Thermal equipment

Abstract

To provide a technique which enables a heat pump to operate stably and continuously.SOLUTION: A control section can execute first operation to heat liquid by operating a heat pump at first power consumption and second operation to heat the liquid by operating the heat pump at second power consumption which is larger than the first power consumption. The control section can also set a normal mode without setting an upper limit value for power consumption of the heat pump and a restrained mode with the upper limit value set for the power consumption. In the restrained mode, the upper limit value for the power consumption of the heat pump is set based on the power consumption of an element other than the heat pump in thermal equipment and the heat pump is operated at the power consumption of the heat pump less than the set upper limit value. When setting the upper limit value for the power consumption of the heat pump to a value less than a predetermined standard value in the restrained mode, execution of the second operation may be prohibited.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The technology disclosed in this specification relates to thermal equipment. [Background technology]

[0002] Patent Document 1 discloses a hot water supply system. The hot water supply system of Patent Document 1 includes a heat pump type heating section that heats up the hot water in the hot water storage tank, and an auxiliary heating section that can heat the hot water supplied from the hot water storage tank to the hot water outlet section. The hot water supply system of Patent Document 1 can perform a heat pump only operation in which the hot water in the hot water storage tank is heated by the heat pump type heating section, and an auxiliary heating combined operation in which the hot water in the hot water storage tank is heated and the auxiliary heating section heats the hot water simultaneously when the amount of heat is insufficient only by the heat pump type heating section. The heat pump only operation includes a first mode of heating and a second mode of heating, which have different heating capacities. The heating capacity of the heating in the first mode is higher than the heating capacity of the heating in the second mode, and the heat pump efficiency of the heating in the first mode is lower than the heat pump efficiency of the heating in the second mode. In the hot water supply system of Patent Document 1, under certain conditions where a large amount of hot water is expected to be produced or where a large amount of hot water is already produced and therefore heating in the second mode is likely to result in a lack of heat, heating in the first mode is performed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-27740 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a thermal device equipped with a heat pump, when a mode with a high heating capacity of the heat pump is set, the power consumption of the heat pump increases, which may cause a breaker to trip and the heat pump to stop unexpectedly. For example, in a situation where the power consumption of elements other than the heat pump in a thermal device connected to the branch wiring of a distribution board is high, the power consumption of the entire thermal device increases, increasing the possibility that the heat pump will stop unexpectedly. This specification provides a technology that can keep the heat pump operating stably. [Means for solving the problem]

[0005] In a first aspect of the present technology, a thermal device includes a heat pump that heats a liquid, and a control unit that controls the heat pump. The control unit is capable of executing a first operation in which the heat pump is operated at a first power consumption to heat a liquid, and a second operation in which the heat pump is operated at a second power consumption higher than the first power consumption to heat a liquid, and is capable of setting a normal mode in which an upper limit value of the power consumption of the heat pump is not set, and a suppression mode in which an upper limit value of the power consumption of the heat pump is set, and in the suppression mode, an upper limit value of the power consumption of the heat pump is set according to power consumption of elements other than the heat pump in the thermal device, and the heat pump is operated so that the power consumption of the heat pump is less than the set upper limit value. When the suppression mode is set, if the upper limit value of the power consumption of the heat pump is set to less than a predetermined reference value, the control unit may prohibit execution of the second operation.

[0006] According to this configuration, by prohibiting execution of the second operation when the upper limit value of the heat pump's power consumption is set below a predetermined reference value, it is possible to prevent the second operation from being executed in a situation where the upper limit value of the heat pump's power consumption is low. This makes it possible to prevent the heat pump from stopping unexpectedly due to high power consumption of the heat pump. For example, it is possible to prevent the heat pump from stopping due to a breaker tripping. As a result, it is possible to keep the heat pump operating stably.

[0007] In a second aspect, in the above first aspect, the control unit may lift the prohibition of the second operation when a predetermined lifting condition is satisfied after prohibiting execution of the second operation.

[0008] According to this configuration, by canceling the prohibition of the second operation, the second operation with high power consumption can be executed again. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram showing a schematic configuration of a storage type water heater according to an embodiment of the present invention. [Diagram 2] 11 is a flowchart of a second boiling operation process in the embodiment. [Diagram 3] 13 is a flowchart of a second boiling operation process in a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] (Storage type water heater 104) As shown in FIG. 1, a storage type water heater 104 (an example of thermal equipment) of the embodiment includes an HP (heat pump) unit 4, a tank unit 6, and a burner unit 8.

[0011] (HP unit 4) The HP unit 4 is a heat source that uses electric power to absorb heat from outside air and heat water (an example of a liquid). The HP unit 4 includes an HP heat source 17 that includes a compressor 10, a condenser 12, an expansion valve 14, and an evaporator 16. The HP unit 4 absorbs heat from outside air and heats water by circulating a refrigerant (e.g., a fluorocarbon-based refrigerant) through the compressor 10, the condenser 12, the expansion valve 14, and the evaporator 16 in that order. The compressor 10 pressurizes the refrigerant to make it high temperature and high pressure. The condenser 12 cools the refrigerant by heat exchange with water. An HP forward path 19 and an HP return path 21 are connected to both ends of the water flow path of the condenser 12, respectively. The expansion valve 14 depressurizes the refrigerant to make it low temperature and low pressure. The evaporator 16 heats the refrigerant by heat exchange with outside air. The HP unit 4 further includes a circulation pump 18 that circulates water through the condenser 12, a feed thermistor 20 that detects the temperature of the water flowing into the condenser 12, a return thermistor 22 that detects the temperature of the water flowing out of the condenser 12, an outdoor air temperature thermistor 23 that detects the outdoor air temperature, and an HP controller 24 that controls the operation of each component of the HP unit 4.

[0012] The HP unit 4 of the storage type water heater 104 is configured to be electrically connected to, for example, a first outdoor outlet. The HP unit 4 is indirectly connected to one branch wiring of an indoor distribution board via the first outdoor outlet. For example, the power plug of the HP unit 4 is inserted into the first outdoor outlet. In this configuration, power is supplied to the HP unit 4 via the first outdoor outlet, and the HP unit 4 operates using that power.

[0013] The tank unit 6 of the storage type water heater 104 is configured to be electrically connected to, for example, a second outdoor outlet. The tank unit 6 is indirectly connected to one branch wiring of an indoor distribution board via the second outdoor outlet. For example, the power plug of the tank unit 6 is inserted into the second outdoor outlet. In this configuration, power is supplied to the tank unit 6 via the second outdoor outlet, and the tank unit 6 operates using that power.

[0014] (Tank Unit 6) The tank unit 6 includes a tank 30, a mixing valve 32, and a bypass control valve 34. The tank 30 is a sealed container that is covered with a heat insulating material on the outside and stores water inside. The capacity of the tank 30 in this embodiment is, for example, 100 liters. When the circulation pump 18 of the HP unit 4 is driven, the water at the bottom of the tank 30 is sent to the condenser 12 via the tank forward path 31 and the HP forward path 19. The water heated in the condenser 12 and heated to a high temperature is returned from the top of the tank 30 to the inside of the tank 30 via the HP return path 21 and the tank return path 33. When the water heated by the HP unit 4 flows into the tank 30, a temperature stratification is formed inside the tank 30, in which a layer of high temperature water is piled up on a layer of low temperature water. The tank 30 is equipped with an upper thermistor 36 that detects the temperature of the upper water, an intermediate thermistor 37 that detects the temperature of the intermediate water, and a lower thermistor 38 that detects the temperature of the lower water.

[0015] Tap water is supplied to the tank unit 6 via a water supply path 40. A pressure reducing valve 42 for reducing the water supply pressure and a water inlet thermistor 44 for detecting the water supply temperature are attached to the water supply path 40. The water supply path 40 branches into a tank water supply path 46 that communicates with the bottom of the tank 30 and a tank bypass path 48 that communicates with the mixing valve 32. Check valves 50 and 52 are attached to the tank water supply path 46 and the tank bypass path 48, respectively. A water-side water volume sensor 54 for detecting the flow rate of tap water flowing into the mixing valve 32 is attached to the tank bypass path 48. The top of the tank 30 and the mixing valve 32 are connected via a tank hot water outlet path 56. A check valve 58 and a hot water volume sensor 60 for detecting the flow rate of water from the tank 30 that flows into the mixing valve 32 are attached to the tank hot water outlet path 56.

[0016] The mixing valve 32 mixes tap water flowing in from the tank bypass path 48 and water from the tank 30 flowing in from the tank hot water outlet path 56, and sends the mixed water to a first hot water supply path 62. The mixing valve 32 drives a valve body by a stepping motor (not shown) and adjusts the opening degree on the tank bypass path 48 side (opening degree on the water side) and the opening degree on the tank outlet path 56 side (opening degree on the hot water side). A mixing thermistor 64 that detects the temperature of the water sent out from the mixing valve 32 is attached to the first hot water supply path 62.

[0017] Hot water is supplied from the tank unit 6 to hot water supply locations such as a kitchen, a shower, and a faucet via a second hot water supply path 66. A hot water supply outlet thermistor 68 for detecting the temperature of water supplied to the hot water supply location, and a check valve 70 are attached to the second hot water supply path 66. The first hot water supply path 62 and the second hot water supply path 66 are connected by a hot water supply bypass path 72. A bypass control valve 34 is attached to the hot water supply bypass path 72. The tank unit 6 further includes a tank controller 74 for controlling the operation of each component of the tank unit 6. The tank controller 74 includes a memory 76 for storing predetermined information.

[0018] (Burner unit 8) The burner unit 8 includes a burner 80, a heat exchanger 82, a bypass servo 84, a water volume servo 86, and a water filling valve 88. The burner 80 is an auxiliary heat source device that heats water flowing through the heat exchanger 82 by burning fuel gas (e.g., city gas). Fuel gas is supplied to the burner 80 through a gas supply pipe (not shown). Water flows into the heat exchanger 82 from the first hot water supply path 62 of the tank unit 6 through a burner forward path 90. The water that has passed through the heat exchanger 82 flows out to the second hot water supply path 66 of the tank unit 6 through a burner return path 92. The burner forward path 90 is equipped with a water volume servo 86 that adjusts the flow rate of water flowing through the burner forward path 90 and a water volume sensor 91 that detects the flow rate of water flowing through the burner forward path 90. The burner forward path 90 and the burner return path 92 are connected through a burner bypass path 94. A bypass servo 84 is attached to the connection between the burner outward path 90 and the burner bypass path 94. The bypass servo 84 adjusts the flow rate of water flowing from the burner outward path 90 to the burner bypass path 94. A burner hot water thermistor 96 that detects the temperature of the water flowing out from the heat exchanger 82 is attached to the burner return path 92. A water filling path 98 branches off from the burner return path 92. A water filling valve 88 is attached to the water filling path 98. Water is filled into the bathtub, which is the hot water supply point, from the burner unit 8 via the water filling path 98.

[0019] The burner unit 8 further includes a burner controller 97 and a remote control 99 capable of communicating with the burner controller 97. The burner controller 97 controls the operation of each component of the burner unit 8. The remote control 99 accepts various operational inputs from the user via switches, buttons, etc. The remote control 99 also notifies the user of various information related to the settings and operation of the storage type water heater 104 by display and voice.

[0020] The HP controller 24, the tank controller 74, the burner controller 97, and the remote control 99 each include a control unit such as a CPU, a ROM, and a RAM, and a storage unit such as an EEPROM, and the control unit executes various processes according to the programs stored in the storage unit. The HP controller 24 and the tank controller 74 can communicate with each other. The tank controller 74 and the burner controller 97 can communicate with each other. Therefore, the HP controller 24, the tank controller 74, and the burner controller 97 cooperate to perform control, and the hot water storage type water heater 104 can perform various operations such as boiling operation and hot water supply operation. Hereinafter, the HP controller 24, the tank controller 74, and the burner controller 97 are collectively referred to simply as controllers (an example of a control unit).

[0021] (Boiling operation) In the boiling operation, the storage type water heater 104 drives the HP unit 4 to heat the water in the tank 30. When the boiling operation is started, the controller drives the compressor 10 of the HP heat source 17 to circulate the refrigerant through the compressor 10, the condenser 12, the expansion valve 14, and the evaporator 16 in that order, and drives the circulation pump 18 to circulate the water between the tank 30 and the condenser 12. As a result, the water sucked out from the bottom of the tank 30 is heated to the boiling target temperature in the condenser 12 and returned to the top of the tank 30. When the temperature detected by the forward thermistor 20 reaches the boiling target temperature, the controller determines that all the water in the tank 30 has been replaced with water heated to the boiling target temperature, and ends the boiling operation.

[0022] (First boiling operation, second boiling operation) The first boiling operation is an operation in which the HP unit 4 operates at a first power consumption during boiling operation. The HP unit 4 operates at the first power consumption to heat the water in the tank 30. The first power consumption is the power consumption of the entire HP unit 4. The HP unit 4 consumes power, for example, in the compressor 10 and the circulation pump 18. In the first boiling operation, the controller operates the HP unit 4 such that the power consumption of the HP unit 4 becomes the first power consumption.

[0023] The second boiling operation is an operation in which the HP unit 4 operates at a second power consumption during the boiling operation. The HP unit 4 operates at the second power consumption to heat the water in the tank 30. The second power consumption is greater than the first power consumption. Therefore, the heating capacity of the second boiling operation is higher than the heating capacity of the first boiling operation. The second boiling operation is sometimes called a high capacity operation or a maximum capacity operation. The second power consumption is the power consumption of the entire HP unit 4. The HP unit 4 consumes power, for example, in the compressor 10 and the circulation pump 18. In the second boiling operation, the controller operates the HP unit 4 so that the power consumption of the HP unit 4 is the second power consumption.

[0024] In the storage type hot water heater 104, in the boiling operation, either a first boiling operation or a second boiling operation is executed. The first boiling operation is executed periodically, for example. Specifically, the controller executes the first boiling operation when a predetermined boiling execution time arrives. The controller may also execute the first boiling operation when a user inputs an instruction to execute the first boiling operation.

[0025] The second boiling operation is performed, for example, when a large amount of hot water flows out of the tank 30 as a result of the bathtub being filled with hot water. The second boiling operation is also performed, for example, when the amount of hot water stored in the tank 30 is small. Specifically, the controller performs the second boiling operation when the flow rate detected by the hot water side water level sensor 60 is equal to or greater than a predetermined reference flow rate. The controller performs the second boiling operation when the temperature detected by the upper thermistor 36 is lower than the hot water supply set temperature. The controller may also perform the second boiling operation when an instruction to perform the second boiling operation is input by a user operation.

[0026] The second boiling operation is executed in preference to the first boiling operation. For example, when the execution condition of the second boiling operation is satisfied while the first boiling operation is being executed, the controller stops the first boiling operation and executes the second boiling operation in preference.

[0027] (Hot water supply operation) In hot water supply operation, water at the set hot water supply temperature is supplied to the hot water supply location. The set hot water supply temperature is a temperature set by the user. When the combined flow rate (also called the hot water supply flow rate) of the flow rate detected by the water-side water flow sensor 54 and the hot water-side water flow sensor 60 reaches or exceeds the minimum operating flow rate, the controller determines that hot water supply to the hot water supply location has started by opening the faucet or filling the bathtub with water. Depending on the temperature detected by the upper thermistor 36, the controller executes the following non-combustion hot water supply operation or combustion hot water supply operation.

[0028] The controller executes non-combustion hot water supply operation when the temperature detected by the upper thermistor 36 is equal to or higher than the hot water supply set temperature. In non-combustion hot water supply operation, the controller prohibits the combustion operation of the burner 80 and adjusts the opening of the mixing valve 32 so that the temperature detected by the mixing thermistor 64 becomes the hot water supply set temperature. As a result, water whose temperature has been adjusted to the hot water supply set temperature is supplied to the hot water supply location.

[0029] Moreover, when the temperature detected by the upper thermistor 36 is lower than the hot water supply set temperature, the controller executes the combustion hot water supply operation. In the combustion hot water supply operation, the controller permits the combustion operation of the burner 80 and adjusts the opening of the mixing valve 32 so that the temperature detected by the mixing thermistor 64 is lower than the hot water supply set temperature by the minimum heating capacity of the burner 80. In this case, high-temperature water supplied from the upper part of the tank 30 and low-temperature water supplied from the water supply path 40 are mixed in the mixing valve 32, heated to the hot water supply set temperature by the burner 80, and supplied to the hot water supply location. The controller adjusts the heating capacity of the burner 80 so that the water heated by the burner 80 becomes the hot water supply set temperature. The combustion hot water supply operation also includes a case where the mixing valve 32 is fully closed on the tank 30 side. That is, a case where water is not supplied from the tank 30 and only the water supplied from the water supply path 40 is heated by the burner 80 is also included.

[0030] If the hot water flow rate falls below the minimum operating flow rate while the above-mentioned non-combustion hot water supply operation or combustion hot water supply operation is being performed, the controller determines that hot water supply to the hot water supply point has ended due to the faucet being closed or the bathtub being filled with water, for example, and ends the hot water supply operation.

[0031] (Normal mode, Suppression mode) The normal mode is a mode in which no upper limit is set for the power consumption of the HP unit 4. In boiling operation in the normal mode, the storage type water heater 104 heats the water in the tank 30 in a state in which no upper limit is set for the power consumption of the HP unit 4. In the normal mode, the storage type water heater 104 is capable of performing a first boiling operation and a second boiling operation.

[0032] The suppression mode is a mode in which an upper limit value of the power consumption of the HP unit 4 is set. In the boiling operation in the suppression mode, the storage type water heater 104 heats the water in the tank 30 in a state in which an upper limit value of the power consumption of the HP unit 4 is set. The upper limit value of the power consumption of the HP unit 4 in the suppression mode can be changed. For example, the controller changes the setting of the upper limit value of the power consumption of the HP unit 4 in the suppression mode according to the power consumption of the tank unit 6 and the power consumption of the burner unit 8. For example, the controller changes the setting of the power value obtained by subtracting the power consumption of the tank unit 6 and the power consumption of the burner unit 8 from the allowable power that is set in advance below the capacity of the breaker as the upper limit value of the power consumption of the HP unit 4. The controller changes the upper limit value of the power consumption of the HP unit 4 at a predetermined time interval (for example, 10 second intervals), for example. The controller may change the upper limit value of the power consumption of the HP unit 4 in the suppression mode, for example, every time the power consumption of the tank unit 6 and / or the power consumption of the burner unit 8 changes.

[0033] The storage type hot water heater 104 can execute the first boiling operation and the second boiling operation within a limited range in the suppression mode. When executing the first boiling operation in the suppression mode, the controller controls the operation of the HP unit 4 so that the first power consumption of the HP unit 4 is less than a set upper limit value.

[0034] Furthermore, in the suppression mode, the storage type water heater 104 can execute the second boiling operation only when the set upper limit value of the power consumption of the HP unit 4 is equal to or greater than a predetermined reference value. The predetermined reference value is a value equal to or greater than the second power consumption of the HP unit 4. When executing the second boiling operation in the suppression mode, the controller controls the operation of the HP unit 4 so that the power consumption of the HP unit 4 is less than the set upper limit value (an upper limit value equal to or greater than the predetermined reference value).

[0035] On the other hand, in the suppression mode, the storage type water heater 104 cannot execute the second boiling operation if the set upper limit value of the power consumption of the HP unit 4 is less than the predetermined reference value. The controller prohibits execution of the second boiling operation if the set upper limit value of the power consumption of the HP unit 4 is less than the predetermined reference value.

[0036] The controller sets either a normal mode or a suppression mode in controlling the storage type hot water heater 104. For example, when the HP unit 4 and the tank unit 6 are connected to one branch wiring of the same distribution board, the controller sets the suppression mode when the power consumption of the tank unit 6 increases. On the other hand, the controller sets the normal mode when the HP unit 4 is connected to a dedicated branch wiring (i.e., when the HP unit 4 and the tank unit 6 are connected to different branch wiring). In a modified example, the controller sets the normal mode when the storage type hot water heater 104 is connected to a storage battery and the amount of electricity stored in the storage battery is equal to or greater than a predetermined reference amount. On the other hand, the controller sets the suppression mode when the amount of electricity stored in the storage battery is less than a predetermined reference amount. When the controller sets the normal mode, for example, the controller generates information indicating that the normal mode is set (for example, a normal mode flag) and stores it in the memory 76 of the tank controller 74. When the controller sets the suppression mode, for example, the controller generates information indicating that the suppression mode is set (for example, a suppression mode flag) and stores it in the memory 76.

[0037] In a modified example, the controller may set the suppression mode in accordance with the power supply and demand situation at the power company. Also, for example, when a device other than the storage type water heater 104 is connected to the storage battery, the controller may set the suppression mode in the storage type water heater 104 in order to supply power to the other device. Also, the controller may set the suppression mode in the storage type water heater 104 in accordance with an instruction from a user or the operating status of the storage type water heater 104, regardless of the power supply and demand situation at the power company or the charge status of the storage battery.

[0038] (Second boiling operation process; Figure 2) Next, the second boiling operation process executed by the controller will be described. The second boiling operation process is started, for example, when the power supply of the storage type hot water heater 104 is turned on. As shown in FIG. 2, in S12 of the second boiling operation process, the controller monitors whether or not an instruction to execute the second boiling operation is input. The instruction to execute the second boiling operation is input to the controller, for example, when the flow rate detected by the hot water side water amount sensor 60 is equal to or higher than a predetermined reference flow rate. In a modified example, the instruction to execute the second boiling operation may be input to the controller when the temperature detected by the upper thermistor 36 is lower than the hot water supply set temperature. Also, the instruction to execute the second boiling operation may be input to the controller by a user operation. When the instruction to execute the second boiling operation is input to the controller (YES in S12), the process proceeds to S14. When the instruction to execute the second boiling operation is not input (NO in S12), the process of S12 continues.

[0039] In S14, the controller determines whether or not suppression mode is set in the storage type hot water heater 104. The suppression mode is a mode in which an upper limit value for power consumption of the HP unit 4 is set. The controller determines that the suppression mode is set, for example, if a suppression mode flag exists in the memory 76 of the tank controller 74. If the suppression mode is set (YES in S14), the process proceeds to S16. On the other hand, if the suppression mode is not set (NO in S14), the process proceeds to S30. In this embodiment, if the suppression mode is not set, the normal mode is set.

[0040] In S30 after NO in S14, the controller permits the storage type water heater 104 to perform the second boiling operation, and performs the second boiling operation. The controller operates the HP unit 4 at a second power consumption that is greater than the first power consumption.

[0041] In S16 after YES in S14, the controller determines whether or not the upper limit of power consumption of the HP unit 4 set in suppression mode is equal to or greater than a predetermined reference value. If the upper limit of power consumption of the HP unit 4 set in suppression mode is equal to or greater than the predetermined reference value (YES in S16), the process proceeds to S18. On the other hand, if the upper limit of power consumption of the HP unit 4 set in suppression mode is less than the predetermined reference value (NO in S16), the process proceeds to S22.

[0042] In S18 after YES in S16, the controller permits storage type water heater 104 to perform the second boiling operation, and performs the second boiling operation. When performing the second boiling operation, the controller operates HP unit 4 such that the second power consumption of HP unit 4 is less than the upper limit value set in the suppression mode.

[0043] In the next step S20, the controller determines whether or not the upper limit value of the power consumption of the HP unit 4 set in the suppression mode is less than a predetermined reference value. The controller sets the upper limit value of the power consumption of the HP unit 4 in the suppression mode, for example, according to the power consumption of the tank unit 6 and the power consumption of the burner unit 8. Therefore, the upper limit value of the power consumption of the HP unit 4 set in the suppression mode may fluctuate. If the upper limit value of the power consumption of the HP unit 4 set in the suppression mode is less than the predetermined reference value (YES in S20), the process proceeds to S22. If not, that is, if the state in which the upper limit value of the power consumption of the HP unit 4 set in the suppression mode is equal to or greater than the predetermined reference value is maintained (NO in S20), the process returns to S18.

[0044] In S22 after YES in S20 or NO in S16, the controller prohibits the second boiling operation from being performed in the suppression mode. Therefore, the hot water storage type water heater 104 does not perform the second boiling operation (if the second boiling operation is already being performed, the second boiling operation being performed is stopped).

[0045] In S22, the controller may execute the first boiling operation instead of the second boiling operation. When executing the first boiling operation, the controller operates the HP unit 4 so that the first power consumption of the HP unit 4 is less than the upper limit value set in the suppression mode.

[0046] In the next S24, the controller judges whether or not a predetermined cancellation condition is satisfied. For example, the controller judges that the predetermined cancellation condition is satisfied when a predetermined time (e.g., 2:00) of a day arrives. In a modified example, the controller judges that the predetermined cancellation condition is satisfied when a predetermined time (e.g., 12 hours) has elapsed since the second boiling operation was prohibited in S22 above. The controller may also calculate the end time of hot water supply use for a day by learning or the like, and judge that the cancellation condition is satisfied when that time arrives. If the predetermined cancellation condition is satisfied (YES in S24), the process proceeds to S26. If the predetermined cancellation condition is not satisfied (NO in S24), the processes of S22 and S24 are continued.

[0047] In S26 after YES in S24, the controller cancels the prohibition of the second boiling operation set in S22. In S26, the controller may resume the second boiling operation. After S26, the process returns to S12.

[0048] The storage type water heater 104 of the embodiment has been described above. As described above, in the storage type water heater 104, the controller is configured to set an upper limit value of the power consumption of the HP unit 4 in the suppression mode according to the power consumption of elements other than the heat pump (for example, the tank unit 6 and the burner unit 8), and to operate the HP unit 4 so that the power consumption of the HP unit 4 is less than the set upper limit value. When setting the suppression mode, if the upper limit value of the power consumption of the HP unit 4 is set to less than a predetermined reference value, the controller prohibits the execution of the second operation (see S22 in FIG. 2).

[0049] According to this configuration, by prohibiting execution of the second operation when the upper limit value of the power consumption of the HP unit 4 is set to less than a predetermined reference value, it is possible to prevent the second operation from being executed in a situation where the upper limit value of the power consumption of the HP unit 4 is low. This makes it possible to prevent the HP unit 4 from unexpectedly stopping due to high power consumption of the HP unit 4. For example, it is possible to prevent the HP unit 4 from stopping due to tripping of a breaker in a distribution board. As a result, it is possible to keep the HP unit 4 operating stably.

[0050] Furthermore, if a predetermined cancellation condition is satisfied after prohibiting the execution of the second operation, the control unit cancels the prohibition of the second operation (see S26 in FIG. 2). According to this configuration, by canceling the prohibition of the second operation, the second operation with high power consumption can be executed again.

[0051] (Modification) (1) The above technology can also be applied to thermal equipment (for example, heating equipment) other than the storage type water heater 104. In this case, the HP unit 4 is used, for example, to heat a liquid for heating (for example, antifreeze liquid).

[0052] (2) The storage type water heater 104 may have one or more modes other than the normal mode and the suppression mode. The controller may be capable of performing boiling operation in the normal mode, the suppression mode, and one or more modes other than those.

[0053] (3) As shown in FIG. 3, in the second boiling operation process of the modified example, if the predetermined cancellation condition is not met in S24 (NO in S24), the process may return to S14, and the process after S14 may be executed.

[0054] Although each embodiment has been described in detail above, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and variations of the specific examples exemplified above. The technical elements described in this specification or drawings exhibit technical utility alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or drawings can achieve multiple objectives simultaneously, and achieving one of these objectives is itself technically useful. [Explanation of symbols]

[0055] 4:HP unit 6: Tank unit 8: Burner unit 17: HP heat source 30: Tank 80: Burner 104: Storage water heater

Claims

1. A heat pump for heating a liquid; A thermal device comprising a control unit for controlling the heat pump, The control unit is a first operation in which the heat pump is operated at a first power consumption to heat a liquid; a second operation in which the heat pump is operated at a second power consumption greater than the first power consumption to heat a liquid; and a normal mode in which an upper limit value of the power consumption of the heat pump is not set; A suppression mode that sets an upper limit value of the power consumption of the heat pump; In the suppression mode, an upper limit value of the power consumption of the heat pump is set according to the power consumption of elements other than the heat pump in the thermal equipment, and the heat pump is operated so that the power consumption of the heat pump is less than the set upper limit value, When the suppression mode is set, if an upper limit value of power consumption of the heat pump is set to less than a predetermined reference value, the thermal equipment prohibits execution of the second operation.

2. The thermal device according to claim 1 , wherein the control unit is configured to cancel the prohibition of the second operation when a predetermined cancel condition is satisfied after prohibiting the execution of the second operation.

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