JP6533717B2 - Hot water supply system - Google Patents

Description

  The present invention relates to a hot water supply system.

  Patent Document 1 includes a heat pump that absorbs heat from the outside air, a tank that stores a heat medium heated by the heat pump, a supply unit that supplies hot water to a hot water utilization location using heat in the tank, and a control device. A hot water system is disclosed. The control device executes low-temperature storage hot water operation to operate the heat pump so that the temperature of the heat medium after heating by the heat pump becomes lower than 60 ° C., and in a specific case, the temperature of the heat medium after heating by the heat pump is 60 ° C. Execute the high temperature hot water storage operation to operate the heat pump so as to become the above.

  When operating the heat pump of the hot water supply system, the heating capacity per power consumption (COP (Coefficient Of Performance; also referred to as “coefficient of performance”)) improves as the temperature of the heat medium after heating is lowered. The hot water supply system of Patent Document 1 is intended to efficiently heat the heat medium by performing the low temperature storage operation, and is included in the hot water supplied to the hot water utilization location by performing the high temperature storage operation in a specific case. We are trying to sterilize potential fungi (such as Legionella).

JP, 2015-38397, A

  In the technology of Patent Document 1, the heat pump is operated using power supplied from a commercial power source. On the other hand, in recent years, the heat pump of the hot water supply system may be operated by the power supplied from the solar power generator. When power is generated by a solar power generator, surplus power may occur depending on weather conditions and the amount of power used.

  In the present specification, a hot water supply system capable of efficiently storing heat using surplus power is disclosed.

  The hot water supply system disclosed in the present specification includes a solar power generator, a heat pump operated using power supplied from the solar power generator, which absorbs heat from the outside air to heat the heat medium, and stores the heat. A supply means for supplying hot water to a hot water utilization location using heat stored in the tank, a tank circulation path for circulating a heat medium between the heat pump and the tank, and a controller. The control device uses the surplus power when there is surplus power obtained by removing the used power from the generated power generated by the solar power generator, and the heat medium passing through the heat pump outlet side of the tank circuit. Low temperature hot water operation to operate the heat pump so that the low temperature target temperature becomes lower than 60 ° C, and after the low temperature hot water operation fills the tank with the heat medium at the low temperature target temperature, surplus power exists In this case, using the surplus power, a high-temperature hot-water storage operation is performed to operate the heat pump such that the temperature of the heat medium passing through the outlet side of the heat pump in the tank circuit is 60 ° C. or higher .

  In the above-described hot water supply system, when surplus power is present, low-temperature hot water storage operation is performed using the surplus power. As a result, the surplus power can be used effectively to store heat, and at the same time, the heat medium can be efficiently heated. Furthermore, in the above-described hot water supply system, after the heat medium having the low temperature target temperature is filled in the tank by the low temperature storage operation, the high temperature storage operation is performed using the excess power when the excess power exists. As a result, after the heat medium of the low temperature target temperature is filled in the tank, if there is surplus power, heat storage can be performed by effectively utilizing the surplus power. Therefore, according to the above-described hot water supply system, heat storage can be efficiently performed using the surplus power.

The figure which shows the structure of the hot-water supply system 2 typically. The flowchart of the normal thermal storage driving | operation which the hot-water supply system 2 of 1st Example performs. The flowchart of the surplus power storage operation which hot-water supply system 2 of a 1st example performs. The flowchart of the driving | operation before the electric power generation start which the hot-water supply system 2 of 2nd Example performs. The flowchart of the driving | operation before the electric power generation start which the hot-water supply system 2 of 3rd Example performs.

  The main features of the embodiment described below are listed. The technical elements described below are technical elements that are independent of each other and exhibit technical usefulness by themselves or various combinations, and are not limited to the combinations described in the claims at the time of filing. Absent.

(Feature 1) It is preferable that the heat pump is also operable using power supplied from a commercial power source. The control device is the timing before the solar power generator of the day starts the power generation, the average amount of heat used per day in the past first period, and the average surplus per day in the past first period The amount of heat generated when operating the heat pump using the amount of electric power is compared, and if the average amount of heat used is larger than the amount of heat generated as expected, using the electric power supplied from the commercial power supply The first type of pre-stored hot water operation to operate the heat pump is executed so that the heat of the first difference heat amount, which is the difference between the heat amount and the expected heat generation, is stored, and the average heat use is less than the expected heat generation It is preferable not to execute the first type of pre-stored hot water operation.

  In the above-described hot water supply system, when the average amount of heat used is equal to or less than the predetermined amount of heat generated, it is predicted that the average amount of heat used can be covered by operating the heat pump using surplus power. In such a case, the above-described hot water supply system can prevent the first type of pre-stored-hot-water operation using power supplied from a commercial power source. According to the above-described hot water supply system, it is possible to effectively utilize surplus power and to suppress useless storage operation using a commercial power supply.

(Feature 2) The control device further includes the first differential heat quantity and the heat quantity in the tank when the heat medium of the low temperature target temperature is filled in the tank, when the first type of preliminary storage operation is to be performed. When the first difference heat amount is larger than the low-temperature full heat storage amount, the temperature of the heat medium on the outlet side of the heat pump reaches the high-temperature target temperature using electric power supplied from a commercial power source. The first operation of storing the heat of the first difference heat amount in the tank is performed by operating the heat pump in the following manner, and when the first difference heat amount is equal to or less than the low temperature full heat storage amount, It is preferable to execute the second operation of storing the heat of the first difference heat amount in the tank by operating the heat pump so that the temperature of the heat medium flowing on the outlet side becomes the low temperature target temperature.

  According to this configuration, the hot water supply system performs the second operation without performing the first operation when the first difference heat amount is less than or equal to the low temperature full heat storage amount (ie, when the first difference heat amount is relatively small). By carrying out, it can be suppressed that unnecessary heat storage is performed.

(Feature 3) The control device compares the average sunshine duration per day in the past second period with the predicted sunshine duration on the day before the solar power generator starts power generation, (A) When the predicted sunshine time is equal to or greater than the average sunshine time, the first type of pre-stored hot water operation is executed when the average heat quantity is larger than the planned heat quantity, and the first heat capacity is less than the planned heat quantity. (B) If the predicted sunshine duration is shorter than the average sunshine duration, the predicted power generation amount that the solar power generator is expected to generate during the predicted sunshine duration is the first past period Calculate the predicted surplus power amount excluding the average power consumption per day in and compare the average used heat amount with the predicted generated heat amount generated when the heat pump is operated using the power of the predicted surplus power amount. , The average amount of heat used is estimated If it is larger than the heat quantity, the heat pump is operated to use the power supplied from the commercial power source so that the heat of the second difference heat quantity, which is the difference between the average use heat quantity and the predicted heat generation quantity, is given to the heat medium It is preferable to execute two types of pre-stored hot water operation and not to execute the second type pre-stored hot water operation when the average amount of heat used is equal to or less than the predicted amount of heat generated.

  According to the above configuration, when the predicted sunshine duration is equal to or greater than the average sunshine duration, the hot water supply system performs the first type of pre-stored hot water operation according to the result of comparing the average amount of heat used and the expected amount of heat generated. Change whether to execute or not. On the other hand, if the predicted sunshine duration is shorter than the average sunshine duration, the hot water supply system changes whether to execute the second type of pre-stored hot water operation, according to the result of comparing the average heat consumption with the predicted heat generation. That is, the hot water supply system can change the operation content according to the predicted sunshine period. Also, the predicted sunshine time may vary depending on the content of the weather forecast for the day. Therefore, according to the above configuration, the hot water supply system can execute an appropriate operation to cover the average amount of heat used according to the content of the weather forecast on the current day.

(Feature 4) It is preferable that the supply means further include a heat source machine that heats the hot water supplied to the hot water utilization site using the heat generated by burning the fuel.

  According to this configuration, even if it is not possible to prepare the hot water of the temperature required at the hot water utilization location even if the heat in the tank is used, the required temperature can be obtained by heating the hot water with the heat source unit Hot water can be supplied to the hot water utilization point.

(First embodiment)
(System configuration; Fig. 1)
As shown in FIG. 1, the hot water supply system 2 of this embodiment includes the heat pump 10, the tank 20, the tank circulation passage 30, the tap water introduction passage 40, the supply passage 50, the burner heating device 60, and sunlight A generator 70, a commercial power supply path 80, and a controller 90 are provided.

  The heat pump 10 is a heat source that absorbs water from the outside air and heats the water passing through the tank circulation path 30. The heat pump 10 can be operated using the power supplied from the solar power generator 70 and can be operated using the power supplied from the commercial power supply via the commercial power supply passage 80. Although not illustrated, the heat pump 10 compresses the refrigerant by compressing the refrigerant by a refrigerant circulation path for circulating the refrigerant (for example, natural refrigerant R290, fluorocarbon refrigerant R32, etc.), an evaporator for exchanging heat between the outside air and the refrigerant, A heat exchanger for performing heat exchange between the high pressure compressor, water passing through the tank circulation path 30, and an expansion valve for reducing the pressure of the refrigerant after the heat exchange to obtain a low temperature and a low pressure There is.

  The tank 20 stores the hot water heated by the heat pump 10. The tank 20 is of a closed type and is covered on the outside by a heat insulating material. Water is stored in the tank 20 until the water is full. In the present embodiment, the capacity of the tank 20 is 100L. Thermistors 22a, 22b, 22c and 22d are attached to the tank 20 at predetermined intervals in the height direction of the tank 20. Each thermistor 22a to 22d measures the temperature of water at the mounting position. For example, the thermistors 22a, 22b, 22c, 22d respectively measure the temperature of water at positions 60L, 40L, 20L, 5L from the top of the tank.

  The tank circulation passage 30 is connected at its upstream end to the lower part of the tank 20 and connected at its downstream end to the upper part of the tank 20. A circulation pump 36 is interposed in the tank circulation passage 30. The circulation pump 36 pumps the water in the tank circulation passage 30 from the upstream side to the downstream side. Further, the tank circulation passage 30 passes through a heat exchanger (not shown) of the heat pump 10. Therefore, when the heat pump 10 is operated, the water in the tank circulation passage 30 is heated by the heat exchanger of the heat pump 10. Therefore, when the circulation pump 36 and the heat pump 10 are operated, the water in the lower part of the tank 20 is heated by the heat pump 10, and the heated water is returned to the upper part of the tank 20. That is, the tank circulation passage 30 is a water passage for storing heat in the tank 20. Further, thermistors 32 and 34 are interposed on the inlet side (i.e., upstream side) and the outlet side (i.e., downstream side) of the heat pump 10 in the tank circulation path 30, respectively. The thermistor 32 is derived from the lower part of the tank 20 and measures the temperature of water before it is heated by the heat pump 10. The thermistor 34 measures the temperature of the hot water after being heated by the heat pump 10.

  The tap water introduction path 40 is connected at its upstream end to a tap water supply source 42. The downstream side of the tap water introduction passage 40 is branched into a first introduction passage 40 a and a second introduction passage 40 b. The downstream end of the first introduction passage 40 a is connected to the lower portion of the tank 20. The downstream end of the second introduction passage 40b is connected to the middle of a supply passage 50 described later. A mixing valve 44 is provided at the connection between the downstream end of the second introduction passage 40 b and the supply passage 50. The mixing valve 44 adjusts the amount of mixing the water in the second introduction passage 40 b with the hot water flowing through the supply passage 50.

  The supply path 50 is connected to the upper end of the tank 20 at its upstream end. As described above, the second introduction passage 40b of the tap water introduction passage 40 is connected in the middle of the supply passage 50, and the mixing valve 44 is provided at the connection portion. A burner heating device 60 is interposed in the supply passage 50 downstream of the connection with the second introduction passage 40b. Further, a thermistor 52 is interposed in the supply passage 50 on the downstream side of the burner heating device 60. The thermistor 52 measures the temperature of the supplied hot water. The burner heating device 60 heats the water in the supply passage 50 so that the temperature of the hot water measured by the thermistor 52 matches the hot water supply set temperature. The downstream end of the supply path 50 is connected to a hot water utilization point (for example, a kitchen, a bathtub, etc.).

  The solar power generator 70 is a device for generating power by receiving sunlight. The electric power generated by the solar power generator 70 is supplied to various devices including the components of the hot water supply system 2 through the controller 90. For example, the electric power generated by the solar power generator 70 is used for various applications such as the operation of an air conditioner (not shown) in addition to the operation of the heat pump 10 and the circulation pump 36.

  The commercial power supply path 80 is a power cord for connecting to the commercial power and receiving power from the commercial power. The power supplied from the commercial power supply through the commercial power supply path 80 is supplied to various devices including the components of the hot water supply system 2 through the control device 90.

  The controller 90 is electrically connected to the above-described components of the hot water supply system 2 and controls the operation of each component. Although not shown in FIG. 1, the control device 90 is connected to a remote control having an operation unit to which a user can input various instructions and a display unit capable of displaying various information. Control device 90 also includes power source switching means for switching whether power for operating each element of hot water supply system 2 is supplied from commercial power supply path 80 or supplied from solar power generator 70. ing.

  Next, the operation of the hot water supply system 2 of the present embodiment will be described. The hot water supply system 2 of the present embodiment can execute a heat storage operation and a hot water supply operation. The heat storage operation that can be performed by the hot water supply system 2 includes a normal heat storage operation performed using power supplied from a commercial power supply (see FIG. 2) and a surplus performed using surplus power of power generated by the solar power generator 70. There are two types of operation: power storage operation (see FIG. 3). Each operation will be described below.

(Normal heat storage operation; Fig. 2)
In the normal heat storage operation, the heat pump 10 is operated using the power supplied from the commercial power supply via the commercial power supply path 80, and the water generated in the heat pump 10 heats the water in the tank 20. The user of the hot water supply system 2 of the present embodiment operates the operation unit of the remote control to select one of the two operation modes of the "normal heat storage operation mode" and the "surplus power heat storage operation mode" in advance. it can. The control device 90 executes the normal heat storage operation of FIG. 2 when the normal heat storage operation mode is selected by the user.

  At S10, control device 90 determines whether 72 hours have elapsed since the previous execution of the high-temperature hot water storage operation. As will be described in detail later, in the high-temperature storage operation, the target temperature Tb of hot water after heating by the heat pump 10 (that is, the temperature detected by the thermistor 34; hereinafter referred to as "target outlet temperature Tb") becomes 90.degree. The heat pump 10 and the circulation pump 36 are operated. If 72 hours or more have elapsed since the previous execution of the high-temperature water storage operation at the time of S10, the control device 90 determines YES in S10, and proceeds to S14. On the other hand, at S10, if 72 hours have not elapsed since the previous execution of the high temperature hot water storage operation, the control device 90 determines NO in S10 and proceeds to S12.

  In S12, the control device 90 sets the target outlet temperature Tb to a temperature (Ts + 5 ° C) that is 5 ° C higher than the hot water supply set temperature Ts. The hot water supply set temperature Ts is a set temperature of the hot water supplied to the hot water use location. The user of the hot water supply system 2 can set the hot water supply set temperature Ts by operating the operation unit of the remote control. In the present embodiment, the hot water supply set temperature Ts can be set between 35 ° C and 45 ° C. When S12 ends, the process proceeds to S16.

  In S14, the controller 90 sets the target outlet temperature Tb to 90.degree. When S14 ends, the process proceeds to S16.

  In S16, the control device 90 determines whether the temperature detected by the thermistor 22d (that is, the temperature of the water stored in the upper portion of the tank 20) is equal to or lower than the hot water supply set temperature Ts. If the temperature detected by the thermistor 22d is equal to or lower than the hot water supply set temperature Ts, the control device 90 determines YES in S16, and proceeds to S18. In the case of YES in S16, it means that the hot water of the hot water supply set temperature Ts is not stored in the tank 20 at this time. On the other hand, when the temperature detected by the thermistor 12 is higher than the hot water supply set temperature Ts, the control device 90 determines NO in S16, and returns to S10. In the case of NO at S16, it means that hot water having a temperature higher than the hot water supply set temperature Ts is stored in the tank 20 at this time.

  In S18, the controller 90 operates the heat pump 10 and the circulation pump 36. At this time, the controller 90 operates the heat pump 10 so that the outlet temperature of the heat pump 10 (ie, the outlet temperature of the thermistor 34) becomes the target outlet temperature Tb (Ts + 5 ° C or 90 ° C) set in S12 or S14. Let More specifically, the controller 90 adjusts the number of revolutions of the compressor motor so that the outlet temperature of the heat pump 10 becomes the target outlet temperature Tb set in S12 or S14.

  When the circulation pump 36 operates, the water in the tank 20 circulates in the tank circulation passage 30. That is, when the water present in the lower part of the tank 20 is introduced into the tank circulation path 30 and the introduced water passes through the heat exchanger in the heat pump 10, the heat is set in S12 or S14 by the heat of the refrigerant. It is heated to the target outlet temperature Tb. The water heated to the target outlet temperature Tb is returned to the top of the tank 20. Thus, water of the target outlet temperature Tb is stored in the tank 20. As a result, a layer of high temperature water is formed in the upper part of the tank 20, and a layer of low temperature water is formed in the lower part.

  In the following, the operation in the case where the heat pump 10 and the circulation pump 36 are operated such that the outlet temperature of the heat pump 10 becomes the target outlet temperature Tb (Ts + 5 ° C) set in S18 Call. On the other hand, the operation in the case where the heat pump 10 and the circulation pump 36 are operated so that the outlet temperature of the heat pump 10 becomes the target outlet temperature Tb (90 ° C.) set in S14 in S18 Call it When the heat pump 10 and the circulation pump 36 are operated in S18, the process proceeds to S20.

  In S20, the controller 90 determines that the temperature detected by the thermistor 32 (that is, the temperature of water derived from the lower portion of the tank 20 and supplied to the heat pump 10) is equal to or higher than the target outlet temperature Tb set in S12 or S14. Monitor if it will be. By operating the heat pump 10 and the circulation pump 36 in the above S18 and continuing the low temperature storage operation or the high temperature storage operation, the hot water of the target outlet temperature Tb is reached above the tank 20 (the target outlet depending on the operating condition of the heat pump 10 Hot water having a temperature higher than the temperature Tb is continuously stored. When hot water having a temperature equal to or higher than the target outlet temperature Tb is stored up to the lower part of the tank 20 (that is, the inside of the tank 20 is filled with hot water at a temperature equal to or higher than the target outlet temperature Tb) Hot water having a temperature of Tb or more is derived. In this case, the control device 90 determines YES in S20, and proceeds to S22.

  In S22, the controller 90 stops the heat pump 10 and the circulation pump 36. As a result, the low temperature storage operation or the high temperature storage operation ends. When S22 ends, the control device 90 returns to the first step, and executes the processing after S10 again.

  When performing the above-described low-temperature storage operation (target outlet temperature Tb = Ts + 5 ° C.), the heating capacity (COP) per power consumption is higher and the heating efficiency is also better than when performing the high-temperature storage operation. Therefore, heating can be efficiently performed when the low-temperature storage operation is performed. Moreover, it has been found by investigations by the present inventors that by setting the temperature of the hot water to 60 ° C. or higher, it is possible to sterilize fungi (such as Legionella bacteria) which may be contained in the hot water. By performing the above-mentioned high-temperature storage operation (target outlet temperature Tb = 90 ° C.) every 72 hours, the fungi possibly contained in the warm water in the tank 20 are sterilized, and the warm water having a possibility of fungal propagation is a warm water It can be appropriately prevented from being supplied to the use place.

(Excess electric power storage operation; Fig. 3)
In the surplus power storage operation, the heat pump 10 is operated using the surplus power obtained by removing the used power from the generated power generated by the solar power generator 70, and the water generated in the heat pump 10 is used to heat the water in the tank 20 It is. The control device 90 executes the surplus power storage operation of FIG. 3 when the surplus power storage operation mode is selected by the user.

  In S30, the control device 90 monitors that excess power is present at 200 W or more. Specifically, the control device 90 determines whether or not the state in which the surplus power is 200 W or more continues for a predetermined period (for example, 2 minutes). As described above, the surplus power is power obtained by removing the used power from the generated power generated by the solar power generator 70. Here, the power used is, for example, power used for applications other than the operation of the heat pump 10 and the circulation pump 36, such as the operation of an air conditioner (not shown). If the state where the surplus power is 200 W or more continues for a predetermined period, the control device 90 determines YES in S30, and proceeds to S32. On the other hand, when the surplus power does not exist 200 W or more (that is, NO in S30), the controller 90 continues the normal operation of FIG. 2 until the state where the surplus power 200 W or more continues for a predetermined period. Perform the same operation as the heat storage operation.

  In S32, the control device 90 determines whether the temperature detected by the thermistor 22a (that is, the temperature of the water stored in the lower part of the tank 20) is equal to or lower than the hot water supply set temperature Ts. If the temperature detected by the thermistor 22a is equal to or lower than the hot water supply set temperature Ts, the control device 90 determines YES in S32, and proceeds to S34. On the other hand, when the temperature detected by the thermistor 22a is higher than the hot water supply setting temperature Ts, the control device 90 determines NO in S32, and returns to S30.

  In S34, the control device 90 sets the target outlet temperature Tb to the hot water supply setting temperature Ts + 5 ° C using the surplus power to operate the heat pump 10 and the circulation pump 36. That is, in S34, the control device 90 starts the low temperature hot water storage operation using the surplus power.

  In the subsequent S35 and S36, the controller 90 monitors whether excess power is present at 200 W or more, and the temperature detected by the thermistor 32 (that is, the water derived from the lower portion of the tank 20 and supplied to the heat pump 10 Of the target outlet temperature Tb (ie, Ts + 5.degree. C.). By continuously performing the low-temperature storage operation started in S34, the hot water having a temperature equal to or higher than the target outlet temperature Tb (that is, Ts + 5 ° C) is continuously stored in the upper portion of the tank 20. When hot water having a temperature equal to or higher than the outlet temperature Tb is stored up to the lower part of the tank 20 (that is, the inside of the tank 20 is filled with hot water having a temperature equal to or higher than the outlet temperature Tb) Hot water of temperature is derived. In this case, the control device 90 determines YES in S36, and proceeds to S38. In addition, after the low-temperature storage operation is started in S34, if the surplus power falls below 200 W before it is determined as YES in S36 (that is, when it is determined as NO in S35), the controller 90 at that time. The low temperature hot water storage operation using the surplus power started in S34 is stopped, and the process returns to S30, and the process after S30 is executed again. In this case, the control device 90 performs the same operation as the normal heat storage operation of FIG. 2 until it is determined YES in S30 again.

  In S38, the control device 90 determines whether excess power is present at 200 W or more even at this time. If the state where the surplus power is 200 W or more continues for a predetermined period even at this time, the control device 90 determines YES in S38, and proceeds to S40.

  In S40, the control device 90 sets the target outlet temperature Tb to 90 ° C. using the surplus power to operate the heat pump 10 and the circulation pump 36. At this time, the controller 90 does not stop the heat pump 10 and the circulation pump 36 once. The controller 90 adjusts the outlet temperature of the heat pump 10 to be 90 ° C. by adjusting the rotational speed of the motor of the compressor of the heat pump 10 operated in S34. That is, in S40, the control device 90 shifts from the low temperature storage operation using excess power to the high temperature storage operation using excess power without stopping the heat pump 10.

  In the subsequent S41 and S42, the controller 90 monitors whether excess power is present at 200 W or more, and the temperature detected by the thermistor 32 (that is, the water derived from the lower portion of the tank 20 and supplied to the heat pump 10 Of the target outlet temperature Tb (ie, 90.degree. C.). By continuing the high temperature storage operation started at S40, hot water having a temperature equal to or higher than the target outlet temperature Tb (that is, 90 ° C.) is continuously stored in the upper portion of the tank 20. When the hot water having a temperature equal to or higher than the outlet temperature Tb is stored up to the lower part of the tank 20, the control device 90 determines YES in S42, and proceeds to S44. It should be noted that, after shifting to the high temperature storage operation at S40, if the surplus power falls below 200 W before it is determined as YES at S42 (that is, when it is determined as NO at S41), the controller 90 at that time. While stopping the high temperature hot water storage operation started by S40, it returns to S30 and performs the process after S30 again. In this case, the control device 90 performs the same operation as the normal heat storage operation of FIG. 2 until it is determined YES in S30 again.

  In S44, the controller 90 stops the heat pump 10 and the circulation pump 36. Thus, the high temperature hot water storage operation ends. When S44 ends, the control device 90 returns to the first step, and executes the processing after S30 again. At the end of S44, there is a high possibility that the state in which the surplus power is 200 W or more continues (YES in S30). In that case, the control device 90 repeatedly performs monitoring of S30 and S32 until the determination of S32 is YES again.

(Hot water supply operation)
The hot water supply operation is an operation of supplying the hot water in the tank 20 to the hot water use point. The hot water supply operation can also be performed during the above-described heat storage operation. When the hot water supply tap at the hot water utilization point is opened, tap water flows into the lower part of the tank 20 from the tap water introduction passage 40 (first introduction passage 40 a) by the water pressure from the tap water supply source 42. At the same time, the hot water in the upper part of the tank 20 is supplied to the hot water utilization point via the supply passage 50.

  When the temperature of the hot water supplied from the tank 20 to the supply passage 50 (i.e., the temperature measured by the thermistor 22d) is higher than the hot water supply set temperature Ts, the controller 90 opens the mixing valve 44 to set the second introduction passage 40b. To introduce the tap water into the supply channel 50. In this case, the hot water supplied from the tank 20 and the tap water supplied from the second introduction passage 40 b are mixed in the supply passage 50. The controller 90 adjusts the degree of opening of the mixing valve 44 so that the temperature of the hot water supplied to the hot water utilization site (that is, the temperature of the hot water measured by the thermistor 52) matches the hot water supply set temperature Ts. On the other hand, when the temperature of the hot water supplied from the tank 20 to the supply passage 50 is lower than the hot water supply set temperature Ts, the control device 90 operates the burner heating device 60. In this case, the hot water passing through the supply passage 50 is heated by the burner heating device 60. The control device 90 controls the output of the burner heating device 60 so that the temperature of the hot water supplied to the hot water utilization point matches the hot water supply set temperature Ts.

  The configuration and the operation content of the hot water supply system 2 of the present embodiment have been described above. The hot water supply system 2 of the present embodiment first executes a low-temperature hot water storage operation using the surplus electric power, when the surplus electric power is 200 W or more (YES in S30 of FIG. 3) (S34). As a result, the surplus power can be used effectively to store heat, and at the same time, the heat medium can be efficiently heated. Furthermore, in the hot water supply system 2 of the present embodiment, the surplus electric power is 200 W or more when the detected temperature of the thermistor 32 (that is, the temperature of the hot water at the inlet side of the heat pump 10) reaches Ts + 5 ° C after execution of the low temperature storage operation. When it exists (YES in S38), the high temperature hot water storage operation is performed using the surplus power (S40). As a result, when warm water of Ts + 5 ° C is stored in the tank 20 by the low temperature storage operation using the surplus power, the high temperature storage operation is performed when the surplus power further exists, and the surplus power is effectively utilized. Heat storage can be performed. Therefore, according to the hot water supply system 2 of the present embodiment, heat storage can be efficiently performed using the surplus power.

  Further, in the present embodiment, the burner heating device 60 is provided in the supply passage 50 so that the hot water passing through the supply passage 50 can be heated. Therefore, even when the hot water introduced from the tank 20 into the supply passage 50 does not reach the temperature required at the hot water utilization site, the hot water of the required temperature can be obtained by heating the hot water with the burner heating device 60 Can be supplied to the hot water utilization point.

  Here, the correspondence between the description of the present embodiment and the description of the claims will be described. Water is an example of a "heat medium". The hot water supply set temperature Ts + 5 ° C. is an example of the “low temperature target temperature”. Further, 90 ° C. is an example of the “high temperature target temperature”. The burner heating device 60 is an example of a "heat source unit".

Second Embodiment
The second embodiment will be described focusing on differences from the first embodiment. The basic configuration and the operation content of the hot water supply system 2 of the present embodiment are the same as the hot water supply system 2 of the first embodiment (see FIGS. 1 to 3). In the present embodiment, the hot water supply system 2 is different from the first embodiment in that the operation before the start of power generation (see FIG. 4) is further performed. The operation before the start of power generation that is executed by the hot water supply system 2 of the present embodiment will be described with reference to FIG. 4.

(Operation before the start of power generation; Fig. 4)
The operation before the start of power generation is the operation performed at the timing before the solar power generator 70 starts power generation on one day. In the case where the surplus power storage operation mode is selected by the user and the control device 90 has a timing (for example, 5 am every day) before the solar power generator 70 starts power generation in one day Then, the pre-generation operation shown in FIG. 4 is performed.

  In S50, first, the control device 90 uses the amount of heat (amount of heat used) of the hot water supplied to the hot water utilization point in the past seven days to average the amount of heat used per day for the past seven days (hereinafter referred to as “average use Calculate the heat quantity). Then, the control device 90 calculates an average surplus power amount per day for the past seven days (hereinafter referred to as “average surplus power amount”). Next, the control device 90 calculates the amount of heat to be generated when the heat pump 10 is operated using the electric power of the above average surplus electric energy (hereinafter referred to as “predetermined amount of heat generation”).

  Next, in S52, the control device 90 determines whether the average amount of heat used is larger than the predetermined amount of heat generated. If the average amount of heat used is larger than the predetermined amount of heat generated, the controller 90 determines YES in S52, and proceeds to S54. The case of YES in S52 is a case where the estimated amount of heat generation can not cover the average amount of heat used. On the other hand, when the average amount of heat used is equal to or less than the predetermined amount of heat generated (that is, when it is possible to obtain the average amount of heat used by the predetermined amount of heat generated), the controller 90 determines NO in S52. In this case, the controller 90 ends the operation before the start of power generation.

  In S54, the control device 90 calculates a first difference heat amount which is a difference between the average heat use amount and the planned heat generation amount. In the following S56, it is determined whether the first difference heat amount is larger than the heat amount in the tank 20 (hereinafter referred to as "low-temperature full heat storage amount") when the tank 20 is filled with hot water at the hot water supply set temperature Ts + 5 ° C. If the first difference heat amount is larger than the low temperature full heat storage amount, the controller 90 determines YES in S56, and proceeds to S60. The case of YES in S56 is a case where the first differential heat quantity can not be covered with the low temperature full heat storage amount. On the other hand, when the first difference heat amount is equal to or less than the low temperature full heat storage amount (that is, when the low temperature full heat storage amount can provide the first difference heat amount), the controller 90 determines NO in S56 and proceeds to S58.

  In S58, the controller 90 sets the target outlet temperature Tb to the hot water supply set temperature Ts + 5 ° C. When S58 ends, the process proceeds to S62.

  In S60, the controller 90 sets the target outlet temperature Tb to 90.degree. When S60 ends, the process proceeds to S62.

  In S62, the control device 90 is a hot water necessary to cover the hot water of the target outlet temperature Tb at which the first differential heat amount is set based on the first differential heat amount and the target outlet temperature Tb set at S58 or S60. Calculate an amount (hereinafter referred to as “first set hot water amount”).

  Next, at S64, the controller 90 operates the heat pump 10 and the circulation pump 36. At this time, the controller 90 operates the heat pump 10 such that the outlet temperature of the heat pump 10 becomes the target outlet temperature Tb (Ts + 5 ° C. or 90 ° C.) set in S58 or S60. That is, in S64, the control device 90 executes the low temperature storage operation or the high temperature storage operation.

  Next, in S66, the control device 90 monitors that the hot water of the target outlet temperature Tb set in S58 or S60 is stored in the tank 20 by the first set hot water amount. Specifically, in S66, whether or not the hot water of the target outlet temperature Tb is stored in the tank 20 by the first set amount of hot water is monitored by monitoring the temperatures detected by the thermistors 22a to 22d. If the hot water of the target outlet temperature Tb is stored in the tank 20 by the first set amount of hot water, the control device 90 determines YES in S66, and ends the pre-generation start operation.

  The configuration and the operation content of the hot water supply system 2 of the present embodiment have been described above. In the hot water supply system 2 of the present embodiment, when the average amount of heat used is equal to or less than the predetermined amount of generated heat (NO in S52 of FIG. 4), the average amount of used heat can be covered by operating the heat pump 10 using surplus power. Is expected. In this embodiment, in such a case, it is possible not to execute the hot water storage operation using the power supplied from the commercial power source (that is, the hot water storage operation of S64 in FIG. 4). According to the hot water supply system 2 of the present embodiment, it is possible to effectively utilize surplus power and to suppress wasteful hot water storage operation using a commercial power supply.

  Furthermore, in the present embodiment, when the first differential heat amount is equal to or less than the low-temperature full heat storage amount (ie, the first differential heat amount is relatively small; NO in S56 of FIG. 4), By performing the low temperature storage operation (S58, S62, S64) without performing the high temperature storage operation, unnecessary heat storage can be suppressed.

  The correspondence between the description of the present embodiment and the description of the claims will be described. The past seven days is an example of the “first past period”. The high temperature hot water storage operation or the low temperature hot water storage operation performed in S64 is an example of the “first type of preliminary heat storage operation”. Further, the high temperature storage operation performed in S64 is an example of the “first operation”, and the low temperature storage operation performed in S64 is an example of the “second operation”.

Third Embodiment
The third embodiment is a modification of the second embodiment. The third embodiment will be described focusing on differences from the second embodiment. The basic configuration and operation contents of the hot water supply system 2 of the present embodiment are the same as those of the hot water supply system 2 of the second embodiment (see FIGS. 1 to 4). However, in the present embodiment, the control device 90 is connected to a network (not shown), and weather information (for example, weather forecast, past sunshine hours, etc.) stored in a server (not shown) via the network. The second embodiment differs from the second embodiment in that it can be acquired. Accordingly, in the present embodiment, a part of the content of the operation before the start of power generation is different from that of the second embodiment. Moreover, with reference to FIG. 5, the driving | operation before the electric power generation start which the hot-water supply system 2 of a present Example performs is demonstrated.

(Operation before the start of power generation; Fig. 5)
Also in the present embodiment, the controller 90 has the surplus power storage operation mode selected by the user, and the timing before the solar power generator 70 starts power generation (for example, 5 am every day) ), The operation before the start of power generation in FIG. 5 is performed.

  In S70, first, the control device 90 calculates an average sunshine time per day in the past 7 days (hereinafter referred to as an "average sunshine time") using the sunshine hours in the past 7 days. Further, the control device 90 specifies the sunshine duration predicted on the current day (hereinafter referred to as “predicted sunshine duration”) based on the weather forecast of the current day. In S70, the control device 90 acquires the past seven days of sunshine duration, the weather forecast of the current day, and the like by accessing a server (not shown) via the network.

  At S72, the controller 90 determines whether the predicted sunshine period is shorter than the average sunshine period. If the predicted sunshine period is shorter than the average sunshine period, the controller 90 determines YES in S72, and proceeds to S74. The case of YES in S72 is a case in which the sunshine duration on the current day is expected to be short (that is, the weather is relatively bad) compared to the sunshine duration in the past seven days. On the other hand, if the predicted sunshine time is equal to or greater than the average sunshine time (ie, it is predicted that the weather is relatively good), the controller 90 determines NO in S72, and proceeds to S50 of FIG. In this case, the control device 90 executes the processing of S50 to S66 of FIG. 4 (that is, the processing of the same content as the operation before the start of power generation of the second embodiment). The processes of S50 to S66 in FIG. 4 are as described above, and thus detailed description will be omitted.

  In S74, first, the control device 90 calculates the average amount of heat used. The method of calculating the average amount of heat used is as described above (see S50 in FIG. 4). Next, the control device 90 calculates the amount of power generation that the solar power generator 70 is expected to generate during the predicted sunshine period (hereinafter referred to as “predicted power generation amount”). Then, the control device 90 calculates an amount of power (hereinafter, referred to as “predicted surplus power amount”) obtained by subtracting the average used power amount per day in the past 7 days from the predicted power generation amount. Furthermore, the control device 90 calculates the amount of heat generated when the heat pump 10 is operated using the electric power of the predicted surplus electric energy (hereinafter referred to as “estimated generated heat amount”).

  Next, in S76, the control device 90 determines whether the average amount of heat used is larger than the estimated amount of heat generated. If the average heat use amount is larger than the predicted heat generation amount, the controller 90 determines YES in S76, and proceeds to S78. The case of YES in S76 is a case where the estimated amount of heat generation can not cover the average amount of heat used. On the other hand, when the average amount of heat used is equal to or less than the estimated amount of heat generated (that is, when the estimated amount of heat can be used to obtain the average amount of heat used), the controller 90 determines NO in S76. In this case, the controller 90 ends the operation before the start of power generation.

  In S78, the control device 90 calculates a second differential heat quantity which is a difference between the average heat quantity used and the predicted heat quantity generated. In the following S80, the control device 90 determines whether the second difference heat amount is larger than the low temperature full heat storage amount. If the second difference heat amount is larger than the low temperature full heat storage amount, the controller 90 determines YES in S80, and proceeds to S84. On the other hand, when the second difference heat amount is equal to or less than the low temperature full heat storage amount, the controller 90 determines NO in S80, and proceeds to S82.

  In S82, the controller 90 sets the target outlet temperature Tb to the hot water supply set temperature Ts + 5 ° C. When S82 ends, the process proceeds to S86.

  In S84, the controller 90 sets the target outlet temperature Tb to 90 ° C. When S84 ends, the process proceeds to S86.

  In S86, the controller 90 is required to cover the second difference heat amount with the hot water of the set target exit temperature Tb based on the second difference heat amount and the target outlet temperature Tb set in S82 or S84. The amount of hot water (hereinafter referred to as "the second set amount of hot water") is calculated.

  Next, in S88, the controller 90 operates the heat pump 10 and the circulation pump 36. At this time, the controller 90 operates the heat pump 10 such that the outlet temperature of the heat pump 10 becomes the target outlet temperature Tb (Ts + 5 ° C. or 90 ° C.) set in S82 or S84. That is, in S88, the control device 90 executes the low temperature storage operation or the high temperature storage operation.

  Next, in S90, the control device 90 monitors that the hot water of the target outlet temperature Tb set in S82 or S84 is stored in the tank 20 by the second set hot water amount. Specifically, in S90, whether or not the hot water of the target outlet temperature Tb is stored in the tank 20 by the second set amount of hot water is monitored by monitoring the temperatures detected by the thermistors 22a to 22d. If the hot water of the target outlet temperature Tb is stored in the tank 20 by the second set amount of hot water, the control device 90 determines YES in S90, and ends the pre-generation start operation.

  The configuration and the operation content of the hot water supply system 2 of the present embodiment have been described above. In the present embodiment, when the predicted sunshine duration is equal to or greater than the average sunshine duration (NO in S72 of FIG. 5), the hot water supply system 2 compares the average amount of heat used with the estimated amount of heat generated (S52 of FIG. 4) In accordance with this, it is determined whether or not the hot water storage operation (ie, the high temperature hot water storage operation or the low temperature hot water storage operation (S64)) is to be performed. On the other hand, if the predicted sunshine time is shorter than the average sunshine time (YES in S72 of FIG. 5), the hot water supply system 2 stores the hot water operation (ie, according to the result of comparing the average amount of heat used and the estimated amount of heat generated (S76). It is changed whether or not the high temperature storage operation or the low temperature storage operation (S88) is to be performed. That is, in the present embodiment, the hot water supply system 2 can change the operation content according to the predicted sunshine duration. Also, the predicted sunshine time may vary depending on the content of the weather forecast for the day. Therefore, according to the present embodiment, the hot water supply system 2 can execute an appropriate operation to cover the average amount of heat used according to the content of the weather forecast on that day.

  The correspondence between the description of the present embodiment and the description of the claims will be described. The past seven days is an example of the “second past period”. The high temperature hot water storage operation or the low temperature hot water storage operation performed in S88 is an example of the “second type of preliminary heat storage operation”.

  As mentioned above, although each Example was described in detail, these are only an illustration and do not limit a claim. The art set forth in the claims includes various variations and modifications of the specific examples illustrated above.

(Modification 1) In the first embodiment, the controller 90 sets the detection temperature of the thermistor 32 (that is, the temperature of the hot water on the inlet side of the heat pump 10) to a target after execution of the low temperature storage operation (S34 in FIG. 3). At the time when the outlet temperature Tb (ie, Ts + 5 ° C) is reached (YES in S36), excess power is used without stopping the heat pump 10 and the circulation pump 36 when excess power exists 200 W or more (YES in S38). The high temperature hot water storage operation which has been performed is executed (S40). Not limited to this, the control device 90 may temporarily stop the heat pump 10 and the circulation pump 36 while transitioning from the low temperature storage operation to the high temperature storage operation. In this modification as well, “the excess power is present after the heat medium of the low temperature target temperature is filled in the tank by the low temperature storage operation, the excess power is used to output the heat pump outlet side of the tank circulation path The heat storage operation is performed such that the heat pump is operated such that the temperature of the heat medium passing through the heat transfer target reaches a high temperature target temperature of 60 ° C. or higher.

(Modification 2) In the second embodiment and the third embodiment, the controller 90 calculates the first set hot water amount (S62 in FIG. 4) until the first set hot water amount is stored in the tank 20. Execute hot water storage operation (low temperature hot water storage operation or high temperature hot water storage operation). Similarly, in the third embodiment, the control device 90 calculates the second set hot water amount (S86 in FIG. 5), and executes the hot water storage operation until the first set hot water amount is stored in the tank 20. Not limited to this, the control device 90 may not calculate the first (second) set hot water amount in the operation before the start of power generation. In that case, in the operation before the start of power generation, the control device 90 continues until the detected temperature of the thermistor 32 becomes equal to or higher than the target outlet temperature Tb (that is, until warm water having a temperature equal to or higher than the target outlet temperature Tb is filled in the tank 20), A heat storage operation may be performed.

(Modification 3) In the first embodiment, the controller 90 starts the low-temperature storage operation using the surplus power (S34) when the surplus power is 200 W or more (YES in S30 of FIG. 3). The threshold value for the control device 90 to start the low-temperature storage operation using the surplus power is not limited to 200 W, and may be any threshold value.

(Modification 4) In the second embodiment and the third embodiment, the controller 90 determines the average amount of heat used, the average amount of surplus power, and the estimated amount of heat generated based on the amount of heat used and the amount of surplus power for the past seven days. It is calculating (S50 of FIG. 4). In the third embodiment, the control device 90 calculates the average sunshine duration based on the past seven days of weather information (S70 in FIG. 5). The amount of heat used and the amount of surplus power for the controller 90 to calculate the average amount of heat used, the average amount of surplus power, and the estimated amount of heat generated are not limited to the amounts of heat used and excess power for the past seven days. The amount of heat used and the amount of surplus power for any period may be used. Similarly, the past weather information for the control device 90 to calculate the average sunshine duration is not limited to the weather information for the past seven days, and may be weather information for an arbitrary past period.

(Modification 5) The target outlet temperature Tb when the control device 90 performs the low temperature storage operation is not limited to the hot water supply setting temperature Ts + 5 ° C, and any temperature may be set as long as it is a temperature lower than 60 ° C. In addition, the target outlet temperature Tb when the control device 90 performs the low-temperature storage operation is not limited to 90 ° C., and a temperature of 60 ° C. or higher (that is, fungi (Legionella bacteria etc. that may be contained in the warm water in the tank 20 ) Can be set to any temperature if it is a sterilizable temperature).

(Modification 6) In the first embodiment, the condition for the control device 90 to start the low temperature storage operation (S34) using surplus power is that the detected temperature of the thermistor 22a becomes a temperature equal to or lower than the hot water supply set temperature Ts. It is not limited to. In the surplus power storage operation, the control device 90 may start the low-temperature hot water storage operation using the surplus power, when the condition for confirming that the other is not in the fully stored state is satisfied.

  The technical elements described in the present specification or the drawings exhibit technical usefulness singly or in various combinations, and are not limited to the combinations described in the claims at the time of application. In addition, the techniques exemplified in the present specification or the drawings can simultaneously achieve a plurality of purposes, and achieving one of the purposes itself has technical utility.

2: Hot water supply system 10: Heat pump 12: Thermistor 20: Tank 22a: Thermistor 22b: Thermistor 22c: Thermistor 22d: Thermistor 30: Tank circulation path 32: Thermister 34: Thermistor 36: Circulation pump 40: Tap water introduction path 40a: 1st Introduction path 40b: second introduction path 42: tap water supply source 44: mixing valve 50: supply path 52: thermistor 60: burner heating device 70: solar power generator 80: commercial power supply path 90: control device

Claims (5)

Solar power generator,
A heat pump which is operated using electric power supplied from a solar power generator and absorbs heat from the outside air to heat the heat medium,
A tank that stores heat,
Supply means for supplying hot water to the hot water utilization location using the heat stored in the tank;
A tank circulation path for circulating a heat medium between the heat pump and the tank;
And a controller.
The controller is
If there is surplus power obtained by removing the used power from the generated power generated by the solar power generator, the temperature of the heat medium passing through the outlet side of the heat pump in the tank circuit is 60 using the surplus power. Execute a low-temperature hot-water storage operation that operates the heat pump to achieve a low-temperature target temperature lower than ° C,
After the heat medium of the low temperature target temperature is filled in the tank by the low temperature storage operation, if there is surplus power, using the surplus power, the heat medium passing through the outlet side of the heat pump in the tank circulation path Execute a high-temperature storage hot water operation to operate the heat pump so that the temperature reaches a high-temperature target temperature of 60 ° C. or higher,
Hot water supply system. The heat pump can also be operated using power supplied from a commercial power source,
The controller is
Before the solar power generator starts generating electricity of the day, the power of the average amount of heat used per day in the past first period and the average surplus power per day in the past first period Compare the amount of heat generated when the heat pump is operated using
When the average amount of heat used is larger than the amount of heat generated in advance, the power of the first differential heat amount, which is the difference between the average amount of heat used and the amount of heat generated in advance, is stored in the tank Execute the first type of pre-stored hot water operation to operate the heat pump,
When the average amount of heat used is equal to or less than the amount of heat generated as planned, the first type of pre-stored hot water operation is not performed,
The hot water supply system according to claim 1. The controller is
Furthermore, when the first type of pre-stored hot water operation is to be performed, the first differential heat quantity is compared with the low-temperature full heat storage amount which is the heat quantity in the tank when the heat medium of the low temperature target temperature is filled in the tank. And
When the first difference heat amount is larger than the low temperature full heat storage amount, the heat pump is operated by using the power supplied from the commercial power source so that the temperature of the heat medium at the outlet side of the heat pump becomes the high temperature target temperature. 1) Run the first operation to store the heat of differential heat in the tank,
When the first differential heat quantity is equal to or less than the low temperature full heat storage amount, the first differential heat quantity is operated by operating the heat pump such that the temperature of the heat medium flowing in the outlet side of the heat pump in the tank circulation path becomes the low temperature target temperature. Perform a second operation that stores the heat of
The hot water supply system according to claim 2. The controller is
At the timing before the solar power generator starts power generation, compare the average sunshine hours per day in the past second period with the predicted sunshine hours of the day,
(A) When the predicted sunshine time is equal to or greater than the average sunshine time
If the average amount of heat used is greater than the amount of heat generated as planned, execute the first type of pre-stored hot water operation,
If the average amount of heat used is equal to or less than the amount of heat generated as planned, the type 1 advance storage operation is not performed.
(B) If the predicted sunshine duration is shorter than the average sunshine duration,
Calculate the predicted surplus power amount excluding the average power consumption per day in the past 1st period from the predicted power generation amount that the solar power generator is expected to generate during the predicted sunshine period,
Compare the average amount of heat used with the estimated amount of heat generated when the heat pump is operated using the power of the predicted surplus power,
When the average amount of heat used is larger than the estimated amount of heat generated, the heat of the second difference heat amount, which is the difference between the average amount of heat used and the estimated amount of heat generated, is given to the heat medium Run the second type of pre-stored hot water operation to drive the heat pump,
If the average amount of heat used is less than the expected amount of heat generated, the second type of pre-stored hot water operation is not performed,
The hot water supply system according to claim 2 or 3. The hot water supply system according to any one of claims 1 to 4, wherein the supply means further comprises a heat source unit which heats the hot water supplied to the hot water utilization site using the heat generated by burning the fuel.

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