JP6826896B2 - Hot water supply system - Google Patents

Description

The techniques disclosed herein relate to hot water supply systems.

The hot water supply system disclosed in Patent Document 1 is connected to a tank for storing water, a heat pump for boiling water, a lower part of the tank, a tank water supply path for supplying water to the lower part of the tank, and a lower part of the tank. It is connected to the heat pump and has a tank outbound route that supplies water to the heat pump from the bottom of the tank. In addition, this hot water supply system is connected to the upper part of the tank and the heat pump, and is connected to the tank return path that supplies the hot water after boiling by the heat pump from the heat pump to the upper part of the tank, and to the upper part of the tank. It is equipped with a tank hot water route that discharges hot water from the top of the tank. Further, this hot water supply system includes a first temperature detection device, a second temperature detection device, and a control device. The first temperature detecting device detects the temperature of water in the tank going path. The second temperature detector detects the temperature of the water stored in the lower part of the tank. The control device can perform a boiling operation of boiling water with a heat pump and a hot water supply operation of supplying hot water in a tank to a hot water supply location.

In the hot water supply system of Patent Document 1, when the control device executes the boiling operation, the water stored in the tank is boiled by the heat pump, and the hot water (high temperature water) after the boiling is stored in the tank. When the entire tank is filled with hot water boiled by the heat pump (that is, when the tank is full), the boiling operation ends. When the entire tank is filled with hot water (that is, when the tank is full), the detection temperature of the first temperature detector and the detection temperature of the second temperature detector are equal to or higher than the predetermined reference temperature (for example, 35 ° C). become.

Further, in the hot water supply system of Patent Document 1, when the control device executes the hot water supply operation, hot water is discharged from the tank through the hot water discharge path of the tank, and the hot water in the tank is reduced. On the other hand, since water is supplied to the tank through the tank water supply path at the same time as the hot water is discharged, the water in the tank increases. Since the tank water supply path is connected to the lower part of the tank, when water is supplied to the tank through the tank water supply path, the hot water stored in the lower part of the tank is replaced with water. In addition, the hot water in the tank going path connected to the lower part of the tank is also replaced with water. When the hot water in the tank going path and the hot water stored in the lower part of the tank are replaced with water, the detection temperature of the first temperature detection device and the detection temperature of the second temperature detection device are less than the predetermined reference temperature (for example, 35 ° C.). become. When the hot water in the tank going route and the hot water stored in the lower part of the tank are replaced with water, usually, the hot water in the tank going route is replaced with water first, and then the hot water stored in the lower part of the tank is replaced. Replaces water.

Japanese Unexamined Patent Publication No. 2016-191485

In the hot water supply operation in the hot water supply system, a large amount of hot water may be discharged from the tank through the tank hot water supply route. For example, when hot water is poured into a bathtub, a large amount of hot water is required for hot water filling, and a large amount of hot water is discharged from the tank through the tank discharge route. Alternatively, if the user of the hot water system uses the shower, a large amount of hot water for the shower is required. In such a case, even when the entire tank is filled with hot water (that is, the tank is full), there may be a shortage of hot water to supply to the hot water supply location. Therefore, in order to make up for the lack of hot water, an additional boiling operation may be performed. That is, when the control device is executing the hot water supply operation, the boiling operation is additionally executed. More specifically, when the control device executes the hot water supply operation, the hot water in the tank is reduced in the hot water supply operation, and at the same time, water is supplied into the tank through the tank water supply path and the hot water in the tank going path is replaced with water. As a result, the detection temperature of the first temperature detection device fixed to the tank going path becomes less than a predetermined reference temperature (for example, 35 ° C.). When the detection temperature of the first temperature detection device becomes less than a predetermined reference temperature, the control device executes an additional boiling operation.

As mentioned above, when water is supplied into the tank through the tank water supply route, the hot water in the tank outbound route is usually replaced with water first, and then the hot water stored in the lower part of the tank becomes water. Replace. Therefore, when the detection temperature of the first temperature detection device and the detection temperature of the second temperature detection device are compared, the detection temperature of the first temperature detection device becomes low first, and then the detection temperature of the second temperature detection device becomes low. become. In this case, there is no problem. However, on the contrary, the detection temperature of the second temperature detection device may be lowered first, and then the detection temperature of the first temperature detection device may be lowered. For example, due to the long length of the tank going path, when the hot water in the tank going path is replaced with water, the time for that may be long. Then, the hot water stored in the lower part of the tank may be replaced with water first, and then the hot water in the tank going route may be replaced with water. Therefore, the detection temperature of the second temperature detection device may be lowered first, and then the detection temperature of the first temperature detection device may be lowered. In this case, if the control device executes an additional boiling operation when the detection temperature of the first temperature detecting device becomes less than a predetermined reference temperature (for example, 35 ° C.), the additional boiling operation is delayed. become. That is, the hot water already stored in the lower part of the tank is replaced with water, and the detection temperature of the second temperature detection device fixed to the lower part of the tank is lower than the predetermined reference temperature (for example, 35 ° C.). Regardless, no additional boiling operation will be performed. In this case, there is a problem because the timing of executing the additional boiling operation is delayed.

Therefore, the present specification provides a technique capable of executing the boiling operation at the earliest possible timing when a large amount of hot water is required.

The hot water supply system disclosed in the present specification includes a tank for storing water, a heat pump for boiling water by a boiling operation, and a tank water supply path connected to the lower part of the tank and supplying water to the lower part of the tank. It is connected to the lower part of the tank and the heat pump, and has a tank going path for supplying water to the heat pump from the lower part of the tank. Further, the hot water supply system is connected to the upper part of the tank and the heat pump, and is connected to a tank return path for supplying hot water after being boiled by the heat pump from the heat pump to the upper part of the tank, and to the upper part of the tank. It is connected and has a tank hot water discharge route for hot water to be discharged from the upper part of the tank. Further, the hot water supply system includes a flow rate detecting device that detects the flow rate of hot water discharged from the tank through the tank hot water flow path, a first temperature detecting device that detects the temperature of water in the tank going path, and the tank. It is equipped with a second temperature detection device that detects the temperature of the water stored in the lower part and a control device. When the detected flow rate of the flow rate detecting device is equal to or higher than a predetermined reference flow rate, the control device performs a boiling operation by the heat pump when the detection temperature of the first temperature detecting device is lower than the predetermined reference temperature. When the detection flow rate of the flow rate detection device is equal to or higher than the predetermined reference flow rate and the detection temperature of the first temperature detection device is equal to or higher than the predetermined reference temperature, the second temperature detection device is executed. When the detected temperature of is less than a predetermined reference temperature, the boiling operation by the heat pump is executed.

In the hot water supply system, a large amount of hot water may be discharged from the tank through the tank hot water supply route. For example, when hot water is poured into a bathtub, a large amount of hot water is required for hot water filling, and a large amount of hot water is discharged from the tank through the tank discharge route. At this time, the detected flow rate of the flow rate detecting device that detects the flow rate of the hot water discharged from the tank becomes equal to or higher than the predetermined reference flow rate. At this time, according to the above configuration, if the detection temperature of the first temperature detection device that detects the temperature of the water in the tank going path is less than a predetermined reference temperature, the control device executes the boiling operation. .. As a result, the boiling operation can be executed at an early timing. The flow rate detecting device can directly or indirectly detect the amount of hot water discharged from the tank. For example, the amount of hot water discharged from the tank may be detected directly from the amount of hot water flowing through the hot water supply path of the tank, or indirectly from the amount of hot water supplied to the hot water supply location.

Further, according to the above configuration, even when the detection temperature of the first temperature detection device is equal to or higher than a predetermined reference temperature, the second temperature detection device detects the temperature of the water stored in the lower part of the tank. If the detected temperature of is less than the predetermined reference temperature, the control device executes the boiling operation. As a result, the boiling operation can be executed at an early timing. For example, in the above hot water supply system, when water is supplied from the tank through the tank hot water supply route and water is supplied to the tank through the tank water supply route, the hot water in the tank outbound route and the hot water stored in the lower part of the tank are stored. Replaces water. At this time, for example, due to the long length of the tank going path, the time required for replacing the hot water in the tank going path with water may be long. As a result, the hot water stored in the lower part of the tank may be replaced with water first, and then the hot water in the tank going route may be replaced with water. As a result, it may take a long time for the detection temperature of the first temperature detection device to be lower than the predetermined reference temperature. That is, the detection temperature of the second temperature detection device may be lowered first, and then the detection temperature of the first temperature detection device may be lowered. However, according to the above configuration, even if the timing at which the detection temperature of the first temperature detection device becomes low is delayed, control is performed when the detection temperature of the second temperature detection device is less than a predetermined reference temperature. Since the device executes the boiling operation, the boiling operation can be executed at an early timing. Therefore, according to the above configuration, the boiling operation can be executed at the earliest possible timing when a large amount of hot water is required.

In the above hot water supply system, the tank going path may include a rising portion extending upward from the tank side toward the heat pump side. Further, the first temperature detecting device may detect the temperature of water in the tank going path at a position on the heat pump side from the end of the rising portion on the tank side.

According to such a configuration, since the tank going path is provided with an ascending portion extending upward, it is difficult for the hot water in the tank going path to be replaced with water, and the time for replacing the hot water with water becomes longer. As a result, the timing at which the detection temperature of the first temperature detection device becomes low is further delayed. Therefore, in such a configuration, when the detection temperature of the first temperature detection device is equal to or higher than a predetermined reference temperature, the boiling operation is executed based on the detection temperature of the second temperature detection device instead of the first temperature detection device. The above configuration is particularly effective.

It is a figure which shows typically the schematic structure of the hot water supply system which concerns on Example. It is a flowchart which shows the process executed in a hot water supply system.

The hot water supply system 2 according to the embodiment will be described with reference to the drawings. FIG. 1 is a diagram schematically showing a schematic configuration of a hot water supply system 2 according to an embodiment. The hot water supply system 2 includes an HP (heat pump) unit 4, a tank unit 6, and a burner unit 8.

The HP unit 4 is a heat source that heats water by absorbing heat from the outside air. The HP unit 4 includes a compressor 10, a condenser 12, an expansion valve 14, and an evaporator 16. The HP unit 4 circulates a refrigerant (for example, a chlorofluorocarbon-based refrigerant) in the order of a compressor 10, a condenser 12, an expansion valve 14, and an evaporator 16 to absorb heat from the outside air and boil water. The compressor 10 pressurizes the refrigerant to a high temperature and high pressure. The condenser 12 cools the refrigerant by heat exchange with water. The HP going path 19 and the HP returning 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 a low temperature and a low pressure. The evaporator 16 heats the refrigerant by exchanging heat with the outside air. The HP unit 4 further includes a circulation pump 18 that circulates water in the condenser 12, a forward thermista 20 that detects the temperature of the water flowing into the condenser 12, and a return thermista 22 that detects the temperature of the water flowing out of the condenser 12. It includes an HP outside air temperature thermistor 23 that detects the outside air temperature, and an HP controller 24 that controls the operation of each component of the HP unit 4.

The tank unit 6 includes a tank 30, a mixing valve 32, and a bypass control valve 34. The tank 30 is a closed container whose outside is covered with a heat insulating material and which stores water inside. The capacity of the tank 30 of this embodiment is, for example, 100 liters.

The tank unit 6 includes a tank going path 31 and a tank returning path 33. The tank going path 31 is connected to the lower part of the tank 30 and the HP unit 4, and supplies water to the HP unit 4 from the lower part of the tank 30. Further, the tank going path 31 includes an ascending portion 35 extending diagonally upward from the tank 30 side toward the HP unit 4 side. In the rising portion 35, the tank 30 side is located lower than the HP unit 4 side. The tank return path 33 is connected to the upper part of the tank 30 and the HP unit 4, and supplies the hot water after being boiled by the HP unit 4 from the HP unit 4 to the upper part of the tank 30.

When the circulation pump 18 of the HP unit 4 is driven, the water in the lower part of the tank 30 is sent to the condenser 12 via the tank going path 31 and the HP going path 19. The water heated by the condenser 12 and becoming hot is returned from the upper part of the tank 30 into 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 hot water (hot water) is stacked on a layer of low temperature water.

The tank unit 6 includes an upper thermistor 36, an intermediate thermistor 37, a lower thermistor 38, and a path thermistor 39. The upper thermistor 36 is fixed to the upper part of the tank 30, the middle thermistor 37 is fixed to the middle part of the tank 30, and the lower thermistor 38 is fixed to the lower part of the tank 30. In this embodiment, the upper thermistor 36 is located 6 liters from the top of the tank 30, the middle thermistor 37 is located 12 liters from the top of the tank 30, and the lower thermistor 38 is the tank 30. It is located 30 liters from the top of the. The upper thermistor 36 detects the temperature of the water stored in the upper part of the tank 30, the middle thermistor 37 detects the temperature of the water stored in the middle part of the tank 30, and the lower thermistor 38 detects the temperature of the water stored in the lower part of the tank 30. Detects the temperature of the water stored in the. Further, the path thermistor 39 is fixed to the ascending portion 35 extending above the tank going path 31. The path thermistor 39 is fixed at a position close to the HP unit 4. The path thermistor 39 detects the temperature of the water in the rising portion 35 extending above the tank going path 31. The path thermistor 39 detects the temperature of the water in the tank going path 31 at a position on the HP unit 4 side from the end 35a on the tank 30 side of the rising portion 35. The path thermistor 39 fixed to the tank going path 31 is an example of the first temperature detecting device. The lower thermistor 38 fixed to the lower part of the tank 30 is an example of the second temperature detecting device.

Tap water is supplied to the tank unit 6 via the 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 is branched into a tank water supply path 46 that communicates with the lower part of the tank 30 and a tank bypass path 48 that communicates with the mixing valve 32. The tank water supply path 46 is connected to the lower part of the tank 30 and supplies water to the lower part of the tank 30. Check valves 50 and 52 are attached to the tank water supply path 46 and the tank bypass path 48, respectively. Further, a water-side flow rate 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 upper part of the tank 30 and the mixing valve 32 communicate with each other via the hot water discharge path 56 of the tank. The tank hot water passage 56 is connected to the upper part of the tank 30, and hot water is discharged from the upper part of the tank 30. A check valve 58 and a hot water side flow rate sensor 60 for detecting the flow rate of hot water from the tank 30 flowing into the mixing valve 32 are attached to the hot water discharge path 56 of the tank. The hot water side flow rate sensor 60 detects the flow rate of hot water discharged from the tank 30 through the tank discharge path 56.

The mixing valve 32 mixes tap water flowing from the tank bypass path 48 and water (hot water) from the tank 30 flowing from the tank hot water supply path 56, and sends the tap water to the first hot water supply path 62. The mixing valve 32 drives the valve by a stepping motor to adjust the opening degree on the tank bypass path 48 side (opening on the water side) and the opening degree on the tank discharge path 56 side (opening on the hot water side). A mixing thermistor 64 for detecting the temperature of water delivered from the mixing valve 32 is attached to the first hot water supply path 62.

From the tank unit 6, hot water is supplied to hot water supply points such as a kitchen, a shower, and a curan 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. A hot water supply bypass route 72 communicates between the first hot water supply route 62 and the second hot water supply route 66. 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. The tank controller 74 controls the operation of each component of the tank unit 6. Further, the tank controller 74 includes a memory 75. The memory 75 contains, for example, information related to the hot water supply record such as the hot water supply start time, the hot water supply amount, and the hot water supply end time of the hot water supply system 2 in the past predetermined period (for example, 7 days), the scheduled start time of the boiling operation, and the boiling. Stores information related to boiling operation such as temperature, amount of boiling water, and scheduled end time.

The burner unit 8 includes a burner 80, a heat exchanger 82, a bypass servo 84, a water amount servo 86, and a hot water valve 88. The burner 80 is an auxiliary heat source machine that heats the water flowing through the heat exchanger 82 by burning the fuel gas. Fuel gas is supplied to the burner 80 via the 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 outbound 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. A water amount servo 86 that adjusts the flow rate of water flowing through the burner outbound route 90 and a water amount sensor 91 that detects the flow rate of water flowing through the burner outbound route 90 are attached to the burner outbound route 90. The burner outbound route 90 and the burner return route 92 communicate with each other via the burner bypass route 94. A bypass servo 84 is attached to the connection portion between the burner outbound route 90 and the burner bypass route 94. The bypass servo 84 adjusts the flow rate of water flowing from the burner outbound path 90 to the burner bypass path 94. A burner hot water supply thermistor 96 that detects the temperature of the water flowing out of the heat exchanger 82 is attached to the burner return path 92. From the burner return route 92, the hot spring route 98 branches off. In the burner return route 92, a hot water valve 88 is attached to the hot water path 98. From the burner unit 8, hot water is supplied to the bathtub, which is a hot water supply point, via the hot water route 98. The hot water route 98 supplies the hot water discharged from the tank 30 to the bathtub.

The burner unit 8 further includes a burner controller 100 that controls the operation of each component of the burner unit 8 and a remote controller 102. The remote controller 102 can communicate with the burner controller 100. Further, the remote controller 102 can communicate with the tank controller 74 via the burner controller 100. The remote controller 102 accepts various operation inputs from the user via switches, buttons, and the like. The various inputs are, for example, an execution instruction for the boiling operation and an execution instruction for the hot water supply operation, which will be described later. In addition, the remote controller 102 notifies the user of various information regarding the setting and operation of the hot water supply system 2 by display or voice.

The HP controller 24 and the tank controller 74 can communicate with each other. The tank controller 74 and the burner controller 100 can communicate with each other. Therefore, when the HP controller 24, the tank controller 74, and the burner controller 100 cooperate to control the hot water supply system 2, the hot water supply system 2 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 100 are collectively referred to as a controller.

Next, the operation of the hot water supply system 2 will be described. The hot water supply system 2 can execute the boiling operation and the hot water supply operation.

(Boiling operation)
In the boiling operation, the hot water supply system 2 drives the HP unit 4 to heat the water in the tank 30. The boiling operation may be executed by inputting an execution instruction of the boiling operation from the remote controller 102, or may be executed when the hot water supply operation described later is being executed. Further, the boiling operation may be executed when the scheduled start time of the boiling operation, which is preset and stored in the memory 75, arrives.

When the boiling operation is started, the HP controller 24 drives the compressor 10 to circulate the refrigerant in the order of the compressor 10, the condenser 12, the expansion valve 14, and the evaporator 16 and also drives the circulation pump 18. Then, water is circulated between the tank 30 and the condenser 12. As a result, the water sucked out from the lower part of the tank 30 is heated to the boiling temperature (for example, 45 ° C.) in the condenser 12 and returned to the upper part of the tank 30. When the amount of boiling water (for example, 30 liters) of the water in the tank 30 is replaced with water (hot water) heated to the boiling temperature, the HP controller 24 ends the boiling operation. Alternatively, when the heated water (hot water) is filled in the entire tank 30 (that is, when the tank 30 is full), the HP controller 24 ends the boiling operation.

(Hot water supply operation)
In the hot water supply operation, water at the hot water supply set temperature is supplied to the hot water supply location. In the controller, the total flow rate (also referred to as hot water supply flow rate) of the flow rate detected by the water side flow rate sensor 54 and the flow rate detected by the hot water side flow rate sensor 60 is equal to or higher than the minimum operating flow rate (for example, 2.4 liters / min). Then, it is judged that the hot water supply has been started by opening the hot water supply location or filling the bathtub with hot water. Then, the controller executes the following non-combustion hot water supply operation or combustion hot water supply operation according to the temperature detected by the upper thermistor 36.

When the temperature detected by the upper thermistor 36 is equal to or higher than the hot water supply set temperature, the controller executes the non-combustion hot water supply operation. In the non-combustion hot water supply operation, the controller prohibits the combustion operation of the burner 80 and adjusts the opening degree 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.

If the temperature detected by the upper thermistor 36 is less 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 mixes the temperature detected by the mixing thermistor 64 so that the temperature is lower than the set temperature of the hot water supply by the minimum heating capacity of the burner 80. The opening degree of the valve 32 is adjusted. In this case, the high-temperature water supplied from the upper part of the tank 30 and the low-temperature water supplied from the water supply path 40 are mixed by the mixing valve 32 and then heated to the hot water supply set temperature by the burner 80 to reach the hot water supply location. Is supplied to.

If the hot water supply flow rate falls below the minimum operating flow rate during the above non-combustion hot water supply operation or combustion hot water supply operation, the controller determines that the hot water supply has ended due to the closing of the hot water supply location or the end of the hot water supply to the bathtub. And end the hot water supply operation.

Next, the process executed by the hot water supply system 2 will be described. FIG. 2 is a flowchart showing a process executed by the hot water supply system 2. As shown in FIG. 2, first, in step S11, the controller of the hot water supply system 2 determines whether or not the current time is a predetermined pre-boil time for hot water supply operation. The predetermined pre-boiling time is not particularly limited, but is predetermined, for example, based on the time when the hot water supply operation was executed in the past. For example, if the hot water supply operation is performed at 19:00 on average in the past week, today's predetermined pre-boil time is set to 18:00, which is one hour before that. When the current time reaches a predetermined pre-boil time, the controller determines Yes in step S11 and proceeds to step S12. On the other hand, if the current time is not the predetermined pre-boil time, the controller determines No in step S11 and stands by.

In the following step S12, the controller executes the pre-boiling operation by the HP unit 4. When the pre-boiling operation is executed, the low-temperature water in the tank 30 is boiled by the HP unit 4 to become hot water (hot water). The hot water (hot water) that has been boiled by the HP unit 4 is stored in the tank 30. When the tank 30 is full, the controller ends the pre-boil operation. When the tank 30 is full, the entire tank 30 is filled with hot water (hot water). Therefore, the detection temperatures of the upper thermistor 36, the middle thermistor 37, and the lower thermistor 38 fixed to the tank 30 are equal to or higher than a predetermined reference temperature (for example, 35 ° C.). The detection temperature of the upper thermistor 36, the middle thermistor 37, and the lower thermistor 38 is, for example, 45 ° C. Further, when the tank 30 is full, the inside of the tank going route 31 is also filled with hot water (hot water). Therefore, the detection temperature of the path thermistor 39 fixed to the tank going path 31 is also equal to or higher than a predetermined reference temperature (for example, 35 ° C.). The detection temperature of the path thermistor 39 is, for example, 45 ° C. By the pre-boiling operation in step S12, hot water for the hot water supply operation described later is stored in the tank 30.

In the following step S13, the controller executes the hot water supply operation. The hot water supply operation is executed, for example, by the user opening the hot water supply location. Alternatively, when the predetermined hot water filling time is reached, the hot water supply operation is automatically executed to fill the bathtub with hot water. In the hot water supply operation, the hot water in the tank 30 is supplied to the hot water supply location. When the hot water supply operation is executed, the hot water stored in the tank 30 is discharged. Then, the hot water in the tank going route 31 and the hot water in the tank 30 decrease. More specifically, when the hot water supply operation is executed, the hot water stored in the upper part of the tank 30 is discharged through the tank hot water passage 56, and the hot water in the tank going route 31 and the hot water stored in the lower part of the tank 30 are discharged. Moves upwards. On the other hand, since water is continuously supplied to the lower part of the tank 30 through the tank water supply path 46, the hot water in the tank going path 31 and the hot water in the tank 30 decrease, while the water increases by that amount. I will continue. Since the tank water supply path 46 is connected to the lower part of the tank 30, the amount of water in the lower part of the tank 30 increases. In addition, water increases in the tank going route 31. That is, hot water is discharged from the upper part of the tank 30 through the tank hot water passage 56, and water is supplied to the lower part of the tank 30 through the tank water supply path 46, so that the hot water in the tank going path 31 and the lower part of the tank 30 are stored. The hot water that was used to replace it with water. With the hot water supply operation, the amount of water in the tank going path 31 and in the lower part of the tank 30 increases.

When the hot water in the tank going route 31 and the hot water stored in the lower part of the tank 30 are replaced with water due to the hot water supply operation, usually, the hot water in the tank going route 31 is replaced with water first, and then the tank. The hot water stored in the lower part of 30 is replaced with water. First, the inside of the tank going path 31 is filled with water, and then the lower part of the tank 30 is filled with water. Therefore, when the detection temperature of the path thermistor 39 fixed to the tank going path 31 and the detection temperature of the lower thermistor 38 fixed to the lower part of the tank 30 are compared, the detection temperature of the path thermistor 39 is the detection of the lower thermistor 38. It becomes cold before the temperature.

However, contrary to the above, the detection temperature of the lower thermistor 38 may become lower than the detection temperature of the path thermistor 39. In the above-mentioned hot water supply system 2, the tank going path 31 is provided with a rising portion 35 extending upward from the tank 30 side toward the HP unit 4 side. Therefore, when the hot water in the tank going path 31 and the hot water stored in the lower part of the tank 30 are replaced with water, the hot water is not replaced with water at an early stage in the rising portion 35 extending above the tank going path 31, and the water is not replaced. It may take some time to replace with. As a result, the hot water stored in the lower part of the tank 30 may be replaced with water first, and then the hot water in the tank going route 31 may be replaced with water. First, the lower part of the tank 30 is filled with water, and then the inside of the tank going path 31 is filled with water. Further, in the above-mentioned hot water supply system 2, the path thermistor 39 is fixed to the rising portion 35 extending above the tank going path 31, and detects the temperature of the water in the rising portion 35. Therefore, when the detection temperature of the path thermistor 39 fixed to the tank going path 31 and the detection temperature of the lower thermistor 38 fixed to the lower part of the tank 30 are compared, the detection temperature of the lower thermistor 38 is the detection of the path thermistor 39. It may cool before the temperature.

In addition, the above hot water supply operation may require a large amount of hot water. For example, when bathing a bathtub, a large amount of hot water may be required for the hot water. Alternatively, if the user uses the shower, a large amount of hot water for the shower may be required. In such a case, even if the pre-boiling operation is executed in step S11 above, the hot water to be supplied to the hot water supply location may be insufficient by itself. That is, even if the tank 30 is full, there may be a shortage of hot water. Therefore, it is preferable to additionally boil the water in the tank 30 in order to make up for the lack of hot water. Further, in order to prevent the hot water in the tank 30 from running out, it is preferable to boil the water in the tank 30 at the earliest possible stage. Therefore, the hot water supply system 2 executes the following processing.

In step S14 after the hot water supply operation is executed, the controller determines whether or not the detected flow rate of the hot water side flow rate sensor 60 is equal to or higher than a predetermined reference flow rate (for example, 5 liters / min). When a large amount of hot water is required in the hot water supply operation in step S13, the flow rate of hot water discharged from the tank 30 through the tank going path 31 increases. For example, a large amount of hot water is discharged through the tank going route 31 in order to fill the bathtub with hot water. Therefore, the detected flow rate of the hot water side flow rate sensor 60 becomes large. If the detected flow rate of the hot water side flow rate sensor 60 is equal to or higher than the predetermined reference flow rate in step S14, the controller determines Yes and proceeds to step S15. On the other hand, if the detected flow rate of the hot water side flow rate sensor 60 is not (less than) a predetermined reference flow rate, the controller determines No in step S14 and ends the process.

Subsequently, in step S15, the controller determines whether or not the detection temperature of the path thermistor 39 is less than a predetermined reference temperature (for example, 35 ° C.). If the detection temperature of the path thermistor 39 is less than a predetermined reference temperature (for example, 35 ° C.), the controller determines Yes in step S15 and proceeds to step S17. On the other hand, if the detection temperature of the path thermistor 39 is not less than (or more than) a predetermined reference temperature (for example, 35 ° C.), the controller determines No in step S15 and proceeds to step S16.

In step S16 after determining No in step S15, the controller determines whether or not the detection temperature of the lower thermistor 38 is less than a predetermined reference temperature (for example, 35 ° C.). If the detection temperature of the lower thermistor 38 is less than a predetermined reference temperature (for example, 35 ° C.), the controller determines Yes in step S16 and proceeds to step S17. On the other hand, if both of the detected temperatures of the lower thermistor 38 are not less than (or more than) a predetermined reference temperature (for example, 35 ° C.), the controller determines No in step S16 and returns to step S15.

Subsequently, in step S17, the controller executes an additional boiling operation by the HP unit 4. When the additional boiling operation is executed, the low temperature water in the tank 30 is boiled by the HP unit 4 to become hot water (hot water). The hot water (hot water) that has been boiled by the HP unit 4 is stored in the tank 30. When the tank 30 is full, the controller ends the additional boiling operation.

The configuration and operation of the hot water supply system 2 of the embodiment have been described above. As is clear from the above description, the hot water supply system 2 of the embodiment is connected to the tank 30 for storing water, the HP unit 4 for boiling water by the boiling operation, and the lower part of the tank 30, and is connected to the lower part of the tank 30. It is provided with a tank water supply path 46 for supplying water to the lower part, a tank going path 31 which is connected to the lower part of the tank 30 and the HP unit 4 and supplies water to the HP unit 4 from the lower part of the tank 30. Further, the hot water supply system 2 is connected to the upper part of the tank 30 and the HP unit 4, and has a tank return path 33 for supplying the hot water after being boiled by the HP unit 4 from the HP unit 4 to the upper part of the tank 30. It is connected to the upper part of the tank 30 and includes a tank hot water passage 56 for discharging hot water from the upper part of the tank 30. Further, the hot water supply system 2 includes a hot water side flow rate sensor 60 that detects the flow rate of hot water discharged from the tank 30 through the tank hot water flow path 56, a path thermistor 39 that detects the temperature of water in the tank outbound path 31, and the tank 30. It is equipped with a lower thermistor 38 that detects the temperature of the water stored in the lower part of the water and a controller. When the detection flow rate of the hot water side flow sensor 60 is equal to or higher than the predetermined reference flow rate (for example, 5 liters / min), the controller determines that the detection temperature of the path thermistor 39 is less than the predetermined reference temperature (for example, 35 ° C.). Is when the HP unit 4 executes an additional boiling operation, or when the detected flow rate of the hot water side flow sensor 60 is equal to or higher than the predetermined reference flow rate and the detection temperature of the path thermistor 39 is equal to or higher than the predetermined reference temperature. Executes the additional boiling operation by the HP unit 4 when the detected temperature of the lower thermistor 38 is lower than the predetermined reference temperature.

That is, when the detection temperature of the path thermistor 39 becomes lower than the detection temperature of the lower thermistor 38, the controller executes an additional boiling operation based on the detection temperature of the path thermistor 39. Further, when the detection temperature of the lower thermistor 38 becomes lower than the detection temperature of the path thermistor 39, the additional boiling operation is executed based on the detection temperature of the lower thermistor 38.

In the hot water supply system 2, a large amount of hot water may be discharged from the tank 30 through the tank hot water supply path 56. For example, when hot water is poured into a bathtub, a large amount of hot water is required for hot water filling, and a large amount of hot water is discharged from the tank 30 through the tank discharge path 56. At this time, the detected flow rate of the hot water side flow rate sensor 60 that detects the flow rate of the hot water discharged from the tank 30 becomes equal to or higher than the predetermined reference flow rate. At this time, according to the above configuration, if the detection temperature of the path thermistor 39 for detecting the temperature of the water in the tank going path 31 is less than a predetermined reference temperature, the controller executes the boiling operation. As a result, the boiling operation can be executed at an early timing.

Further, according to the above configuration, even when the detection temperature of the path thermistor 39 is not lower than (or higher than) the predetermined reference temperature, the lower thermistor detects the temperature of the water stored in the lower part of the tank 30. When the detected temperature of 38 is less than a predetermined reference temperature, the controller executes the boiling operation. As a result, the boiling operation can be executed at an early timing. That is, in the above-mentioned hot water supply system 2, when water is supplied from the tank 30 through the tank hot water supply path 56 and water is supplied to the tank 30 through the tank water supply path 46, the hot water in the tank going path 31 and the tank 30 The hot water stored at the bottom replaces the water. At this time, for example, due to the long length of the tank going path 31, the time for replacing the hot water in the tank going path 31 with water may be long. As a result, the hot water stored in the lower part of the tank 30 may be replaced with water first, and then the hot water in the tank going path 31 may be replaced with water. As a result, it may take a long time for the detection temperature of the path thermistor 39 fixed to the tank going path 31 to be lower than the predetermined reference temperature. As a result, the detection temperature of the lower thermistor 38 may be lowered first, and then the detection temperature of the path thermistor 39 may be lowered. That is, the timing at which the detection temperature of the path thermistor 39 becomes low is delayed. However, according to the above configuration, the detection temperature of the lower thermistor 38 fixed to the lower part of the tank 30 is lower than the predetermined reference temperature even when the timing at which the detection temperature of the path thermistor 39 becomes low is delayed. In this case, the controller executes the boiling operation, so that the boiling operation can be executed at an early timing. Therefore, according to the above configuration, the boiling operation can be executed at the earliest possible timing when a large amount of hot water is required.

Further, in the above-mentioned hot water supply system 2, the tank going path 31 is provided with a rising portion 35 extending upward from the tank 30 side toward the HP unit 4 side. Further, the path thermistor 39 detects the temperature of the water in the rising portion 35 extending above the tank going path 31.

According to such a configuration, since the tank going path 31 is provided with the rising portion 35 extending upward, it is difficult for the hot water in the tank going path 31 to be replaced with water, and the time for replacing the hot water with water becomes longer. The path thermistor 39 detects the temperature of the water in the tank going path 31 at a position on the HP unit 4 side from the end 35a on the tank 30 side of the rising portion 35. As a result, the timing at which the detection temperature of the path thermistor 39 becomes low is further delayed. Therefore, in such a configuration, when the detection temperature of the path thermistor 39 is equal to or higher than a predetermined reference temperature, the above-mentioned configuration in which the boiling operation is executed based on the detection temperature of the lower thermistor 38 instead of the path thermistor 39 is particularly suitable. It is effective.

Although one embodiment has been described above, the specific embodiment is not limited to the above embodiment. In the following description, the same reference numerals will be given to the same configurations as those in the above description, and the description thereof will be omitted.

In the above embodiment, the tank going path 31 includes an ascending portion 35 extending upward from the tank 30 side toward the HP unit 4 side, but the present invention is not limited to this configuration, and the ascending portion 35 extending upward is not limited to this configuration. It is not necessary to have. Further, in the above embodiment, the path thermistor 39 is configured to detect the temperature of water in the rising portion 35 extending above the tank going path 31, but the configuration is not limited to this. In another embodiment, the path thermistor 39 may be configured to detect the temperature of water in the tank going path 31 other than the rising portion 35 extending upward.

Further, in the above embodiment, the route thermistor 39 is fixed to the ascending portion 35 of the tank going route 31, but the present invention is not limited to this configuration. In another embodiment, the route thermistor 39 may be fixed not to the ascending portion 35 of the tank going path 31 but to the tank going path 31 on the downstream side (HP unit 4 side) of the ascending portion 35. Even with such a configuration, the path thermistor 39 can detect the temperature of the water in the tank going path 31 at a position on the HP unit 4 side from the end 35a on the tank 30 side of the rising portion 35.

Further, in the above embodiment, the amount of hot water discharged from the tank 30 is directly detected by the hot water side flow rate sensor 60, but the present invention is not limited to this configuration. The hot water side flow rate sensor 60 attached to the tank hot water passage 56 is an example of a flow rate detecting device. In another embodiment, for example, the amount of hot water discharged from the curan or shower may be detected, and the amount of hot water discharged from the tank 30 may be calculated based on the detected value and the water supply temperature. That is, the amount of hot water discharged from the tank 30 may be indirectly detected.

Although specific examples of the present invention have been described in detail above, these are merely examples and do not limit the scope of claims. The techniques described in the claims include various modifications and modifications of the specific examples illustrated above. The technical elements described herein or in the drawings exhibit their technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the techniques illustrated in the present specification or drawings can achieve a plurality of purposes at the same time, and achieving one of the purposes itself has technical usefulness.

2: Hot water supply system 4: HP unit 6: Tank unit 8: Burner unit 24: HP controller 30: Tank 31: Tank outbound route 33: Tank return route 35: Ascending part 36: Upper thermistor 37: Middle part thermistor 38: Lower thermistor 39: Path thermistor 40: Water supply path 46: Tank water supply path 56: Tank hot water supply path 60: Hot water side flow sensor 74: Tank controller 75: Memory 80: Burner 82: Heat exchanger 100: Burner controller

Claims (2)

A tank to store water and
A heat pump that boils water by boiling operation,
A tank water supply path that is connected to the lower part of the tank and supplies water to the lower part of the tank,
A tank going path that is connected to the lower part of the tank and the heat pump and supplies water to the heat pump from the lower part of the tank.
A tank return path that is connected to the upper part of the tank and the heat pump and supplies hot water after being boiled by the heat pump from the heat pump to the upper part of the tank.
A tank hot water route that is connected to the upper part of the tank and discharges hot water from the upper part of the tank,
A flow rate detection device that detects the flow rate of hot water discharged from the tank through the tank discharge path, and
A first temperature detection device that detects the temperature of water in the tank going path, and
A second temperature detector that detects the temperature of the water stored in the lower part of the tank, and
Equipped with a control device
When the detected flow rate of the flow rate detecting device is equal to or higher than a predetermined reference flow rate, the control device performs a boiling operation by the heat pump when the detection temperature of the first temperature detecting device is lower than the predetermined reference temperature. When the detection flow rate of the flow rate detecting device is equal to or higher than the predetermined reference flow rate and the detection temperature of the first temperature detecting device is equal to or higher than the predetermined reference temperature, the second temperature detecting device is executed. A hot water supply system that executes a boiling operation by the heat pump when the detected temperature of is less than a predetermined reference temperature. The tank going path includes a rising portion extending upward from the tank side toward the heat pump side.
The hot water supply system according to claim 1, wherein the first temperature detecting device detects the temperature of water in the tank going path at a position on the heat pump side from the end of the rising portion on the tank side.

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