JP4113512B2 - Hot water use system - Google Patents

Description

  The present invention relates to a hot water utilization system using a heat exchanger.

  Conventionally, a hot water storage tank for storing hot water, hot water generating means for heating water in the hot water storage tank, a heat exchanger for exchanging heat of hot water stored in the upper side of the hot water in the hot water storage tank, A hot water use system comprising a heat load terminal to which a heat medium having a high temperature by an exchanger is supplied, and a hot water return means for returning warm water having an intermediate temperature that has been lowered after passing through the heat exchanger to a hot water storage tank. It is known (see, for example, Patent Document 1).

By the way, in general, in a hot water utilization system with a heat exchanger, a heat medium of 70 ° C. is sent to a heat load terminal (for example, a bathroom heater / dryer) in accordance with the winter season that requires the most heat. Yes. Therefore, it was necessary to store high-temperature water at 90 ° C. in the hot water storage tank. That is, since a high temperature water of 90 ° C. is transferred to the heat medium with a heat exchanger and controlled to be 70 ° C., a certain temperature difference is required. On the other hand, in the summer season when most heat is not needed, if a low temperature (for example, 55 ° C) heat medium is sent to the heat load terminal, the required performance can be exhibited. You only have to store it. Nevertheless, the conventional system has been a system that stores hot water of 90 ° C. in a hot water storage tank all year round, which causes unnecessary energy loss.
JP 2003-185251 A

  The present invention has been invented in view of the above-described conventional problems, and can control the temperature of the heat medium to the heat load terminal according to the season and can control the temperature of the hot water stored in the hot water storage tank, thereby saving energy. It is an object to provide a hot water use system that can be realized.

In order to solve the above problems, in the invention described in claim 1, hot water storage tank 1 for storing hot water, hot water generating means 2 for heating water in hot water storage tank 1, and hot water from the upper side of hot water storage tank 1 are used. The primary side circulation path 7 returning to the lower side of the hot water storage tank 1 through the primary side pipe 4a of the heat exchanger 4 and the heat exchanger primary pump 5, and one end of the secondary side pipe 4b of the heat exchanger 4 The heated heat medium 9 is supplied to the inlet side of the heat load terminal 10 and the heat medium 9 discharged from the outlet side of the heat load terminal 10 is returned to the other end of the secondary side pipe 4b of the heat exchanger 4. A hot water utilization system comprising a secondary side circulation path 8 and a heat medium temperature sensor 11 for detecting the temperature of the heat medium 9 in the secondary side circulation path 8, wherein the hot water generating means 2 is a hot water storage tank 1. Of water taken out from the lower side of the water and returned to the upper side of the hot water storage tank 1 A path 14, a heating-side pump 15 that extracts water into the flowing water path 14, a heat pump 3 that heats the water extracted into the flowing water path 14, and a hot water temperature sensor 16 that detects the temperature of hot water heated by the heat pump 3. The temperature detecting means 13 for detecting the current season, and the temperature of the heat medium 9 is made variable according to the season detected by the season detecting means 13, and the temperature of the hot water in the hot water storage tank 1 is varied. And a controller 12 for controlling the number of revolutions per unit time of the heating side pump 15 so as to be different from each other.

With such a configuration, the temperature of the hot water stored in the hot water storage tank 1 can be automatically controlled according to the season, and the set temperature of the heat medium 9 is 55 ° C. particularly in the summer season when heat is not required most. In this case, the hot water temperature of the hot water storage tank 1 may be 70 ° C., and it is not necessary to heat the hot water storage tank 1 to 90 ° C. throughout the year. Therefore, the energy required to store hot water in the hot water storage tank 1 can be reduced, and the temperature of the hot water storage tank 1 is lowered, so that heat radiation therefrom can also be reduced.

In the invention described in claim 2, the hot water storage tank 1 for keeping hot water warm, the hot water generating means 2 for heating the water in the hot water storage tank 1, hot water is taken out from the upper side of the hot water tank 1, and heat exchange is performed The primary side circulation path 7 returning to the lower side of the hot water storage tank 1 through the primary side pipe 4a and the heat exchanger primary pump 5 of the heat exchanger 4 and the one end of the secondary side pipe 4b of the heat exchanger 4 were heated. A secondary side circulation path for supplying the heat medium 9 to the inlet side of the heat load terminal 10 and returning the heat medium 9 discharged from the outlet side of the heat load terminal 10 to the other end of the secondary side pipe 4b of the heat exchanger 4 8 and a heat medium temperature sensor 11 for detecting the temperature of the heat medium 9 supplied to the inlet side of the heat load terminal 10 , wherein the hot water generating means 2 is connected to the hot water storage tank 1. Water flowing out from the lower side and returning to the upper side of the hot water storage tank 1 A path 14, a heating-side pump 15 that extracts water into the flowing water path 14, a heat pump 3 that heats the water extracted into the flowing water path 14, and a hot water temperature sensor 16 that detects the temperature of hot water heated by the heat pump 3. The heat storage primary pump 5 and the hot water storage according to each divided period so that one year is divided into a plurality of periods and the set temperature of the heat medium 9 is different according to each divided period. In order to switch between the plurality of seasonal control modes, and a control unit 12 having a plurality of different seasonal control modes for controlling the number of rotations per unit time of the heating pump 15 so that the temperature of the hot water in the tank 1 is different. The season detecting means 13 is provided.

By setting it as such a structure, in setting the temperature of the heat medium 9 supplied to the heat load terminal 10 to the temperature according to a season, the season control mode selected in the season detection means 13 is the hot water storage tank 1's. Instead of changing the temperature of the hot water, by changing the number of rotations of the heat exchanger primary pump 5, a system that controls the temperature of the heat medium 9 to the target set temperature is adopted, so that The temperature of the heat medium 9 to the load terminal 10 can be controlled, and the temperature of the hot water stored in the hot water storage tank 1 can be automatically controlled according to the season. Especially in the summer season when the heat is not required, the heat medium 9 When the set temperature is 55 ° C., the hot water temperature of the hot water storage tank 1 only needs to be 70 ° C., and there is no need to heat to 90 ° C. throughout the year as in the past. Therefore, the energy required to store hot water in the hot water storage tank 1 can be reduced, and the temperature of the hot water storage tank 1 is lowered, so that heat radiation therefrom can also be reduced.

  In the invention according to claim 3, the season detecting means 13 is preferably composed of a calendar function circuit unit 13a built in the control unit 12 for managing season information. In this case, the calendar function circuit unit 13a controls the calendar function circuit unit 13a. The system can be slimmed down as a whole by being incorporated in the unit 12, and it is not necessary to separately provide a sensor or the like for detecting the season, so that maintenance of the sensor is also unnecessary.

  In the invention according to claim 4, the season detecting means 13 is preferably composed of an air temperature sensor 13b for detecting the outside air temperature. In this case, the control by the outside air temperature is performed according to the temperature of the next day. Control of the load terminal 10 and temperature control stored in the hot water storage tank 1 are possible, and unnecessary energy loss can be further reduced.

  Further, in the invention described in claim 5, the season detection means 13 preferably comprises a tap water temperature sensor 13c for detecting the temperature of tap water supplied to the hot water storage tank 1, and in this case, control by tap water is performed. Since the daily temperature change of the tap water is small, the processing after the temperature measurement is simplified, and there is an advantage that the fluctuation factor of the outside air can be eliminated.

In the hot water utilization system according to the present invention, since the temperature of the hot water stored in the hot water storage tank can be automatically controlled according to the season, it is possible to reduce the energy required to store the hot water in the hot water storage tank in summer. At the same time, by reducing the temperature of the hot water storage tank, heat radiation from the hot water tank can be reduced. As a result, it becomes possible to efficiently operate a hot water utilization system using a heat exchanger, and unnecessary energy loss can be reduced.

  Hereinafter, the present invention will be described based on embodiments shown in the accompanying drawings.

  FIG. 1 shows an example of a hot water use system of the present embodiment, and FIG. 2 shows a block diagram of the hot water use system.

The hot water utilization system includes a hot water storage tank 1 for storing hot water, hot water generating means 2 for heating water in the hot water storage tank 1, hot water taken out from the upper side of the hot water storage tank 1, and a primary side pipe of the heat exchanger 4 4a and the primary side circulation path 7 returning to the lower side of the hot water storage tank 1 through the heat exchanger primary pump 5 and the heat medium 9 heated from one end of the secondary side pipe 4b of the heat exchanger 4 The secondary side circulation path 8 for supplying the heat medium 9 supplied to the inlet side of the terminal 10 and discharged from the outlet side of the thermal load terminal 10 to the other end of the secondary side pipe 4b of the heat exchanger 4, and the thermal load A heat medium temperature sensor 11 for detecting the temperature of the heat medium 9 supplied to the entry side of the terminal 10, and a controller 12 having a plurality of different seasonal control modes, and the plurality of seasonal control modes. Season detecting means 13 for switching between There. In this example, water or antifreeze is used as the heat medium 9 of the heat load terminal 10, tap water is used as the water in the hot water storage tank 1, and a CO ₂ heat pump unit is used as the hot water generating means 2. However, it is not limited to these.

  At the lower end of the hot water storage tank 1, a tap water supply port 17, a low-temperature water outlet 18 that leads to the inlet side of the flowing water path 14 of the heat pump unit, and a return that leads to the return side of the primary circulation path 7 of the heat exchanger 4. The hot water storage tank 1 is provided at its upper end with a hot water return port 20 leading to the return side of the flowing water path 14 and a hot water supply path for sending hot water to a hot water supply device such as a bath or a shower. A hot water outlet 21 leading to 22 is provided.

The heat pump unit constituting the hot water generating means 2 includes a flowing water path 14 that takes out low-temperature water from the lower side of the hot water tank 1 and returns it to the upper side of the hot water tank 1, and a heating side pump 15 that takes water into the flowing water path 14. A CO ₂ heat pump 3 that heats the low-temperature water taken out into the flowing water path 14 to make high-temperature water (70 to 90 ° C.), and a hot-water temperature sensor that detects the temperature of the hot water heated by the CO ₂ heat pump 3 16. Here, the CO ₂ heat pump 3 encloses high pressure CO ₂ in its pipe, performs heat absorption and heat dissipation by compressing and expanding using CO ₂ as a heat medium, and the heat radiating portion is connected to the flowing water path 14. By interposing it in the middle, the low temperature water can be heated and returned to the upper side of the hot water storage tank 1 as the high temperature water.

  From the middle of the hot water supply path 22, the primary side circulation path 7 of the heat exchanger 4 branches off. A primary side pipe 4a of the heat exchanger 4 is provided in the middle of the primary side circulation path 7, and a heat exchanger primary pump 5 is provided downstream of the primary side pipe 4a. The heat exchanger primary pump 5 is for returning the hot water from the upper side of the hot water storage tank 1 to the lower side of the hot water storage tank 1 through the hot water supply path 22 through the primary pipe 4 a of the heat exchanger 4. In response to a signal from the control unit 12, the rotational speed (designated flow rate) of the heat exchanger primary pump 5 per unit time is determined.

  The secondary side pipe 4 b of the heat exchanger 4 is provided in the secondary side circulation path 8 of the heat load terminal 10. Heat of the hot water from the hot water storage tank 1 is transmitted to the heat medium 9 by the heat exchanger 4, and is supplied as a high-temperature heat medium 9 to a heat load terminal 10 including a bathroom heating dryer. Further, in the secondary circulation path 8, the heat medium temperature sensor 11 is disposed on the downstream side of the secondary side pipe 4 b of the heat exchanger 4, and the heat exchanger secondary pump 6 is disposed on the upstream side. ing. The heat medium temperature sensor 11 measures the temperature of the heat medium 9 sent to the heat load terminal 10 and sends the result to the controller 12.

  The control unit 12 has a calendar function circuit unit 13a as a season detection means 13 as shown in FIG. The calendar function circuit unit 13a is constituted by, for example, a microcomputer that manages year, month, date, and time. For example, a year is divided into two periods, a winter season and a summer season, and a signal (a signal indicating the winter season or a signal indicating the summer season) corresponding to the current period is output. To do. Further, the control unit 12 is provided with a summer mode circuit 23 for executing the summer season control mode and a winter mode circuit 24 for executing the winter season control mode, and the signal outputted from the calendar function circuit unit 13a is provided. In response to this, either the summer mode circuit 23 or the winter mode circuit 24 is switched.

  The control unit 12 selects and executes a seasonal control mode corresponding to the current season based on a seasonal signal obtained from the calendar function circuit unit 13a. That is, in the summer, the summer mode circuit 23 is selected by the calendar function circuit unit 13a, and the summer seasonal control mode is executed. In the summer season control mode, the set temperature of the heat medium 9 is 55 ° C., and the set temperature is compared with the temperature detected by the heat medium temperature sensor 11. At this time, if the temperature of the heat medium temperature sensor 11 is higher, a signal for lowering the number of revolutions per unit time of the heat exchanger primary pump 5 is output. Thereby, the flow rate per unit time of the hot water passing through the primary side pipe 4a of the heat exchanger 4 is decreased, and the temperature of the heat medium 9 is decreased. Conversely, when the temperature of the heat medium temperature sensor 11 is lower, a signal for increasing the number of revolutions per unit time of the heat exchanger primary pump 5 is output. Thereby, the flow rate per unit time of the hot water passing through the primary side pipe 4a of the heat exchanger 4 is increased, and the temperature of the heat medium 9 is increased. By repeating this, the temperature of the heat medium 9 can reach the target temperature for summer season (55 ° C.). On the other hand, in the winter season, the winter mode circuit 24 is selected to execute the winter season control mode. In the winter season control mode, the temperature of the heat medium 9 is set to 70 ° C., the set temperature is compared with the temperature detected by the heat medium temperature sensor 11, and the temperature of the heat medium 9 is set in the same manner as described above. The target temperature for winter season (70 ° C.) is reached.

Further, in the example shown in FIG. 1, the control unit 12 rotates the heating side pump 15 per unit time so that the temperature of the hot water in the hot water storage tank 1 varies depending on the season control mode switched by the season detection means 13. It also has a function to control the number. FIG. 4 shows an example of the block diagram. In this example, when the summer season control mode is executed, the control unit 12 sets the temperature of the hot water sent to the hot water storage tank 1 to 75 ° C., and compares the set temperature with the temperature detected by the hot water temperature sensor 16. At this time, when the temperature of the hot water temperature sensor 16 is higher, the control unit 12 outputs a signal for lowering the number of revolutions per unit time of the heating pump 15. Thereby, the flow rate per unit time of the hot water passing through the CO ₂ heat pump 3 shown in FIG. 1 can be reduced, and the temperature of the hot water can be lowered. Conversely, when the temperature of the hot water temperature sensor 16 is lower The control unit 12 outputs a signal for increasing the number of rotations per unit time of the heating pump 15. Thereby, the flow rate per unit time of the hot water passing through the CO ₂ heat pump 3 is increased, and the temperature of the hot water can be increased. By repeating this, the temperature of the hot water sent to the hot water storage tank 1 can reach the target temperature (70 ° C.). On the other hand, when the winter season control mode is executed, the set temperature of the hot water sent to the hot water storage tank 1 is 90 ° C., and the set temperature and the temperature detected by the hot water temperature sensor 16 are compared and the same as described above. In this way, the temperature of the hot water sent to the hot water storage tank 1 is made to reach the target temperature for winter season (90 ° C.). Thereby, the temperature of the hot water stored in the hot water storage tank 1 can be automatically controlled according to the season. A temperature sensor 50 for detecting the temperature of hot water in the hot water storage tank 1 is provided below the hot water storage tank 1. For example, the temperature in the hot water storage tank 1 exceeds 70 ° C. in summer and 90 ° C. in winter. In this case, the heating side pump 15 is stopped by a signal from the temperature sensor 50.

  According to the above configuration, when the temperature of the heat medium 9 supplied to the heat load terminal 10 is set to a temperature according to the season, the season control mode selected by the season detection means 13 is the temperature of the hot water in the hot water storage tank 1. The heat load terminal 10 according to the season is adopted by adopting a system that controls the temperature of the heat medium 9 to a target set temperature by changing the rotation speed of the heat exchanger primary pump 5 instead of changing The temperature of the heat medium 9 can be controlled, and the temperature of the hot water stored in the hot water storage tank 1 can be varied according to the season, and the set temperature of the heat medium 9 is particularly high in the summer season when the heat is not required. In the case of 55 ° C., the hot water temperature of the hot water storage tank 1 only needs to be 70 ° C., and it is not necessary to heat to 90 ° C. throughout the year as in the past. Therefore, the energy required to store hot water in the hot water storage tank 1 can be reduced, and the temperature of the hot water storage tank 1 is lowered, so that heat radiation therefrom can also be reduced. As a result, it is possible to efficiently operate a hot water utilization system using the heat exchanger 4, and an unnecessary energy loss can be reduced.

  Moreover, since the season detection means 13 of this example comprises a calendar function circuit section 13a that is built in the control section 12 and manages the season information, the season detection means 13 is incorporated into the control section 12 to reduce the overall system. In addition, since it is not necessary to separately provide a sensor or the like for detecting the season, maintenance of the sensor is unnecessary. The calendar function circuit unit 13a is constituted by, for example, a calendar clock mechanism having a receiver of a satellite signal receiving means (GPS) that receives a satellite signal and extracts time information of year / month / day / hour / minute / second from the satellite signal. Is also possible.

  In the embodiment of FIG. 2, the summer mode circuit 23 and the winter mode circuit 24 are illustrated as an example of the seasonal control mode. However, as shown in FIG. 3, an intermediate mode circuit 25 for autumn and spring may be added. . In the intermediate mode circuit 25, for example, the temperature of the heat medium 9 is set to a substantially intermediate value between 70 ° C. in winter and 55 ° C. in summer, and the temperature of hot water in the hot water storage tank 1 is 90 ° C. in winter and 70 ° C. in summer. Set to approximately the middle value of. This makes it possible to achieve energy saving even in the middle of spring and autumn other than summer and winter.

  5 and 6 show an example in which an air temperature sensor 13b that measures the outside air temperature is used as the season detection means 13. FIG. Other configurations are basically the same as those in FIG. 1, and corresponding portions are denoted by the same reference numerals and description thereof is omitted. In this example, the control unit 12 measures and averages the temperature data for one day from the temperature of the temperature sensor 13b. When the average value is high (for example, 15 ° C. or higher), the set temperature of the heat medium 9 is set to 55 ° C. and compared with the heat medium temperature sensor 11. Conversely, when the average value is low (for example, less than 15 ° C.), the set temperature of the heat medium 9 is set to 70 ° C. and compared with the heat medium temperature sensor 11. In any case, when the temperature of the heat medium temperature sensor 11 is higher, a signal for lowering the number of revolutions per unit time of the heat exchanger primary pump 5 is issued, and in the primary side pipe 4a of the heat exchanger 4 The flow rate per unit time is reduced, and conversely, when the temperature of the heat medium temperature sensor 11 is lower, a signal for increasing the number of revolutions per unit time of the heat exchanger primary pump 5 is issued to perform heat exchange. The flow rate per unit time in the primary side pipe 4a of the vessel 4 is increased. Thereby, the temperature of the heat medium 9 can be made to reach the target temperature. Thus, by adopting a control system based on the outside air temperature, it becomes possible to control the thermal load terminal 10 in accordance with the air temperature of the next day, and the temperature control stored in the hot water storage tank 1, thereby reducing unnecessary energy loss. Can be further improved.

  FIG. 7 shows an example in which a tap water temperature sensor 13c that detects the temperature of tap water supplied to the hot water storage tank 1 is used as the season detection means 13, and FIG. An example is shown. Other configurations are basically the same as those in FIG. 1, and corresponding portions are denoted by the same reference numerals and description thereof is omitted. In this example, the current temperature of tap water is detected by the tap water temperature sensor 13 c and input to the control unit 12. When the temperature value of the tap water detected by the tap water temperature sensor 13 c is high (for example, 15 ° C. or more), the control unit 12 sets the set temperature of the heat medium 9 to 55 ° C. and compares it with the heat medium temperature sensor 11. Conversely, when the temperature value detected by the tap water temperature sensor 13 c is low (for example, less than 15 ° C.), the set temperature of the heat medium 9 is set to 70 ° C. and compared with the heat medium temperature sensor 11. In any case, when the temperature of the heat medium temperature sensor 11 is higher, a signal for lowering the rotational speed per unit time of the heat exchanger primary pump 5 is issued, and the heat exchanger 4 in the primary side pipe 4a Reduce the flow rate per unit time. On the other hand, when the temperature of the heat medium temperature sensor 11 is lower, a signal for increasing the rotational speed per unit time of the heat exchanger primary pump 5 is issued, and the heat exchanger 4 per unit time in the primary side pipe 4a of the heat exchanger 4 is given. Increase flow rate. Thereby, the temperature of the heat medium 9 can be made to reach the set temperature in the summer or winter season. Therefore, the control with tap water has a merit that since the temperature change per day is small, the processing after the temperature measurement is simplified, and the fluctuation factor of the outside air can be eliminated.

  Note that the numerical values of the set temperature of the heat medium 9 and the temperature of the hot water storage tank 1 described in the above embodiment are merely examples, and can be appropriately changed.

It is explanatory drawing of the hot water utilization system of one Embodiment of this invention. It is a block diagram relevant to the control part same as the above. It is a block diagram of other embodiments. It is a block diagram of other embodiment. It is a block diagram of other embodiment. It is explanatory drawing of the hot water utilization system of FIG. It is explanatory drawing of the hot water utilization system of other embodiment. It is a graph which shows an example of the temperature change for one year of the tap water used in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hot water storage tank 2 Hot water production | generation means 3 Heat pump 4 Heat exchanger 4a Primary side piping 4b Secondary side piping 5 Heat exchanger primary pump 7 Primary side circulation path 8 Secondary side circulation path 9 Heat medium 10 Heat load terminal 11 Heat medium Temperature sensor 12 Control unit 13 Season detection means 13a Calendar function circuit unit 13b Temperature sensor 13c Tap water temperature sensor 14 Flow path 15 Heating side pump 16 Hot water temperature sensor

Claims (5)

Hot water storage tank for storing hot water, hot water generating means for heating the water in the hot water storage tank, hot water is taken out from the upper side of the hot water storage tank, passed through the primary side piping of the heat exchanger and the heat exchanger primary pump, Heat that is supplied to the inlet side of the heat load terminal and discharged from the outlet side of the heat load terminal while supplying the heated heat medium from one end of the primary side circulation path returning to the lower side and the secondary side pipe of the heat exchanger. A hot water utilization system comprising a secondary side circulation path for returning the medium to the other end of the secondary pipe of the heat exchanger, and a heat medium temperature sensor for detecting the temperature of the heat medium in the secondary side circulation path. The hot water generating means heats the water taken out into the flowing water path, a flowing water path for taking out water from the lower side of the hot water tank and returning it to the upper side of the hot water tank, a heating pump for taking water into the flowing water path, and With heat pump and heat pump Is composed of a hot water temperature sensor for detecting the temperature of the heated was heated, and seasonal detecting means for detecting the current season, while the set temperature of the heating medium varied in accordance with the detected season the season detecting means And a control unit that controls the number of revolutions per unit time of the heating-side pump so that the temperature of the hot water in the hot water storage tank is different . Hot water storage tank for storing hot water, hot water generating means for heating the water in the hot water storage tank, hot water is taken out from the upper side of the hot water storage tank, and passes through the primary side piping of the heat exchanger and the heat exchanger primary pump. The primary side circulation path returning to the lower side of the heat exchanger and the heated heat medium from one end of the secondary side pipe of the heat exchanger are supplied to the inlet side of the heat load terminal and discharged from the outlet side of the heat load terminal Hot water comprising a secondary side circulation path for returning the heat medium to the other end of the secondary side pipe of the heat exchanger, and a heat medium temperature sensor for detecting the temperature of the heat medium supplied to the inlet side of the heat load terminal In the utilization system, the hot water generating means is configured to take out water from the lower side of the hot water storage tank and return it to the upper side of the hot water storage tank, a heating side pump for taking out water into the flowing water path, and take out into the flowing water path. A heat pump that heats water Is composed of a hot water temperature sensor for detecting the temperature of the heated hot water by the heat pump, by dividing one year into a plurality of periods, the heat exchanger primary, as the set temperature of the heating medium is different depending on each divided period was And a controller having a plurality of different seasonal control modes for controlling the number of revolutions per unit time of the heating-side pump so that the temperature of the hot water in the hot water storage tank differs according to each divided period. And a hot water utilization system comprising season detection means for switching the plurality of season control modes.   The hot water utilization system according to claim 1 or 2, wherein the season detection means comprises a calendar function circuit part built in the control part and manages season information.   The hot water utilization system according to claim 1 or 2, wherein the season detection means comprises an air temperature sensor for detecting an outside air temperature. The season detecting means, hot water utilization system of claim 1 or claim 2, wherein the consisting of tap water temperature sensor for detecting the temperature of the tap water supplied to the hot water storage tank.

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