JP6944832B2 - Hot water supply system - Google Patents

Description

The present invention relates to a hot water supply system provided with a heat pump type heating unit capable of supplying hot water to a hot water storage tank.

Conventionally, there is known a hot water supply system capable of storing hot water generated by a heat pump type heating unit in a hot water storage tank and further heating hot water supplied from the hot water storage tank to a hot water supply terminal by a gas heater. For example, in the hot water supply system disclosed in Patent Document 1 (Japanese Unexamined Patent Publication No. 2013-11495), when the hot water storage tank runs out of hot water, in addition to boiling the hot water in the hot water storage tank by the heat pump type heating unit, the gas heater The heating operation is performed by. As a result, even if the hot water storage tank runs out of hot water, the supply of hot water to the hot water supply terminal is ensured.

By the way, the heat pump type heating unit is generally operated at a heating capacity (frequency) that maximizes the heat pump efficiency (COP) according to the outside air temperature regardless of the required amount of heat. That is, even if a sufficient amount of heat can be secured only by the boiling operation by the heat pump type heating unit, or even if the amount of heat is insufficient due to a large amount of hot water or the like and heating by the gas heater is required, the heat pump type heating unit Is uniformly operated at the heating capacity (frequency) at which the COP is maximized.

On the other hand, when the COP of the heat pump type heating unit is converted into the primary energy efficiency and compared with the primary energy efficiency of the auxiliary heating unit such as a gas heater, the efficiency of the heat pump type heating unit is higher. There are many. Therefore, in the operation in which the heat pump type heating unit is used to boil with the above heating capacity and the amount of heat is insufficient, for example, when the hot water storage tank runs out of hot water, the auxiliary heating unit is also used for heating. It may not be optimal as the overall energy efficiency of the system including the heat pump type heating unit and the auxiliary heating unit.

An object of the present invention is to provide a hot water supply system capable of optimizing the overall energy efficiency of a system including a heat pump type heating unit and an auxiliary heating unit.

The hot water supply system of the present invention has a hot water storage tank for storing hot water, a hot water outlet for supplying hot water from the hot water storage tank to the user side, a heat pump type heating unit for boiling hot water in the hot water storage tank, and a hot water outlet from the hot water storage tank. It is provided with an auxiliary heating unit capable of heating the supplied hot water, a hot water discharge amount detection unit that detects the amount of hot water supplied from the hot water storage tank to the hot water discharge unit, and a control unit that predicts the amount of hot water discharged from the hot water storage tank. When the amount of heat is insufficient only by the heat pump independent operation in which the hot water in the hot water storage tank is boiled by the heat pump type heating unit and the hot water in the hot water storage tank by the heat pump type heating unit, the hot water in the hot water storage tank is boiled and assisted. It is configured so that it can be operated in combination with auxiliary heating in which hot water is heated by the heating unit at the same time. The heat pump independent operation includes boiling in the first mode and boiling in the second mode, which have different heating capacities from each other. The heating capacity of the boiling in the first mode is higher than the heating capacity of the boiling in the second mode, and the heat pump efficiency of the boiling in the first mode is that of the boiling in the second mode. Lower than heat pump efficiency. Further, when the control unit predicts a large amount of hot water to be stored in the hot water storage tank in the boiling in the second mode, or determines that a large amount of hot water is generated, the first Boiling is performed in the mode, and then, when the amount of heat is insufficient only by operating the heat pump alone, the auxiliary heating combined operation is performed.

According to this configuration, the ratio of the heating amount by the auxiliary heating unit to the heating amount of the entire system can be reduced, so that the overall energy efficiency of the entire hot water supply system can be optimized.

In the above hot water supply system, the heating capacity of boiling in the first mode is larger than the heating capacity at which the COP is maximized at the outside air temperature at that time, and the primary energy efficiency of boiling in the first mode is large. May be greater than or equal to the primary energy efficiency when the auxiliary heating unit is operated independently.

According to this configuration, it is possible to prevent the primary energy efficiency of the heat pump type heating unit from becoming lower than the primary energy efficiency of the auxiliary heating unit, and it is possible to suppress a decrease in the energy efficiency of the entire hot water supply system.

In the above hot water supply system, a hot water storage amount detecting unit for detecting the hot water storage amount of the hot water storage tank is further provided, and when the hot water storage amount detected by the hot water storage amount detection unit becomes smaller than the first hot water storage amount, boiling in the second mode is performed. When the raising is started and the second hot water storage amount becomes smaller than the first hot water storage amount, the boiling in the second mode may be changed to the boiling in the first mode.

According to this configuration, the amount of hot water in the hot water storage tank is reduced and the operation of the auxiliary heating unit can be suppressed, so that the overall energy efficiency of the hot water supply system can be optimized.

In the above hot water supply system, a bathtub 10a to which hot water is supplied from a hot water outlet is further provided, and when a hot water filling instruction for supplying hot water of a target temperature is given to the bathtub 10a, boiling is performed in the first mode. You may.

According to this configuration, the amount of hot water in the hot water storage tank is reduced due to the large amount of hot water discharged by the hot water filling, and the operation of the auxiliary heating unit can be suppressed, so that the overall energy efficiency of the hot water supply system can be optimized.

In the above hot water supply system, the control unit has a history information storage unit that stores the history information of the hot water discharge amount and the hot water discharge time detected by the hot water discharge amount detection unit, and the scheduled hot water discharge amount and the hot water discharge scheduled time based on the history information of the history information storage unit. It may further have a hot water supply prediction unit for predicting. In this case, when the heat pump type heating unit is operated so that the planned amount of hot water that is predicted by the hot water forecasting unit is stored in the hot water storage tank by the scheduled hot water discharge time, there is a hot water that is not predicted by the hot water forecasting unit. In addition, it is configured to perform boiling in the first mode.

According to this configuration, the amount of hot water in the hot water storage tank is reduced and the operation of the auxiliary heating unit can be suppressed, so that the overall energy efficiency of the hot water supply system can be optimized.

The hot water supply system may further include a hot water storage amount detection unit that detects the amount of hot water stored in the hot water storage tank. The control unit has a history information storage unit that stores the history information of the hot water discharge amount and the hot water discharge time detected by the hot water discharge amount detection unit, and a hot water discharge prediction that predicts the hot water discharge scheduled amount and the hot water discharge scheduled time based on the history information of the history information storage unit. It may further have a unit. In this case, when the planned hot water storage amount is larger than the total value of the hot water storage amount detected by the hot water storage amount detection unit and the hot water storage planned amount at the scheduled hot water discharge time when the operation is performed by boiling in the second mode. It is configured to boil in the first mode.

According to this configuration, the amount of hot water in the hot water storage tank is reduced and the operation of the auxiliary heating unit can be suppressed, so that the overall energy efficiency of the hot water supply system can be optimized.

In the above hot water supply system, the heat pump type heating unit has a refrigerant circuit to which a compressor, a radiator, an expansion mechanism, and an evaporator are connected and a refrigerant circulates, and boiling in the first mode is the outside air temperature. When they are the same, the frequency of the compressor may be higher than that of the boiling in the second mode.

According to this configuration, by increasing the frequency of the compressor, it is possible to cover the heating capacity required for boiling in the first mode.

In the above hot water supply system, the heat pump type heating unit is connected to the compressor, the heat source side heat exchanger, the expansion mechanism, and the user side heat exchanger, and blows air to the refrigerant circuit in which the refrigerant circulates and the heat source side heat exchanger. It may have a fan for heat exchange. In this case, the fan rotation speed in the boiling in the first mode may be configured to be higher than the fan rotation speed in the boiling in the second mode when the outside air temperature is the same.

According to this configuration, by increasing the rotation speed of the fan, it is possible to cover the heating capacity required for boiling in the first mode.

The block diagram of the hot water supply system which concerns on one Embodiment of this invention. The block diagram of the control part of the hot water supply system of FIG. The figure which shows the change of COP when the heating capacity of a heat pump part changes. The figure which shows the change of the primary energy efficiency when the heating capacity of a heat pump part changes. The flowchart explaining the operation of the hot water supply system of FIG. The time chart explaining the operation of the hot water supply system of FIG. The flowchart explaining the operation of the hot water supply system which concerns on modification A. The flowchart explaining the operation of the hot water supply system which concerns on modification B. The figure which shows the change of the usage charge per unit capacity when the heating capacity of a heat pump part changes. The figure which shows the change of the carbon emission amount per unit capacity when the heating capacity of a heat pump part changes.

(1) Configuration of Hot Water Supply System 1 FIG. 1 shows a configuration diagram of the hot water supply system 1 according to the embodiment of the present invention. The hot water supply system 1 includes a heat pump unit 2 (heat pump type heating unit), a hot water circuit unit 3 having a hot water storage tank 5, and a gas heater 6 (an example of an auxiliary heating unit). The heat pump unit 2 generates hot water to be stored in the hot water storage tank 5. The hot water supply terminal 10 (an example of a hot water outlet) discharges hot water from the hot water storage tank 5. If necessary, the hot water in the hot water storage tank 5 is further heated by the gas heater 6 before being discharged.

(1-1) Configuration of Heat Pump Unit 2 The heat pump unit 2 has a refrigerant circuit 41 in which a refrigerant circulates. In the refrigerant circuit 41, the compressor 11, the outdoor heat exchanger (heat source side heat exchanger) 12, the expansion valve (an example of the expansion mechanism) 13, and the hot water supply heat exchanger (utility side heat exchanger) 16 are connected to the refrigerant pipe 40. It consists of being connected by. The fan 15 is arranged so as to face the outdoor heat exchanger 12. The outside air temperature sensor 21 detects the outside air temperature.

In the boiling operation in which hot water is stored in the hot water storage tank 5, as shown by the arrow R1 in FIG. 1, the refrigerant discharged from the compressor 11 goes to the hot water supply heat exchanger 16, the expansion valve 13, and the outdoor heat exchanger 12. A heating cycle is formed in which the refrigerant flows in order and returns to the compressor 11 after passing through the outdoor heat exchanger 12. In this case, the hot water supply heat exchanger 16 functions as a condenser, and the outdoor heat exchanger 12 functions as an evaporator. In this boiling operation, the hot water for hot water supply is heated by exchanging heat between the hot refrigerant for hot water supply and the hot water for hot water supply that has flowed in from the discharge side of the compressor 11 in the heat exchanger 16 for hot water supply.

(1-2) Configuration of Hot Water Circuit Unit 3 The hot water circuit unit 3 is connected to the hot water supply heat exchanger 16. The hot water circuit unit 3 is configured such that the hot water storage tank 5, the pump 17, and the hot water supply heat exchanger 16 are connected by a water pipe 45 so that hot water circulates. In the hot water circuit unit 3, the discharge side of the pump 17 is connected to the hot water inlet of the hot water supply heat exchanger 16, and the suction side of the pump 17 is connected to one end of the hot water storage tank 5. The hot water outlet of the hot water supply heat exchanger 16 is connected to the other end of the hot water storage tank 5.

In the hot water circuit unit 3, hot water that exchanges heat with the refrigerant flowing through the hot water supply heat exchanger 16 circulates. Specifically, when the boiling operation is executed, the hot water flowing out of the hot water storage tank 5 is supplied to the hot water supply heat exchanger 16 by the pump 17, and the hot water heated by the hot water supply heat exchanger 16 is supplied to the hot water storage tank. It is returned to 5.

A hot water outlet temperature sensor 22 is arranged near the hot water outlet of the hot water supply heat exchanger 16 to detect the temperature of the hot water flowing out from the hot water supply heat exchanger 16. The hot water storage tank 5 is provided with a plurality of hot water storage temperature sensors 5a to 5d (hot water storage amount detection unit), and detects the hot water storage amount according to the water temperature detected by each of the hot water storage temperature sensors 5a to 5d. The outside air temperature sensor 21, the hot water outlet temperature sensor 22, and the hot water storage temperature sensors 5a to 5d may be any as long as they can output the detected temperature to the control unit 30.

(1-3) Configuration of Hot Water Supply Terminal 10 and Gas Heater 6 Hot water in the hot water storage tank 5 is configured so that hot water can be discharged via the hot water supply terminal 10. The gas heater 6 is arranged between the hot water storage tank 5 and the hot water supply terminal 10, and has a heating unit 6a. The hot water storage tank 5, the gas heater 6, and the hot water supply terminal 10 are connected by a water pipe 47. The gas heater 6 can heat the hot water supplied from the hot water storage tank 5 before it is supplied to the hot water supply terminal 10. The hot water supply terminal 10 makes it possible for the user to use the hot water in the hot water storage tank 5, and the hot water can be discharged to the bathtub 10a.

The water pipe 46 is provided with a flow rate sensor 23 (flow rate detection unit), and detects the flow rate of hot water supplied from the hot water storage tank 5 to the hot water supply terminal 10. The flow rate sensor 23 may be provided in a water pipe other than the water pipe 46 as long as it can detect the amount of hot water supplied from the hot water storage tank 5.

As described above, the hot water supply system 1 includes a heat pump unit 2 (heat pump type heating unit) capable of supplying hot water to the hot water storage tank 5, and a gas capable of heating hot water supplied from the hot water storage tank 5 to the hot water supply terminal 10. It has a heater 6 (auxiliary heating unit). The hot water supply system 1 has a boiling operation in which hot water is stored in the hot water storage tank 5 by the heat pump unit 2, and hot water supplied from the hot water storage tank 5 as needed when the hot water in the hot water storage tank 5 is supplied to the hot water supply terminal 10. Is possible to perform an additional heating operation in which the gas heater 6 is used, and the operation of the hot water supply system 1 includes a heat pump independent operation in which only the boiling operation is performed, an auxiliary heating independent operation in which only the additional heating operation is performed, and boiling. It can be divided into auxiliary heating combined operation in which operation and additional heating operation are performed at the same time.

(1-4) Configuration of Control Unit 30 of Hot Water Supply System 1 The control unit 30 of the hot water supply system 1 is composed of a CPU, a ROM, a RAM (all not shown), and the like. As shown in FIG. 2, the control unit 30 of the hot water supply system 1 includes a hot water shortage determination unit 31, a COP curve storage unit 32, a COP curve calculation unit 33, an efficiency calculation unit 34a, a capacity derivation unit 35, and boiling. It has a raising control unit 36, a hot water supply control unit 37, a history information storage unit 38, and a hot water supply prediction unit 39. The input side of the control unit 30 is connected to the hot water storage temperature sensors 5a to 5d attached to the side surface of the hot water storage tank 5, the remote controller 20, the outside air temperature sensor 21, the hot water discharge temperature sensor 22, and the flow rate sensor 23. There is. The output side of the control unit 30 is connected to the compressor 11, the fan 15, the heating unit 6a, and an actuator such as a pump 17. The input from the remote controller 20 is transmitted to each of the heat pump unit 2 and the hot water circuit unit 3.

The hot water shortage determination unit 31 determines whether or not the amount of hot water stored in the hot water storage tank 5 has decreased (the ratio of hot water in the hot water storage tank 5 has decreased) and the hot water has run out (whether or not it is necessary to perform boiling operation). To judge. In the present embodiment, when the temperature detected by the hot water storage temperature sensor 5b attached to the side surface of the hot water storage tank 5 is lower than the hot water storage target temperature by a predetermined temperature or more, the hot water shortage determination unit 31 of the hot water in the hot water storage tank 5 Assuming that the ratio has decreased and the hot water has run out (the amount of hot water stored has fallen below the specified value), it is judged that the boiling operation is necessary. The hot water discharge target temperature is input by operating the remote controller 20 by the user.

The COP curve storage unit 32 stores a plurality of COP curves, and the plurality of COP curves correspond to various outside air temperatures and hot water target temperatures, respectively. As shown in FIG. 3, the COP curve has a heating capacity (compressor frequency) on the horizontal axis and a COP on the vertical axis, and shows the heating capacity of the heat pump unit 2 and the COP at that heating capacity. As shown in FIG. 3, the COP of the heat pump unit 2 has a maximum value b in the heating capacity a1.

When it is determined that the boiling operation needs to be performed, the COP curve calculation unit 33 calculates the COP curve based on the outside air temperature and the hot water target temperature at that time. In the present embodiment, since the COP curve storage unit 32 stores a plurality of COP curves, the COP curve calculation unit 33 can select the outside air temperature at that time from the COP curves stored in the COP curve storage unit 32. Acquire the COP curve based on the target temperature of hot water. The outside air temperature is the temperature detected by the outside air temperature sensor 21, and the hot water target temperature is the temperature input by the remote controller 20.

The efficiency calculation unit 34a calculates the primary energy efficiency of the heat pump unit 2 based on the COP curve acquired by the COP curve calculation unit 33. In the present embodiment, the efficiency calculation unit 34a calculates the primary energy efficiency by using the primary energy conversion coefficient 0.369 for each COP curve. Therefore, as shown in FIG. 4, the curve of the primary energy efficiency calculated based on the COP curve has the heating capacity on the horizontal axis and the primary energy efficiency on the vertical axis, and the heating capacity of the heat pump unit 2 and its heating capacity. It shows the primary energy efficiency in. As shown in FIG. 4, the curve of the primary energy efficiency calculated based on the COP curve has the maximum value c in the heating capacity a1. In FIG. 4, the primary energy efficiency of the gas heater 6 is shown as d.

The capacity deriving unit 35 derives the heating capacity of the heat pump unit 2 based on the COP curve of FIG. The capacity deriving unit 35 sets the heating capacity of the boiling operation according to the amount of hot water that can be boiled and the predicted amount of hot water discharged by a predetermined time, which will be described later, or other operating conditions. The heating capacity of the gas heater 6 when the auxiliary heating combined operation is performed is derived from the difference between the temperature of the hot water supplied from the hot water storage tank 5 and the temperature of the hot water required when the hot water is discharged from the hot water supply terminal 10. After that, it is derived based on the heating capacity of the heat pump unit 2 that is insufficient.

The boiling control unit 36 controls the frequency of the compressor 11, the rotation speed of the pump 17, and the rotation speed of the fan 15. Specifically, the boiling control unit 36 controls the frequency of the compressor 11 and the rotation speed of the fan 15 during the boiling operation based on the heating capacity of the heat pump unit 2 derived by the capacity extraction unit 35. The boiling control unit 36 keeps the frequency of the compressor 11 constant and controls the rotation speed of the pump 17 so as to reach the hot water target temperature.

The hot water discharge control unit 37 controls the heating unit 6a of the gas heater 6 when an additional heating operation is performed at the time of hot water discharge, based on the heating capacity of the gas heater 6 derived by the capacity extraction unit 35.

The history information storage unit 38 stores the amount of hot water discharged per unit time detected by the flow rate sensor 23 as history information in association with the measurement time. The history information storage unit 38 stores, for example, the fluctuation tendency of the amount of hot water discharged for each time zone and the total amount of hot water discharged in one day (or each day of the week) as history information.

The hot water discharge prediction unit 39 analyzes the time zone in which a large amount of hot water is discharged by the user and the amount of hot water discharged as a pattern based on the history information of the history information storage unit 38 described above. Based on this hot water discharge pattern, the hot water discharge amount and the hot water discharge time are predicted. Control unit 30, at predetermined time intervals (e.g., every 10 minutes), a hot water storage amount detected by the stored hot water temperature sensor 5a~5d of the hot water storage tank 5, a current time Therefore predicted tapping prediction unit 39 a predetermined time (e.g. Compare with the amount of hot water discharged within (2 hours). Here, when the predicted hot water output amount is larger than the hot water storage amount, the control unit 30 instructs the start of the boiling operation.

(2) Explanation of heating operation by the hot water supply system 1 As described above, the hot water supply system 1 operates the heat pump independently to boil the hot water storage tank 5 by the heat pump unit 2 alone, and the gas heater 6 alone from the hot water storage tank 5 to the hot water supply terminal. Auxiliary heating independent operation for heating the hot water supplied to No. 10 and auxiliary heating combined operation for simultaneously executing the boiling operation by the heat pump unit 2 and the additional heating operation by the gas heater 6 are possible.

When the amount of hot water stored in the hot water storage tank 5 is low, or when a large amount of hot water is predicted by the hot water discharge prediction unit 39, the boiling operation is performed. Of the boiling operations, the heat pump independent operation includes operation in the normal boiling mode (an example of boiling in the second mode) and operation in the rapid boiling mode (boiling in the first mode), which will be described later. One example). When there is a large amount of hot water that exceeds the amount of hot water stored in the hot water storage tank 5, or when the amount of heat is insufficient to supply hot water at the desired temperature to the user even if the boiling operation is performed, the auxiliary heating combined operation is performed. Will be done. In this case, in parallel with the boiling operation, an additional heating operation is performed in which the hot water supplied from the hot water storage tank 5 is further heated by the heating unit 6a. As a result, hot water at a desired temperature is supplied to the user even when the amount of hot water stored in the hot water storage tank 5 is small.

(2-1) Description of Normal Boiling Mode (Example of Boiling in Second Mode) In the present embodiment, the amount of hot water stored in the hot water storage tank 5 is a predetermined value (for example, with respect to a tank capacity of 100 L of the hot water storage tank 5). , 40L) or less, or during the night time when hot water is not expected to come out for a long time and the electricity rate is low, the operation in the boiling mode is usually performed. Further, the current amount of hot water storage, even if less than the volume of the melt teemed within two hours from the current time to be thus predicted tapping prediction unit 39, operating in the normal boiling mode is executed.

When the operation is performed in the normal boiling mode, the capacity deriving unit 35 derives the heating capacity of the heat pump unit 2 as a1 so that the heating capacity maximizes the COP in the COP curve of FIG. Then, the boiling control unit 36 controls the frequency of the compressor 11 and the rotation speed of the pump 17 based on the heating capacity a1 until the hot water temperature detected by the hot water temperature sensor 22 reaches the target hot water temperature. In normal boiling mode operation, the heat pump unit operates with the capacity to maximize the heat pump efficiency.

(2-2) Explanation of rapid boiling mode (an example of boiling in the first mode) On the other hand, when it is necessary to rapidly increase the amount of hot water stored, the operation in the rapid boiling mode is performed. .. In the present embodiment, when a sufficient amount of hot water cannot be secured by the operation in the normal boiling mode, the operation in the rapid boiling mode is executed. For example, after the current amount of hot water stored falls below the planned amount of hot water to be discharged within 2 hours from the current time and the operation in the normal boiling mode is started, there is a hot water that is not predicted by the hot water prediction unit 39, and the normal boiling is performed. In the operation in the raising mode, when the boiling is not completed by a predetermined time, the operation in the rapid boiling mode is executed.

When the operation is performed in the rapid boiling mode, the capacity deriving unit 35 heats the heat pump unit 2 so that the primary energy efficiency of the heat pump unit 2 is the same as the primary energy efficiency of the gas heater 6. Derive the ability. Therefore, as shown in FIG. 4, the capacity deriving unit 35 determines that the primary energy efficiency of the heat pump unit 2 is the primary energy efficiency of the gas heater 6 based on the primary energy efficiency curve calculated based on the COP curve. The heating capacity of the heat pump unit 2 is derived as a2 so as to be the same as d. Then, the boiling control unit 36 controls the frequency of the compressor 11 and the rotation speed of the pump 17 so that the hot water temperature detected by the hot water temperature sensor 22 becomes the target hot water temperature based on the heating capacity a2.

After the hot water temperature detected by the hot water temperature sensor 22 reaches the target hot water temperature, the frequency (frequency based on the heating capacity a2) higher than the frequency during operation in the normal boiling mode (frequency based on the heating capacity a1) The compressor 11 is controlled, and the pump 17 is controlled at a frequency higher than the rotation speed of the pump 17 during operation in the normal boiling mode. In this way, since the pump 17 is driven at a large rotation speed during operation in the rapid boiling mode, the flow rate of hot water circulating in the hot water circuit unit 3 increases, and normal boiling is performed while maintaining the hot water temperature constant. The amount of hot water stored in the hot water storage tank 5 can be increased per unit time as compared with the operation in the mode.

(2-3) Explanation of operation with auxiliary heating In the present embodiment, the amount of hot water stored in the hot water storage tank 5 is insufficient, and the temperature of the hot water supplied from the hot water storage tank 5 to the hot water supply terminal 10 is higher than the temperature required by the user. When it becomes low, the auxiliary heating combined operation is performed.

When the auxiliary heating combined operation is performed, first, the capacity deriving unit 35 derives the heating capacity of the heat pump unit 2 as a1 so that the heating capacity maximizes the COP in the COP curve of FIG. Then, the boiling control unit 36 controls the frequency of the compressor 11 and the rotation speed of the pump 17 so that the hot water discharge temperature detected by the hot water discharge temperature sensor 22 becomes the target hot water discharge temperature based on the heating capacity a1. The heating capacity of the gas heater 6 is derived based on the heating capacity of the heat pump unit 2 that is insufficient after the heating capacity of the heat pump unit 2 is derived. Be driven. Even in the auxiliary heating combined operation, the heat pump unit 2 is operated with the ability to maximize the heat pump efficiency, as in the operation in the normal boiling mode.

(3) Explanation of Heat Pump Independent Operation Using Flow Chart The operation of the hot water supply system 1 of the present embodiment will be described with reference to FIG. The flowchart of FIG. 5 describes the flow of processing for the heat pump independent operation by the control unit 30, where S represents a step and the number following it represents a step number.

In step S1, it is determined whether the amount of hot water stored in the hot water storage tank 5 can be additionally boiled based on the detection temperature of the hot water storage temperature sensor 5d installed at the bottom of the side surface of the hot water storage tank 5. When the temperature of the hot water storage temperature sensor 5d is lower than x degrees (for example, 60 degrees), it is determined that additional boiling is possible.

Next, in step S2, the current amount of hot water stored detected by the hot water storage temperature sensors 5a to 5d of the hot water storage tank 5 is compared with the amount of hot water scheduled to be discharged from the current time predicted by the hot water forecasting unit 39 to 2 hours later. .. The planned amount of hot water is calculated from the water supply temperature at the current time and the hot water supply set temperature or hot water filling set temperature set by the user from the remote controller 20. Here, when the current amount of hot water stored is smaller than the amount of hot water scheduled to be discharged within 2 hours, the time T and the planned amount of hot water discharged 2 hours after the current time are stored in the control unit 30 (step S3), and the heat pump unit 2 The operation in the normal boiling mode is started (step S4). The capacity deriving unit 35 derives the heating capacity of the heat pump unit 2 as a1 so that the heating capacity maximizes the COP in the COP curve. Then, the boiling control unit 36 controls the frequency of the compressor 11 and the rotation speed of the pump 17 so as to have the heating capacity a1, and performs the boiling operation. On the other hand, in step S2, when the current hot water storage amount is larger than the hot water storage amount within 2 hours, the hot water storage amount within 2 hours from the current time can be sufficiently covered by the current hot water storage amount. Therefore, the process returns to step S1 and continues to determine whether the additional boiling operation is possible.

When the operation in the normal boiling mode is started in step S4, in step S5, the flow rate sensor 23 confirms whether or not hot water is discharged from the hot water supply terminal 10. If there is no hot water, the operation in the normal boiling mode is continued (step S6), and it is determined whether or not the amount of hot water stored in the hot water storage tank 5 can be additionally heated (step S7). If the detection temperature of the hot water storage temperature sensor 5d is 60 degrees or higher and additional boiling is not possible, the boiling operation is terminated. If the detection temperature of the hot water storage temperature sensor 5d is less than 60 degrees and additional boiling is possible, the process proceeds to step S8, and the expected amount of hot water discharged within 2 hours is compared with the current amount of hot water stored. In step S8, when the current amount of hot water stored is larger than the amount of hot water scheduled to be discharged within 2 hours, the boiling operation is terminated. If the current amount of hot water stored is smaller than the planned amount of hot water to be discharged within 2 hours, the process returns to step S5 and the presence or absence of hot water is confirmed.

On the other hand, if there is hot water in step S5, the process proceeds to step S9. In step S9, it is confirmed whether the predicted amount of hot water discharged up to the time T stored in step S3 can be boiled by normal boiling. That is, the current amount of insufficient hot water is calculated and compared with the amount of hot water that can be boiled by operating in the normal boiling mode. The amount of insufficient hot water (estimated amount of hot water discharged until time T) is calculated based on the water supply temperature and the hot water supply set temperature or hot water filling set temperature set by the user from the remote controller 20. If the current amount of insufficient hot water is smaller than the amount of hot water that can be boiled by the operation in the normal boiling mode, the process proceeds to step S6, the boiling operation by the operation in the normal boiling mode is continued, and the above-mentioned steps S7 to S7 to The determination in step S8 is performed. On the other hand, if the current amount of insufficient hot water is larger than the amount of hot water that can be boiled in the normal boiling mode, it is predicted that the amount of hot water stored will be insufficient at time T, so the operation in the rapid boiling mode will be performed. The operation is changed to the boiling operation according to (step S10). In this case, the capacity deriving unit 35 determines the heating capacity of the heat pump unit 2 to be a2, and the boiling control unit 36 controls the frequency of the compressor 11 and the rotation speed of the pump 17 so as to have the heating capacity a2. Perform boiling operation.

After the operation in the rapid boiling mode is started, it is confirmed from the detection temperature of the hot water storage temperature sensor 5d whether the additional boiling operation is possible (step S11). If the detection temperature of the hot water storage temperature sensor 5d is 60 degrees or higher, the boiling operation is terminated. If the detection temperature of the hot water storage temperature sensor 5d is less than 60 degrees, the process proceeds to step S12, and the planned amount of hot water to be discharged within 2 hours is compared with the current amount of hot water stored. If the planned amount of hot water to be discharged within 2 hours is smaller than the current amount of hot water stored, a sufficient amount of hot water is stored and the boiling operation is terminated. If the planned amount of hot water to be discharged within 2 hours is larger than the current amount of hot water stored, the process returns to step S9, and the current amount of insufficient hot water is compared with the amount of hot water that can be boiled by operating in the normal boiling mode.

(4) Explanation of Heat Pump Independent Operation Using Time Chart Next, the operation of the hot water supply system 1 described using the flowchart of FIG. 5 will be described by applying it to the hot water discharge state of FIG. FIG. 6 is a diagram showing an example of the hot water discharge status and the boiling status in the evening to night time zone in which hot water is generally generated frequently and boiling operation is likely to occur in a day, and the vertical axis is the hot water storage tank 5. The amount of hot water stored (left axis) and the amount of hot water discharged (right axis) are shown, and the horizontal axis shows the time. The solid line shows the actual change in the amount of hot water stored, and the broken line shows the change in the amount of hot water stored predicted at time t0.

The hot water storage tank 5 can store 100 L of hot water in total, and the heat pump unit 2 can boil 30 L / H in normal boiling mode and 45 L / H in rapid boiling mode. do. The amount of hot water discharged and the amount of hot water stored is checked every 10 minutes. At time t0 (18:00), the amount of hot water stored in the hot water storage tank 5 is 50 L. A hot water discharge of 10 L from time t4 to t5 (19:10 to 19:30) and a hot water discharge of 97.5 L from time t7 (20:00) (not shown) are predicted by the hot water forecasting unit 39. ing. It is assumed that the hot water is not predicted at the time after that.

At time t0, in the flowchart of FIG. 5, as shown in step S1, it is determined whether the hot water storage tank 5 can be additionally boiled. At time t0, the temperature of the hot water storage temperature sensor 5d is lower than 60 degrees, and it is determined that additional boiling is possible. Compare with the planned amount of hot water to be discharged within 2 hours from the predicted current time (step S2). Here, within 2 hours, that is, by 20:00 (time t7), as described above, there are two hot water discharges, 10 L hot water and 97.5 L hot water, and a total of 107.5 L hot water is predicted. Therefore, since the current amount of hot water stored is smaller than the amount of hot water scheduled to be discharged until time t7, the time t7 and the planned amount of hot water discharged 107.5 L are stored (step S3), and the operation in the normal boiling mode is started (step). S4).

When the operation in the normal boiling mode is started, the flow rate sensor 23 confirms whether or not hot water is discharged from the hot water supply terminal 10 (step S5). Since there is no hot water until time t1, the boiling operation by the operation in the normal boiling mode is continued (step S6), and during the time t0 to t1, the operation in the normal boiling mode is continued and the step The determination in steps S5 to S8 is repeated.

Next, at time t1 (18:40), the hot water is confirmed (step S5). Then, the process proceeds to step S9, and it is confirmed whether the predicted hot water discharge amount (107.5 L) can be boiled by the time t7 (20:00) in the boiling operation by the operation in the normal boiling mode. The amount of hot water stored at time t1 is 62.5 L, and the amount of insufficient hot water is 45 L. The amount of hot water that can be boiled by the operation in the normal boiling mode by the time t7 is 40 L (30 L / H × 1 hour 20 minutes). That is, since the current amount of insufficient hot water is larger than the amount of hot water that can be boiled in the normal boiling mode, the operation is changed to the rapid boiling mode (step S10).

After the operation is started in the rapid boiling mode, the judgments of steps S11 and S12 in the flowchart of FIG. 5 are made, but the planned amount of hot water (107.5 L) within 2 hours is larger than the current amount of hot water (62.5 L). Due to its large size, operation in the rapid boiling mode is continued. At times t2 to t5, steps S9 to S12 are repeated, and the operation in the rapid boiling mode is continued.

At time t6 (19:50), the amount of insufficient hot water becomes 5 L in step S9, and the amount of hot water that can be boiled by the operation in the normal boiling mode by time t7 also becomes 5 L (30 L / H × 10 minutes). .. That is, the current amount of insufficient hot water is less than or equal to the amount of hot water that can be boiled by operating in the normal boiling mode. Therefore, since it is predicted that a sufficient amount of hot water can be secured by the operation in the normal boiling mode, the process proceeds to step S6, and the operation in the rapid boiling mode is changed to the operation in the normal boiling mode. Subsequently, the process proceeds to step S7 and step S8, but the operation in the normal boiling mode is continued.

Then, even at time t7 (20:00), the hot water is not confirmed in step S5, and the operation in the normal boiling mode continues (step S6). Subsequently, in step S7, it is determined that additional boiling is possible, but in step S8, the planned amount of hot water to be discharged within 2 hours (until 22:00) is 97.5 L (the hot water is discharged only once at 20:00). , The amount of hot water stored is 97.5 L, the amount of hot water stored exceeds the planned amount of hot water to be discharged, and the boiling operation (operation in the normal boiling mode) is completed.

As described above, according to the hot water supply system 1 of the present embodiment, a large amount of hot water is expected to be discharged, or a large amount of hot water is generated, so that a certain amount of heat is likely to be insufficient in the operation in the normal boiling mode. As an example, it is a condition that the current hot water storage amount is less than the hot water discharge amount within a predetermined time from the current time predicted by the hot water discharge prediction unit 39, and a sufficient hot water storage amount cannot be secured by the boiling operation by the normal boiling operation. As a result, a rapid boiling operation is performed. As a result, the heating ratio due to the auxiliary heating combined operation can be reduced by performing the rapid boiling by the operation in the rapid boiling mode, so that the overall energy efficiency of the entire hot water supply system 1 can be improved.

(5) Modification Examples Various modifications will be described below. Since the configuration of the following modification is the same as that of the above-described embodiment except for those described in particular, the description thereof will be omitted, and only the parts different from the above-described embodiment will be described below.

(5-1) Modification A
In the modified example A, the amount of hot water stored in the hot water storage tank 5 is an example of a predetermined condition in which a large amount of hot water is expected to be discharged or a large amount of hot water is generated, so that the amount of heat is likely to be insufficient in the boiling in the normal boiling operation. Is less than the specified value and it is judged that the hot water has run out, and even though the boiling by the operation in the normal boiling mode is started, when the amount of hot water stored is further reduced, the operation in the rapid boiling mode is performed. Will be. The amount of hot water stored is confirmed by the temperature detected by the hot water storage temperature sensors 5a to 5d attached to the side surface of the hot water storage tank 5. According to this example, the temperature detected by the hot water storage temperature sensor 5b is lower than the hot water storage target temperature by a predetermined temperature or more, and the hot water storage amount is the first hot water storage amount (for example, 40 L with respect to the tank capacity 100 L of the hot water storage tank 5). After the operation in the normal boiling mode is started, the hot water storage temperature sensor 5a provided above the hot water storage tank 5 becomes lower than the hot water storage target temperature by a predetermined temperature or more, and the first When the second hot water storage amount (for example, 20 L) is smaller than the hot water storage amount, the operation in the rapid boiling mode is performed.

FIG. 7 shows a flowchart of this modification. In step S101, it is determined whether the detection temperature of the hot water storage temperature sensor 5b is lower than y degrees (for example, 60 degrees). When the detection temperature of the hot water storage temperature sensor 5b is lower than y degrees, the hot water storage amount is equal to or less than a predetermined value (first predetermined value, for example, 40 L), and it is determined that the hot water has run out. The operation is started (step S102). After starting the operation in the normal boiling mode, it is confirmed whether or not hot water is discharged from the hot water supply terminal 10 (step S103). If there is no hot water, the operation in the normal boiling mode is performed while repeating the determinations in steps S103 and S105 until the detected temperature of the hot water storage temperature sensor 5b becomes y degrees or higher. When the detection temperature of the hot water storage temperature sensor 5b becomes y degrees or higher, it is determined that the hot water storage amount of the hot water storage tank 5 is sufficient, and the boiling operation is terminated.

On the other hand, if hot water is confirmed in step S103, the process proceeds to step S104, and the detection temperature of the hot water storage temperature sensor 5a arranged above the hot water storage temperature sensor 5b in the hot water storage tank 5 is from z degrees (for example, 60 degrees). Judge if it is low. Here, it is determined whether or not the amount of hot water stored is a second predetermined value (for example, 20 L), which is even lower than the first predetermined value determined to run out of hot water. If the detected temperature is z degrees or higher, the process proceeds to step S105, and the operation in the normal boiling mode is performed while repeating the determinations in steps S103 and S105 until the detected temperature of the hot water storage temperature sensor 5b becomes y degrees or higher.

When the detected temperature is lower than z degrees, the amount of hot water stored is equal to or less than the second predetermined value. Therefore, it is judged that the increase in the amount of hot water is insufficient in the operation in the normal boiling mode, and the rapid boiling mode is used. Operation is started (step S106). After the operation in the rapid boiling mode is started, the detected temperature of the hot water storage temperature sensor 5a is measured (step S107), and the operation in the rapid boiling mode is continued until the detected temperature reaches z degrees or higher. When the detected temperature becomes z degrees or higher, the operation is changed to the normal boiling mode (step S108), and the boiling operation is continued. Then, it is confirmed by the detection temperature of the hot water storage temperature sensor 5b whether the hot water continues to run out, and when the detected temperature becomes y degrees or higher and the hot water running out state is resolved, the boiling operation is terminated.

With such a configuration, even if the history information is not accumulated in the history information storage unit 38 immediately after the power is turned on and the hot water discharge pattern cannot be analyzed by the hot water supply prediction unit 39, it is assisted. The operation frequency of the combined heating operation can be reduced, and the energy efficiency of the entire hot water supply system 1 can be improved. Further, since the auxiliary heating combined operation is predicted from the amount of hot water stored by the hot water storage temperature sensors 5a to 5d provided in the hot water storage tank 5, the energy efficiency of the entire hot water supply system 1 can be improved by simple control.

(5-2) Modification B
In the modified B, a large amount of hot water is expected to be discharged, or a large amount of hot water is generated. When there is an instruction to fill the bathtub 10a with hot water having a target temperature, the operation in the rapid boiling mode is performed.

FIG. 8 shows a flowchart of this modification. In step S201, it is confirmed whether or not there is a hot water filling instruction. When the hot water filling instruction is given, the process proceeds to step S202, the measurement of the timer T1 of the control unit 30 is started, and the confirmation of the timer T1 is continued until the timer T1 reaches α minutes (for example, 5 minutes) in step S203. .. When the timer T1 reaches the α minute, the timer T1 is reset (step S204), and it is confirmed whether the hot water filling is continued (step S205). If the hot water filling instruction is not continued at this point, the process returns to step S201 and waits until the next hot water filling instruction is given. If the hot water filling instruction is continued, the boiling operation in the rapid boiling mode is started (step S206). It is presumed that the timer T1 supplied water to the lower part of the hot water storage tank 5 by leaving a predetermined time from the reception of the hot water filling instruction to the start of the boiling operation.

When the operation in the rapid boiling mode is started, it is confirmed whether the hot water filling is completed (step S207). The completion of hot water filling is determined by determining that the amount of hot water supplied to the bathtub 10a has reached the hot water filling set amount, or by a termination instruction from the remote controller 20. When it is determined in step S207 that the hot water filling is completed, the measurement of the timer T2 is started (step S208). Then, the detection temperature of the hot water storage temperature sensor 5d installed at the bottom of the side surface of the hot water storage tank 5 becomes x degrees (for example, 60 degrees) or more (step S209), or the measurement time of the timer T2 is β minutes (for example, 20 minutes). (Step S210), the operation in the rapid boiling mode is continued while repeating the determinations of steps S209 and S210. When the detection temperature of the hot water storage temperature sensor 5d becomes x degrees or higher, or when β minutes have elapsed, the timer T2 is reset (step S211) to end the boiling operation.

With such a configuration, even if the history information is not accumulated in the history information storage unit 38 immediately after the power is turned on and the hot water discharge pattern cannot be analyzed by the hot water supply prediction unit 39, it is assisted. The operation frequency of the combined heating operation can be reduced, and the energy efficiency of the entire hot water supply system 1 can be improved. Further, particularly when the capacity of the hot water storage tank 5 is relatively small, there is a high possibility that the hot water storage tank 5 runs out of hot water due to hot water filling and the gas heater (auxiliary heating unit) 6 needs to be operated. Therefore, by starting the operation in the rapid boiling mode at the stage when the hot water filling instruction is given, the rapid boiling can be started earlier, so that the operation frequency of the auxiliary heating combined operation is reduced and the entire hot water supply system 1 is operated. Energy efficiency can be improved. After the completion of hot water filling, bathing is expected, and a large amount of hot water is expected to be taken out by the shower. By continuously operating in the rapid boiling mode, it is possible to reduce the operation frequency of the auxiliary heating combined operation even when a large amount of hot water is expected to be discharged after the completion of hot water filling, and the entire hot water supply system 1 can be operated. Energy efficiency can be improved.

In this modified example, the operation in the rapid boiling mode was started α minutes after receiving the hot water filling instruction, but the operation in the rapid boiling mode may be started immediately after receiving the instruction. If the operation in the rapid boiling mode is started immediately after receiving the instruction, more hot water can be boiled, and as a result, the operation frequency of the auxiliary heating combined operation can be reduced.

(5-3) Modification C
In the present embodiment, when hot water is discharged during the operation in the normal boiling mode, it is confirmed whether the predicted hot water discharge amount up to time T can be boiled by the operation in the normal boiling mode. However, if the outside air temperature detected by the outside air temperature sensor 21 falls below a predetermined temperature or drops above a predetermined temperature instead of the presence or absence of hot water, is it possible to boil by operating in the normal boiling mode? Confirmation may be performed. By doing so, even if the outside air temperature drops during the operation in the normal boiling mode and the amount of hot water that can be boiled decreases due to the operation in the normal boiling mode, the operation frequency of the auxiliary heating combined operation is performed. Can be reduced, and the energy efficiency of the entire hot water supply system 1 can be improved.

In addition, when the temperature of the water (water supply temperature) mixed when the hot water of the hot water storage tank 5 is supplied to the hot water supply terminal 10 is equal to or lower than the predetermined temperature, or when the temperature is lowered by the predetermined temperature or more, instead of the presence or absence of hot water supply. In addition, it may be confirmed whether boiling is possible by operating in the normal boiling mode. When the hot water supply set temperature or the hot water filling set temperature set by the user exceeds the predetermined temperature, or rises above the predetermined temperature, it may be confirmed whether the boiling is possible by the operation in the normal boiling mode. By doing so, even if the predicted amount of hot water required by the predetermined time T increases during the operation in the normal boiling mode, the operation frequency of the auxiliary heating combined operation can be reduced, and the hot water supply system 1 The overall energy efficiency can be improved.

(5-4) Modification D
In the above-described embodiment, the efficiency calculation unit 34a derives the primary energy efficiency of the heat pump unit 2 based on the COP curve acquired by the COP curve calculation unit 33, and determines the primary energy efficiency of the gas heater 6. The heating capacity of the operation in the rapid boiling mode was calculated by comparison. However, the usage charge of the heat pump unit 2 is calculated based on the COP curve acquired by the COP curve calculation unit 33, and the heating capacity of the operation in the rapid boiling mode is calculated by comparing with the usage charge of the gas heater 6. It may be derived.

FIG. 9 shows the relationship between the heating capacity (horizontal axis) and the usage charge per unit heating capacity (vertical axis) for the heat pump unit 2 and the gas heater 6. In the modified example D, the control unit 30 has a usage charge calculation unit 34b, and the usage charge calculation unit 34b calculates the usage charge per unit heating capacity based on the COP curve acquired by the COP curve calculation unit 33. calculate. Each usage fee is calculated by multiplying the consumption per unit time by the usage fee unit price. Since the power consumption of the heat pump unit 2 is calculated by dividing the heating capacity by the COP, as shown in FIG. 9, the usage charge per unit capacity changes depending on the heating capacity and becomes the minimum value e in the heating capacity a1. On the other hand, in the gas heater 6, the usage charge per unit capacity is a constant usage charge f regardless of the heating capacity.

When the operation is performed in the normal boiling mode, the capacity deriving unit 35 derives the heating capacity of the heat pump unit 2 as a1 so that the heating capacity maximizes the COP in the COP curve of FIG. Then, the boiling control unit 36 controls the frequency of the compressor 11 and the rotation speed of the pump 17 based on the heating capacity a1 until the hot water temperature detected by the hot water temperature sensor 22 reaches the target hot water temperature. That is, in the normal boiling mode operation, the heat pump unit 2 operates with the ability to maximize the heat pump efficiency.

On the other hand, when the operation is performed in the rapid boiling mode, the capacity deriving unit 35 has a heating capacity of the heat pump unit 2 so that the usage charge of the heat pump unit 2 is the same as the usage charge of the gas heater 6. Is derived. Therefore, as shown in FIG. 9, the capacity deriving unit 35 makes the usage charge of the heat pump unit 2 the same as the usage charge f of the gas heater 6 based on the usage charge curve calculated based on the COP curve. In addition, the heating capacity of the heat pump unit 2 is derived as a3. Then, the boiling control unit 36 controls the frequency of the compressor 11 and the rotation speed of the pump 17 based on the heating capacity a3 until the hot water temperature detected by the hot water temperature sensor 22 reaches the target hot water temperature.

With such a configuration, it is possible to prevent the usage charge of the heat pump unit 2 from becoming higher than the usage charge of the gas heater 6, and it is possible to suppress an increase in the usage charge of the entire hot water supply system 1.

(5-5) Modification E
Further, the carbon emission amount of the heat pump unit 2 is calculated based on the COP curve acquired by the COP curve calculation unit 33, and the carbon emission amount of the gas heater 6 is compared with the heating of the operation in the rapid boiling mode. The ability may be derived.

FIG. 10 shows the relationship between the heating capacity (horizontal axis) and the carbon emission amount per unit heating capacity (vertical axis) for the heat pump unit 2 and the gas heater 6. In the modification E, the control unit 30 has a carbon emission calculation unit 34c, and the carbon emission calculation unit 34c has carbon per unit heating capacity based on the COP curve acquired by the COP curve calculation unit 33. Calculate emissions. Each carbon emission amount is calculated by dividing the carbon dioxide emission factor per unit capacity by the equipment efficiency. The heat pump unit 2 is driven by electric power. Therefore, the carbon emission amount per unit capacity of the heat pump unit 2 is calculated by dividing the carbon dioxide emission amount per unit capacity in power generation by the COP, and as shown in FIG. 10, the carbon emission amount per unit capacity is the heating capacity. It changes with the above and becomes the minimum value g in the heating capacity a1. On the other hand, in the gas heater 6, the carbon emission amount per unit capacity is a constant carbon emission amount h regardless of the heating capacity.

When the operation is performed in the normal boiling mode, the capacity deriving unit 35 derives the heating capacity of the heat pump unit 2 as a1 so that the heating capacity maximizes the COP in the COP curve of FIG. Then, the boiling control unit 36 controls the frequency of the compressor 11 and the rotation speed of the pump 17 based on the heating capacity a1 until the hot water temperature detected by the hot water temperature sensor 22 reaches the target hot water temperature. That is, in the normal boiling mode operation, the heat pump unit 2 operates with the ability to maximize the heat pump efficiency.

On the other hand, when the operation is performed in the rapid boiling mode, the capacity deriving unit 35 of the heat pump unit 2 so that the carbon emission amount of the heat pump unit 2 is the same as the carbon emission amount of the gas heater 6. Derived the heating capacity. Therefore, as shown in FIG. 10, the capacity deriving unit 35 has the same carbon emission amount h of the heat pump unit 2 as the carbon emission amount h of the gas heater 6 based on the carbon emission amount curve calculated based on the COP curve. The heating capacity of the heat pump unit 2 is derived as a4 so as to be. Then, the boiling control unit 36 controls the frequency of the compressor 11 and the rotation speed of the pump 17 based on the heating capacity a4 until the hot water temperature detected by the hot water temperature sensor 22 reaches the target hot water temperature.

With such a configuration, it is possible to suppress the carbon emission amount of the heat pump unit 2 from becoming higher than the carbon emission amount of the gas heater 6, and it is possible to suppress an increase in the carbon emission amount of the entire hot water supply system 1.

(5-6) Modification F
In the above-described embodiment, the heating capacity of the heat pump unit 2 is derived so that the primary energy efficiency in the heating capacity (a2) during operation in the rapid boiling mode is the same as the primary energy efficiency d of the gas heater 6. bottom. However, the setting of the heating capacity is not limited to this, and when the outside air temperature is the same, the heating capacity of the heat pump unit 2 during operation in the rapid boiling mode is the same as that during operation in the normal boiling mode. Various as long as it is larger than the heating capacity (a1) and the heat pump efficiency of the heat pump unit 2 during operation in the rapid boiling mode is lower than the heat pump efficiency of the heat pump unit 2 during operation in the normal boiling mode. Can be set.

Similarly, in the above-mentioned modified examples D and F, the usage fee per unit capacity or the carbon emission amount per unit capacity in the heating capacity (a3 or a4) during operation in the rapid boiling mode is the gas heater. The heating capacity of the heat pump unit 2 was derived so as to be the same as 6. However, the setting of the heating capacity is not limited to this, and when the outside air temperature is the same, the heating capacity of the heat pump unit 2 during operation in the rapid boiling mode is the same as that during operation in the normal boiling mode. As long as it is larger than the heating capacity (a1) and the heat pump efficiency of the heat pump unit 2 during operation in the rapid boiling mode is higher than the heat pump efficiency of the heat pump unit 2 during operation in the normal boiling mode. Various settings are possible.

Regarding the modification D, the heating capacity in the rapid boiling mode is larger than the heating capacity at which the COP is maximized at the outside air temperature at that time, and the usage fee per unit capacity in the rapid boiling mode is gas. It may be less than or equal to the usage fee per unit capacity of the heater 6. Further, in the modified example E, the heating capacity in the rapid boiling mode is larger than the heating capacity at which the COP is maximized at the outside air temperature at that time, and the carbon emission amount per unit capacity in the rapid boiling mode is increased. However, it may be less than or equal to the carbon emission amount per unit capacity of the gas heater 6.

Further, regarding the heating capacity during operation in the normal boiling mode, the heating capacity of the heat pump unit 2 is derived as a1 so as to maximize the COP in the COP curve, but the heating capacity is not limited to this. The heating capacity during operation in the normal boiling mode can be variously set within a range in which the COP is relatively high.

(5-7) Modification G
In the above-described embodiment, in the operation in the rapid boiling mode, the boiling control unit 36 is based on the heating capacity a2, and the frequency of the compressor 11 is reached until the hot water temperature detected by the hot water temperature sensor 22 reaches the target hot water temperature. Was controlled. However, as a method of setting the heating capacity, instead of or in addition to this, the boiling control unit 36 sets the hot water discharge temperature detected by the hot water discharge temperature sensor 22 as the target hot water discharge temperature based on the heating capacity a2. As described above, the rotation speed of the fan 15 arranged to face the outdoor heat exchanger 12 may be controlled.

In this case, after the hot water temperature detected by the hot water temperature sensor 22 reaches the target hot water temperature, the rotation speed (heating capacity) is larger than the rotation speed (rotation speed based on the heating capacity a1) during operation in the normal boiling mode. The fan 15 is controlled by the rotation speed based on a2), and the pump 17 is controlled at a rotation speed higher than the rotation speed of the pump 17 during operation in the normal boiling mode. In this way, since the pump 17 is driven at a large rotation speed during operation in the rapid boiling mode, the flow rate of hot water circulating in the hot water circuit unit 3 increases, and normal boiling is performed while maintaining the hot water temperature constant. The amount of hot water stored in the hot water storage tank 5 can be increased per unit time as compared with the operation in the mode.

Although the embodiments of the present invention have been described above with reference to the drawings, it should be considered that the specific configuration is not limited to these embodiments. The scope of the present invention is shown by the scope of claims rather than the description of the above-described embodiment, and further includes all modifications within the meaning and scope equivalent to the scope of claims.

For example, in the above-described embodiment and modification, the case where the hot water supply system 1 has the gas heater 6 as the auxiliary heating unit has been described, but the auxiliary heating unit is not limited to the gas heater 6. Therefore, the hot water supply system 1 may have another heating unit such as an electric heater as an auxiliary heating unit. As the auxiliary heating unit, the present invention can be applied as long as it is a heating means other than the heat pump unit 2 and the primary energy efficiency is lower than that of the heat pump unit 2. More specifically, when compared with the heating capacity that maximizes the COP of the heat pump unit 2, the primary energy efficiency of the auxiliary heating unit is lower than the primary energy efficiency of the heat pump unit 2. Combustion-type heating means such as electric heaters and gases correspond to this.

By utilizing the present invention, the overall energy efficiency of the entire hot water supply system can be improved by reducing the ratio of the amount of heat generated by the auxiliary heating unit to the amount of heat of the entire system.

2 Heat pump section (heat pump type heating section)
5 Hot water storage tanks 5a to 5d Hot water storage temperature sensor (hot water storage amount detector)
6 Gas heater (auxiliary heating unit)
10 Hot water supply terminal (hot water outlet)
10a Bathtub 11 Compressor 12 Outdoor heat exchanger (heat source side heat exchanger)
13 Expansion valve (expansion mechanism)
15 Fan 16 Heat exchanger for hot water supply (heat exchanger on the user side)
23 Flow rate sensor (hot water discharge amount detection unit)
30 Control unit 38 History information storage unit 39 Hot water discharge prediction unit 41 Refrigerant circuit

Japanese Unexamined Patent Publication No. 2013-11495

Claims (8)

Hot water storage tank (5) for storing hot water and
A hot water outlet (10) that supplies hot water from the hot water storage tank (5) to the user side,
A heat pump type heating unit (2) for boiling hot water in the hot water storage tank (5), and
An auxiliary heating unit (6) capable of heating hot water supplied from the hot water storage tank (5) to the hot water outlet unit (10), and
A hot water discharge amount detection unit (23) for detecting the amount of hot water supplied from the hot water storage tank (5) to the hot water discharge unit (10),
A control unit (30) that predicts the amount of hot water discharged from the hot water storage tank (5), and
With
The heat pump independent operation in which the hot water of the hot water storage tank (5) is boiled by the heat pump type heating unit (2), and
Auxiliary heating combined operation in which hot water is boiled in the hot water storage tank (5) and hot water is heated by the auxiliary heating unit (6) at the same time.
Is possible,
The heat pump independent operation includes boiling in the first mode and boiling in the second mode, which have different heating capacities from each other.
The heating capacity of boiling in the first mode is higher than the heating capacity of boiling in the second mode, and the heat pump efficiency of boiling in the first mode is higher than that of the second mode. Lower than the heat pump efficiency of boiling in
When the control unit (30) predicts a large amount of hot water to be stored in the hot water storage tank (5) less than a predetermined amount in boiling in the second mode, or the large amount of hot water is generated. If it is determined that the heat pump is boiled in the first mode, and then the auxiliary heating combined operation is performed when the heat amount is insufficient only by the heat pump independent operation.
Hot water supply system. The heating capacity of boiling in the first mode is larger than the heating capacity at which the COP is maximized at the outside air temperature at that time, and the primary energy efficiency of boiling in the first mode assists the heating capacity. It is higher than the primary energy efficiency when the heating unit (6) is operated independently.
The hot water supply system according to claim 1. A hot water storage amount detecting unit (5a to 5d) for detecting the hot water storage amount of the hot water storage tank (5) is further provided.
When the hot water storage amount detected by the hot water storage amount detection unit (5a to 5d) becomes smaller than the first hot water storage amount, boiling in the second mode is started.
When the second hot water storage amount is smaller than the first hot water storage amount, the boiling in the first mode is performed from the boiling in the second mode.
The hot water supply system according to claim 1 or 2. A bathtub (10a) to which hot water is supplied from the hot water outlet (10) is further provided.
When there is a hot water filling instruction to supply hot water of a target temperature to the bathtub (10a), boiling is performed in the first mode.
The hot water supply system according to claim 1 or 2. The control unit (30)
A history information storage unit (38) that stores history information of the amount of hot water discharged and the time of hot water discharged detected by the hot water discharge amount detection unit, and
A hot water forecasting unit (39) that predicts a hot water scheduled amount and a hot water scheduled time based on the history information of the history information storage unit (38).
Have,
When the heat pump type heating unit (2) is operated so that the planned hot water discharge amount predicted by the hot water discharge prediction unit (39) is stored in the hot water storage tank (5) by the scheduled hot water discharge time, the hot water discharge prediction unit (2) When there is a hot water that is not predicted by the part (39), boiling in the first mode is performed.
The hot water supply system according to claim 1 or 2. A hot water storage amount detecting unit (5a to 5d) for detecting the hot water storage amount of the hot water storage tank (5) is further provided.
The control unit (30)
A history information storage unit (38) that stores history information of the amount of hot water discharged and the time of hot water discharged detected by the hot water discharge amount detection unit (23), and
A hot water forecasting unit (39) that predicts a hot water scheduled amount and a hot water scheduled time based on the history information of the history information storage unit (38).
Have,
The planned amount of hot water is the sum of the amount of hot water stored detected by the hot water storage amount detection unit (5a to 5d) and the planned amount of hot water stored at the scheduled hot water discharge time when the operation is performed by boiling in the second mode. If it is larger than the value, the boiling in the first mode is performed.
The hot water supply system according to claim 1 or 2. The heat pump type heating unit (2) is connected to a compressor (11), a heat source side heat exchanger (12), an expansion mechanism (13), and a user side heat exchanger (16), and a refrigerant through which the refrigerant circulates. Has a circuit (41)
Hot water is supplied to the hot water storage tank (5) using the user-side heat exchanger (16).
The boiling in the first mode has a higher frequency of the compressor (11) than the boiling in the second mode when the outside air temperature is the same.
The hot water supply system according to any one of claims 1 to 6. The heat pump type heating unit (2) is connected to a compressor (11), a heat source side heat exchanger (12), an expansion mechanism (13), and a user side heat exchanger (16), and a refrigerant circulates. It has a circuit (41) and a fan (15) that blows air to the heat source side heat exchanger (12) to exchange heat.
Hot water is supplied to the hot water storage tank (5) using the user-side heat exchanger (16).
In the boiling in the first mode, when the outside air temperature is the same, the rotation speed of the fan (15) is larger than that in the boiling in the second mode.
The hot water supply system according to any one of claims 1 to 6.

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