Hot water supply system
The hot water supply system addresses excessive power consumption by prioritizing water heating over anti-freeze operations and using a control device to manage energy efficiency and power usage, ensuring efficient energy use and anti-freeze protection.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- RINNAI CORP
- Filing Date
- 2022-09-06
- Publication Date
- 2026-06-04
Smart Images
Figure 0007870227000001 
Figure 0007870227000002 
Figure 0007870227000003
Abstract
Description
Technical Field
[0001] The technology disclosed in this specification relates to a hot water supply system.
Background Art
[0002] Patent Document 1 discloses a hot water supply system connected to a bathtub, comprising a heat pump for heating water, a tank for storing the water heated by the heat pump, a combustion heating device for burning fuel to heat the water, an electric heater for heating a pipe through which the water flows, the heat pump, the combustion heating device, and a control device for controlling the operations of the heat pump, the combustion heating device, and the electric heater. The control device is capable of performing a boiling-up operation of heating the water by the heat pump and storing the heated water in the tank, a hot water filling operation of supplying the water stored in the tank to the bathtub and supplying the water heated by the combustion heating device to the bathtub, and a freeze prevention operation of heating the pipe by the electric heater.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] For example, in a house where a hot water supply system is installed, a contract power is set with an electric power company. If the total power consumption of the house exceeds the contract power, problems such as a higher electricity bill will occur. Therefore, there may be a case where it is desired to suppress the excessive power consumption of the hot water supply system in order to keep the total power consumption of the house below the contract power. This specification provides a technology capable of suppressing the excessive power consumption of the hot water supply system.
Means for Solving the Problems
[0005] In a first aspect of this technology, the hot water supply system includes a heat pump for heating water, a tank for storing the water heated by the heat pump, a combustion heating device for heating the water by burning fuel, an electric heater for heating the pipes through which the water flows, and a control device for controlling the operation of the heat pump, the combustion heating device, and the electric heater. The control device is capable of performing a boiling operation in which the heat pump heats the water and stores the heated water in the tank, a filling operation in which the water stored in the tank is supplied to the bathtub and the water heated by the combustion heating device is supplied to the bathtub, and an anti-freeze operation in which the electric heater heats the pipes. The control device performs the boiling operation in conjunction with the filling operation, and when the situation in which the boiling operation in conjunction with the filling operation should be performed and the situation in which the anti-freeze operation should be performed overlap, the control device prioritizes the execution of the boiling operation, thereby preventing the boiling operation and the anti-freeze operation from being performed simultaneously.
[0006] Generally, the energy efficiency of a heat pump is superior to that of a combustion heating device. Therefore, during bath filling, water stored in the tank is preferentially supplied to the bathtub. However, if the tank capacity is relatively small (e.g., 70L), there is a risk of running out of hot water in the tank during bath filling, which requires a relatively large amount of hot water (e.g., 200L). If the tank runs out of hot water, water heated by the combustion heating device is supplied to the bathtub to compensate. With the above configuration, running a water heating operation in conjunction with the bath filling operation can suppress the running out of hot water in the tank and reduce fuel consumption in the combustion heating device. As a result, the energy efficiency of the hot water supply system during bath filling can be improved. However, with this configuration, if the water heating operation and the anti-freeze operation associated with the bath filling operation are performed simultaneously, the heat pump and electric heater will operate at the same time, which may lead to excessive power consumption of the hot water supply system. According to the above configuration, the water heating operation associated with the bath filling operation is given priority, and it is prohibited to perform the water heating operation and the freeze prevention operation simultaneously. Therefore, it is prohibited for the heat pump and electric heater to operate at the same time. This improves the energy efficiency of the hot water supply system during the bath filling operation and prevents the hot water supply system from consuming excessive power.
[0007] In a second aspect of this technology, in the first aspect described above, the control device may specify the time at which the hot water filling operation is scheduled to start as the hot water filling start time, and may prohibit the start of the freeze prevention operation prior to the hot water filling start time so that the freeze prevention operation is not running at the hot water filling start time.
[0008] If the anti-freeze operation is running when the bath filling operation starts, it is necessary to interrupt the ongoing anti-freeze operation in order to prioritize the water heating operation that accompanies the bath filling operation. Interrupting the ongoing anti-freeze operation results in wasted electricity consumed by that operation. With the above configuration, it is possible to avoid the anti-freeze operation being running when the bath filling operation starts. This prevents the interruption of the ongoing anti-freeze operation and avoids wasting electricity.
[0009] In a third aspect of this technology, in the second aspect described above, the control device may determine the start time of the hot water filling operation based on past operating records of the hot water filling operation.
[0010] One way to determine the start time for filling the bathtub is to have the user input the start time. However, this method requires the user to input the start time, which is inconvenient for the user. With the above configuration, the control device determines the start time for filling the bathtub based on past operating records of the bathtub filling operation. Therefore, the user does not need to input the start time, which improves user convenience.
[0011] In a fourth aspect of this technology, in any one of the first to third aspects described above, the water heating operation may include a normal water heating operation in which the output of the heat pump is set to a first output, and a high-output water heating operation in which the output of the heat pump is set to a second output higher than the first output. The water heating operation performed independently of the hot water filling operation may be the normal water heating operation. The water heating operation performed in conjunction with the hot water filling operation may be the high-output water heating operation. The control device may allow the normal water heating operation and the freeze prevention operation to be performed simultaneously, and may prohibit the high-output water heating operation and the freeze prevention operation from being performed simultaneously.
[0012] In the above configuration, a high-power heating operation is provided in conjunction with the bath filling operation to further improve the energy efficiency of the hot water supply system during the bath filling operation. During the high-power heating operation, the heat pump consumes a relatively large amount of power. Therefore, if the electric heater is operated during the high-power heating operation, the power consumption of the hot water supply system may become excessive. On the other hand, during the normal heating operation, which is not associated with the bath filling operation, the heat pump consumes a relatively small amount of power. Therefore, even if the electric heater is operated during the normal heating operation, the power consumption of the hot water supply system is unlikely to become excessive. If the anti-freeze operation were prohibited not only during the high-power heating operation but also during the normal heating operation, the time period during which the anti-freeze operation can be performed would be excessively limited, making it impossible to properly prevent the pipes from freezing. According to the above configuration, the anti-freeze operation is prohibited during the high-power heating operation, and is permitted during the normal heating operation. Therefore, it is possible to properly prevent the pipes from freezing while suppressing excessive power consumption of the hot water supply system.
[0013] In a fifth aspect of this technology, in any one of the first to fourth aspects described above, the hot water supply system may have a normal mode and a power suppression mode in which it operates at a suppression power lower than or equal to the maximum power consumption in the normal mode. The control device may, in the normal mode, allow the heating operation and the freeze prevention operation associated with the hot water filling operation to be performed simultaneously, and may, in the power suppression mode, prohibit the heating operation and the freeze prevention operation associated with the hot water filling operation from being performed simultaneously.
[0014] In power reduction mode, due to the setting of the reduced power, if the water heating operation and freeze prevention operation associated with the bath filling operation are performed simultaneously, there is a high possibility that the power consumption of the hot water supply system will exceed the reduced power. With the above configuration, in power reduction mode, the water heating operation associated with the bath filling operation takes priority, and the simultaneous execution of the water heating operation and freeze prevention operation is prohibited. Therefore, even in power reduction mode, the water heating operation associated with the bath filling operation can be performed. This prevents the power consumption of the hot water supply system from exceeding the reduced power, prevents the tank from running out of hot water, and reduces fuel consumption in the combustion heating device. As a result, the energy efficiency of the hot water supply system during bath filling operation can be improved.
[0015] In this specification, the power consumed per unit time by an electrical device is referred to as "power consumption." Power consumption is expressed, for example, in VA (volt-amperes). The energy generated per unit time by an electrical device through power consumption is referred to as "output." For example, the heating capacity of a heat pump is called the output of the heat pump. Output is expressed, for example, in W (watts). The product of power consumption and the operating time of the electrical device is called "energy consumption." Energy consumption is expressed, for example, in Wh (watt-hours). [Brief explanation of the drawing]
[0016] [Figure 1] This diagram schematically shows the configuration of the hot water supply system 2 according to the embodiment. [Figure 2] This diagram schematically shows an example of the operating history (time when the bath filling operation started) for a specific household over the past 7 days, stored in the non-volatile memory 75 of the hot water supply system 2 according to the embodiment. [Figure 3] This is a flowchart of the first hot water filling adaptation process executed by the controller of the hot water supply system 2 according to the embodiment. [Figure 4] This is a part of the flowchart for the second bath filling adaptation process performed by the controller of the hot water supply system 2 according to the embodiment. [Figure 5]It is a part of the flowchart of the second hot water draining adaptation process executed by the controller of the hot water supply system 2 according to the embodiment. [Figure 6] It is a part of the flowchart of the second hot water draining adaptation process executed by the controller of the hot water supply system 2 according to the embodiment. [Figure 7] It is the flowchart of the freeze prevention operation start reception process executed by the controller of the hot water supply system 2 according to the embodiment. [Figure 8] It is a diagram showing an example of the time transition of the power consumption of the hot water supply system 2 when the hot water supply system 2 according to the embodiment is in the normal mode. [Figure 9] It is a diagram showing an example of the time transition of the power consumption of the hot water supply system 2 when the hot water supply system 2 according to the embodiment is in the power suppression mode.
Mode for Carrying Out the Invention
[0017] (Embodiment) As shown in FIG. 1, the hot water supply system 2 according to the present embodiment includes a HP (heat pump) unit 4, a tank unit 6, and a burner unit 8.
[0018] HP Unit 4 is a heat source that heats water by absorbing heat from the outside air. HP Unit 4 is equipped with a compressor 10, a condenser 12, an expansion valve 14, and an evaporator 16. HP Unit 4 heats water by absorbing heat from the outside air by circulating a refrigerant (e.g., a fluorocarbon refrigerant) in the order of compressor 10, condenser 12, expansion valve 14, and evaporator 16. The compressor 10 pressurizes the refrigerant to high temperature and high pressure. The condenser 12 cools the refrigerant by heat exchange with water. HP supply path 19 and HP return path 21 are connected to both ends of the water flow path of the condenser 12, respectively. The expansion valve 14 reduces the pressure of the refrigerant to low temperature and low pressure. The evaporator 16 heats the refrigerant by heat exchange with the outside air. The HP unit 4 further includes a circulation pump 18 for circulating water to the condenser 12, an HP supply thermistor 20 for detecting the temperature of the water flowing into the condenser 12, an HP return thermistor 22 for detecting the temperature of the water flowing out of the condenser 12, an HP ambient temperature thermistor 23 for detecting the ambient temperature, and an HP controller 24 for controlling the operation of each component of the HP unit 4.
[0019] The tank unit 6 includes a tank 30, a mixing valve 32, a bypass control valve 34, and a tank ambient temperature thermistor 39 for detecting ambient temperature. The tank 30 is a sealed container that stores water inside, with its exterior covered in insulating material. The capacity of the tank 30 in this embodiment is, for example, 70 L. 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 supply path 31 and the HP supply path 19. The water, heated to a high temperature in the condenser 12, is returned to the tank 30 from the top of the tank via the HP return path 21 and the tank return path 33. The tank supply path 31 and the tank return path 33 are fitted with first electric heaters 35 that consume power to heat the tank supply path 31 and the tank return path 33. When water heated by the HP unit 4 flows into the tank 30, a temperature-stratified layer is formed inside the tank 30, with a layer of high-temperature water on top of a layer of low-temperature water. The tank 30 is equipped with an upper thermistor 36 for detecting the temperature of the upper water, an intermediate thermistor 37 for detecting the temperature of the middle water, and a lower thermistor 38 for detecting the temperature of the lower water. In this embodiment, the upper thermistor 36 is located 12L from the top of the tank 30, the intermediate thermistor 37 is located 18L from the top of the tank 30, and the lower thermistor 38 is located 40L from the top of the tank 30.
[0020] The tank unit 6 is supplied with tap water via a water supply path 40. The water supply path 40 is equipped with a pressure reducing valve 42 for reducing the water supply pressure, an inlet water thermistor 44 for detecting the water supply temperature, and a first electric heater 35 that consumes power to heat 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 installed in the tank water supply path 46 and the tank bypass path 48, respectively. The tank water supply path 46 is also equipped with a first electric heater 35 that consumes power to heat the tank water supply path 46. The tank bypass path 48 is equipped with a water-side water flow sensor 54 for detecting the flow rate of tap water flowing into the mixing valve 32 and a first electric heater 35 that consumes power to heat 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. The tank hot water outlet path 56 is equipped with a check valve 58, a first electric heater 35 that consumes electricity to heat the tank hot water outlet path 56, and a hot water flow sensor 60 that detects the flow rate of water from the tank 30 into the mixing valve 32.
[0021] The mixing valve 32 mixes tap water flowing in from the tank bypass path 48 with water from the tank 30 flowing in from the tank hot water outlet path 56 and sends the mixture to the first hot water supply path 62. The mixing valve 32 is driven by a stepping motor to adjust the opening degree on the tank bypass path 48 side (opening degree on the cold water side) and the opening degree on the tank hot water outlet path 56 side (opening degree on the hot water side). A mixing thermistor 64 is installed in the first hot water supply path 62 to detect the temperature of the water sent out from the mixing valve 32. In addition, in the first hot water supply path 62, first electric heaters 35 are installed on the upstream and downstream sides of the connection between the first hot water supply path 62 and the hot water bypass path 72, respectively, to heat the first hot water supply path 62 by consuming electricity.
[0022] Hot water is supplied from the tank unit 6 to hot water supply points such as the kitchen, shower, and faucets via the second hot water supply path 66. The second hot water supply path 66 is equipped with a hot water outlet thermistor 68 for detecting the temperature of the water supplied to the hot water supply points, and a check valve 70. In addition, in the second hot water supply path 66, first electric heaters 35 are installed on the upstream and downstream sides of the connection point between the second hot water supply path 66 and the hot water bypass path 72, respectively, to heat the second hot water supply path 66 by consuming electricity. The first hot water supply path 62 and the second hot water supply path 66 are connected by the hot water bypass path 72. The hot water bypass path 72 is equipped with a bypass control valve 34 and a first electric heater 35 that consumes electricity to heat the hot water bypass path 72.
[0023] The tank unit 6 further includes a tank controller 74 and a remote control 76 that can communicate with the tank controller 74. The tank controller 74 controls the operation of each component of the tank unit 6. The tank controller 74 is equipped with non-volatile memory 75. The remote control 76 accepts various operation inputs from the user via switches, buttons, etc. The remote control 76 also notifies the user of various information regarding the settings and operation of the hot water supply system 2 through displays and voice.
[0024] The burner unit 8 includes a burner 80, a heat exchanger 82, a bypass servo 84, a water flow servo 86, a hot water supply valve 88, and a burner ambient temperature thermistor 85 for detecting ambient temperature. The burner 80 is a combustion heating device that heats the water flowing through the heat exchanger 82 by burning fuel gas. Fuel gas is supplied to the burner 80 via a gas supply pipe 81. Water from the first hot water supply path 62 of the tank unit 6 flows into the heat exchanger 82 via the 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 via the burner return path 92. The burner forward path 90 is equipped with a second electric heater 83 that consumes power to heat the burner forward path 90, a water flow servo 86 that adjusts the flow rate of water flowing through the burner forward path 90, and a water flow sensor 91 that detects the flow rate of water flowing through the burner forward path 90. The burner supply path 90 and the burner return path 92 are connected via a burner bypass path 94. A second electric heater 83 is installed in the burner bypass path 94 to heat the burner bypass path 94 by consuming power. A bypass servo 84 is installed at the connection point between the burner supply path 90 and the burner bypass path 94. The bypass servo 84 adjusts the flow rate of water from the burner supply path 90 to the burner bypass path 94. A burner hot water thermistor 96 is installed in the burner return path 92 to detect the temperature of the water flowing out of the heat exchanger 82. A hot water supply path 98 branches off from the burner return path 92. In the burner return path 92, a second electric heater 83 is installed downstream of the branch point of the hot water supply path 98 to heat the burner return path 92 by consuming power. Furthermore, in the burner return path 92, the hot water filling path 98 is equipped with a hot water filling valve 88 and a second electric heater 83 that consumes electricity to heat the hot water filling path 98. Hot water is supplied from the burner unit 8 to the bathtub, which is the hot water supply point, via the hot water filling path 98. The burner unit 8 is further equipped with a burner controller 100 that controls the operation of each component of the burner unit 8.
[0025] The HP unit 4, tank unit 6, and burner unit 8 of the hot water supply system 2 are supplied with power from the power supply unit 9. The power supply unit 9 comprises a distribution board 102, a storage battery 104, and a switch 106. The distribution board 102 is connected to the commercial power supply 108 and distributes the power supplied from the commercial power supply 108 to the switch 106 and the storage battery 104. The storage battery 104 is a secondary battery, such as a lithium-ion secondary battery. The storage battery 104 can charge the power supplied from the commercial power supply 108 via the distribution board 102, or it can discharge the charged power to the switch 106. The storage battery 104 has a built-in protection circuit (not shown) that cuts off the discharge to the switch 106 when the discharged power exceeds the upper limit discharge power (e.g., 850 VA). The switch 106 switches between a state in which it supplies power from the commercial power supply 108 via the distribution board 102 to the HP unit 4, tank unit 6, and burner unit 8, and a state in which it supplies power from the storage battery 104 to the HP unit 4, tank unit 6, and burner unit 8. When power is supplied normally from the commercial power supply 108, the switch 106 supplies power from the commercial power supply 108 via the distribution board 102 to the HP unit 4, tank unit 6, and burner unit 8. When power is not supplied normally from the commercial power supply 108, the switch 106 supplies power from the storage battery 104 to the HP unit 4, tank unit 6, and burner unit 8. In this embodiment, the state of the hot water supply system 2 when the power source is the commercial power supply 108 is called "normal mode," and the state of the hot water supply system 2 when the power source is the storage battery 104 is called "power suppression mode." In power reduction mode, the hot water supply system 2 operates at a reduced power level (e.g., 650 VA) lower than the maximum power consumption in normal mode. The power source for the hot water supply system 2 is identified, for example, by an energy management system (not shown) provided separately from the hot water supply system 2. The energy management system transmits information indicating the identified power source to the tank controller 74. Based on the information received from the energy management system, the tank controller 74 switches the mode of the hot water supply system 2.
[0026] The HP controller 24 and the tank controller 74 can communicate with each other. The tank controller 74 and the burner controller 100 can also communicate with each other. Therefore, by the coordinated control of the HP controller 24, the tank controller 74, and the burner controller 100, the hot water supply system 2 can perform various operations such as heating, hot water supply, filling the bathtub, and freeze prevention. Hereafter, the HP controller 24, the tank controller 74, and the burner controller 100 will be collectively referred to simply as "controllers".
[0027] Next, the various operations of the hot water supply system 2 will be explained. The hot water supply system 2 can perform heating operation, hot water supply operation, bath filling operation, and freeze prevention operation.
[0028] (boiling operation) During the heating operation, the hot water supply system 2 drives the HP unit 4 to heat the water in the tank 30. During the heating operation, the HP controller 24 drives the compressor 10 to circulate the refrigerant in the order of compressor 10, condenser 12, expansion valve 14, and evaporator 16, and also drives the circulation pump 18 to circulate water between the tank 30 and the condenser 12. As a result, the water drawn from the bottom of the tank 30 is heated in the condenser 12 to the target heating temperature and returned to the top of the tank 30.
[0029] The water heating operation includes a normal heating operation in which the output of HP unit 4 is set to the first output (e.g., 2.3 kW) and a high-output heating operation in which the output of HP unit 4 is set to the second output (e.g., 3.9 kW). In this embodiment, the first output is the rated output of HP unit 4. The second output is higher than the rated output.
[0030] The target water heating temperature in normal operation and the target water heating temperature in high-power operation are both set to a temperature suitable for hot water supply (for example, 45°C). In water heating operation, the water heating flow rate by the HP unit 4 changes according to the output of the HP unit 4. The water heating flow rate in normal operation is, for example, 0.9 L / min, and the water heating flow rate in high-power operation is, for example, 1.6 L / min.
[0031] High-power heating operation is performed in conjunction with the bath filling operation, as described below. On the other hand, normal heating operation is performed independently of the bath filling operation. For example, normal heating operation is performed automatically when the heating setting time, which is set via the remote control 76, arrives.
[0032] (Hot water supply operation) During hot water supply operation, water at the set hot water temperature is supplied to the hot water supply location. The controller determines that a hot water supply location, such as a faucet, has been opened when the sum of the flow rate detected by the cold water flow sensor 54 and the flow rate detected by the hot water flow sensor 60 (also called the hot water supply flow rate) exceeds the minimum operating flow rate (for example, 2.4 L / min). Then, depending on the temperature detected by the upper thermistor 36, the controller executes either the non-combustion hot water supply operation or the combustion hot water supply operation described below.
[0033] If the temperature detected by the upper thermistor 36 is equal to or above the hot water supply set temperature, the controller performs non-combustion hot water supply operation. In non-combustion hot water supply operation, the controller prohibits 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 that has been temperature-adjusted to the hot water supply set temperature is supplied to the hot water supply location.
[0034] If the temperature detected by the upper thermistor 36 is below the hot water supply set temperature (i.e., the tank 30 runs out of hot water), the controller performs combustion hot water supply operation. In combustion hot water supply operation, the controller allows the burner 80 to operate 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, the high-temperature water supplied from the top of the tank 30 to the tank hot water outlet path 56 and the low-temperature water supplied from the water supply path 40 are mixed in the mixing valve 32, then heated to the hot water supply set temperature by the burner 80 and supplied to the hot water supply location.
[0035] If the hot water flow rate falls below the minimum operating flow rate while either the non-combustion or combustion hot water supply operation described above is being performed, the controller will determine that the hot water supply point has been shut off and will terminate the hot water supply operation.
[0036] (Water filling operation) When the controller is instructed to start the bathtub filling operation via the remote control 76, it starts the bathtub filling operation. During the bathtub filling operation, the controller opens the bathtub filling valve 88 and supplies water at the set bathtub temperature to the bathtub. The bathtub filling operation consists of the non-combustion bathtub filling operation and the combustion bathtub filling operation described below. Depending on the temperature detected by the upper thermistor 36, the controller performs either the non-combustion bathtub filling operation or the combustion bathtub filling operation.
[0037] If the temperature detected by the upper thermistor 36 is equal to or higher than the set temperature for filling the bathtub, the controller performs a non-combustion bathtub filling operation. In non-combustion bathtub filling operation, the controller prohibits 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 set temperature for filling the bathtub. In this case, the high-temperature water supplied from the top of the tank 30 to the tank outlet path 56 and the low-temperature water supplied from the water supply path 40 are mixed in the mixing valve 32. As a result, water that has been adjusted to the set temperature for filling the bathtub is supplied to the bathtub. In addition, the controller performs a heating operation (specifically, a high-power heating operation) in conjunction with the non-combustion bathtub filling operation. This allows high-temperature water to be supplied from the HP unit 4 to the top of the tank 30, thereby preventing the tank 30 from running out of hot water.
[0038] If the temperature detected by the upper thermistor 36 is below the set temperature for filling the bathtub (i.e., if the tank 30 runs out of hot water), the controller performs combustion-based bathtub filling. In combustion-based bathtub filling, the controller allows the burner 80 to operate and adjusts the opening of the mixing valve 32 so that the temperature detected by the mixing thermistor 64 is lower than the set temperature for filling the bathtub by the minimum heating capacity of the burner 80. In this case, the high-temperature water supplied from the top of the tank 30 to the tank outlet path 56 and the low-temperature water supplied from the water supply path 40 are mixed in the mixing valve 32, then heated to the set temperature for filling the bathtub by the burner 80 and supplied to the bathtub. In addition, the controller performs a heating operation (specifically, a high-power heating operation) in conjunction with the combustion-based bathtub filling operation. This allows high-temperature water to be supplied from the HP unit 4 to the top of the tank 30, thereby preventing the tank 30 from running out of hot water.
[0039] During the non-combustion or combustion-based bath filling operation described above, if the amount of hot water supplied to the bathtub reaches a predetermined amount (e.g., 200L), the controller terminates the bath filling operation. The amount of hot water supplied to the bathtub is calculated, for example, based on the detection result of the water volume sensor 91.
[0040] (Anti-freezing operation) If the outside temperature is low and a long period of time passes without the water heating, hot water supply, or bath filling operations being performed, the water stagnating in each path of the hot water supply system 2 (i.e., the piping of the hot water supply system 2) may freeze. If the water freezes, the water heating, hot water supply, and bath filling operations cannot be performed until the frozen water thaws. Therefore, the hot water supply system 2 in this embodiment performs an anti-freeze operation to prevent the water in each path from freezing.
[0041] The freeze prevention operation in this embodiment is performed when the condition that "any one of the ambient temperatures detected by the HP ambient temperature thermistor 23, the tank ambient temperature thermistor 39, and the burner ambient temperature thermistor 85 falls below a predetermined temperature" is met. In this specification, this condition is referred to as the "condition for performing freeze prevention operation".
[0042] When the freeze prevention operation is started, the controller simultaneously drives multiple first electric heaters 35 and multiple second electric heaters 83 (hereinafter simply referred to as "electric heaters 35 and 83"). The controller continues to drive the electric heaters 35 and 83 while the freeze prevention operation is running. This heats each path of the hot water supply system 2, preventing the water from freezing inside these paths. The controller determines the operating time of the freeze prevention operation according to the ambient temperature at the time the freeze prevention operation is started. For example, the controller determines a longer operating time for the freeze prevention operation if the ambient temperature at the time the freeze prevention operation is started is lower. Once the operating time has elapsed, the controller stops the electric heaters 35 and 83 and ends the freeze prevention operation.
[0043] (Learning control of the start time for filling the bathtub) As shown in Figure 2, the controller stores the operating history of a specific household for the past seven days in non-volatile memory 75. In this embodiment, the controller stores the time when the bath filling operation started during the past seven days in non-volatile memory 75. The controller identifies the earliest time among the times when the bath filling operation started during the past seven days as the "bath filling start time B1". In the example shown in Figure 2, the controller identifies 18:00 as the bath filling start time B1.
[0044] (Water filling preparation treatment) While power is supplied to the hot water supply system 2, the controller repeatedly performs the bath filling adaptation process. The bath filling adaptation process consists of the first bath filling adaptation process shown in Figure 3 and the second bath filling adaptation process shown in Figures 4 to 6. When the hot water supply system 2 is in normal mode, the controller performs the first bath filling adaptation process. When the hot water supply system 2 is in power suppression mode, the controller performs the second bath filling adaptation process.
[0045] (Figure 3: First hot water filling adaptation treatment) In S2, the controller executes the freeze prevention operation start request process (see Figure 7). In the freeze prevention operation start request process, it is determined whether or not the conditions for performing freeze prevention operation are met. If the conditions for performing freeze prevention operation are met, freeze prevention operation is started. After S2, the process proceeds to S4.
[0046] In S4, the controller determines whether or not the start of the bath filling operation has been instructed via the remote control 76. If the start of the bath filling operation has not been instructed (NO), the process returns to S2. If the start of the bath filling operation has been instructed (YES), the process proceeds to S6.
[0047] In S6, the controller starts high-power heating operation simultaneously with the start of the bath filling operation. After S6, the process proceeds to S8.
[0048] In S8, the controller executes the freeze prevention operation start acceptance process (see Figure 7). After S8, the process proceeds to S10.
[0049] In S10, the controller determines whether the first output transition condition has been met. In this embodiment, the "first output transition condition" is the condition that "the temperature detected by the lower thermistor 38 exceeds the temperature obtained by subtracting a predetermined temperature (for example, 5°C) from the target boiling temperature for the boiling operation." During the hot water filling operation, hot water is stored in the upper part of the tank 30 by the high-power boiling operation and hot water is dispensed from the upper part of the tank 30 by the hot water filling operation simultaneously. On the other hand, after the hot water filling operation is completed, only hot water is stored in the upper part of the tank 30 by the high-power boiling operation. For this reason, the first output transition condition can also be said to be a condition for determining whether the water in the tank 30 has been heated to a relatively high temperature by the high-power boiling operation after the hot water filling operation is completed. If the first output transition condition has not been met (if NO), the process returns to S8. If the first output transition condition has been met (if YES), the process proceeds to S12.
[0050] In S12, the controller terminates the high-power boiling operation that started in S6 and begins normal boiling operation. After S12, the process proceeds to S14.
[0051] In S14, the controller executes the freeze prevention operation start acceptance process (see Figure 7). After S14, the process proceeds to S16.
[0052] In S16, the controller determines whether the boiling termination condition has been met. In this embodiment, the "boiling termination condition" is the condition that "the temperature detected by the lower thermistor 38 becomes the target boiling temperature for the boiling operation." In other words, the boiling termination condition can also be said to be a condition for determining whether the tank 30 is full. Here, "full" means the state in which the water in the tank 30 has been boiled to the target boiling temperature. If the boiling termination condition has not been met (NO), the process returns to S14. If the boiling termination condition has been met (YES), the process proceeds to S18.
[0053] In S18, the controller terminates the normal water heating operation that was started in S12. After S18, the first water filling adaptation process is completed.
[0054] (Figure 7: Processing for requesting the start of anti-freezing operation) In S102, the controller determines whether or not freeze protection operation is in progress. If freeze protection operation is not in progress (NO), the process proceeds to S102.
[0055] In S104, the controller determines whether the conditions for performing anti-freezing operation are met. If the conditions for performing anti-freezing operation are met (YES), the process proceeds to S106.
[0056] In S106, the controller starts the anti-freeze operation.
[0057] If it is determined in S102 that de-icing operation is in progress (YES), if it is determined in S104 that the conditions for performing de-icing operation are not met (NO), or after S106, the de-icing operation start request process ends.
[0058] (Figure 4: Steps S22 to S50 of the second hot water filling adaptation process)
[0059] In S22, the controller determines whether the bath filling start time B1 has been identified. For example, if the user has been away for a long period of time, such as on a trip, and there is no operating history for the past 7 days, the bath filling start time B1 cannot be identified, and the determination is NO. If the bath filling start time B1 has been identified (YES), the process proceeds to S24.
[0060] In S24, the controller determines whether the current time has passed time B0. Time B0 is a predetermined time α before the start time of filling the bathtub B1. This predetermined time α is set to a time longer than the maximum operating time of the anti-freeze operation. The "maximum operating time of the anti-freeze operation" refers to the longest time among the times determined to be the operating time of the anti-freeze operation. Furthermore, the determination that "the current time has passed time B0" is made only once per day. If the current time has passed time B0 (YES), the process proceeds to S26.
[0061] In S26, the controller determines whether the conditions for performing de-icing operation are met. If the conditions for performing de-icing operation are met (YES), the process proceeds to S28. If the conditions for performing de-icing operation are not met (NO), the process proceeds to S30.
[0062] In S28, instead of starting the anti-freeze operation, the controller turns on the operation carryover flag. The "operation carryover flag" here refers to information stored in the non-volatile memory 75. After S28, the process proceeds to S30.
[0063] In S30, the controller determines whether or not the start of the bath filling operation has been instructed via the remote control 76. If the start of the bath filling operation has not been instructed (NO), the process returns to S26. If the start of the bath filling operation has been instructed (YES), the process proceeds to S32.
[0064] In S32, the controller starts high-power heating operation at the same time as the start of the bath filling operation. After S32, the process proceeds to S34.
[0065] In S34, the controller determines whether the conditions for performing de-icing operation are met. If the conditions for performing de-icing operation are met (YES), the process proceeds to S36. If the conditions for performing de-icing operation are not met (NO), the process proceeds to S38.
[0066] In S36, instead of starting the anti-freeze operation, the controller turns on the operation carryover flag. After S36, the process proceeds to S38.
[0067] In S38, the controller determines whether the first output transition condition has been met. If the first output transition condition has not been met (NO), the process returns to S34. If the first output transition condition has been met (YES), the process proceeds to S40.
[0068] In S40, the controller terminates the high-power boiling operation that started in S32 and begins normal boiling operation. After S40, the process proceeds to S42.
[0069] In S42, the controller determines whether the operation carryover flag is ON or OFF. If the operation carryover flag is ON (YES), the process proceeds to S44. If the operation carryover flag is OFF (NO), the process proceeds to S46.
[0070] In S44, the controller starts the freeze prevention operation. The controller then turns off the operation carryover flag. After S44, the process proceeds to S46.
[0071] In S46, the controller executes the freeze prevention operation start acceptance process (see Figure 7). After S46, the process proceeds to S48.
[0072] In S48, the controller determines whether the boiling termination condition has been met. If the boiling termination condition has not been met (NO), the process returns to S46. If the boiling termination condition has been met (YES), the process proceeds to S50.
[0073] At S50, the controller terminates the normal water heating operation that started at S40. After S50, the second water filling adaptation process is completed.
[0074] (Figure 5: From S52 to S58 of the second hot water filling adaptation treatment) If it is determined in S22 that the start time B1 for filling the bathtub is not specified (i.e., NO), the process proceeds to S52. In S52, the controller executes the freeze prevention operation start acceptance process (see Figure 7). After S52, the process proceeds to S54.
[0075] In S54, the controller determines whether or not the start of the bath filling operation has been instructed via the remote control 76. If the start of the bath filling operation has not been instructed (NO), the process returns to S52. If the start of the bath filling operation has been instructed (YES), the process proceeds to S56.
[0076] In S56, the controller determines whether or not freeze protection operation is in progress. If freeze protection operation is in progress (YES), the process proceeds to S58. If freeze protection operation is not in progress (NO), the process proceeds to S32 in Figure 4.
[0077] In S58, the controller interrupts the ongoing anti-freeze operation. After S58, the process proceeds to S32 in Figure 4.
[0078] (Figure 6: Steps S60 to S68 of the second hot water filling adaptation process) If it is determined in S24 that the current time has not yet reached time B0 (i.e., NO), the process proceeds to S60. In S60, the controller executes the freeze prevention operation start acceptance process (see Figure 7). After S60, the process proceeds to S62.
[0079] In S62, the controller determines whether the current time has passed time B0. If the current time has passed time B0 (YES), the process proceeds to S26 in Figure 4. If the current time has not passed time B0 (NO), the process proceeds to S64.
[0080] In S64, the controller determines whether or not the start of the bath filling operation has been instructed via the remote control 76. If the start of the bath filling operation has not been instructed (NO), the process returns to S60. If the start of the bath filling operation has been instructed (YES), the process proceeds to S66.
[0081] In S66, the controller determines whether or not defrosting operation is in progress. If defrosting operation is in progress (YES), the process proceeds to S68. If defrosting operation is not in progress (NO), the process proceeds to S32 in Figure 4.
[0082] In S68, the controller interrupts the ongoing anti-freeze operation. After S68, the process proceeds to S32 in Figure 4.
[0083] (Regarding the differences in operation for each mode of the hot water supply system 2) Figures 8 and 9 show an example of the time progression of power consumption of the hot water supply system 2 when the hot water supply system 2 operates according to the hot water filling adaptation process. In Figures 8 and 9, the power consumption of the HP unit 4 during high-power heating operation is P H The power consumption of HP unit 4 during normal boiling operation is set to P N The power consumption of the electric heaters 35 and 83 during operation in freeze prevention mode is P AF This is shown as follows. In this embodiment, power consumption P H and power consumption P AF The total value exceeds the suppressed power. On the other hand, power consumption P N and power consumption P AF The total value is less than the suppressed power.
[0084] As shown in Figure 8, in normal mode, even while the hot water filling operation (and high-power heating operation) is in progress, the anti-freeze operation will start immediately if the conditions for the anti-freeze operation are met. Thus, in normal mode, it is permissible for the hot water filling operation (and high-power heating operation) and the anti-freeze operation to be performed simultaneously.
[0085] As shown in Figure 9, in power reduction mode, while the bath filling operation (and high-power heating operation) is running, the anti-freeze operation will not start even if the conditions for performing the anti-freeze operation are met. In this case, the anti-freeze operation will start after the bath filling operation (and high-power heating operation) is completed. Thus, in power reduction mode, if the conditions for performing the bath filling operation (and high-power heating operation) and the conditions for performing the anti-freeze operation overlap, the bath filling operation (and high-power heating operation) takes priority. This prevents the bath filling operation (and high-power heating operation) and the anti-freeze operation from running simultaneously.
[0086] (Regarding the configuration that prohibits the execution of anti-freeze operation due to the second hot water filling adaptation process) In power reduction mode, when the bath filling start time B1 is specified, the start of the anti-freeze operation is prohibited from the time the current time has passed time B0 until the high-power heating operation is completed (see S24 to S40 in Figure 4). In this embodiment, even if the anti-freeze operation is started just before the current time passes time B0, the anti-freeze operation will be completed at the latest by the time the current time reaches the bath filling start time B1. As a result, in power reduction mode, the execution of the anti-freeze operation is prohibited from the time the bath filling start time B1 has passed until the high-power heating operation is completed.
[0087] Furthermore, if the bath filling start time B1 is not specified, or if the current time has not yet passed time B0, the ongoing anti-freeze operation will be interrupted at the time the bath filling operation (and high-power heating operation) starts (see S58 in Figure 5 and S68 in Figure 6). After the anti-freeze operation is interrupted, the start of the anti-freeze operation is prohibited until the high-power heating operation is completed. For this reason, in power suppression mode, regardless of the bath filling start time B1, the execution of the anti-freeze operation is prohibited from the time the bath filling operation (and high-power heating operation) starts until the high-power heating operation is completed.
[0088] (modified version) In the above embodiment, a configuration was described in which the burner 80 heats water by the combustion of fuel gas. In another embodiment, the burner 80 may heat water by the combustion of a fuel other than fuel gas (for example, a liquid fuel such as kerosene).
[0089] In the above embodiment, a configuration was described in which the controller switches the mode of the hot water supply system 2 based on information received from the energy management system. In another embodiment, the controller may switch the mode of the hot water supply system 2 based on instructions from the user via the remote control 76.
[0090] In the above embodiment, the anti-freezing operation may consist of a first anti-freezing operation in which a plurality of first electric heaters 35 are driven, and a second anti-freezing operation in which a plurality of second electric heaters 83 are driven. In this case, the conditions for performing the first anti-freezing operation and the conditions for performing the second anti-freezing operation may be set separately. For example, the conditions for performing the first anti-freezing operation may be that "the ambient temperature detected by the tank ambient temperature thermistor 39 is below a predetermined temperature." The conditions for performing the second anti-freezing operation may be that "the ambient temperature detected by the burner ambient temperature thermistor 85 is below a predetermined temperature."
[0091] In the above embodiment, a configuration was described in which the controller continues to drive the electric heaters 35 and 83 while the anti-freeze operation is being performed. In another embodiment, the controller may repeatedly drive and dedrive the electric heaters 35 and 83 at a predetermined cycle while the anti-freeze operation is being performed.
[0092] In the above embodiment, a configuration was described in which the controller determines the bath filling start time B1 based on the bath filling operation record for the past 7 days. In another embodiment, the controller may determine the bath filling start time B1 based on the bath filling operation record for the past month. In yet another embodiment, the controller may determine the bath filling start time B1 based on the bath filling operation record for the past 7 weeks for a specific day of the week.
[0093] In the above embodiment, a configuration was described in which the controller performs a first bath filling adaptation process when the hot water supply system 2 is in normal mode. In another embodiment, the controller may perform a second bath filling adaptation process when the hot water supply system 2 is in normal mode. In this case, the normal mode may include a first normal mode in which the controller performs the first bath filling adaptation process, and a second normal mode in which the controller performs the second bath filling adaptation process.
[0094] In the above embodiment, a configuration was described in which the controller determines the bath filling start time B1 based on past operating records of the bath filling operation. In another embodiment, the controller may determine the bath filling start time B1 in a different way. For example, the bath filling start time B1 may be input to the remote control 76, and the controller may determine the bath filling start time B1 based on the input to the remote control 76.
[0095] In the above embodiment, a configuration was described in which the controller starts the heating operation (specifically, high-power heating operation) at the same time as the start of the bath filling operation (see S6 in Figure 3 and S32 in Figure 4). In another embodiment, the controller may start the high-power heating operation at a time that is predetermined (for example, 5 minutes) before (or after) the bath filling start time B1. In this specification, the expression "performed in conjunction with the bath filling operation" encompasses all of the above embodiments.
[0096] In the above embodiment, a configuration was described in which the water heating operation performed independently of the water filling operation is a normal water heating operation, and the water heating operation performed in conjunction with the water filling operation is a high-power water heating operation. In another embodiment, both the water heating operation performed independently of the water filling operation and the water heating operation performed in conjunction with the water filling operation may be normal water heating operations. This allows for the execution of the anti-freeze operation immediately after the water filling operation is completed.
[0097] In the above embodiment, the controller may determine the time when the hot water filling operation ends (hot water filling end time) based on past operating records of the hot water filling operation, similar to the hot water filling start time B1. In this case, the controller may prohibit the execution of the anti-freeze operation during the time period from the hot water filling start time B1 to the hot water filling end time, and allow the execution of the anti-freeze operation during other time periods. Even with the above configuration, it is possible to prohibit the simultaneous execution of the hot water filling operation (and high-power heating operation) and the anti-freeze operation.
[0098] (Correspondence) In this specification, HP unit 4 is an example of a heat pump. Burner 80 is an example of a combustion heating device. Controller is an example of a control device. Furthermore, a configuration in which the start of the anti-freeze operation is prohibited after a predetermined time B0 has elapsed from the start time of filling the bathtub B1 by a predetermined time α is an example of a configuration in which the start of the anti-freeze operation is prohibited prior to the start time of filling the bathtub so that the anti-freeze operation is not running at the start time of filling the bathtub.
[0099] The technical elements described herein or in the drawings demonstrate technical usefulness individually or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Furthermore, the technologies illustrated herein or in the drawings can achieve multiple objectives simultaneously, and achieving even one of these objectives constitutes technical usefulness in itself. [Explanation of symbols]
[0100] 2: Hot water supply system 4: HP Unit 6: Tank Unit 8: Burner Unit 9: Power supply unit 10: Compressor 12: Condenser 14: Expansion valve 16: Evaporator 18: Circulation pump 19: Route to HP 20: HP-bound thermistor 21: HP return route 22: HP return thermistor 23: HP Outdoor Temperature Thermistor 24: HP Controller 30: Tank 31: Route to the tank 32: Mixing valve 33: Tank return route 34: Bypass control valve 35: First electric heater 36: Upper thermistor 37: Intermediate thermistor 38: Lower thermistor 39: Tank outside air temperature thermistor 40: Water supply route 42: Pressure Reducing Valve 44: Inlet thermistor 46: Tank water supply route 48: Tank bypass route 50: Check valve 52: Check valve 54: Water side water volume sensor 56: Tank hot water outlet route 58: Check valve 60: Hot water flow sensor 62: First hot water supply route 64: Mixed Thermistor 66: Second hot water supply route 68: Hot water outlet thermistor 70: Check valve 72: Hot water bypass route 74: Tank Controller 75: Non-volatile memory 76: Remote control 80: Burner 81: Gas supply pipe 82: Heat exchanger 83: Second electric heater 84: Bypass Servo 85: Burner ambient temperature thermistor 86: Water volume servo 88: Hot water valve 90: Outbound journey to Burna 91: Water volume sensor 92: Return trip to Burna 94: Burner Bypass Route 96: Burner hot water thermistor 98: Bathtub filling route 100: Burner Controller 102: Distribution board 104: Storage Battery 106: Switch 108:Commercial power supply
Claims
1. A hot water supply system connected to a bathtub, A heat pump that heats water, A tank for storing the water heated by the heat pump, A combustion heating device that heats the water by burning fuel, An electric heater that heats the pipe through which the water flows, The system comprises the heat pump, the combustion heating device, and a control device for controlling the operation of the electric heater. The control device is The water is heated by the heat pump and the heated water is stored in the tank in a boiling operation, A hot water filling operation is performed, in which the water stored in the tank is supplied to the bathtub, and the water heated by the combustion heating device is supplied to the bathtub. The electric heater can be used to perform a freeze prevention operation, which involves heating the piping, The control device is In conjunction with the aforementioned bath filling operation, the aforementioned heating operation is performed. If the conditions for performing the aforementioned water heating operation and the conditions for performing the aforementioned anti-freeze operation overlap, the water heating operation will be given priority, thereby preventing the water heating operation and the anti-freeze operation from being performed simultaneously. The control device is The time at which the aforementioned hot water filling operation is scheduled to begin is identified as the hot water filling start time. A hot water supply system that prohibits the start of the freeze prevention operation prior to the start time of filling the hot water, so that the freeze prevention operation is not running at the start time of filling the hot water.
2. The hot water supply system according to claim 1, wherein the control device determines the start time of the hot water filling operation based on past operating records of the hot water filling operation.
3. A hot water supply system connected to a bathtub, A heat pump that heats water, A tank for storing the water heated by the heat pump, A combustion heating device that heats the water by burning fuel, An electric heater that heats the pipe through which the water flows, The system comprises the heat pump, the combustion heating device, and a control device for controlling the operation of the electric heater. The control device is The water is heated by the heat pump and the heated water is stored in the tank in a boiling operation, A hot water filling operation is performed, in which the water stored in the tank is supplied to the bathtub, and the water heated by the combustion heating device is supplied to the bathtub. The electric heater can be used to perform a freeze prevention operation, which involves heating the piping, The control device is In conjunction with the aforementioned bath filling operation, the aforementioned heating operation is performed. If the conditions for performing the aforementioned water heating operation and the conditions for performing the aforementioned anti-freeze operation overlap, the water heating operation will be given priority, thereby preventing the water heating operation and the anti-freeze operation from being performed simultaneously. The aforementioned heating operation includes a normal heating operation in which the output of the heat pump is set to a first output, and a high-output heating operation in which the output of the heat pump is set to a second output that is higher than the first output. The boiling operation performed independently of the aforementioned hot water filling operation is the normal boiling operation, The boiling operation performed in conjunction with the aforementioned hot water filling operation is the aforementioned high-power boiling operation. The control device is The above-mentioned normal boiling operation and the above-mentioned freeze prevention operation are permitted to be performed simultaneously. A hot water supply system that prohibits the simultaneous execution of the high-power heating operation and the freeze prevention operation.
4. The hot water supply system has a normal mode and a power suppression mode in which it operates at a suppression power lower than or equal to the maximum power consumption in the normal mode. The control device is In the aforementioned normal mode, the boiling operation and the freeze prevention operation associated with the hot water filling operation are permitted to be performed simultaneously. A hot water supply system according to any one of claims 1 to 3, wherein in the power reduction mode, the simultaneous execution of the boiling operation and the freeze prevention operation associated with the hot water filling operation is prohibited.