JP5821002B2 - Hot water system - Google Patents

Description

  The present invention relates to a hot water supply system.

  Conventionally, a hybrid hot water supply system using a heat pump type hot water heater and an electric water heater has been proposed (see, for example, Patent Document 1).

  In the hot water supply system described in Patent Document 1, when the amount of hot water stored in the heat pump type hot water heater decreases, the electric water heater is operated and hot water is supplied from the electric water heater so that hot water does not run out.

JP 2009-97804 A

  In the hot water supply system of Patent Document 1 described above, in summer when the amount of hot water used is small, a heat pump water heater can provide the necessary amount of hot water, so that an auxiliary electric water heater may not be used for a long time. is there. In this case, there is a possibility that the water quality deteriorates due to, for example, corruption of water accumulated in the pipe connecting the hot water supply pipe to the load and the electric water heater. In addition, when switching to hot water supply from an electric water heater, the temperature of the hot water from the electric water heater does not rise easily because the heat exchange part of the electric water heater is cold, and the water accumulated in the piping also cools. Therefore, there is a possibility that cold water is temporarily supplied to the hot water supply load.

  The present invention has been made in view of the above-mentioned problems, and the object of the present invention is to provide a hot water supply system in which water having deteriorated water quality or cold water is hardly supplied when switched to hot water supply from an auxiliary water heater. It is to provide.

In order to solve the above problems, a hot water supply system of the present invention includes a first hot water supply system using a heat pump, an auxiliary hot water heater, and a first opening / closing provided in a first pipe connecting a main hot water heater and a hot water supply load. a valve, and a second on-off valve provided in the second pipe connecting the auxiliary water heater and hot water supply load, during the hot water supply load and drainage dedicated drainage pipe that is not connected to the second pipe A third on-off valve provided, a main water heater, an auxiliary water heater, and a hot water controller for controlling the first to third on-off valves, the hot water controller from the main water heater to the auxiliary Before switching the hot water supply source to the water heater, the third on-off valve is opened with the second on-off valve closed, and the water from the auxiliary water heater is drained through the drain pipe , and after drainage, The second on-off valve is configured to open after the third on-off valve is closed. It is characterized in. Here, the water from the auxiliary water heater is drained before the hot water source is switched to the auxiliary water heater, but the drained water is not limited to cold water but includes cold water, hot water (hot water), and medium temperature water.

In this hot water supply system, when hot water is not supplied from the auxiliary water heater for a predetermined period, it is also preferable to drain the water from the auxiliary water heater through the drainage pipe .

In this hot water supply system, the hot water supply control unit controls the operation of the main water heater and the auxiliary hot water heater based on the detection result of the hot water amount detection unit that detects the amount of hot water in the hot water storage tank that stores hot water heated by the heat pump, When the amount of hot water detected by the hot water amount detection unit falls below a predetermined first threshold value while the hot water supply is being supplied from the main water heater to the hot water supply load, the hot water supply control unit operates the auxiliary water heater, It is also preferable that water is drained through drainage piping , and after draining, the hot water supply source to the hot water supply load is switched from the main water heater to the auxiliary water heater.

In this hot water supply system, the hot water control unit drains the water from the auxiliary water heater through the drainage pipe, then supplies the hot water from both the main water heater and the auxiliary water heater, and then switches to hot water from the auxiliary water heater. It is also preferable.

  In this hot water supply system, when the amount of hot water detected by the hot water amount detection unit becomes equal to or greater than a predetermined second threshold in a state where the hot water supply is switched from the auxiliary hot water heater, the hot water supply control unit supplies the hot water supply source to the hot water supply load from the auxiliary water heater. It is also preferable to switch to the main water heater and stop the auxiliary water heater.

  According to the present invention, since the water from the auxiliary water heater is drained before the hot water source is switched from the main water heater to the auxiliary water heater, the quality of the water accumulated in the pipe from the auxiliary water heater deteriorates. Even if it is, the possibility that the water is supplied to the hot water supply load can be reduced. Also, since the water from the auxiliary water heater is drained before the hot water source is switched to the auxiliary water heater, it takes time to get warm water from the auxiliary water heater, or the piping from the auxiliary water heater is cold. Even when water is accumulated, the possibility that cold water is supplied to the hot water supply load can be reduced.

It is a system configuration figure of a hot-water supply system using the hot-water supply control device of this embodiment. It is explanatory drawing explaining operation | movement same as the above. It is a time chart explaining operation | movement same as the above.

  An embodiment of a hot water supply system according to the present invention will be described with reference to FIGS.

FIG. 1 is a schematic system configuration diagram of a hot water supply system A of the present embodiment. The hot water supply system A includes a main water heater 1, an auxiliary water heater 2, a control panel 3 serving as a hot water supply control unit, an on-off valve 4 (first on-off valve), and an on-off valve 5 (second on-off valve) . A drain valve 6 (third on-off valve) and a temperature sensor 7 are provided as main components.

The main water heater 1 heats the water supplied from the water supply pipe 11 with the heat pump 1a and stores the hot water in the hot water storage tank 1b. The hot water stored in the hot water storage tank 1b is sent to the hot water supply pipe 14 connected to the hot water supply load 20 via the hot water supply pipe 12 (first pipe) and the on-off valve 4, and the hot water supply load 20 (for example, a dishwasher). And used for hot water supply currants, etc.). In addition, since the structure of the heat pump 1a is well-known conventionally, the description is abbreviate | omitted.

The auxiliary water heater 2 includes a heating source different from that of the main water heater 1, and in this embodiment, the auxiliary water heater 2 is a gas water heater that heats water with a gas burner (heating source) that burns combustible gas such as city gas. It is configured. The auxiliary water heater 2 ignites the gas burner when the flow rate of the water flowing in from the water supply pipe 11 exceeds a certain amount, heats the water in a heat exchanging section disposed above the gas burner, and boiles the hot water. The hot water supply pipe 14 is supplied via the pipe 13 and the on-off valve 5. A hot water supply pipe 13 (second pipe) that connects between the hot water outlet of the auxiliary water heater 2 and the hot water supply pipe 14 is connected to the drainage pipe 15 via the drain valve 6. In addition, since the structure of a gas water heater is well-known conventionally, the description is abbreviate | omitted.

  The on-off valves 4 and 5 and the drain valve 6 are each configured by an electrically controlled on-off valve that switches to an open state or a closed state in accordance with a drive signal input from the control panel 3.

  The temperature sensor 7 is configured using a resistance temperature detector such as a thermistor, for example, measures the temperature of hot water stored in the hot water storage tank 1b of the main water heater 1 at one or more level positions, and controls the measurement result. Output to panel 3.

  The control panel 3 includes an arithmetic processing unit 31, a memory 32, a timer 33, and a drive circuit 34.

  The arithmetic processing unit 31 performs general control of the hot water supply system A by executing a built-in program. The calculation processing unit 31 receives the measurement result of the temperature sensor 7 and calculates how much hot water above a predetermined temperature is stored based on the hot water temperature at a predetermined level in the hot water storage tank 1b. And in the arithmetic processing part 31, based on the detection result of the amount of hot water stored in the hot water storage tank 1b, operation control of the main water heater 1 and the auxiliary hot water heater 2, and switching control of the on-off valves 4, 5 and the drain valve 6 are performed. Do. Here, the temperature sensor 7 and the arithmetic processing unit 31 constitute a hot water amount detection unit that calculates the amount of hot water stored in the hot water storage tank 1b.

  The drive circuit 34 outputs a drive signal to the corresponding on-off valve 4, 5 or drain valve 6 based on the control signal input from the arithmetic processing unit 31, and switches to the open state or the closed state.

  In the memory 32, various threshold values and a count time by the timer 33 are set. Here, as the threshold value, the detected temperature T1 of the temperature sensor 7 corresponding to the amount of hot water in the hot water storage tank 1b when the hot water supply source is switched from the main water heater 1 to the auxiliary water heater 2 is referred to as the first threshold value. Is set. Further, as a threshold value, the detected temperature T2 (> T1) of the temperature sensor 7 corresponding to the amount of hot water in the hot water storage tank 1b when the hot water supply source is returned from the auxiliary water heater 2 to the main water heater 1 (this amount of hot water is referred to as a second threshold value). Is set. In addition, as the counting time, before switching the hot water supply source to the auxiliary water heater 2, the time for draining the water from the auxiliary water heater 2 (this time is referred to as the drainage time), the water from the auxiliary water heater 2 is periodically The time interval until the water is drained (this time interval is called the drainage time interval) is stored. In the present embodiment, the drainage time for draining before switching to the auxiliary water heater 2 is set to 1 minute, for example, and the drainage time interval is set to 3 days, for example. The drainage time and the drainage time interval may be set as appropriate according to the intended use.

  Here, the control operation by the arithmetic processing unit 31 will be described with reference to FIGS. FIG. 2 is an explanatory diagram showing the relationship between the hot water temperature detected by the temperature sensor 7 and the open / close state of the on-off valves 4 and 5. FIG. 3 is a time chart for explaining the operation of each part when the hot water supply source is switched from the main water heater 1 to the auxiliary water heater 2.

  When the temperature detected by the temperature sensor 7 is higher than the threshold value T1 set in the memory 32, that is, when the amount of hot water in the hot water storage tank 1b is larger than the first threshold value, the arithmetic processing unit 31 opens the on-off valve 4 5 and a control signal for switching the drain valve 6 to the closed state is output to the drive circuit 34. The drive circuit 34 switches the on-off valve 4 to an open state and the on-off valve 5 and the drain valve 6 to a closed state based on a control signal from the arithmetic processing unit 31. In this case, hot water is supplied from the main water heater 1 to the hot water supply load 20. Moreover, water does not flow into the auxiliary water heater 2, and the gas burner is extinguished. Therefore, hot water is always supplied from the main water heater 1 using the heat pump, which has a lower running cost and less carbon dioxide emission than the auxiliary water heater 2 such as a gas water heater.

  On the other hand, when a large amount of hot water is used in the hot water supply load 20 and the amount of hot water in the hot water storage tank 1b decreases, the temperature detected by the temperature sensor 7 decreases. When the temperature detected by the temperature sensor 7 is equal to or lower than T1, that is, when the amount of hot water in the hot water storage tank 1b is equal to or lower than the first threshold value, the arithmetic processing unit 31 performs control to switch the hot water supply source from the main water heater 1 to the auxiliary water heater 2. Do. The switching control operation in this case will be described with reference to FIG.

  When the temperature detected by the temperature sensor 7 becomes equal to or lower than T1 at time t1 (that is, when the amount of hot water in the hot water storage tank 1b becomes equal to or lower than the first threshold value), the arithmetic processing unit 31 first sends a control signal for opening the drain valve 6 to the drive circuit. 34, and the timer 33 starts the counting operation of the drainage time Ta. At this time, the drain valve 6 is switched to the open state by the drive circuit 34, and the water accumulated in the hot water supply pipe 13 is drained through the drain pipe 15, so that the auxiliary hot water heater 2 is stopped while it is stopped. The water accumulated in the hot water pipe 13 is drained. Further, since the amount of water flowing through the auxiliary water heater 2 becomes a certain amount or more, the auxiliary water heater 2 ignites the gas burner and starts the heating operation. However, the temperature of the hot water from the auxiliary water heater 2 does not rise immediately because the heat exchanger is cold, but the water from the auxiliary water heater 2 is drained until the drainage time Ta elapses from time t1. Since the water is drained through the service pipe 15, cold water is not supplied to the hot water supply load 20. Here, the water from the auxiliary water heater 2 is drained before the hot water source is switched to the auxiliary water heater 2, but the drained water is not limited to cold water. That is, the drained water includes cold water, warm water (hot water), and medium temperature water regardless of the temperature. The drainage time Ta may be set as appropriate depending on the pipe length, the capacity of the heat exchange unit, and the like.

  And if said drainage time Ta passes from the time t1 (time t2), the arithmetic processing part 31 will drive the control signal which switches the drain valve 6 to a closed state, and the control signal which switches the on-off valve 5 to an open state. 34. At this time, the on-off valves 4 and 5 are both opened, and hot water is supplied from both the main water heater 1 and the auxiliary water heater 2 to the hot water supply load 20. Therefore, even when the hot water temperature of the auxiliary water heater 2 is not sufficiently high, cold water is not sent to the hot water supply load 20 by mixing the hot water from the hot water heater 1 and supplying hot water.

  Thereafter, when a predetermined time Tb (for example, 10 seconds) elapses from time t2, the arithmetic processing unit 31 outputs a control signal for switching the on-off valve 4 to the closed state to the drive circuit 34, and the drive circuit 34 closes the on-off valve 4 Switch to state. At this time, since the on-off valve 4 is switched to the closed state and the on-off valve 5 is switched to the open state, the hot water supply from the main water heater 1 is stopped and the hot water supply 20 is supplied from only the auxiliary water heater 2. During the hot water supply from the auxiliary water heater 2, the heat pump 1a of the main water heater 1 continues the operation of heating the water from the water supply pipe 11 and storing it in the hot water storage tank 1b, and the amount of hot water in the hot water storage tank 1b increases.

  When the temperature detected by the temperature sensor 7 is equal to or higher than T2 (that is, when the amount of hot water in the hot water storage tank 1b is equal to or higher than the second threshold value), the arithmetic processing unit 31 switches the open / close valve 4 to the open state and the open / close valve 5 to the closed state. A control signal is output to the drive circuit 34. At this time, the open / close valve 4 is switched to the open state and the open / close valve 5 is switched to the closed state by the drive circuit 34, and hot water is supplied from the main water heater 1 to the hot water supply load 20. Moreover, since the on-off valve 5 is closed, water does not flow to the auxiliary water heater 2, so the auxiliary water heater 2 extinguishes the gas burner and stops its operation.

  As described above, the control panel 3 serving as the hot water supply control unit switches to the hot water supply from the auxiliary water heater 2 when the hot water supply capacity of the main water heater 1 using the heat pump is reduced. Before switching to the auxiliary water heater 2, the water from the auxiliary water heater 2 is drained. Then, the control panel 3 switches the hot water supply source from the main water heater 1 to the auxiliary water heater 2 after the draining operation.

Thereby, when switching the hot water supply source to the auxiliary water heater 2, it is possible to reduce the possibility that the cold water accumulated in the hot water supply pipe 13 connecting between the auxiliary water heater 2 and the hot water supply pipe 14 is supplied to the hot water supply load 20. . Moreover, when the heat exchange part of the auxiliary water heater 2 is cooled, it takes time until the temperature of the hot water rises. However, since the water from the auxiliary water heater 2 is drained before switching to the auxiliary water heater 2, the activation is started. It is possible to reduce the possibility that cold water from the auxiliary water heater 2 is sometimes supplied to the hot water supply load. In addition, when the hot water supply capacity of the main water heater 1 is reduced, hot water is not easily generated by supplying hot water from the auxiliary water heater 2. The arithmetic processing unit 31 of the control panel 3 determines that the drainage has been completed when a predetermined time has elapsed from the start of drainage, and terminates the drainage operation. The draining operation may be terminated when the hot water temperature of the water heater 2 becomes equal to or higher than a predetermined temperature.

  In addition, the control panel 3 serving as a hot water supply control unit includes an arithmetic processing unit 31 that controls operations of the main water heater 1 and the auxiliary water heater 2 based on the detection result of the hot water amount detection unit that detects the amount of hot water stored in the hot water storage tank 1b. ing. When the amount of hot water detected by the hot water amount detection unit falls below a predetermined first threshold in a state where hot water is supplied from the main water heater 1 to the hot water supply load 20, the arithmetic processing unit 31 drains the water from the auxiliary water heater 2, After the drainage operation, the arithmetic processing unit 31 switches the hot water supply source for the hot water supply load 20 from the main water heater 1 to the auxiliary water heater 2.

  Thus, when the hot water supply source is switched to the auxiliary water heater 2, cold water accumulated in the hot water supply pipe 13 connecting between the auxiliary hot water heater 2 and the hot water supply pipe 14, or cold water discharged from the auxiliary water heater 2 at the time of start-up is supplied. The possibility of being supplied to the load 20 can be reduced.

  Further, in the arithmetic processing unit 31, after draining the water from the auxiliary water heater 2, the hot water is supplied from both the main water heater 1 and the auxiliary water heater 2, and then switched to the hot water from the auxiliary water heater 2.

  Thereby, at the time of switching to the auxiliary water heater 2, it is possible to provide a period during which hot water is supplied from both the main water heater 1 and the auxiliary water heater 2, and hot water from the main water heater 1 and hot water from the auxiliary water heater 2 can be supplied. The possibility of supplying cold water to the hot water supply load 20 can be further reduced by mixing and supplying hot water.

  In addition, when the amount of hot water detected by the hot water amount detection unit becomes equal to or greater than a predetermined second threshold in the state where the hot water supply from the auxiliary water heater 2 is switched, the arithmetic processing unit 31 supplies the hot water supply source to the hot water supply load 20 as the auxiliary water heater 2. Is switched to the main water heater 1 and the auxiliary water heater 2 is stopped.

  Thereby, hot water can be supplied from the main water heater 1 using a heat pump with low running cost and low carbon dioxide emission.

  By the way, in the control panel 3, when the amount of hot water stored in the hot water storage tank 1b decreases, the hot water supply source is switched from the main hot water heater 1 to the auxiliary hot water heater 2, but only the main hot water heater 1 is used in summer when the consumption of hot water is low. There is a possibility that the hot water is supplied and the auxiliary water heater 2 is not used for a long time. If the auxiliary water heater 2 has been stopped for a long time, ignition failure of the gas burner included in the auxiliary water heater 2 may occur, or the water in the hot water supply pipe 13 connecting the auxiliary water heater 2 and the hot water supply pipe 14 may be spoiled. There is sex.

  Therefore, the arithmetic processing unit 31 of the control panel 3 causes the timer 33 to perform a counting operation at a predetermined drainage time interval. If the auxiliary water heater 2 is not performing a hot water supply operation when the timer 33 counts up, the arithmetic processing unit 31 outputs a control signal for opening the drain valve 6 to the drive circuit 34 and A counting operation for a predetermined drainage time (for example, 1 minute) is started. At this time, the drain valve 6 is switched to the open state by the drive circuit 34 and the water accumulated in the hot water supply pipe 13 is drained. Further, since the amount of water flowing through the auxiliary water heater 2 becomes a certain amount or more, the auxiliary water heater 2 ignites the gas burner and performs an operation of heating the water by the heat exchange unit.

  When the timer 33 completes the drain time counting operation, the arithmetic processing unit 31 outputs a control signal for switching the drain valve 6 to the closed state to the drive circuit 34, and then starts the timer 33 to count the drain time interval. Let At this time, since the drive circuit 34 switches the drain valve 6 to the closed state, drainage is stopped and water does not flow to the auxiliary water heater 2, so the auxiliary water heater 2 extinguishes the gas burner and stops its operation.

When hot water is supplied from the auxiliary water heater 2 at the time when the timer 33 completes the drain time interval counting operation, the arithmetic processing unit 31 keeps the drain valve 6 closed and resets the timer 33. Then, the draining time interval counting operation is executed again.

  As described above, the arithmetic processing unit 31 drains water from the auxiliary water heater 2 when the hot water supply from the auxiliary water heater 2 is not performed for a predetermined period (the above drain time interval).

  Thereby, since the water from the auxiliary water heater 2 is drained when the hot water supply from the auxiliary water heater 2 is not performed for a predetermined period (the above drainage time interval), the auxiliary water heater 2 is operated periodically. Thus, the malfunction of the auxiliary water heater 2 is less likely to occur. In addition, since the water in the pipe connecting between the auxiliary water heater 2 and the hot water supply pipe 14 is periodically drained, water does not remain in the pipe for a long time. The possibility of water rot can be reduced.

A hot-water supply system 1 main water heater 1a pump 1b hot water storage tank 2 auxiliary water heaters 3 control panel (hot water supply control section)
4 on- off valve (first on-off valve)
5 On-off valve (second on-off valve)
6 Drain valve (third on-off valve)
7 Temperature sensor (hot water detector)
12 Hot water supply pipe (first pipe)
13 Hot water supply pipe (second pipe)
15 Drainage pipe 20 Hot water supply load 31 Calculation processing section (hot water supply control section, hot water amount detection section)
32 Memory 33 Timer 34 Drive circuit

Claims (5)

A main water heater using a heat pump, an auxiliary water heater,
A first on-off valve provided in a first pipe connecting the main water heater and a hot water supply load;
A second on-off valve provided in a second pipe connecting the auxiliary water heater and the hot water supply load;
A third on-off valve provided between the second pipe and drainage pipes of the drainage dedicated the hot water supply load is not connected,
A hot water supply control unit for controlling the main water heater, the auxiliary water heater, and the first to third on-off valves;
The hot water supply control unit opens the third on-off valve with the second on-off valve closed before switching the hot water supply source from the main water heater to the auxiliary water heater. Is drained through the drainage pipe , and after draining, the third on-off valve is closed and then the second on-off valve is opened. The hot water supply system according to claim 1, wherein when no hot water is supplied from the auxiliary water heater, the water from the auxiliary water heater is drained through the drain pipe . The hot water control unit controls operations of the main water heater and the auxiliary water heater based on a detection result of a hot water amount detection unit that detects the amount of hot water in a hot water storage tank that stores hot water heated by the heat pump,
When the amount of hot water detected by the hot water amount detection unit falls below a predetermined first threshold in a state where hot water is supplied from the main water heater to the hot water supply load, the hot water control unit operates the auxiliary water heater, The water from the auxiliary water heater is drained through the drain pipe , and after draining, the hot water source to the hot water load is switched from the main water heater to the auxiliary water heater. A hot water supply system according to any one of the above. The hot water supply control unit drains the water from the auxiliary water heater through the drain pipe, and then supplies hot water in both the main water heater and the auxiliary water heater, and then supplies the hot water from the auxiliary water heater. The hot water supply system according to claim 3, wherein the hot water supply system is switched.   When the amount of hot water detected by the hot water amount detection unit is equal to or greater than a predetermined second threshold in a state where the hot water supply is switched from the auxiliary water heater, the hot water control unit supplies the hot water source to the hot water load as the auxiliary water heater. The hot water supply system according to claim 3, wherein the auxiliary water heater is stopped while switching from the main water heater to the main water heater.

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