JP2017223421A - Heat medium heating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat medium heating device for heating a heat medium with high cost efficiency by using information on an electricity unit price in which a unit price changes in dependence on a time zone when electricity is used.SOLUTION: A heat medium heating device 2 is a device that secures a scheduled amount of heat medium at a planned temperature at a scheduled time. The heat medium heating device 2 includes an HP (heat pump) unit 6, a tank 10, a controller 110, and a management device 121. The controller 110 carries out boiling operation of the HP unit 6 such that water of the tank 10 becomes a target temperature. The management device 121 acquires an electricity unit price dependent on a time zone and an estimated outside air temperature. The controller 110 sets a plurality of times (temporary times) before the scheduled time, calculates an electricity cost required when it is presumed that boiling operation is started at each temporary time so that the scheduled amount of a heat medium can be secured at the planned temperature at the scheduled time on the basis of the information acquired by the management device 121, and starts boiling operation at a temporary time when an electricity cost is the lowest.SELECTED DRAWING: Figure 1

Description

  The technology disclosed in this specification relates to a heat medium heating device.

  In recent years, there has been proposed a system that collects information on electrical equipment in a building (information such as operating state and power consumption) to improve energy saving (for example, Patent Document 1). Such a system is called HEMS (Home Energy Management System) or BEMS (Building Energy Management System). Patent Document 1 discloses a technique in which an electric heating medium heating device such as a heat pump is also incorporated in the HEMS, and the heat pump is operated in accordance with an instruction from a control device of the HEMS.

JP 2015-29360 A

  Currently, electricity prices vary depending on the time of use, and the electricity price (electricity charge per kWh) will fluctuate. However, in the future, the time zone will be further subdivided, and the electricity price may change finely according to the time zone. is expected. The present specification provides a heating medium heating device that heats a heating medium at low cost using information on a unit price of electricity whose unit price varies depending on a time zone to be used.

  One embodiment of the technology disclosed in this specification can be embodied in the following heat medium heating device. The heat medium heating device is a device that secures a predetermined amount of heat medium at a predetermined temperature at a predetermined time. The heating medium heating device includes an electric heat pump, a tank, a controller, and an information acquisition device. The heat pump uses electric power to heat the heat medium with the heat of the outside air. The tank stores a heat medium heated by a heat pump. The controller performs a boiling operation for driving the heat pump so that the heat medium in the tank reaches a target temperature. The information acquisition apparatus can acquire the unit price of electricity whose unit price (electricity charge per unit amount of electricity) varies depending on the time zone in which electricity is used, and the expected outside air temperature after the current time. This heat medium heating device can use the heat of the heat medium stored in the tank for at least one of heating and hot water supply. One advantage of storing the heating medium in the tank is that there is room for choice in starting the boiling operation even if a predetermined amount of heating medium is secured at the scheduled temperature at the scheduled time. Therefore, the controller of the heating medium heating device disclosed in this specification performs the following processing. The controller sets a plurality of times (temporary times) before the scheduled time. Based on the information acquired by the information acquisition device, the controller reduces the electric cost required when it is assumed that the heating operation is started at each temporary time so that a predetermined amount of heat medium can be secured at the planned temperature at the scheduled time. calculate. And a controller starts a boiling operation at the temporary time with the lowest electric cost.

  The heating medium heating device uses that the heating medium heating device having a tank has a room for selection at the start time of the boiling operation. The heating medium heating device can acquire time-dependent electricity unit price information and perform a cooking operation at a scheduled time at a time when a predetermined amount of the heating medium can be secured at the lowest cost.

An example of calculating the electrical cost is as follows. The controller executes the following processes (1) to (5) for each temporary time.
(1) Obtain the electricity unit price and the predicted outside air temperature at the provisional time.
(2) Boiling that starts at the tentative time by adding the heat medium temperature drop due to heat release from the tank to the scheduled time from the completion of the boiling operation to the scheduled time, assuming that the boiling operation is started at the tentative time Determine the target temperature for lifting operation.
(3) The coefficient of performance of the heat pump is obtained from the target temperature determined in (2) above and the predicted outside air temperature at the temporary time. The coefficient of performance is sometimes called COP (Coefficient Of Performance).
(4) The boiling operation that starts at the temporary time by subtracting the current heat amount of the heating medium in the tank from the heat amount (temporary heat amount) of the heating medium in the tank at the completion of the boiling operation that starts at the temporary time. Calculate the required amount of heat to be added to the heating medium.
(5) Calculate (the necessary heat amount / coefficient of performance) × the electricity unit price at the tentative time) and the electricity cost when the boiling operation is started at the tentative time.

Another aspect of the technology disclosed in the present specification can be embodied in the following heat medium heating device. The heating medium heating device includes an electric heater and a combustion heater for heating the heating medium, a controller for controlling the electric heater and the combustion heater, and an information acquisition device. The information acquisition device acquires a unit price of electricity whose unit price changes depending on a time zone in which electricity is used, and a unit price of fuel per unit calorie of fuel burned by the combustion heater. Then, the controller executes the following process.
(1) While specifying the coefficient of performance of the electric heater when the heating medium is heated to the target temperature with the electric heater, the combustion heater when the heating medium is heated to the target temperature with the combustion heater Specify the coefficient of performance.
(2) "Electric cost = unit price of electricity / coefficient of performance of electric heater" and "fuel cost = unit price of fuel / coefficient of performance of combustion heater" are calculated. The electric cost means the cost required to raise the heating medium per unit volume by 1 ° C. by the electric heater. The fuel cost means the cost required to raise the heating medium per unit volume by 1 ° C. by the combustion heater.
(3) When the electric cost is lower than the fuel cost, the heating medium is heated to the target temperature using the electric heater, and when the fuel cost is lower than the electric cost, the heating medium is set to the target temperature using the combustion type heater. Until heated. When the heat medium having the same target temperature is obtained by the above process, the heat medium can be heated by selecting the lower one of the electric heater and the combustion heater.

  An example of the electric power heater is an electric heat pump that heats the heat medium with the heat of the outside air. In that case, the information acquisition device acquires the outside air temperature, and the controller specifies the coefficient of performance of the heat pump when the heat medium is raised to the target temperature by the heat pump from the acquired outside air temperature and the target temperature. The coefficient of performance of the heat pump depends on the temperature of the outside air that is the heat source. The heating medium heating device can calculate the electrical cost more accurately in consideration of the outside air temperature. Compare electricity costs and fuel costs more accurately.

  Each of the heating medium heating devices described above uses information on the unit price of electricity whose unit price varies depending on the time zone in which electricity is used, and uses the one with the lowest electricity cost or the lower cost of fuel and fuel. The heating medium can be heated. Details and further improvements of the technology disclosed in this specification will be described in the following “DETAILED DESCRIPTION”.

It is a block diagram of the heat-medium heating apparatus 2 of an Example. It is a flowchart of a boiling operation (cost evaluation boiling operation). It is a graph which illustrates the starting time determination process of cost evaluation boiling operation. FIG. 3A is a graph showing an example of an outdoor air temperature and a time-dependent electricity unit price. FIG. 3B is a graph showing the target temperature at each temporary time. FIG. 3C is a graph showing the coefficient of performance at each provisional time. FIG. 3D is a graph showing the amount of heat required at each temporary time. FIG. 3E is a graph showing the electrical cost at each temporary time. It is a flowchart of heating operation (cost evaluation heating operation). It is a graph which shows an example of the effect of cost evaluation heating operation. FIG. 5A is a graph showing an example of an outdoor air temperature, a gas unit price, and a time zone-dependent electricity unit price. FIG. 5B is a graph showing the coefficient of performance of the HP unit and the heating water heating burner. FIG. 5C is a graph of electric cost and fuel cost.

  The heat medium heating device 2 of the embodiment will be described with reference to the drawings. As shown in FIG. 1, the heat medium heating device 2 according to this embodiment includes a tank unit 4, a heat pump (HP) unit 6, a combustion unit 8, and a management device 121.

The HP unit 6 includes a refrigerant circulation path 52 for circulating a refrigerant (for example, an HFC refrigerant such as R32 and a CO ₂ refrigerant such as R744), an air heat exchanger 54, a fan 56, a compressor 62, and a four-way valve 58. And a hot water supply water heat exchanger 63, a check valve 64, a heating water heat exchanger 65, a check valve 66, an expansion valve 60, and the circulation pump 22.

  The air heat exchanger 54 exchanges heat between the outside air blown by the fan 56 driven by electric power and the refrigerant in the refrigerant circuit 52. The compressor 62 is driven by electric power, and pressurizes and sends out the gas phase refrigerant. The hot water supply water heat exchanger 63 exchanges heat between the refrigerant in the refrigerant circulation path 52 and hot water supply water in the tank water circulation path 20 described later. The heating water heat exchanger 65 exchanges heat between the refrigerant in the refrigerant circuit 52 and heating water in the HP circuit 88 described later. The expansion valve 60 adiabatically expands and decompresses the liquid phase refrigerant. The heat pump 50 is configured by the air heat exchanger 54, the compressor 62, the hot water supply water heat exchanger 63 or the heating water heat exchanger 65, and the expansion valve 60. The heat pump 50 is an electric heat pump that heats hot water supply water or heating water, which is a heat medium, by heat of outside air by circulating a refrigerant.

  The four-way valve 58 is a flow path switching valve that switches a refrigerant flow path in the heat pump 50. The four-way valve 58 has four ports a, b, c and d. The four-way valve 58 can be switched between a state where the port a and the port b communicate with each other, a port c and the port d communicate with each other, and a state where the port a and the port d communicate with each other and the port b and the port c communicate with each other. It is. The port a of the four-way valve 58 is connected to the refrigerant inlet of the heating water heat exchanger 65. The refrigerant outlet of the heating water heat exchanger 65 is connected to the refrigerant inlet of the expansion valve 60 via a check valve 66. The port b of the four-way valve 58 is connected to the refrigerant inlet of the compressor 62. The port c of the four-way valve 58 is connected to the refrigerant inlet of the hot water supply water heat exchanger 63. The refrigerant outlet of the hot water supply water heat exchanger 63 is connected to the refrigerant inlet of the expansion valve 60 via a check valve 64. The port d of the four-way valve 58 is connected to the refrigerant outlet of the compressor 62. In the heat medium heating device 2 of the present embodiment, the refrigerant flow switching operation in the four-way valve 58 is performed by temporarily increasing the rotational speed of the compressor 62.

  When the four-way valve 58 is in a state where the port a and the port b communicate with each other and the port c and the port d communicate with each other, in the heat pump 50, the high-temperature and high-pressure gas-phase refrigerant sent from the compressor 62 is It flows into the heat exchanger 63. When passing through the hot water supply water heat exchanger 63, the refrigerant dissipates heat and condenses, and enters a liquid phase state. The liquid-phase refrigerant that has passed through the hot water supply water heat exchanger 63 is decompressed by the expansion valve 60. The low-temperature and low-pressure liquid phase refrigerant that has passed through the expansion valve 60 flows into the air heat exchanger 54. When the refrigerant passes through the air heat exchanger 54, it absorbs heat and evaporates to be in a gas phase state. The gas phase refrigerant that has passed through the air heat exchanger 54 is returned to the compressor 62. That is, in this case, the HP unit 6 absorbs heat from the outside air by the air heat exchanger 54 and heats the hot water supply water by the hot water supply water heat exchanger 63.

  When the four-way valve 58 is in a state where the port a and the port d communicate with each other and the port b and the port c communicate with each other, in the heat pump 50, the high-temperature and high-pressure gas-phase refrigerant sent from the compressor 62 is heated. It flows into the heat exchanger 65. The refrigerant dissipates heat and condenses when passing through the heating water heat exchanger 65 and enters a liquid phase state. The liquid-phase refrigerant that has passed through the heating water heat exchanger 65 is decompressed by the expansion valve 60. The low-temperature and low-pressure liquid phase refrigerant that has passed through the expansion valve 60 flows into the air heat exchanger 54. When the refrigerant passes through the air heat exchanger 54, it absorbs heat and evaporates to be in a gas phase state. The gas phase refrigerant that has passed through the air heat exchanger 54 is returned to the compressor 62. That is, in this case, the HP unit 6 absorbs heat from the outside air with the air heat exchanger 54 and heats the heating water with the heating water heat exchanger 65.

  The HP unit 6 includes an HP controller 102. The HP controller 102 includes a CPU, a ROM, a RAM, and the like. Various operation programs are stored in the ROM. The RAM temporarily stores various signals input to the HP controller 102 and various data generated in the course of execution of processing by the CPU. The HP controller 102 controls the operation of each component of the HP unit 6 by the CPU executing processing based on information stored in the ROM or RAM.

  The tank unit 4 includes a tank 10. The tank 10 stores hot water supply water heated by the HP unit 6. In the present embodiment, the hot water supply water stored in the tank 10 is tap water. The tank 10 is a hermetically sealed type, and the outside is covered with a heat insulating material. Water for hot water supply is stored in the tank 10 until it is full. The thermistors 12, 14, 16 and 18 are attached to the tank 10 at substantially equal intervals in the height direction of the tank 10. Each thermistor 12, 14, 16, 18 measures the temperature of the hot water at the mounting position. The heat storage state of the tank 10 can be specified from the detected temperatures of the thermistors 12, 14, 16, and 18.

  The tank water circulation path 20 has an upstream end connected to the lower part of the tank 10, passes through the hot water supply water heat exchanger 63 of the HP unit 6, and has a downstream end connected to the upper part of the tank 10. A circulation pump 22 is interposed in the tank water circulation path 20. The circulation pump 22 is an electric pump driven by electric power, and sends out hot water supply water in the tank water circulation path 20 from the upstream side to the downstream side. When the HP unit 6 operates the heat pump 50 and drives the circulation pump 22, the hot water supply water at the lower part of the tank 10 is sent to the hot water supply water heat exchanger 63 and heated, and the heated hot water supply water is supplied to the upper part of the tank 10. Returned to Inside the tank 10, a temperature stratification is formed in which a layer of hot water supply water is stacked on a layer of low temperature hot water supply water.

  The upstream end of the tap water introduction path 24 is connected to a tap water supply source 32 outside the heating medium heating device 2. The downstream side of the tap water introduction path 24 is branched into a first introduction path 24a and a second introduction path 24b. The downstream end of the first introduction path 24 a is connected to the lower part of the tank 10. The downstream end of the second introduction path 24 b is connected in the middle of the first hot water supply path 36. A check valve 26 is interposed in the first introduction path 24a. A check valve 28 is interposed in the second introduction path 24b.

  An upstream end of the first hot water supply path 36 is connected to the upper part of the tank 10. As described above, the second introduction path 24 b of the tap water introduction path 24 is connected to the middle of the first hot water supply path 36. A mixing valve 30 is interposed at the connection between the first hot water supply path 36 and the second introduction path 24b. The mixing valve 30 adjusts the ratio of the flow rate of hot water for hot water flowing into the first hot water supply path 36 from the upper part of the tank 10 and the flow rate of cold tap water flowing into the first hot water supply path 36 from the second introduction path 24b. To do. The first hot water supply path 36 on the downstream side of the connection portion with the second introduction path 24 b passes through the hot water supply heating path 37 of the combustion unit 8 and is connected to the second hot water supply path 39. The first hot water supply path 36 and the second hot water supply path 39 are connected by a heat source unit bypass path 33. A bypass valve 34 is interposed in the heat source bypass path 33. A downstream end of the second hot water supply passage 39 is connected to a hot water tap 38.

  The tank unit 4 includes a tank controller 104. The tank controller 104 includes a CPU, a ROM, a RAM, and the like. Various operation programs are stored in the ROM. The RAM temporarily stores various signals input to the tank controller 104 and various data generated in the course of execution of processing by the CPU. The tank controller 104 controls the operation of each component of the tank unit 4 by the CPU executing processing based on information stored in the ROM or RAM.

  The combustion unit 8 includes a cistern 70, a heating water heating burner 82, and a hot water supply water heating burner 81. The cistern 70 is a container having an open top and stores heating water therein. The heating water in this embodiment is, for example, an antifreeze liquid. The upstream end of the heating water forward path 72 is connected to the cistern 70. A circulation pump 74 is interposed in the heating water passage 72. The circulation pump 74 is an electric pump driven by electric power. When the circulation pump 74 is driven, the heating water in the cistern 70 flows into the heating water forward path 72.

  The downstream end of the heating water outlet path 72 is branched into a burner heating path 73, a low-temperature heating circulation path 75, and a heating bypass path 85. A low temperature heating terminal 78 is attached to the low temperature heating circuit 75. The low temperature heating terminal 78 of the present embodiment is, for example, a floor heating panel. The low temperature heating terminal 78 is heated by heat radiation from the water for heating. A first on-off valve 86 is interposed in the low temperature heating circuit 75. A second on-off valve 87 is interposed in the heating bypass path 85.

  A water heating burner 82 for heating is interposed in the burner heating path 73. The heating water heating burner 82 is a combustion heat source machine that heats the heating water in the burner heating path 73 by burning fuel (for example, fuel gas such as city gas). The downstream end of the burner heating path 73 branches into a high-temperature heating circulation path 77 and a reheating circulation path 79. A high temperature heating terminal 76 is attached to the high temperature heating circuit 77. The high temperature heating terminal 76 of the present embodiment is, for example, a bathroom heating dryer. The high temperature heating terminal 76 heats using the heat of the supplied heating water. Note that an opening / closing valve is built in the high temperature heating terminal 76, and the opening / closing valve is opened when heating is performed at the high temperature heating terminal 76, and is opened / closed when heating is not performed at the high temperature heating terminal 76. The valve is closed. The low temperature heating circuit 75, the high temperature heating circuit 77, and the heating bypass circuit 85 merge at their downstream ends and are connected to the upstream end of the first heating water return path 84.

  The downstream end of the first heating water return path 84 branches into an HP circulation path 88 and an HP bypass path 94. A regulating valve 90 is provided at the downstream end of the first heating water return path 84. The adjustment valve 90 changes the opening degree, thereby allowing the flow rate of the heating water flowing from the first heating water return path 84 to the HP circulation path 88 and the flow rate of the heating water flowing from the first heating water return path 84 to the HP bypass path 94. The ratio of can be changed. The HP circulation path 88 passes through the heating water heat exchanger 65 of the HP unit 6 and is connected to the upstream end of the second heating water return path 96. The HP bypass 94 is connected to the upstream end of the second heating water return path 96 without passing through the heating water heat exchanger 65 of the HP unit 6. The downstream end of the second heating water return path 96 is connected to the cistern 70.

  A reheating heat valve 83 and a reheating heat exchanger 97 are interposed in the reheating circulation path 79. The reheating thermal valve 83 opens and closes the reheating circulation path 79. In the reheating heat exchanger 97, heat is exchanged between the heating water flowing in the recirculation circulation path 79 and the bathtub water flowing in the bathtub water circulation path 91 (hot water supply water stored in the bathtub 98). The downstream end of the recirculation circulation path 79 is connected to the second heating water return path 96.

  The upstream end and the downstream end of the bathtub water circulation path 91 are connected to the side portion of the bathtub 98. A bathtub water circulation pump 99 is interposed in the bathtub water circulation path 91. The bathtub water circulation pump 99 is an electric pump driven by electric power. When the bathtub water circulation pump 99 is driven, the bathtub water sucked out from the bathtub 98 passes through the reheating heat exchanger 97 and is returned to the bathtub 98.

  A hot water supply water heating burner 81 is interposed in the hot water supply heating path 37. The hot water supply water heating burner 81 is a combustion heat source machine that heats hot water supply water in the hot water supply heating path 37 by combustion of fuel (for example, fuel gas such as city gas). From the downstream side of the hot water supply water heating burner 81 of the hot water supply heating path 37, the bathtub pouring path 40 is branched. The bathtub pouring passage 40 is provided with a pouring solenoid valve 42 for opening and closing the bathtub pouring passage 40. The downstream end of the bathtub pouring channel 40 is connected to the bathtub water circulation pump 99.

  The combustion unit 8 includes a combustion controller 106. The combustion controller 106 includes a CPU, a ROM, a RAM, and the like. Various operation programs are stored in the ROM. The RAM temporarily stores various signals input to the combustion controller 106 and various data generated in the course of execution of processing by the CPU. The combustion controller 106 controls the operation of each component of the combustion unit 8 when the CPU executes processing based on information stored in the ROM or RAM. A remote controller 108 is connected to the combustion controller 106. The remote control 108 is provided with various switches for the user to operate the heat medium heating device 2, a liquid crystal display for displaying the operation state of the heat medium heating device 2 to the user, and the like.

  The HP controller 102, the tank controller 104, and the combustion controller 106 can communicate with each other. The HP controller 102, the tank controller 104, and the combustion controller 106 cooperate to control the operation of the heat medium heating device 2. Hereinafter, the HP controller 102, the tank controller 104, and the combustion controller 106 are collectively referred to as a controller 110.

  The controller 110 (that is, the HP controller 102, the tank controller 104, and the combustion controller 106) can further communicate with the management device 121. The management apparatus 121 can obtain information from various external information providing apparatuses via the Internet 122. For example, the management apparatus 121 can acquire an electricity charge or a gas charge from an information providing apparatus (first information providing apparatus 123) of a gas supply company or a power supply company through the Internet 122. Further, the management device 121 can acquire current and future outside air temperatures (predicted outside air temperatures) from an information providing device (second information providing device 124) that provides weather forecast information via the Internet 122. The controller 110 controls the tank unit 4, the HP unit 6, and the combustion unit 8 in a cost-effective manner using the electricity rate, gas rate, and expected outside air temperature obtained through the management device 121. Control for increasing cost efficiency will be described later.

  Next, operation | movement of the heat-medium heating apparatus 2 of a present Example is demonstrated. Hereinafter, the boiling operation, the hot water supply operation, the hot water operation, the heating operation, and the reheating operation performed by the heat medium heating device 2 will be described in order.

(Boiling operation)
The boiling operation is an operation in which the hot water supply water in the tank 10 is heated by the HP unit 6 and the hot water supply water that has reached a high temperature is returned to the tank 10. When performing the boiling operation, the controller 110 switches the four-way valve 58 to a state where the port a and the port b communicate with each other and the port c and the port d communicate with each other to drive the compressor 62 and the fan 56. . The controller 110 drives the circulation pump 22.

  By driving the compressor 62, the refrigerant in the refrigerant circulation path 52 circulates in the order of the compressor 62, the hot water supply water heat exchanger 63, the expansion valve 60, and the air heat exchanger 54. In this case, the refrigerant in the refrigerant circuit 52 passing through the hot water supply water heat exchanger 63 is in a high-temperature and high-pressure gas state. Further, the hot water in the tank 10 circulates in the tank water circulation path 20 by driving the circulation pump 22. That is, hot water supply water existing in the lower part of the tank 10 is introduced into the tank water circulation path 20, and is heated by the heat of the refrigerant in the refrigerant circulation path 52 when the introduced hot water supply water passes through the hot water supply water heat exchanger 63. Then, the heated hot water supply water is returned to the upper part of the tank 10. At this time, the controller 110 controls the operations of the compressor 62, the fan 56, and the circulation pump 22 so that the temperature of the hot water after passing through the hot water water heat exchanger 63 becomes the set boiling temperature. . Thereby, hot water for hot water supply is stored in the tank 10. When the inside of the tank 10 is in a fully stored state filled with high-temperature hot water supply water, the controller 110 ends the boiling operation.

  The controller 110 sets the boiling temperature in the boiling operation. Normally, the boiling temperature in the boiling operation is set to a temperature (for example, 60 ° C.) obtained by adding a predetermined temperature range to the hot water supply set temperature set by the user using the remote control 108. Further, when it is necessary to sterilize the hot water in the tank 10 by heating it to a high temperature, the boiling temperature in the boiling operation is set to a temperature (for example, 90 ° C.) higher than the normal boiling temperature. The In this way, the boiling operation performed at the boiling temperature set higher than the normal boiling temperature is particularly called a refresh operation.

  Further, the heating medium heating device 2 starts the boiling operation at the time when the cost is lowest based on the coefficient of performance (described later) of the HP unit 6 and the unit price of electricity whose rate changes according to the time zone to be used. There is a case. Such an operation is referred to as a cost evaluation heating operation. The cost evaluation heating operation will be described later.

(Hot water operation)
The hot water supply operation is an operation in which hot water supply water adjusted to a hot water supply set temperature is supplied to the hot water tap 38. When the hot-water tap 38 is opened, tap water flows into the lower part of the tank 10 from the tap water introduction path 24 (first introduction path 24a) due to the water pressure from the tap water supply source 32. At the same time, the hot water supply water in the upper part of the tank 10 is supplied to the hot water tap 38 via the first hot water supply path 36.

  When the temperature of the hot water supplied from the tank 10 to the first hot water supply path 36 (that is, the detected temperature of the thermistor 12) is higher than the set hot water temperature, the controller 110 drives the mixing valve 30 to perform the second introduction. Tap water is introduced into the first hot water supply path 36 from the path 24b. Therefore, the hot water supply water supplied from the tank 10 and the tap water supplied from the second introduction path 24 b are mixed in the first hot water supply path 36. The controller 110 adjusts the opening degree of the mixing valve 30 so that the temperature of the hot water supplied to the hot water tap 38 matches the hot water supply set temperature. Such a hot water supply operation is also referred to as a non-combustion hot water supply operation.

  On the other hand, the controller 110 closes the bypass valve 34 when the temperature of the hot water supply water supplied from the tank 10 to the first hot water supply path 36 is lower than the hot water supply set temperature, and the first hot water supply path by the hot water supply water heating burner 81. The hot water supply water passing through 36 is heated. The controller 110 controls the output of the hot water supply water heating burner 81 so that the temperature of the hot water supply water supplied to the hot water tap 38 matches the hot water supply set temperature. Such a hot water supply operation is also referred to as a combustion hot water supply operation.

(Hot water operation)
The hot water operation is an operation in which hot water is applied to the bathtub 98 at the hot water set temperature. When the user instructs the start of hot water operation, the heating medium heating device 2 starts the hot water operation. In the hot water operation, the controller 110 opens the hot water solenoid valve 42. When the hot water solenoid valve 42 is opened, tap water flows into the lower portion of the tank 10 from the tap water introduction path 24 (first introduction path 24 a) due to the water pressure from the tap water supply source 32. At the same time, the hot water supply water in the upper part of the tank 10 is supplied to the bathtub 98 via the first hot water supply path 36, the hot water supply heating path 37, the bathtub pouring path 40, and the bathtub water circulation path 91. In the hot water operation, the temperature of the hot water supplied to the bathtub pouring channel 40 is adjusted to the hot water setting temperature in the same manner as in the hot water operation. When the flow rate of the hot water supplied to the bathtub 98 reaches the hot water set water amount, the controller 110 ends the hot water operation.

(Heating operation)
The heating operation is an operation for heating by the low temperature heating terminal 78 or the high temperature heating terminal 76. When the execution of the heating operation is instructed by the user, the controller 110 drives the circulation pump 74 with the first on-off valve 86 opened and the second on-off valve 87 closed. Further, the controller 110 drives the electric compressor 62 and the fan 56 by switching the four-way valve 58 to a state in which the port a and the port d communicate with each other and the port b and the port c communicate with each other. That is, the HP unit 6 is driven. As a result, the refrigerant in the refrigerant circuit 52 is pressurized by the compressor 62 to become a high-temperature and high-pressure gas state, and the heating water heated when passing through the heating water heat exchanger 65 passes through the cistern 70 and is subjected to low-temperature heating. It is supplied to the terminal 78 and the high temperature heating terminal 76. Further, the controller 110 operates the heating water heating burner 82 as necessary. As a result, the high-temperature heating terminal 76 is supplied with heating water having a higher temperature due to heating by the heating water heating burner 82. In the heating operation, the controller 110 sets the temperature of the heating water supplied to the low temperature heating terminal 78 to the low temperature heating set temperature and the temperature of the heating water supplied to the high temperature heating terminal 76 to the high temperature heating set temperature. Thus, the opening degree of the regulating valve 90, the operation of the HP unit 6, and the output of the heating water heating burner 82 are controlled.

  The heating medium heating device 2 compares the electric cost required to heat the heating water to the set temperature with only the HP unit 6 and the fuel cost required to heat the heating water to the set temperature only with the heating water heating burner 82. Thus, the heating operation can be performed at a lower cost. Such an operation is referred to as a cost evaluation heating operation. The cost evaluation heating operation will be described later.

(Reaping driving)
The chasing operation is an operation for chasing the bathtub water stored in the bathtub 98. When the user instructs the start of the chasing operation, the heating medium heating device 2 starts the chasing operation. In the reheating operation, the controller 110 drives the bathtub water circulation pump 99. Further, the controller 110 drives the circulation pump 74 with the first on-off valve 86 and the second on-off valve 87 closed and the reheating heat operated valve 83 opened. In the reheating operation, heating water is heated by the HP unit 6 and heating water is heated by the heating water heating burner 82 as in the heating operation. Thereby, the bathtub water is sucked out from the bathtub 98 and heated by the reheating heat exchanger 97 by heat exchange with the heating water. The heated bathtub water is returned to the bathtub 98.

  The heating operation, hot water supply operation, hot water operation, heating operation, and reheating operation have been described above. Next, the process of the heating medium heating device 2 for improving cost efficiency will be described. As described above, the heat medium heating device 2 can acquire the electricity bill, the gas fee, and the expected outside air temperature through the management device 121, and can heat water (heat medium) cost-effectively. As described above, the heating medium heating device 2 includes two types of cost-oriented operation modes: a cost evaluation heating operation and a cost evaluation heating operation. Hereinafter, the cost evaluation heating operation and the cost evaluation heating operation will be described.

(Cost evaluation boiling operation)
As described above, the boiling operation is an operation in which the hot water supply water in the tank 10 is heated by the HP unit 6 and the hot water supply water having a high temperature is returned to the tank 10. The controller 110 controls the HP unit 6 so that the hot water supply water in the tank 10 has a set boiling temperature. Hereinafter, for convenience of explanation, “boiling temperature” is referred to as “target temperature”.

  In general households, there are many times when hot water is used in large quantities, such as bathing hours. It is desirable that a predetermined amount of hot water having a predetermined temperature is stored in the tank 10 before such a time period. The heat medium heating device 2 supplies a predetermined amount (scheduled amount) of hot water at a fixed temperature (scheduled temperature) at a predetermined time (scheduled time) every day by a user setting or a learning function of the controller 110. Can be secured. When securing a predetermined amount of hot water in the tank 10 at a predetermined temperature at the predetermined time, there is room for selection at the time of starting the boiling operation. The heating medium heating device 2 can perform this boiling operation at a low cost in consideration of an electricity rate that changes depending on the time zone to be used and an outside air temperature that changes depending on the time.

  One of the parameters affecting the operating cost is the coefficient of performance of the HP unit 6. The HP unit 6 is an electric device that heats hot water supply water using an electric device such as the fan 56 and the compressor 62, and the coefficient of performance (COP) means the heating capacity per unit power consumption. . More specifically, the coefficient of performance of the HP unit 6 is a value obtained by dividing the amount of heat given to the water in the tank 10 by using the HP unit 6 by the electric power consumed to obtain the amount of heat. In other words, the coefficient of performance is the ratio of the amount of heat obtained to the amount of heat supplied. The coefficient of performance of the HP unit 6 changes depending on the outside air temperature and the target temperature. This is because the HP unit 6 is a device that increases the temperature of water by transferring the heat of outside air to water (heating medium).

  Among the parameters that affect the operating cost of the heat medium heating device 2, there are electric charges whose unit prices are different depending on the time zone to be used. In this specification, it is assumed that the electricity rate is expressed as an electricity rate (unit price of electricity) per unit electric energy (1 kWh) so that the following explanation can be easily understood.

  The heating medium heating device 2 determines the time to start the boiling operation in consideration of the predicted outside air temperature and the time-dependent electric unit price in order to secure the predetermined amount of hot water in the tank 10 at the predetermined temperature at the predetermined time. To do. FIG. 2 shows a flowchart of the cost evaluation boiling operation performed by the heat medium heating device 2. The flowchart in FIG. 2 is a process for securing a predetermined amount of hot water in the tank 10 at a predetermined temperature at a predetermined time. Here, it is assumed that the above-described scheduled time, scheduled temperature, and scheduled amount are determined in advance by user settings or by automatic learning control of the controller 110 based on past data.

  First, the controller 110 sets a plurality of temporary times as times before the scheduled time (S2). The provisional time is a time temporarily set to calculate the electric cost required when it is assumed that the boiling operation is started at the scheduled time when the scheduled amount of hot water is stored in the tank 10 at the scheduled temperature. is there. For example, the controller 110 sets a plurality of times before the scheduled time as temporary times at one hour intervals. For example, the controller 110 sets 1 hour before the scheduled time as the first temporary time, sets 2 hours before as the second temporary time, and sets 3 hours before as the third temporary time.

  Next, the controller 110 acquires the electricity unit price and the predicted outside air temperature at each temporary time from the external information providing device through the management device 121 (S3). As described above, the management apparatus 121 is connected to an external information providing apparatus via the Internet 122 and can obtain various information. The controller 110 instructs the management device 121 to obtain the electricity unit price at each temporary time from the first information providing device 123 and obtain the expected outside air temperature at each temporary time from the second information providing device 124. The first information providing device 123 is an information providing device of an electric company, for example, and the second information providing device 124 is an information providing device that provides weather forecast information. The management device 121 transfers the obtained electricity unit price and expected outside air temperature at each temporary time to the controller 110.

  Next, the controller 110 determines the target temperature of the boiling operation at each temporary time (S4). Specifically, the controller 110 calculates a temperature obtained by adding the water temperature decrease due to heat release from the tank to the scheduled temperature from the completion of the boiling operation to the scheduled time assuming that the boiling operation is started at each temporary time. It is determined as the target temperature for the boiling operation starting at the time. The extent to which the water temperature in the tank decreases due to heat radiation from the tank is stored in advance in the controller 110 as a map or as a calculation formula. For example, in the case of a map, for each combination of the amount of water in the tank, the water temperature, and the outside air temperature, the amount of water temperature decrease for each hour is described as a map. The controller 110 refers to the map, adds the water temperature drop caused by the time difference between the scheduled time and each temporary time, and determines the target temperature at each temporary time as the target temperature.

  Next, the controller 110 calculates the coefficient of performance of the HP unit 6 at each temporary time (S5). As described above, the coefficient of performance changes depending on the outside air temperature and the target temperature. The controller 110 stores a map in which a coefficient of performance is written for each set of outside air temperature and target temperature. The controller 110 substitutes the outside air temperature obtained in step S3 and the target temperature determined in step S4 for each temporary time, and obtains a coefficient of performance for each temporary time. The more accurate coefficient of performance is determined in consideration of the temperature of water supplied to the HP unit 6 in addition to the outside air temperature and the target temperature. The controller 110 may store a map in which the outside air temperature, the target temperature, and the supply water temperature are variables.

  Next, the controller 110 calculates the amount of heat (necessary amount of heat) to be added to the water in the tank 10 to complete the boiling operation at each temporary time (S6). The required heat amount is a value obtained by subtracting the heat amount of water in the current tank from the heat amount that the water in the tank should have at the completion of the boiling operation starting at each temporary time. The heat quantity of water in the tank is calculated by an equation of (temperature of water in tank−reference temperature) × water quantity × (heat quantity required to raise 1 g of water by 1 ° C.). Here, “the amount of heat necessary to raise 1 g of water by 1 ° C.” is usually 1 calorie, but in order to maintain consistency with the unit price of electricity, the amount of heat is also shown here in units of [Wh]. The “reference temperature” is the temperature of the water supplied from the tap water supply source 32. Here, the average temperature of the water supplied from the tap water supply source 32 throughout the day is the “reference temperature”. Is set to The purpose of the process of FIG. 2 is to estimate the electrical cost required to obtain a predetermined amount of water at a predetermined temperature at a predetermined time, and it is sufficiently practical to adopt the average temperature as the “reference temperature”. In the controller 110, a “reference temperature” may be set for each time. In addition, the amount of heat in the current tank does not exactly match the amount of heat in the tank immediately before the boiling operation at each temporary time, but to estimate the electrical cost of the heating operation at each temporary time, The difference between the amount of heat and the amount of heat immediately before the boiling operation is practically acceptable.

  The necessary heat amount can also be obtained by multiplying the value obtained by subtracting the current water temperature from the target temperature at each temporary time by the planned water amount and “the amount of heat necessary to raise the water by 1 ° C.”. The calculation formula is substantially equivalent to the calorific value calculation procedure described above.

  Next, the controller 110 calculates the electrical cost at each temporary time (S7). The electricity cost is an electricity bill required to start the boiling operation at each temporary time and achieve the target temperature obtained in step S4. The electric cost can be obtained by ((necessary heat amount / coefficient of performance) × electrical unit price). The unit price of electricity at each temporary time has been acquired in step S3, the required heat quantity is obtained in step S6, and the coefficient of performance is obtained in step S5. In other words, the controller 110 calculates the electrical cost required for the boiling operation at each temporary time when it is assumed that the boiling operation is started at each temporary time.

  Finally, the controller 110 sets a timer so as to start the boiling operation at a temporary time with the lowest electrical cost (S8). Note that the target temperature at that time is a target temperature corresponding to the temporary time set in the timer. Then, the controller 110 starts the boiling operation at the target temperature set at the set time (S9).

  With the above processing, the boiling operation is performed most cost-effectively. An example of the processing of the flowchart of FIG. 2 will be described with reference to the graph of FIG. It should be noted that the graph of FIG. 3 schematically shows the values of each parameter so that the explanation can be easily understood, and does not necessarily match the actual parameter tendency.

  FIG. 3A is a graph showing an example of the predicted outside air temperature and the time-dependent electricity unit price. The horizontal axis in FIG. 3A represents time. Time T0 is the scheduled time. The time required for the boiling operation is assumed to be 30 minutes. The controller 110 sets a time T1 30 minutes earlier than the scheduled time T0 as the first temporary time, sets a time T2 one hour earlier than the temporary time T1 as a second temporary time, and a time one hour earlier than the second temporary time T2. T3 is set to the third provisional time. The setting of a plurality of temporary times is performed in step S2 of FIG.

  The vertical axis on the left side of FIG. 3A represents the unit price of electricity, and the vertical axis on the right side represents the expected outside air temperature. The solid line graph shows the time-dependent electricity unit price, and the dotted line graph shows the change in the predicted outside air temperature. In step S3 of FIG. 2, the controller 110 acquires the electricity unit price and the predicted outside air temperature at each temporary time from the management device 121. In the example of FIG. 3, the electricity unit price for the time period from the provisional time T3 to the provisional time T2 is P3 (yen / kWh), and the electricity unit price for the time period from the provisional time T2 to the provisional time T1 is P2 (yen / kWh). ) And the electricity unit price in the time period from the temporary time T1 to the scheduled time T0 is P1 (yen / kWh). In the example of FIG. 3A, the electricity unit price P1> the electricity unit price P2> the electricity unit price P3. In the graph of FIG. 3, the scheduled time T0 is, for example, 6:00 pm, and the expected outside air temperature decreases from the temporary time T3 to the scheduled time T0.

  FIG. 3B is a graph showing the target temperature at each temporary time. The controller 110 sets a temperature obtained by adding a decrease in the heat medium temperature due to heat radiation from the tank to the scheduled temperature from the completion of the boiling operation to the scheduled time assuming that the boiling operation is started at each temporary time as the target temperature. (Step S4 in FIG. 2). The scheduled temperature is the temperature t0 at the scheduled time T0. Since the required time for the boiling operation is assumed to be 30 minutes, when the boiling operation is started at the temporary time T1, the end time of the boiling operation coincides with the scheduled time T0. At the end of the boiling operation started at the temporary time T1, the water temperature in the tank 10 should have reached the target temperature t1. Since the end time of the boiling operation starting at the temporary time T1 is equal to the scheduled time T0, the target temperature t1 at the temporary time T1 is equal to the planned temperature t0. Further, in this example, it is known in advance that the temperature of the water in the tank 10 decreases by dt (° C.) due to heat radiation for one hour. Assuming that the boiling operation is started at the temporary time T2 and the boiling operation is completed in 30 minutes, the boiling operation completion time is one hour before the scheduled time T0. Since the temperature drop of the water between the boiling operation completion time and the scheduled time T0 is dt (° C.), the target temperature t2 at the temporary time T2 is obtained by adding the temperature drop dt (° C.) to the scheduled temperature t0. The temperature becomes t2. Similarly, when the boiling operation is started at the third temporary time T3, the completion time of the boiling operation is two hours before the scheduled time T0. Therefore, the target temperature t3 of the boiling operation at the third temporary time is the planned temperature. A temperature obtained by adding 2 dt (° C.) of the temperature drop for 2 hours to t0. Thus, the target temperature at each temporary time is determined. Note that the target temperature increases as the difference between the temporary time and the scheduled time increases, so that target temperature t3> target temperature t2> target temperature t1.

  FIG. 3C is a graph showing the coefficient of performance at each provisional time. The controller 110 calculates the coefficient of performance of the HP unit 6 from the difference between the target temperature at each temporary time and the predicted outside air temperature at that temporary time (step S5). As described above, the controller 110 includes a map having the target temperature and the predicted outside air temperature as input variables and the coefficient of performance as an output, and determines the coefficient of performance at each temporary time with reference to the map. In general, the higher the outside air temperature is, the higher the coefficient of performance is, so that the coefficient of performance C1 at the first temporary time T1 <the coefficient of performance C2 at the second temporary time T2 <the coefficient of performance C3 at the third temporary time.

  FIG. 3D is a graph showing the amount of heat required at each temporary time. The controller 110 should subtract the current amount of water in the tank 10 from the amount of water in the tank 10 at the completion of the boiling operation starting at each temporary time, and add it in the boiling operation starting at that temporary time. The required heat quantity is calculated (S6). The higher the target temperature, the greater the amount of heat in the water in the tank 10 at the completion of the boiling operation. Therefore, as the tendency, the greater the time difference between the temporary time and the scheduled time, the greater the required amount of heat. In the example of FIG. 3, the required heat quantity Q1 at the first temporary time T1 <the required heat quantity Q2 at the second temporary time T2 <the required heat quantity Q3 at the third temporary time T3.

  FIG. 3E is a graph showing the electrical cost at each temporary time. The controller 110 calculates ((necessary amount of heat / coefficient of performance) × electrical unit price at each temporary time) and obtains the electric cost when the boiling operation is started at the temporary time (S7). In the example of FIG. 3, the earlier the temporary time, the greater the required heat, but the coefficient of performance also increases and the unit price of electricity decreases. Therefore, the electric cost Y1 at the temporary time T1> the electric cost Y2 at the temporary time T2> the electric cost Y3 at the temporary time T3.

  Finally, the controller 110 compares the electric costs at a plurality of temporary times, sets the temporary time with the lowest electric cost as the start time of the boiling operation (S8), and when the temporary time actually arrives, the boiling operation Is started (S9). In the example of FIG. 3, the unit price of electricity at the third provisional time T3 is the lowest, and the coefficient of performance at the third provisional time T3 is the highest, so that the electricity when starting the boiling operation at the third provisional time is started. The result was the lowest cost. When the third provisional time T3 arrives, the controller 110 starts the boiling operation at the target temperature t3 (S9).

  As described above, in the cost evaluation boiling operation, a predetermined amount of water can be stored in the tank 10 at a predetermined temperature at a predetermined time at a low cost.

(Cost evaluation heating operation)
Next, the cost evaluation heating operation will be described. In the cost evaluation heating operation, the controller 110 compares the electricity charge required to heat the heating water only with the HP unit 6 and the gas charge required to heat the heating water only with the heating water heating burner 82, Heating operation is performed at the lower cost. FIG. 4 shows a flowchart of the cost evaluation heating operation. The flowchart of FIG. 4 is activated when the user designates the heating preset temperature and designates the start of the cost evaluation heating operation with the remote controller 108.

  The controller 110 acquires the unit price of electricity and the unit price of gas from the external information providing apparatus through the management apparatus 121 (S13). As described above, the management apparatus 121 is connected to an external information providing apparatus via the Internet 122 and can obtain various information. The controller 110 instructs the management device 121 to acquire the electricity unit price and gas unit price at the current time from the first information providing device 123. Here, the 1st information provision apparatus 123 represents the information provision apparatus of an electric company and a gas supply company. The management apparatus 121 transfers the obtained electricity unit price and gas unit price at the current time to the controller 110. In addition, although a gas unit price is normally represented by the charge per gas unit volume, it shall represent here by the charge of the gas volume equivalent to the energy of 1 kWh.

  Next, the controller 110 obtains the coefficient of performance of the HP unit 6 at the current time and the coefficient of performance of the water heating burner 82 (S14). The coefficient of performance of the HP unit 6 has been described in the process of step S5 in FIG. The coefficient of performance of the heating water heating burner 82 is a value obtained by dividing the amount of heat obtained by using the heating water heating burner 82 by the amount of heat of the gas consumed to obtain the amount of heat. In other words, the coefficient of performance is the ratio of the amount of heat obtained to the amount of heat of a given fuel. In the present embodiment, the coefficient of performance of the heating water heating burner 82 using gas as fuel is a constant value and is stored in the controller 110 in advance.

  Next, the controller 110 calculates a cost (electric cost) when it is assumed that the heating operation is performed using the HP unit 6 and a cost (fuel cost) when it is assumed that the heating operation is performed using the water heating burner 82 (fuel cost) ( S15). Here, the electricity cost is indicated by an electricity charge required to raise the temperature of the heating water per unit volume by 1 ° C. The fuel cost is indicated by the gas charge required to raise the temperature of the heating water per unit volume by 1 ° C. Specifically, the electric cost is represented by a numerical value obtained by dividing the electricity unit price by the coefficient of performance of the HP unit 6, and the fuel cost is represented by a numerical value obtained by dividing the gas unit price by the coefficient of performance of the heating water heating burner 82.

  Next, the controller 110 compares the electric cost calculated in step S15 with the fuel cost (step S16), and if the electric cost is lower than the fuel cost (step S16: YES), the heating water is set to the set temperature using the HP unit 6. (S17). On the other hand, when the electrical cost is higher than the fuel cost (step S16: NO), the controller 110 heats the heating water to the set temperature using the heating water heating burner 82 (S18).

  By the process of FIG. 4, the heat medium heating device 2 can perform heating efficiently. An example of the processing of the flowchart of FIG. 4 will be described with reference to the graph of FIG. It should be noted that the graph of FIG. 5 schematically shows the values of each parameter so that the explanation can be easily understood, and does not necessarily match the actual parameter tendency.

  FIG. 5 assumes a case where the user commands a cost evaluation heating operation at time Tx and time Ty, respectively. When the user commands a cost evaluation heating operation at time Tx (time Ty), the controller 110 acquires the electricity unit price and gas unit price at the current time (step S13 in FIG. 4). FIG. 5A is a graph showing an example of an outdoor air temperature, a gas unit price, and a time zone-dependent electricity unit price. The horizontal axis in FIG. 5A represents time. The controller 110 acquires the electricity unit price and gas unit price at the current time (time Tx or time Ty). In FIG. 5 (A), the time change of the unit price of electricity and the time change of the outside air temperature are also shown to help understanding. In FIG. 5A, the symbol Phx means the unit price of electricity at time Tx, and the symbol Phy shows the unit price of electricity at time Ty. Further, the symbol Pg indicates the gas unit price. In this example, the gas unit price is constant at the unit price Pg without depending on the time zone. A dotted line in the graph of FIG. 5A indicates a change in the outside air temperature.

  In the example of FIG. 5, the electricity unit price Phx is lower than the gas unit price Pg at the time Tx, but the electricity unit price Phy is higher than the gas unit price Pg at the time Ty. Further, the outside air temperature at time Tx is higher than the outside air temperature at time Ty.

  The controller 110 that has acquired the unit price of electricity, the unit price of gas, and the outside temperature next calculates the coefficient of performance (step S14 in FIG. 4). FIG. 5B shows the coefficient of performance of the HP unit 6 and the heating water heating burner 82. The symbol Chx indicates the coefficient of performance of the HP unit 6 at time Tx, and the symbol Chy indicates the coefficient of performance of the HP unit 6 at time Ty. Symbol Cg indicates the coefficient of performance of the water heating burner 82 for heating. Generally, the higher the outside air temperature, the higher the coefficient of performance of the HP unit 6. The coefficient of performance of the HP unit 6 has been described above, but the coefficient of performance Chx at time Tx when the outside air temperature is high is higher than the coefficient of performance Chy at time Ty when the outside air temperature is low. In this example, the coefficient of performance Cg of the heating water heating burner 82 is constant.

  Next, the controller 110 calculates an electric cost and a fuel cost. FIG. 5C shows a comparison between electric cost and fuel cost. At the time Tx when the outside air temperature is high and the coefficient of performance of the HP unit 6 is also high, the electric cost is lower than the fuel cost. Therefore, the controller 110 heats the heating water using the HP unit 6 in the cost evaluation heating operation starting at time Tx. On the other hand, at the time Ty when the outside air temperature is low and the coefficient of performance of the HP unit 6 is low, the fuel cost is lower than the electrical cost. Accordingly, the controller 110 uses the heating water heating burner 82 to heat the heating water in the cost evaluation heating that starts at time Ty.

  The structure of the heat medium heating device 2, the cost evaluation boiling operation, and the cost evaluation heating operation have been described above. Both the cost evaluation boiling operation and the cost evaluation heating operation can heat water (heat medium) cost-effectively.

  Points to be noted regarding the heat medium heating device 2 of the embodiment will be described. In the illustration of FIG. 5, the gas unit price is assumed to be constant without depending on time. However, the gas unit price may also change according to the time zone in which it is used. In the illustration of FIG. 5, the coefficient of performance of the heating water heating burner 82 is assumed to be constant. The coefficient of performance of the heating water heating burner 82 may also change depending on the temperature of water before heating or the set temperature of heating. In that case, the controller 110 stores a map or a relational expression in which a coefficient of performance is determined with respect to the temperature of water before heating and / or the set temperature.

  Similarly to the cost evaluation heating operation, it is also preferable to perform the cost evaluation additional cooking operation for the additional cooking operation. In other words, the heating medium heating device 2 uses only the HP unit 6 to heat the heating water used for additional cooking to the set temperature, and the heating water used for additional cooking using only the heating water heating burner 82 to the set temperature. Comparing with the fuel cost required for heating, additional cooking may be performed at a lower cost.

  The heat medium heating device 2 may receive electric power from the solar power generation device. In that case, the “unit price of electricity” is the unit price of electricity when receiving power from the solar power generation device. The management device 121 monitors the power generated by the solar power generation device. When the power obtained from the solar power generation device is not sufficient, and the power is supplemented from the commercial power source, the power of the solar power generation device and the commercial power source are supplied. A unit price of electricity may be calculated from the ratio of the electric power and provided to the controller 110.

  The water stored in the tank 10 of the embodiment corresponds to an example of the “heating medium” in claims 1 and 2. The water stored in the cistern 70 corresponds to an example of the “heating medium” in claims 3 and 4. The HP (heat pump) unit 6 of the embodiment corresponds to an example of a “heat pump” in claims 1 and 2. The HP (heat pump) unit 6 corresponds to an example of the “electric heater” in claims 3 and 4. The electric heater according to claims 3 and 4 may be a heater other than the HP (heat pump) unit as long as it is an electric heater. The heating water heating burner 82 corresponds to an example of the “combustion heater” in claims 3 and 4. The combustion heater may be a device that heats the medium by burning fuel (gas or petroleum), and is not limited to the heating water heating burner 82 of the embodiment.

  The controller 110 according to the embodiment corresponds to an example of a “controller” in the claims. The management apparatus 121 according to the embodiment corresponds to an example of an information acquisition apparatus according to the claims. The “controller” and the “information acquisition device” in the claims may be an individual device as hardware and connected to each other via a communication line, or one device may be a “controller”. And the function of the “information acquisition device”.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings can achieve a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

2: Heat medium heating device 4: Tank unit 6: HP unit 8: Combustion unit 10: Tank 22: Circulation pump 32: Tap water supply source 38: Hot water tap 50: Heat pump 54: Air heat exchanger 56: Fan 58: Four-way Valve 60: Expansion valve 62: Compressor 63: Water heat exchanger for hot water supply 65: Water heat exchanger for heating 70: Systurn 81: Water heating heater for hot water supply 82: Water heating burner for heating 97: Reheating heat exchanger 98: Bathtub 99: Bath water circulation pump 102: HP controller 104: Tank controller 106: Combustion controller 108: Remote controller 110: Controller 121: Management device 122: Internet 123: First information providing device 124: Second information providing device

Claims (4)

It is a heat medium heating device that secures a predetermined amount of heat medium at a predetermined temperature at a predetermined time,
An electric heat pump that heats the heat medium with the heat of outside air;
A tank for storing the heat medium heated by the heat pump;
A controller for performing a boiling operation for driving the heat pump so that the heating medium of the tank reaches a target temperature;
An information acquisition device that acquires the unit price of electricity whose unit price changes depending on the time zone in which electricity is used, and the expected outside air temperature after the current time,
With
The controller is
A plurality of times (provisional times) before the scheduled time are set, and based on the information acquired by the information acquisition device, each of the scheduled amounts of heat medium can be secured at the scheduled temperature at the scheduled time. Calculate the electricity cost required when it is assumed that the boiling operation starts at the tentative time,
Start boiling operation at the temporary time with the lowest electricity cost,
A heating medium heating device. For each provisional time, the controller
(1) Obtain the electricity unit price and expected outside air temperature at the temporary time,
(2) The heating medium temperature drop due to heat release from the tank is added to the scheduled temperature from the completion of the boiling operation to the scheduled time when it is assumed that the boiling operation is started at the temporary time. Determine the target temperature of the boiling operation to start,
(3) The coefficient of performance of the heat pump is obtained from the target temperature and the predicted outside air temperature at the temporary time,
(4) The amount of heat of the heat medium in the tank at the time of completion of the boiling operation starting at the temporary time should be subtracted from the amount of heat of the current heat medium in the tank and added at the boiling operation starting at the temporary time Calculate the amount of heat,
(5) Calculate ((necessary heat amount / coefficient of performance) × electrical unit price at the temporary time) to obtain the electric cost when the boiling operation is started at the temporary time.
The heating medium heating device according to claim 1. An electric heater for heating the heating medium;
A combustion heater for heating the heat medium;
A controller for controlling the electric heater and the combustion heater;
An information acquisition device for acquiring a unit price of electricity whose unit price changes depending on a time zone in which electricity is used, and a unit price of fuel per unit amount of fuel burned by the combustion heater,
With
The controller is
While specifying the coefficient of performance of the electric heater when the heating medium is heated to the target temperature with the electric heater, the combustion equation when heating the heating medium to the target temperature with the combustion heater Identify the coefficient of performance of the heater,
"Electric cost = unit price of electricity / coefficient of performance of electric heater" and "fuel cost = unit price of fuel / coefficient of performance of combustion heater" are calculated,
When the electric cost is lower than the fuel cost, the heating medium is heated to the target temperature using the electric heater, and when the fuel cost is lower than the electric cost, the combustion heater is used. Heating the heating medium to the target temperature;
A heating medium heating device. The electric heater is an electric heat pump that heats the heat medium with the heat of the outside air,
The information acquisition device acquires an outside air temperature,
The said controller specifies the coefficient of performance of the said heat pump when raising the said heat medium to the said target temperature with the said heat pump from the acquired said outside temperature and the said target temperature. The heat-medium heating apparatus as described.