° C. taken out from the top of the hot water tank is mixed with low temperature water (water) so that the set hot water temperature (eg 40 ° C.) is reached. The mixing ratio of the mixing valve is changed and adjusted based on the hot water supply operation control. For example, the hot water temperature after mixing is set by feedback control based on the detected values of the inlet temperature of the mixing valve (temperature of hot water from the hot water tank), the temperature of low temperature water, and the hot water temperature after mixing. Thus, the mixing ratio of the mixing valve is changed and adjusted. Even if the heating operation based on the heating operation control is continued, the temperature of the hot water storage at the top is sequentially decreased by the removal of the high temperature water from the hot water storage tank, and the temperature of the extracted high temperature water is also gradually decreased (for example, 50 ° C.). Therefore, the mixing ratio in the mixing valve is gradually changed and adjusted accordingly, and when the use of hot water is finished, the mixing valve stops at the state of the mixing ratio at that time. When entering the hot water standby state, since the removal from the top of the hot water storage tank for hot water supply is also stopped, high temperature water of 65 ° C. is supplied to the top of the hot water storage tank by continuous heating operation, Accordingly, the storage temperature at the top also rises. When the hot water supply is used again (when the hot water is discharged again), the supply of high-temperature water to the mixing valve is started from the top of the hot water tank. At the start of the hot water control, the inlet temperature of the mixing valve is Since the temperature becomes considerably higher (eg, 65 ° C.) than the temperature at the previous stop of hot water supply (eg, 50 ° C.), the mixing valve is rapidly changed from the previous mixing ratio based on the detection of the inlet temperature at this time. Will end up. It is considered that the hot water supply temperature actually supplied may be temporarily destabilized due to a sudden change in the mixing ratio state of the mixing valve.

  In particular, when re-heating (using hot water again) occurs within a short time from the previous hot water use, the user who uses hot water is likely to be the same person, and the hot water temperature is unstable at the start of re-heating. When this occurs, the continuity of the hot water supply temperature is impaired, and as a result, the user's comfort is easily impaired.

  The present invention has been made in view of such circumstances, and the object of the present invention is to provide hot water supply when the use of hot water supply is stopped while the heating operation is being continued by the heating operation control and then stopped. An object of the present invention is to provide a method for controlling a hot water storage and hot water supply apparatus that can avoid destabilization of hot water supply temperature when use is started again and can stably supply hot water at a set hot water supply temperature.

  In order to achieve the object, in the present invention, a hot water storage tank, a water supply pipe connected to the bottom of the hot water tank, a hot water piping connected to the top of the hot water tank, and a high temperature discharged from the hot water piping. Mixing means for supplying hot water after adjusting the temperature to a set hot water supply temperature by mixing water and low temperature water branched and supplied from a branch pipe of the water supply pipe, and a target hot water storage temperature of the low temperature water at the bottom of the hot water tank A heating source control for storing hot water at the target hot water storage temperature in the hot water storage tank using the heat source device, and a heat source device for storing hot water in the hot water storage tank by heating to the top and returning to the top. The hot water storage operation control for performing hot water supply operation at a set hot water supply temperature by changing and adjusting the mixing ratio of the high temperature water and the low temperature water in the mixing means is directed to a control method of a hot water storage hot water supply apparatus as follows. Provide specific execution And the. That is, when the hot water supply operation control is stopped after the heating operation control is being executed and the hot water supply operation control is stopped, the hot water storage operation is stopped at the time when the hot water supply operation control is stopped until a predetermined condition is satisfied. The temperature of the high-temperature water discharged from the top of the tank to the mixing means is forcibly changed and set as the target hot-water storage temperature in the heating operation control (Claim 1).

  In the case of the present invention, from the time when hot water supply operation control is stopped until the predetermined condition is satisfied, the temperature of the hot water discharged to the mixing means at the time when hot water supply operation control is stopped is set to the target hot water storage temperature for heating operation. Control will be executed. That is, the temperature of the hot water heated by the heat source device and returned to the top of the hot water tank to be stored is the same as the temperature of the hot water discharged to the mixing means when the hot water supply operation control is stopped. Become temperature. For this reason, even if hot water supply operation control occurs again, the temperature of the hot water discharged from the top of the hot water storage tank to the mixing means becomes the same temperature as that at the time of the previous stop of hot water supply operation control. Even if the means is in the state of the mixing ratio at the time when the previous hot water supply operation control is stopped, hot water supply at the set hot water supply temperature is reliably performed in the state as it is. For this reason, it is possible to reliably avoid the occurrence of a situation in which the hot water supply temperature becomes unstable at the time of starting the hot water supply operation control again, and the hot water supply at the set hot water supply temperature can be realized stably. It is possible to secure the sex.

  As the “predetermined condition” in the control method of the hot water storage and hot water supply apparatus of the present invention, it is possible to set time to elapse from the time when hot water supply operation control is stopped (claim 2). In this way, even after hot water supply operation control based on the previous use of hot water supply is stopped, even if hot water supply is used again within a relatively short time, the hot water supply temperature is unstable at the start time. It is possible to reliably avoid the occurrence of the situation. In this case, if the mixing means is configured to return to the standard mixture ratio state after the hot water supply operation control is stopped and the mixture ratio state at the time of the stop is maintained for a predetermined standby time, the set time The same time value as the waiting time can be set as (Claim 3). By doing in this way, it becomes possible to more surely avoid the occurrence of the situation of destabilization of the hot water temperature in the use of hot water that may occur in a relatively short time.

  Further, as “predetermined condition” in the control method of the hot water storage and hot water supply apparatus of the present invention, the hot water supply operation control can be started again, and a predetermined time can be passed from the start again ( Claim 4). By doing in this way, destabilization of hot water supply temperature at the time of starting use of hot water supply again can be avoided more reliably.

  Furthermore, in the control method of the hot water storage and hot water supply apparatus of the present invention, the temperature of the high-temperature water that has been discharged to the mixing means at the time of stopping the hot water supply operation control is on the condition that it is higher than the set hot water temperature by a set temperature or more. The forced change setting of the target hot water storage temperature can be permitted (claim 5). That is, if the temperature of the hot water that has been discharged to the mixing means at the time of stopping the hot water supply operation control is not higher than the set hot water temperature by a set temperature or more, the forced change setting of the target hot water storage temperature is not permitted. The heating operation control is continued at the normal target hot water storage temperature. By doing in this way, while the temperature of the high-temperature water that has been discharged to the mixing means is higher than the set hot water supply temperature by a set temperature or more, the start point of using the hot water supply again based on the forced change setting of the target hot water storage temperature However, if the temperature of the high-temperature water falls below a temperature that is higher than the set hot water temperature by a set temperature, the normal target hot water temperature is reached. By continuing the heating operation control based on this, it is possible to reliably avoid the occurrence of a situation where the hot water storage temperature in the hot water storage tank is excessively lowered.

  As described above, according to the control method of the hot water storage and hot water supply apparatus of the present invention, the hot water is discharged to the mixing means when the hot water supply operation control is stopped until the predetermined condition is satisfied after the hot water supply operation control is stopped. Since the heating operation control is executed by setting the temperature of the high-temperature water that has been set as the target hot water storage temperature, the temperature of the high-temperature water discharged from the top of the hot water storage tank to the mixing means even if the hot water supply operation control occurs again, It becomes possible to make the same temperature as that at the time of the previous stop of the hot water supply operation control. For this reason, even if the mixing means is in the state of the mixing ratio at the time when the previous hot water supply operation control is stopped, it is possible to reliably perform hot water supply at the set hot water supply temperature as it is. As a result, it is possible to reliably avoid the occurrence of instability of the hot water supply temperature at the time of starting the hot water supply operation control again, and to realize the hot water supply at the set hot water supply temperature stably, so that the user's comfort is achieved. Can be secured.

  In particular, according to claim 2, after the hot water supply operation control based on the previous use of the hot water supply is stopped by setting the predetermined time to elapse from the stop point of the hot water supply operation control as “predetermined condition”. Even when the hot water supply is used again within a relatively short time, it is possible to reliably avoid the occurrence of a situation where the hot water temperature becomes unstable at the start time. In this case, as set in the third aspect, by setting the same time value as the standby time in which the mixing means is maintained in the mixing ratio state at the time when the use of the hot water supply is stopped last time, It is possible to more reliably realize the avoidance of the situation of destabilization of the hot water temperature in the use of hot water that may occur again.

  Further, according to claim 4, the hot water supply operation control is started again as “predetermined conditions are satisfied”, and a predetermined time has elapsed since the start of the hot water supply operation again. This makes it possible to more reliably avoid instability of the hot water supply temperature at the start point of.

  Further, according to claim 5, the temperature of the target hot water storage temperature is set on the condition that the temperature of the hot water discharged to the mixing means at the time of stopping the hot water supply operation control is higher than the set hot water temperature by a set temperature or more. By allowing the forced change setting, while the temperature of the high-temperature water introduced into the mixing means is higher than the set hot water temperature by a set temperature or more, it is again determined based on the forced change setting of the target hot water temperature. While avoiding the occurrence of a situation in which the hot water temperature at the start of use of the hot water becomes unstable, if the temperature of the high-temperature water is lower than the set temperature higher than the set hot water temperature, By continuing the heating operation control based on the normal target hot water storage temperature, it is possible to reliably avoid the occurrence of a situation in which the hot water storage temperature in the hot water storage tank excessively decreases.

It is a schematic diagram which shows embodiment of this invention. It is a block diagram concerning control of this embodiment. It is a time chart which shows the relationship between the change of the hot water storage temperature of the top part of a hot water storage tank, and the change of the mixing ratio by a mixing valve. FIG. 4 is a diagram corresponding to FIG. 3 in comparison with FIG. 3.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic view of a hot water storage and hot water supply apparatus according to an embodiment of the present invention. The hot water storage hot water supply apparatus includes a heat source device 2, a hot water storage tank 3, a heating circuit 4 for circulating and heating hot water in the hot water storage tank 3 between the heat source apparatus 2, and hot water stored in the hot water storage tank 3. Is combined with a hot water supply circuit 5 for hot water supply. 1 is a water supply pipe, 7 is a mixing valve as a mixing means, and 8 is a controller as a control means for performing heating operation control, hot water supply operation control, and the like.

  The heat source device 2 uses a heat pump, and a compressor 21, a condensation heat exchanger (condenser) 22, an expansion valve 23 as decompression means, and an evaporation heat exchanger (evaporator) 24 are used as refrigerant. These are connected in order by the circulation pipe 25. As the refrigerant circulated through the refrigerant circulation pipe 25, an appropriate HC refrigerant such as propane or CO2 can be employed. Further, the heating circuit 4 condenses the water (low temperature water) from the circulation pipe 41 for circulating hot water stored in the hot water storage tank 3 to and from the condensation heat exchanger 22 and the bottom of the hot water storage tank 3. A circulation pump 42 is provided which is pumped to the heat exchanger 22 and led from the condensation heat exchanger 22 to the top of the hot water tank 2 after heating.

  The hot water tank 3 is composed of, for example, a pressure vessel made of stainless steel or the like, and is filled with water based on a water supply pressure such as tap water from a water supply pipe 6 connected to the bottom of the hot water tank 3. However, the heat source device 2 heat-exchanges and stores hot water with a predetermined target hot water temperature as a target. In the hot water storage tank 3, a plurality (four in the illustrated example) of hot water storage temperature sensors 31, 32, 33, and 34 are installed at respective positions in the vertical direction in order to detect the temperature of the internal hot water storage from the top to the bottom. Yes. The hot water supply circuit 5 has an upstream end connected to the top of the hot water tank 3, and a hot water outlet pipe 51 for introducing high temperature water at the top of the hot water tank 3 into the inlet of the mixing valve 7. There is provided a hot water supply pipe 53 for supplying hot water whose temperature is adjusted by mixing with a water supply from a branch pipe 61 branched in the middle to a hot water tap 52 at the downstream end. An outlet temperature sensor 54 for detecting the temperature of the high-temperature water just before being introduced into the mixing valve 7 is interposed in the hot water supply pipe 51, and a hot water temperature after being mixed by the mixing valve 7 is detected in the hot water supply pipe 53. A hot water temperature sensor 55 and a flow rate sensor 56 are interposed, and a branch water temperature sensor 62 for detecting the temperature of the water supply (low temperature water) is interposed in the branch pipe 61.

  The controller 8 is constituted by a microcomputer equipped with an MPU and a memory, and based on the operation signal output from the remote controller 81 that also functions as a notification means, and the detection signal output from the various temperature sensors 31,. The operation control of the heat source device 2, the heating circuit 4, the hot water supply circuit 5, the mixing valve 7 and the like is executed according to a predetermined program installed. In order to fulfill this function, the controller 8 includes a heating operation control unit 82 and a hot water supply operation control unit 83 as shown in FIG.

  The basic contents of the heating operation control by the heating operation control unit 82 and the hot water supply operation control by the hot water supply operation control unit 83 are as follows. That is, the heating operation control is started when a temperature drop in the hot water tank 3 is detected (for example, the hot water temperature sensor 34 detects a predetermined temperature or less), and the operation of the heat source device 1 and the circulation pump 42 of the heating circuit 4 is started. By controlling, the low temperature water taken out from the bottom of the hot water tank 3 is heated to the target hot water temperature in the condensation heat exchanger 22 to be hot water, and this high temperature water is returned to the top of the hot water tank 3. As the target hot water storage temperature, a predetermined high temperature (for example, 65 ° C.) is normally set, but in a specific case described later, temperature information is obtained from the hot water supply operation control unit 83 and is forcibly changed. . Then, the heating operation control is continued until the hot water tank 3 is filled with the high temperature water having the target hot water temperature (for example, until the hot water temperature sensor 34 detects a predetermined temperature or higher).

  The hot water supply operation control is started by detecting occurrence of hot water use. However, the hot water storage tank 3 is in a state where a predetermined high temperature water is stored particularly at the top, that is, the hot water can be supplied using the high temperature water at the top of the hot water storage tank 3. This is a precondition for starting the hot water supply operation control. The detection of the use of hot water is detected by detecting the flow of a predetermined minimum flow rate or more by opening the hot water tap 51 at the downstream end of the hot water supply circuit 5 by the flow sensor 56. As the hot water supply operation control, the mixing ratio of the mixing valve 7 is changed based on the temperature of the high temperature water by the inlet temperature sensor 54, the temperature of the low temperature water by the water temperature sensor 62, and the temperature after mixing by the hot water temperature sensor 55. The hot water supply at the set hot water supply temperature is supplied to the hot-water tap 52 by changing and adjusting the mixing ratio. That is, when hot water is discharged from the top of the hot water tank 3 to the hot water circuit 51 based on the feed water pressure, and when this hot water is introduced into the mixing valve 7, first, the temperature of the hot water and the temperature of the cold water Based on this, the mixing ratio that can be set to the set hot water temperature is calculated if both are mixed, and based on the detected value of the temperature after mixing at this mixing ratio, the mixing is performed by feedback control so as to converge to the set hot water temperature thereafter. Change and adjust the ratio.

  When the flow becomes less than the minimum operating flow rate due to the operation of closing the hot water tap 52 or the like, the hot water supply operation is stopped and the hot water supply standby state is entered until the next hot water supply is used. At this time, the mixing valve 7 is deactivated at the mixing valve position corresponding to the mixing ratio at the time of stopping the hot water supply operation, and after maintaining the mixing valve position until a predetermined waiting time (for example, 10 minutes) elapses, When the waiting time elapses, the standard mixing valve position is restored. On the other hand, if the hot water supply operation is stopped, the hot water supply operation control unit 83 sends the temperature of the high-temperature water (the detected temperature of the inlet temperature sensor 54) discharged to the mixing valve 7 at the time of the hot water supply operation stop to the heating operation control unit 82. Then, the target hot water storage temperature used so far in the heating operation control is forcibly changed and set to the temperature of the high temperature water at the time of stopping the hot water supply operation. Thereafter, the heating operation control unit 82 continues the heating operation control by setting the temperature of the high-temperature water to the target hot water storage temperature until a predetermined set time has elapsed since the previous stop of the hot water supply operation. In this embodiment, the waiting time of the mixing valve 7 is set as the set time.

  When hot water is used while the above heating operation control is being executed continuously, and after entering the hot water standby state after stopping hot water use, hot water is used again within a relatively short time. The control method according to the present embodiment will be described with reference to a specific example illustrated in FIG.

  That is, when the previous hot water supply is used, high temperature water of 65 ° C. corresponding to the target hot water temperature is discharged from the top of the hot water tank 3 to the mixing valve 7, for example, mixed with low temperature water of 15 ° C. to 40 ° C. In order to adjust the temperature to the set hot water supply temperature, the mixing ratio of high temperature water: low temperature water in the mixing valve 7 is adjusted to 5: 5. Thereafter, it is assumed that the temperature of the hot water discharged from the top of the hot water tank 3 to the mixing valve 7 gradually decreases with the progress of use of the hot water tank 3 and is lowered to 50 ° C. when the hot water supply is stopped. If the temperature of the low-temperature water is 15 ° C., the mixing ratio when the hot water supply is stopped is approximately 7: 3. And until the predetermined standby time elapses, the mixing valve 7 is maintained at a mixing ratio of approximately 7: 3 at the time of hot water use stop, and after the hot water use stop time until a predetermined set time elapses, The heating operation control is executed with the target hot water storage temperature set to 50 ° C., which is the temperature of the high-temperature water that has been discharged to the mixing valve 7 when the hot water supply is stopped. That is, hot water of 50 ° C. is supplied from the heating circuit 4 to the top of the hot water tank 3 to store hot water. Therefore, even if the hot water supply is used again within the set time, the temperature of the hot water discharged from the top of the hot water tank 3 to the mixing valve 7 is 50 ° C., which is the same as that at the previous hot water use stop time, Since the mixing ratio state of the mixing valve 7 is maintained at approximately 7: 3, which is the same as that at the time of the previous stop of hot water supply, hot water supply at the set hot water temperature can be reliably performed as it is. For this reason, it is possible to reliably avoid the occurrence of a situation in which the hot water temperature becomes unstable at the time of starting to use the hot water again, and it is possible to stably realize hot water supply at the set hot water temperature.

  On the other hand, as shown in FIG. 4, when the previous hot water supply is stopped, if the heating operation similar to the previous heating operation control is continued, again within the waiting time. When the hot water supply is used, the hot water temperature becomes unstable at the start time. That is, since the hot water supply to the mixing valve 7 is stopped by the previous stop of hot water supply, hot water having a target hot water temperature of 65 ° C. is supplied from the heating circuit 4 to the top of the hot water tank 3 and stored. The hot water storage temperature at the top of No. 3 is raised from the aforementioned 50 ° C. to 65 ° C. at an early stage. For this reason, when the hot water supply is used again, high temperature water of 65 ° C. is discharged from the top of the hot water storage tank 3 to the mixing valve 7, and the mixing ratio state maintained so far (almost 7: 3) When the water is mixed with water, hot water is supplied at a temperature higher than the set hot water temperature, and the hot water temperature sensor 55 detects the hot water temperature to change the mixing ratio abruptly. As a result, the hot water temperature is destabilized at the start of reusing hot water.

  In short, in the case of the control method of the present embodiment, the hot water discharged from the top of the hot water storage tank 3 with respect to the mixing valve 7 when the hot water supply is used again within a relatively short time within the set time. Can be made substantially the same as the temperature of the high-temperature water that has been poured out into the mixing valve 7 at the time when the hot water supply operation was stopped the last time, so that the mixing ratio state that was maintained in the mixing valve 7 at the start of re-bathing out If mixing is performed as it is, the hot water supply temperature after mixing can be reliably set to the set hot water supply temperature. In addition, the above is a temperature between the temperature of the high temperature water that has been discharged to the mixing valve 7 when the hot water supply is stopped and the temperature of the high temperature water that is discharged to the mixing valve 7 when the hot water supply is started again. By preventing the difference from occurring as much as possible, the hot water temperature at the start of re-use of the hot water supply is stabilized to avoid the occurrence of a situation where the hot water temperature becomes unstable. Thus, when using the high-temperature water taken out from the top of the hot water tank 3 as various heat exchange heat sources, a greater effect can be obtained. That is, the hot water taken out from the top of the hot water tank 3 is used as a heat source for heat exchange for circulating hot water in the circulation circuit using, for example, a hot water circulation heating device, or, for example, a heat source for reheating in a bath circulation circuit When using as a hot water supply temperature, there is a possibility that the hot water storage temperature at the top of the hot water storage tank 3 will fluctuate greatly in the standby state for re-draining hot water. This has a greater significance in terms of obtaining the effect of avoiding it.

<Other embodiments>
In addition, this invention is not limited to the said embodiment, Other various embodiment is included. That is, the control method of this embodiment can be applied to hot water storage hot water supply apparatuses other than the hot water storage hot water supply apparatus exemplified in the above embodiment. For example, the hot water supply circuit 5 may include an auxiliary heat source machine or a switching mechanism that can supply hot water after selective auxiliary heating by the auxiliary heat source machine.

  In the above-described embodiment, the control of forcibly changing and setting the temperature of the high-temperature water that has been discharged to the mixing valve 7 at the time of the previous stoppage of hot-water supply when the re-heated standby state is entered as the target hot-water storage temperature for heating operation control. Until the set time elapses from the previous hot water supply stoppage time, and the same time value as the standby time during which the mixing valve 7 maintains the mixing ratio state at the previous hot water supply use presentation time is set as the set time. However, the present invention is not limited to this, and the set time may be shorter by a predetermined amount or longer than the standby time.

  Moreover, in the said embodiment, although setting time passes from the last hot water supply use stop time, it is supposed that "predetermined conditions are satisfied", for example, a short time (for example, 1-2) after the hot water supply use is started again. Elapse of minutes) may be defined as “predetermined conditions”. That is, it is assumed that the “predetermined condition” is satisfied when the use of the hot water supply is started again and when the slight time has elapsed since the start. In this case, the use of hot water supply can be detected by the flow sensor 56. In this case, destabilization of the hot water supply temperature at the start of reuse of the hot water supply can be avoided more reliably.

  Furthermore, the above-mentioned forced change setting of the target hot water storage temperature is permitted on the condition that the temperature of the hot water discharged to the mixing valve 7 at the time of the previous stoppage of hot water supply is higher than the set hot water temperature by a set temperature or more. You may make it do. In this case, if the temperature of the high-temperature water that has been discharged to the mixing valve 7 at the time of the previous stoppage of hot water supply is not higher than the set hot water temperature by a set temperature or more, the forced change setting of the target hot water storage temperature is permitted. Instead, the heating operation control is executed based on the original target hot water storage temperature. By doing in this way, while the temperature of the high-temperature water that has been discharged to the mixing valve 7 is higher than the set hot water supply temperature by a set temperature or more, the use of hot water is started again based on the forced change setting of the target hot water storage temperature. While avoiding the occurrence of a situation where the hot water temperature at the time becomes unstable, if the temperature of the high-temperature water falls below the set temperature higher than the set hot water temperature, the normal target hot water temperature By continuing the heating operation control based on the above, it is possible to reliably avoid the occurrence of a situation where the hot water storage temperature in the hot water storage tank 3 is excessively lowered.

  In each of the above-described embodiments, when the hot water standby state is entered, the temperature of the hot water that has been discharged to the mixing valve 7 at the time of the previous stoppage of hot water supply is forcibly changed and set as the target hot water storage temperature for heating operation control. As described above, the temperature detected by the inlet temperature sensor 54 is used as the temperature of the high-temperature water. Instead, for example, the temperature detected by the temperature sensor interposed in the tap water piping 51 near the top of the hot water tank 3 is used. Alternatively, the temperature detected by the hot water storage temperature sensor 31 at the top position of the hot water storage tank 3 may be used.

2 Heat source device 3 Hot water storage tank 4 Heating circuit 5 Hot water supply circuit 6 Water supply piping 7 Mixing valve (mixing means)
51 Hot water supply pipe 61 Branch pipe 82 Heating operation control unit 83 Hot water supply operation control unit

Claims (5)

A hot water storage tank, a water supply pipe connected to the bottom of the hot water tank, a hot water pipe connected to the top of the hot water tank, hot water discharged from the hot water pipe, and a branch pipe from the branch pipe of the water supply pipe are supplied. Mixing means for hot water supply after adjusting the temperature to the set hot water temperature by mixing with low temperature water and heating the low temperature water at the bottom of the hot water tank to the target hot water temperature and returning it to the top A heat source device for storing hot water, heating operation control for storing hot water at the target hot water temperature in the hot water storage tank using the heat source device, and in the mixing means, the high temperature water and low temperature water A hot water storage hot water control method for performing hot water supply operation control for performing hot water supply at a set hot water supply temperature by changing and adjusting the mixing ratio,
If the hot water supply operation control is stopped after the hot water operation control is started in a state where the heating operation control is being executed, the hot water storage tank is stopped at the time when the hot water supply operation control is stopped until a predetermined condition is satisfied. The temperature of the hot water discharged from the top to the mixing means is forcibly changed and set as the target hot water storage temperature in the heating operation control.
A method for controlling a hot water storage and hot water supply apparatus. It is a control method of the hot water storage hot-water supply apparatus of Claim 1,
The control method of the hot water storage hot water supply apparatus is that a set time elapses from the time point when the hot water supply operation control is stopped to satisfy the predetermined condition. It is a control method of the hot water storage hot-water supply apparatus of Claim 2, Comprising:
When the hot water supply operation control is stopped, the mixing means is configured to return to a standard mixing ratio state after the mixing ratio state at the time of the stop is maintained for a predetermined standby time,
The method for controlling a hot water storage and hot water supply apparatus, wherein the same time value as the standby time is set as the set time. It is a control method of the hot water storage hot-water supply apparatus of Claim 1,
Satisfying the predetermined condition means that the hot water supply operation control is started again and a predetermined time has elapsed since the hot water supply operation control is started again. It is a control method of the hot water storage hot-water supply apparatus in any one of Claims 1-4,
The forced change setting of the target hot water storage temperature is permitted on the condition that the temperature of the hot water discharged to the mixing means at the time of stopping the hot water supply operation control is higher than the set hot water supply temperature by a set temperature or more. A method for controlling a hot water storage hot water supply apparatus.

Images