JP6751619B2 - Hot water supply system - Google Patents

Description

The techniques disclosed herein relate to hot water supply systems.

The hot water supply system disclosed in Patent Document 1 includes a heat pump that absorbs heat from the outside air to boil water, a tank that stores hot water boiled by the heat pump, and a supply path that supplies hot water in the tank to a hot water utilization location. It is provided with a setting means capable of setting a hot water supply set temperature at a hot water use location, a water supply channel for supplying water into the tank, a temperature sensor for measuring the water supply temperature, and a control means. The hot water supply system of Patent Document 1 can perform a boiling operation. The boiling operation is an operation of boiling the water in the tank by a heat pump. The hot water boiled by the heat pump is stored in the tank and supplied to the hot water utilization points as needed.

Japanese Unexamined Patent Publication No. 2015-038397

In the hot water supply system, when the boiling operation is executed at a low temperature, the COP (Coefficient Of Performance) in the heat pump can be made higher than that when the boiling operation is executed at a high temperature. Therefore, it is preferable to carry out the boiling operation at the lowest possible temperature.

Further, in the hot water supply system, the temperature of the hot water in the tank decreases with the passage of time due to natural heat dissipation. The longer the hot water stays in the tank, the greater the decrease in temperature. Therefore, if hot water stays in the tank for a long time and the boiling operation is performed at a low temperature, the temperature of the hot water may become lower than the set temperature of the hot water supply at the hot water usage point due to the temperature drop due to natural heat dissipation. is there. Therefore, the present specification provides a technique capable of supplying hot water at a hot water supply set temperature to a hot water utilization location while performing a boiling operation at a low temperature as much as possible to raise the COP.

The hot water supply system disclosed in the present specification includes a heat pump that absorbs heat from the outside air to boil water, a tank that stores hot water boiled by the heat pump, and a supply path that supplies hot water in the tank to hot water utilization points. I have. In addition, the hot water supply system includes a setting means capable of setting a hot water supply set temperature at a hot water usage location, a water supply channel for supplying water into the tank, a temperature sensor for measuring the outside air temperature or the water supply temperature, a storage means, and a control means. And have. The storage means is the first specific information for specifying the first boiling set temperature higher than the hot water supply set temperature from the outside air temperature or the water supply temperature measured by the temperature sensor, and the hot water supply from the first boiling water set temperature from the outside air temperature or the water supply temperature. It stores the second specific information that specifies the second boiling set temperature that is close to the set temperature. When the control means executes the boiling operation of boiling the water in the tank by the heat pump, the entire amount of the hot water boiled by the heat pump is supplied to the hot water utilization location within the first predetermined time from the start of the boiling operation. If it is predicted, the second specific information stored in the storage means is used to specify the second boiling set temperature from the outside air temperature or the water supply temperature measured by the temperature sensor, and if not, the second boiling set temperature is specified. Using the first specific information stored in the storage means, the first boiling set temperature is specified from the outside air temperature or the water supply temperature measured by the temperature sensor, and the water in the tank is the first boiling set temperature or the first boiling temperature. 2 Boiling The boiling operation is executed so that the set temperature is reached.

When it is predicted that the entire amount of hot water boiled by the heat pump will be supplied to the hot water utilization location within the first predetermined time, the hot water will not stay in the tank for longer than the first predetermined time. Therefore, the time that the hot water stays in the tank becomes relatively short. In this case, the boiling operation is executed at the second boiling set temperature which is closer to the hot water supply set temperature than the first boiling set temperature. On the other hand, if this is not the case (when it is predicted that the total amount of hot water boiled by the heat pump will not be supplied to the hot water utilization location within the first predetermined time), the hot water stays in the tank longer than the first predetermined time. Therefore, the hot water stays in the tank for a relatively long time. In this case, the boiling operation is executed according to the first boiling set temperature.

In the hot water supply system, when the boiling operation is performed, if the boiling operation is performed at a low temperature, the COP in the heat pump can be higher than that that the boiling operation is performed at a high temperature. Therefore, it is preferable to carry out the boiling operation at the lowest possible temperature. That is, it is preferable to execute the boiling operation at a temperature as close to the hot water supply set temperature as possible. In addition, the temperature of the hot water in the tank decreases with the passage of time due to natural heat dissipation. The longer the hot water stays in the tank, the greater the decrease in temperature. On the other hand, if the hot water stays in the tank for a short time, the decrease in temperature becomes relatively small.

According to the above configuration, when the hot water stays in the tank for a relatively short time and the temperature drop due to natural heat dissipation is relatively small, the second boiling set temperature is closer to the hot water supply set temperature than the first boiling set temperature. Is performing a boiling operation. That is, the boiling operation is performed at a low temperature. Even if the boiling operation is performed at a low temperature, the decrease in the temperature of the hot water is relatively small, so that the possibility that the temperature of the hot water becomes lower than the set temperature of the hot water supply can be reduced. Further, since the boiling operation is performed at a low temperature, the COP in the heat pump can be increased. Therefore, it is possible to supply hot water at a hot water supply set temperature to a hot water utilization location while performing a boiling operation at a low temperature to raise the COP. On the other hand, when the hot water stays in the tank for a relatively long time and the temperature drop due to natural heat dissipation is relatively large, the boiling operation is executed at the first boiling set temperature. That is, the boiling operation is performed at a high temperature. As a result, even if the hot water stays in the tank for a relatively long time, the possibility that the temperature of the hot water becomes lower than the set temperature of the hot water supply can be reduced.

The figure which shows typically the structure of the hot water supply system 2 which concerns on Example. The figure which shows the 1st specific table, the 2nd specific table and the 3rd specific table which concerns on Example. A graph showing an example of the relationship between time and hot water usage. A graph showing another example of the relationship between time and hot water usage. A graph showing still another example of the relationship between time and hot water usage. The flowchart which shows the control process in the hot water supply system 2 which concerns on Example. The figure which shows the 1st specific table, the 2nd specific table and the 3rd specific table which concerns on other Examples.

The main features of the examples described below are listed. It should be noted that the technical elements described below are independent technical elements and exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Absent.

(Feature 1) The control means may specify the first boiling set temperature or the second boiling set temperature from the outside air temperature measured by the temperature sensor.

The temperature difference between the temperature of the hot water in the tank and the temperature of the outside air becomes a direct factor when the temperature of the hot water in the tank decreases. Therefore, by specifying the first boiling set temperature or the second boiling set temperature from the outside air temperature, it is possible to specify the boiling set temperature according to the heat dissipation state of the hot water.

(Characteristic 2) The control means may specify the first boiling set temperature or the second boiling set temperature from the water supply temperature measured by the temperature sensor.

Normally, the water supply temperature changes according to the outside air temperature. The lower the outside air temperature, the lower the water supply temperature, and the higher the outside air temperature, the higher the water supply temperature. According to the above configuration, even if there is no temperature sensor for measuring the outside air temperature, the boiling set temperature according to the heat dissipation state of the hot water can be specified by the temperature sensor for measuring the supply water temperature. It is not necessary to separately provide a temperature sensor for measuring the outside air temperature.

(Feature 3) The storage means stores the third specific information that specifies the third boiling set temperature that is closer to the hot water supply set temperature than the second boiling set temperature from the outside air temperature or the water supply temperature measured by the temperature sensor. May be good. The control means is a case where it is predicted that the entire amount of hot water boiled by the heat pump will be supplied to the hot water utilization location within the first predetermined time from the start of the boiling operation, and the second predetermined hot water utilization location. When the predicted amount of hot water supplied in time is larger than the predetermined amount, the third boiling setting is set from the outside air temperature or the water supply temperature measured by the temperature sensor using the third specific information stored in the storage means. A boiling operation may be performed so that the temperature is specified and the water in the tank reaches the third boiling set temperature.

When the predicted amount of hot water supplied to the hot water utilization location within the second predetermined time is larger than the predetermined amount, the time that the hot water stays in the tank becomes shorter, and the temperature drop of the hot water becomes smaller. In this case, the boiling operation is executed at the third boiling set temperature which is closer to the hot water supply set temperature than the second boiling set temperature. That is, the boiling operation is performed at a lower temperature. Even if the boiling operation is performed at a low temperature, the temperature drop of the hot water is even smaller, so that the possibility that the temperature of the hot water becomes lower than the set temperature of the hot water supply can be reduced. In addition, since the boiling operation is performed at a lower temperature, the COP in the heat pump can be increased.

(Feature 4) A gas heater that heats the water supplied from the tank to the hot water utilization location by burning the gas may be further provided.

If water is boiled at a boiling set temperature close to the hot water supply set temperature, the temperature of the hot water may become lower than the hot water supply set temperature if the hot water stays in the tank for a long time. Even in this case, according to the above configuration, the water supplied to the hot water utilization location can be heated by the gas heater, so that the water can be heated to the hot water supply set temperature. Therefore, hot water having a set temperature for hot water supply can be reliably supplied to the hot water utilization location.

(Example)
FIG. 1 shows the configuration of the hot water supply system 2 according to the present embodiment. As shown in FIG. 1, the hot water supply system 2 according to the present embodiment includes a tank 10, a tank water circulation passage 20, a water supply passage 30, a supply passage 40, a heat pump 50, a burner heating device 60, and a controller 100. , Equipped with.

The heat pump 50 is a heat source that absorbs heat from the outside air and heats the water in the tank water circulation path 20. The heat pump 50 is a device for boiling water in the tank 10. Although not shown, the heat pump 50 compresses a heat medium circulation path for circulating a heat medium (for example, R32, etc.), an evaporator that exchanges heat between the outside air and the heat medium, and the heat medium to a high temperature and high pressure. A compressor, a condenser that exchanges heat between the water in the tank water circulation path 20 and a high-temperature and high-pressure heat medium, and an expansion valve that depressurizes the heat medium after the heat exchange to reduce the pressure to low temperature and low pressure. It has.

A thermistor 103 (an example of a temperature sensor) is attached to the heat pump 50. The thermistor 103 measures the outside air temperature. The arrangement position of the thermistor 103 is not particularly limited, and for example, the thermistor 103 may be attached to the tank 10.

The tank 10 stores hot water boiled by the heat pump 50. The tank 10 is a closed type, and the outside is covered with a heat insulating material. Water is stored in the tank 10 until it is full. In this embodiment, the capacity of the tank 10 is 100 L. Thermistors 12, 14, 16 and 18 are attached to the tank 10 at predetermined intervals in the height direction of the tank 10. Each thermistor 12, 14, 16 and 18 measures the temperature of the water at its mounting position. For example, each thermistor 12, 14, 16 and 18 measures the temperature of water at positions 6L, 12L, 30L and 50L from the top of the tank 10, respectively.

The upstream end of the tank water circulation path 20 is connected to the lower part of the tank 10, and the downstream end is connected to the upper part of the tank 10. A circulation pump 22 is interposed in the tank water circulation path 20. The circulation pump 22 sends out the water in the tank water circulation path 20 from the upstream side to the downstream side. Further, the tank water circulation path 20 passes through a heat exchanger (not shown) of the heat pump 50. Therefore, when the heat pump 50 is operated, the water in the tank water circulation path 20 is heated by the heat exchanger of the heat pump 50. Therefore, when the circulation pump 22 and the heat pump 50 are operated, the water in the lower part of the tank 10 is heated by the heat pump 50, and the heated water is returned to the upper part of the tank 10. That is, the tank water circulation channel 20 is a water channel for storing heat in the tank 10. A thermistor 24 is interposed on the upstream side of the heat pump 50 of the tank water circulation path 20. The thermistor 24 is derived from the lower part of the tank 10 and measures the temperature of water before passing through the heat pump 50.

The upstream end of the water supply channel 30 is connected to the tap water supply source 31. The water supply channel 30 supplies tap water to the tank 10. A thermistor 32 is interposed in the water supply channel 30. The thermistor 32 measures the water supply temperature of tap water. The downstream side of the water supply channel 30 is branched into a first introduction path 30a and a second introduction path 30b. The downstream end of the first introduction path 30a is connected to the lower part of the tank 10. The downstream end of the second introduction path 30b is connected in the middle of the supply path 40 described later. A mixing valve 42 is provided at a connection portion between the downstream end of the second introduction path 30b and the supply path 40. The mixing valve 42 adjusts the amount of hot water flowing in the supply path 40 to be mixed with the water in the second introduction path 30b.

The upstream end of the supply path 40 is connected to the upper part of the tank 10. As described above, the second introduction passage 30b of the water supply passage 30 is connected in the middle of the supply passage 40, and the mixing valve 42 is provided at the connecting portion. A thermistor 43 is interposed in the supply path 40 on the upstream side of the mixing valve 42. The thermistor 43 measures the temperature of hot water supplied from the tank 10 to the supply path 40. A burner heating device 60 (an example of a gas heater) is interposed in the supply path 40 on the downstream side of the connection portion with the second introduction path 30b. A thermistor 44 is interposed in the supply path 40 on the downstream side of the burner heating device 60. The thermistor 44 measures the temperature of the hot water supplied to the hot water utilization point. The burner heating device 60 heats the water in the supply path 40 so that the temperature of the hot water measured by the thermistor 44 matches the set temperature of the hot water supply. The burner heating device 60 heats water by burning gas. The downstream end of the supply path 40 is connected to a hot water utilization point (for example, a kitchen, a bathtub, etc.).

The controller 100 (an example of the control means) is electrically connected to each component and controls the operation of each component. The controller 100 is connected to a remote controller 104 (an example of setting means) having an operation unit capable of inputting various instructions by the user and a display unit capable of displaying various information. With the remote controller 104, it is possible to set the hot water supply set temperature at the hot water usage location.

The controller 100 includes a memory 102 (an example of storage means). The memory 102 can store various information. The memory 102 stores the first specific table, the second specific table, and the third specific table shown in FIG. The first specific table (an example of the first specific information) shows the correspondence between the outside air temperature and the first boiling set temperature. In the first specific table, the first boiling set temperature can be specified from the outside air temperature measured by the thermistor 103. The second specific table (an example of the second specific information) shows the correspondence between the outside air temperature and the second boiling set temperature. In the second specific table, the second boiling set temperature can be specified from the outside air temperature measured by the thermistor 103. The third specific table (an example of the third specific information) shows the correspondence between the outside air temperature and the third boiling set temperature. In the third specific table, the third boiling set temperature can be specified from the outside air temperature measured by the thermistor 103.

The first boiling set temperature, the second boiling set temperature, and the third boiling set temperature are higher than the hot water supply set temperature. The second boiling set temperature corresponding to a certain outside air temperature is lower than the first boiling set temperature corresponding to the same outside air temperature, and is closer to the hot water supply set temperature than the first boiling set temperature. Further, the third boiling set temperature corresponding to a certain outside air temperature is lower than the second boiling set temperature corresponding to the same outside air temperature, and is closer to the hot water supply set temperature than the second boiling set temperature. For the same outside air temperature, there is a relationship of 1st boiling set temperature> 2nd boiling set temperature> 3rd boiling set temperature> hot water supply set temperature. Focusing on the outside air temperature, it can be said that the relationship is as follows. That is, when comparing the first specific table and the second specific table, the outside air temperature (10 ° C or more and less than 15 ° C) for specifying a certain second boiling set temperature (for example, 44 ° C) is the second boiling setting. It exists up to a temperature range lower than the outside air temperature (20 ° C. or higher and lower than 27 ° C.) for specifying the first boiling set temperature (44 ° C.), which is the same as the temperature (44 ° C.). Further, when comparing the second specific table and the third specific table, the outside air temperature (less than 15 ° C.) for specifying a certain third boiling set temperature (for example, 42 ° C.) is the third boiling set temperature (42 ° C.). It exists up to a temperature range lower than the outside air temperature (20 ° C. or higher and lower than 27 ° C.) for specifying the same second boiling set temperature (42 ° C.) as (° C.).

Next, the operation of the hot water supply system 2 of this embodiment will be described. The hot water supply system 2 can execute the boiling operation and the hot water supply operation. Hereinafter, each operation will be described.

(Boiling operation)
The boiling operation is an operation of heating the water in the tank 10 by the heat generated by the heat pump 50. When the controller 100 instructs the execution of the boiling operation, the heat pump 50 starts operation and the circulation pump 22 rotates.

By operating the heat pump 50, the heat medium circulates in the heat medium circulation path. Further, when the circulation pump 22 rotates, the water in the tank 10 circulates in the tank water circulation path 20. That is, the water existing in the lower part of the tank 10 is introduced into the tank water circulation path 20, and when the introduced water passes through the heat exchanger, it is heated and heated by the heat of the heat medium in the heat medium circulation path. The water is returned to the upper part of the tank 10. As a result, hot water is stored in the tank 10. A layer of hot water is formed in the upper part of the tank 10, and a layer of cold water is formed in the lower part.

(Hot water supply operation)
The hot water supply operation is an operation of supplying the water in the tank 10 to the hot water utilization point. The hot water supply operation can also be performed during the above-mentioned boiling operation. When the hot water tap at the hot water utilization point is opened, tap water flows from the water supply channel 30 (first introduction path 30a) to the lower part of the tank 10 due to the water pressure from the tap water supply source 31. At the same time, the hot water in the upper part of the tank 10 is supplied to the hot water utilization point via the supply path 40.

When the temperature of the water supplied from the tank 10 to the supply path 40 (that is, the measured temperature of the thermistor 43) is higher than the hot water supply set temperature, the controller 100 opens the mixing valve 42 and supplies the water from the second introduction path 30b. Tap water is introduced into the road 40. In this case, the water supplied from the tank 10 and the tap water supplied from the second introduction path 30b are mixed in the supply path 40. The controller 100 adjusts the opening degree of the mixing valve 42 so that the temperature of the hot water supplied to the hot water utilization location matches the hot water supply set temperature. On the other hand, the controller 100 operates the burner heating device 60 when the temperature of the hot water supplied from the tank 10 to the supply path 40 is lower than the hot water supply set temperature. In this case, the hot water passing through the supply path 40 is heated by the burner heating device 60. The controller 100 controls the output of the burner heating device 60 so that the temperature of the hot water supplied to the hot water utilization location matches the hot water supply set temperature.

Next, the control process in the hot water supply system 2 will be described. Since the hot water supply system 2 consumes electric power when executing the boiling operation, the boiling operation may be executed by using the midnight electric power in order to save the electricity bill. In addition, the boiling operation may be executed in the early morning in consideration of the time zone in which the hot water boiled by the boiling operation is used. For example, as shown in FIGS. 3 to 5, the boiling operation may be executed from 5:00 to 6:00 in the morning.

On the other hand, in each household equipped with the hot water supply system 2, it is conceivable that the time zone in which the hot water boiled by the boiling operation is used is different. For example, as shown in FIG. 3, a household that concentrates on using hot water between 6:00 and 7:00 in the morning, and as shown in FIG. 4, concentrates between 12:00 and 13:00 in the afternoon. A household that uses hot water and a household that concentrates on using hot water between 17:00 and 18:00 in the evening as shown in FIG. 5 can be considered. It is possible that the time of day when hot water is used differs depending on the lifestyle of each household.

As shown in FIG. 3, in a household where the boiling operation is executed in the early morning and the hot water is concentrated in the morning, the time until the hot water boiled in the boiling operation is used is short. On the other hand, as shown in FIGS. 4 and 5, in a household where the boiling operation is performed in the early morning and the hot water is concentrated in the daytime and a household where the hot water is concentrated in the evening, the boiling operation is performed. It takes a long time to use the hot water boiled in.

Further, in the hot water supply system 2, a boiling operation may be executed in order to utilize a large amount of hot water. For example, some households use large amounts of hot water to fill bathtubs with hot water. In this case, a boiling operation is performed to fill the bathtub with hot water. For example, as shown in FIG. 3, the boiling operation is executed from 19:00 to 20:00 at night, and a large amount of hot water is used to fill the bathtub between 20:00 and 21:00. Sometimes. A large amount of hot water is required in a short time to fill the bathtub with hot water. In consideration of the above situation, the hot water supply system 2 executes the following control processing. As shown in FIG. 6, first, in S10, the controller 100 of the hot water supply system 2 permits the boiling operation by the heat pump 50. Then, the water in the tank 10 can be boiled by the heat pump 50. For example, the boiling operation becomes feasible at 5:00 in the morning.

In the following S11, the controller 100 measures the outside air temperature. More specifically, the information on the outside air temperature measured by the thermistor 103 is transmitted to the controller 100, and the controller 100 receives the information.

In the following S12, the controller 100 determines whether or not it is predicted that the entire amount of hot water boiled by the heat pump 50 will be supplied to the hot water utilization location within the first predetermined time from the start of the boiling operation. The total amount of hot water boiled by the heat pump 50 is specified in advance by the past learning value of hot water supply use, the capacity of the tank 10, and the like.

Further, the controller 100 predicts the amount of hot water supplied from the tank 10 to the hot water utilization location within the first predetermined time from the start of the boiling operation. The amount of this hot water is predicted based on the learning process. In the learning process, the amount of hot water supplied to the hot water usage location is predicted within the first predetermined time from the start of the boiling operation based on the past hot water usage amount. For example, the controller 100 stores the amount of hot water used every 10 minutes in the memory 102 for the past several days, performs learning processing based on the memory 102, and performs the learning process based on the storage amount, and the hot water use location within a predetermined time from the start of the boiling operation. Predict the amount of hot water supplied to. The first predetermined time from the start of the boiling operation is not particularly limited, and is, for example, 2 hours from the start of the boiling operation.

The controller 100 compares the total amount of hot water boiled by the heat pump 50 with the predicted amount of hot water supplied from the tank 10 to the hot water utilization location within the first predetermined time from the start of the boiling operation. Then, if the total amount of hot water boiled by the heat pump 50 is less than the predicted amount of hot water supplied from the tank 10 to the hot water utilization location within the first predetermined time from the start of the boiling operation, the controller 100 is set to Yes in S12. Judging that, proceed to S13. On the other hand, if the total amount of hot water boiled by the heat pump 50 is larger than the predicted amount of hot water supplied from the tank 10 to the hot water utilization location within the first predetermined time from the start of the boiling operation, the controller 100 is No. 1 in S12. Judging that, proceed to S21.

As shown in FIG. 3, in a household where the boiling operation is executed between 5:00 and 6:00 in the early morning and the hot water is concentrated between 6:00 and 7:00 in the morning, boiling is performed. It takes a short time to use the hot water boiled in the raising operation. Therefore, in this case, the controller 100 may determine Yes in S12.

In addition, as shown in FIG. 3, the boiling operation is executed between 19:00 and 20:00 at night, and hot water is used to fill the bathtub with hot water between 20:00 and 21:00. In households that do, it takes a short time to use the hot water that has been boiled by boiling. Therefore, in this case, the controller 100 may determine Yes in S12.

In S13 after determining Yes in S12 shown in FIG. 6, the controller 100 determines whether or not the predicted amount of hot water supplied from the tank 10 to the hot water utilization location within the second predetermined time is larger than the predetermined amount. To do. More specifically, first, the controller 100 predicts the amount of hot water supplied from the tank 10 to the hot water utilization location within a second predetermined time. The amount of this hot water is predicted based on the learning process. In the learning process, the amount of hot water supplied to the hot water usage location within the second predetermined time is predicted based on the past hot water usage amount. For example, the controller 100 stores the amount of hot water used every 10 minutes in the memory 102 over the past several days, performs learning processing based on the memory 102, and supplies the hot water to the hot water usage location within the second predetermined time. Predict the amount of hot water. The second predetermined time is not particularly limited, and is, for example, 2 hours. In addition, the controller 100 compares the predicted amount of hot water supplied from the tank 10 to the hot water utilization location within the second predetermined time with the predetermined amount. If the predicted amount of hot water supplied from the tank 10 to the hot water utilization location is larger than the predetermined amount within the second predetermined time, the controller 100 determines Yes in S13 and proceeds to S31. That is, when it is predicted that the amount of hot water supplied to the hot water utilization location is large within the second predetermined time, the controller 100 determines Yes in S13 and proceeds to S31. On the other hand, if the predicted amount of hot water supplied from the tank 10 to the hot water utilization location is less than the predetermined amount within the second predetermined time, the controller 100 determines No in S13 and proceeds to S14.

When the predicted amount of hot water supplied from the tank 10 to the hot water utilization location is larger than the predetermined amount within the second predetermined time, it is a case where a large amount of hot water is used in a short time. For example, as shown in FIG. 3, a boiling operation is performed between 19:00 and 20:00 at night, and hot water is used to fill the bathtub between 20:00 and 21:00. At home, use a large amount of hot water in a short time. Therefore, in this case, the controller 100 may determine Yes in S13.

In S21 after determining No in S12 shown in FIG. 6, the controller 100 selects and uses the first specific table from the first specific table to the third specific table stored in the memory 102. The controller 100 specifies the first boiling set temperature corresponding to the outside air temperature measured by the thermistor 103 using the first specifying table.

Further, in S14 after determining No in S13, the controller 100 selects and uses the second specific table from the first specific table to the third specific table stored in the memory 102. The controller 100 specifies the second boiling set temperature corresponding to the outside air temperature measured by the thermistor 103 using the second specifying table.

Further, in S31 after determining Yes in S13, the controller 100 selects and uses the third specific table from the first specific table to the third specific table stored in the memory 102. The controller 100 specifies the third boiling set temperature corresponding to the outside air temperature measured by the thermistor 103 using the third specific table.

In the following S15, the controller 100 starts the boiling operation by the heat pump 50. The water in the tank 10 is boiled by the operation of the heat pump 50. The hot water boiled by the heat pump 50 is stored in the tank 10.

When the first boiling set temperature is specified in S21 above, the controller 100 executes the boiling operation so that the water in the tank 10 reaches the first boiling set temperature. Further, when the second boiling set temperature is specified in S14, the controller 100 executes the boiling operation so that the water in the tank 10 reaches the second boiling set temperature. Further, when the third boiling set temperature is specified in S31 above, the controller 100 executes the boiling operation so that the water in the tank 10 reaches the third boiling set temperature.

In the following S16, the controller 100 determines whether or not the boiling operation by the heat pump 50 is completed. Whether or not the boiling operation is completed can be determined based on, for example, the measured temperatures of the thermistors 12, 14, 16, 18 and 24 mounted on the tank 10. Whether or not the target amount of hot water has been boiled can be determined by the measured temperature of the thermistor at the position corresponding to the amount of boiling water. When the boiling operation by the heat pump 50 is completed, the controller 100 determines Yes in S16 and ends the boiling operation. On the other hand, if the boiling operation by the heat pump 50 is not completed, the controller 100 determines No in S16 and continues the boiling operation.

After the boiling operation is completed or during the boiling operation, the hot water supply operation is executed according to the instruction of the user. In the hot water supply operation, the hot water stored in the tank 10 is supplied to the hot water utilization point. After the total amount of hot water boiled by the heat pump 50 is used, the controller 100 operates the burner heating device 60, and the water supplied to the hot water utilization location is heated by the burner heating device 60. In addition, the controller 100 executes the boiling operation again.

The configuration and operation of the hot water supply system 2 have been described above. As is clear from the above description, the hot water supply system 2 has a heat pump 50 that absorbs heat from the outside air to boil water, a tank 10 that stores hot water boiled by the heat pump 50, and a hot water utilization point in the tank 10. It is provided with a supply path 40 for supplying to. Further, the hot water supply system 2 includes a remote controller 104 capable of setting a hot water supply set temperature at a hot water usage location, a water supply channel 30 for supplying water into the tank 10, a thermistor 103 for measuring the outside air temperature, a memory 102, and a controller 100. And have. The memory 102 sets the first specific table that specifies the first boiling set temperature from the outside air temperature measured by the thermistor 103, and the second boiling set temperature that is closer to the hot water supply set temperature than the first boiling set temperature from the outside air temperature. The second specific table to be specified is stored. When the controller 100 executes the boiling operation of boiling the water in the tank 10 by the heat pump 50, the entire amount of the hot water boiled by the heat pump 50 reaches the hot water utilization location within the first predetermined time from the start of the boiling operation. When it is predicted that the heat will be supplied (see S12 in FIG. 6), the second boiling set temperature is specified from the outside air temperature measured by the thermistor 103 using the second specific table stored in the memory 102. (See S14). Further, in the case other than the above case (when it is predicted that the entire amount of hot water boiled by the heat pump 50 will not be supplied to the hot water utilization location within the first predetermined time from the start of the boiling operation), the controller 100 has a memory. Using the first specific information stored in 102, the first boiling set temperature is specified from the outside air temperature measured by the thermistor 103 (see S21 in FIG. 6). The controller 100 executes the boiling operation so that the water in the tank 10 reaches the first boiling set temperature or the second boiling set temperature.

When it is predicted that the entire amount of hot water boiled by the heat pump 50 will be supplied to the hot water utilization location within the first predetermined time, the hot water will not stay in the tank 10 for longer than the first predetermined time. Therefore, the time for the hot water to stay in the tank 10 is relatively short. For example, as shown in FIG. 3, in a household where a boiling operation is executed between 5:00 and 6:00 in the early morning and hot water is intensively used between 6:00 and 7:00 in the morning. Since the time until the hot water boiled in the boiling operation is used is short, the time for the hot water to stay in the tank 10 is relatively short. In this case, the boiling operation is executed at the second boiling set temperature which is closer to the hot water supply set temperature than the first boiling set temperature. On the other hand, if this is not the case (when it is predicted that the total amount of hot water boiled by the heat pump 50 will not be supplied to the hot water utilization location within the first predetermined time), the hot water will be in the tank 10 longer than the first predetermined time. stay. Therefore, the hot water stays in the tank 10 for a relatively long time. For example, as shown in FIG. 4, in a household where the boiling operation is executed between 5:00 and 6:00 in the early morning and the hot water is concentrated between 12:00 and 13:00 in the daytime. Since it takes a long time to use the hot water boiled in the boiling operation, the time for the hot water to stay in the tank 10 is relatively long. In this case, the boiling operation is executed according to the first boiling set temperature.

In the hot water supply system 2, when the boiling operation is executed at a low temperature, the COP (Coefficient Of Performance) in the heat pump 50 can be made higher than that when the boiling operation is executed at a high temperature. Therefore, it is preferable to carry out the boiling operation at the lowest possible temperature. That is, it is preferable to execute the boiling operation at a temperature as close to the hot water supply set temperature as possible. Further, the temperature of the hot water in the tank 10 decreases with the passage of time due to natural heat dissipation. The longer the hot water stays in the tank 10, the greater the decrease in temperature. On the other hand, if the hot water stays in the tank 10 for a short time, the decrease in temperature becomes relatively small.

According to the above configuration, when the hot water stays in the tank 10 for a relatively short time and the temperature drop due to natural heat dissipation is relatively small, the second boiling setting is closer to the hot water supply set temperature than the first boiling set temperature. The boiling operation is performed depending on the temperature. That is, the boiling operation is performed at a low temperature. Even if the boiling operation is performed at a low temperature, the decrease in the temperature of the hot water is relatively small, so that the possibility that the temperature of the hot water becomes lower than the set temperature of the hot water supply can be reduced. Further, since the boiling operation is performed at a low temperature, the COP in the heat pump 50 can be increased. Therefore, even if the COP is increased and the boiling operation is performed at a low temperature, hot water having a hot water supply set temperature can be supplied to the hot water utilization location. On the other hand, when the hot water stays in the tank 50 for a relatively long time and the temperature drop due to natural heat dissipation is relatively large, the boiling operation is executed at the second boiling set temperature. That is, the boiling operation is performed at a high temperature. As a result, even if the hot water stays in the tank 10 for a relatively long time, the possibility that the temperature of the hot water becomes lower than the set temperature of the hot water supply can be reduced.

Further, in the above-mentioned hot water supply system 2, the controller 100 specifies the first boiling set temperature or the second boiling set temperature from the outside air temperature measured by the thermistor 103.

The outside air temperature becomes a direct factor when the temperature of the hot water in the tank 10 decreases. By specifying the first boiling set temperature or the second boiling set temperature from the outside air temperature, the boiling set temperature can be specified by accurately reflecting the decrease state of the temperature of the hot water.

Further, in the above-mentioned hot water supply system 2, the memory 102 stores a third specific table that specifies the third boiling set temperature that is closer to the hot water supply set temperature than the second boiling set temperature from the outside air temperature measured by the thermistor 103. ing. The controller 100 is a case where it is predicted that the entire amount of hot water boiled by the heat pump 50 will be supplied to the hot water utilization location within the first predetermined time from the start of the boiling operation, and the second is to the hot water utilization location. When the predicted amount of hot water supplied within the predetermined time is larger than the predetermined amount (see S13 in FIG. 6), the outside air temperature measured by the thermistor 103 is used using the third specific table stored in the memory 102. The third boiling set temperature is specified (see S31 in FIG. 6). The controller 100 executes the boiling operation so that the water in the tank 10 reaches the third boiling set temperature.

When the predicted amount of hot water supplied to the hot water utilization location within the second predetermined time is larger than the predetermined amount, the time for the hot water to stay in the tank 10 is further shortened, and the temperature drop of the hot water is further reduced. In this case, the boiling operation is executed at the third boiling set temperature which is closer to the hot water supply set temperature than the second boiling set temperature. That is, the boiling operation is performed at a lower temperature. Even if the boiling operation is performed at a low temperature, the temperature drop of the hot water is even smaller, so that the possibility that the temperature of the hot water becomes lower than the set temperature of the hot water supply can be reduced. Moreover, since the boiling operation is performed at a lower temperature, the COP in the heat pump 50 can be made higher.

Further, the hot water supply system 2 includes a burner heating device 60 that heats the water supplied from the tank 10 to the hot water utilization location by burning gas.

When water is boiled at a boiling set temperature close to the hot water supply set temperature, it is conceivable that the temperature of the hot water becomes lower than the hot water supply set temperature when the hot water stays in the tank 10 for a long time. Even in this case, according to the above configuration, the water supplied to the hot water utilization location can be heated by the burner heating device 60, so that the water can be heated to the hot water supply set temperature. Further, even when the entire amount of hot water boiled by the heat pump 50 is used up, the water can be heated by the burner heating device 60.

Although one embodiment has been described above, the specific embodiment is not limited to the above embodiment. In the above embodiment, the boiling set temperature is specified from the outside air temperature, but the present invention is not limited to this configuration. In another embodiment, the boiling set temperature may be specified from the water supply temperature. In this case, the controller 100 specifies the boiling set temperature from the water supply temperature measured by the thermistor 32 (another example of the temperature sensor) interposed in the water supply channel 30. The memory 102 stores the first specific table, the second specific table, and the third specific table shown in FIG. 7. The first specific table shows the correspondence between the water supply temperature and the first boiling set temperature. In the first specific table, the first boiling set temperature can be specified from the water supply temperature measured by the thermistor 32. The second specific table shows the correspondence between the water supply temperature and the second boiling set temperature. In the second specific table, the second boiling set temperature can be specified from the water supply temperature measured by the thermistor 32. The third specific table shows the correspondence between the water supply temperature and the third boiling set temperature. In the third specific table, the third boiling set temperature can be specified from the water supply temperature measured by the thermistor 32.

According to such a configuration, the thermistor 103 for measuring the outside air temperature can be omitted. Even without the thermistor 103, the boiling set temperature can be specified.

Although specific examples of the present invention have been described in detail above, these are merely examples and do not limit the scope of claims. The techniques described in the claims include various modifications and modifications of the specific examples illustrated above. The technical elements described in the present specification or the drawings exert technical utility alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the techniques illustrated in the present specification or drawings can achieve a plurality of purposes at the same time, and achieving one of the purposes itself has technical usefulness.

2: Hot water supply system 10: Tank 12: Thermistor 14: Thermistor 16: Thermistor 18: Thermistor 20: Tank water circulation path 22: Circulation pump 24: Thermistor 30: Water supply channel 30a: First introduction path 30b: Second introduction path 31: Water supply Water supply source 32: Thermistor 40: Supply path 42: Mixing valve 43: Thermistor 44: Thermistor 50: Heat pump 60: Burner heating device 100: Controller 102: Memory 103: Thermistor 104: Remote control

Claims (5)

A heat pump that absorbs heat from the outside air and boils water,
A tank for storing hot water boiled by the heat pump and
A supply path for supplying hot water in the tank to hot water utilization points, and
A setting means that can set the hot water supply set temperature at the hot water usage location, and
A water supply channel that supplies water to the tank and
A temperature sensor that measures the outside air temperature or water supply temperature,
Memories and
Equipped with control means,
The storage means includes first specific information for specifying a first boiling set temperature higher than the hot water supply set temperature from the outside air temperature or the water supply temperature measured by the temperature sensor, and a first boiling set temperature from the outside air temperature or the water supply temperature. It stores the second specific information that specifies the second boiling set temperature that is closer to the hot water supply set temperature.
When the control means performs a boiling operation of boiling water in the tank by the heat pump, the entire amount of hot water boiled by the heat pump uses the hot water within a first predetermined time from the start of the boiling operation. When it is predicted that the temperature will be supplied to the location, the second boiling set temperature is calculated from the outside air temperature or the water supply temperature measured by the temperature sensor using the second specific information stored in the storage means. If not, the first boiling set temperature is specified from the outside air temperature or the water supply temperature measured by the temperature sensor using the first specific information stored in the storage means, and the tank is specified. A hot water supply system that executes a boiling operation so that the water inside reaches the first boiling set temperature or the second boiling set temperature. The hot water supply system according to claim 1, wherein the control means specifies a first boiling set temperature or a second boiling set temperature from the outside air temperature measured by the temperature sensor. The hot water supply system according to claim 1, wherein the control means specifies a first boiling set temperature or a second boiling set temperature from the water supply temperature measured by the temperature sensor. The storage means stores the third specific information that specifies the third boiling set temperature that is closer to the hot water supply set temperature than the second boiling set temperature from the outside air temperature or the water supply temperature measured by the temperature sensor.
The control means is a case where it is predicted that the entire amount of hot water boiled by the heat pump will be supplied to the hot water utilization location within the first predetermined time from the start of the boiling operation, and the control means is the first to the hot water utilization location. When the predicted amount of hot water supplied within the predetermined time of 2 is larger than the predetermined amount, the outside air temperature or the water supply temperature measured by the temperature sensor using the third specific information stored in the storage means. The hot water supply system according to any one of claims 1 to 3, wherein the third boiling set temperature is specified from the above, and the boiling operation is executed so that the water in the tank reaches the third boiling set temperature. The hot water supply system according to any one of claims 1 to 4, further comprising a gas heater that heats water supplied from the tank to the hot water utilization location by burning gas.

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