JP2003148804A - Hot water temperature control method for solar water heater supplying hot water of table temperature - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hot water control method supplying hot water of a stable temperature even when the hot water temperature (Th) in a hot water tank is changed in some degree. SOLUTION: In controlling the hot water temperature of a solar water heater, the hot water from the hot water tank 15 is adjusted to a temperature of low level TLset not over a lower limit capacity of an auxiliary heat source unit 4, regardless of the change of the hot water Th until the hot water supply is stopped including the start of the hot water supply, in a case when the hot water temperature Th of the hot water tank 15 is less than the setting temperature Tset in starting the hot water supply, and then the hot water is additionally heated and adjusted by the auxiliary heat source unit 4. When the hot water temperature Th in the hot water tank 15 is same as or higher than Tset in starting the hot water supply, the hot water in the hot water tank 15 is cooled by the water through a control part 8 and adjusted under a condition free from the heating by the auxiliary heat source unit 4. Then the hot water from the hot water tank 15 is adjusted to TLset regardless of the change of the hot water temperature Th until the stop of the hot water supply from a time when the hot water temperature Th becomes lower than Tset, and the hot water is additionally heated by the auxiliary heat source unit 4 to be adjusted to a desired hot water temperature.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling hot water supply temperature of a solar water heater comprising a solar water heater (main body) and an auxiliary heat source device connected to the downstream of the solar water heater.

[0002]

2. Description of the Related Art A solar water heater comprising a solar water collector (main body) including a solar heat collector, a hot water storage tank and a control unit, and an auxiliary heat source including a combustion heating unit and a control unit has been conventionally known. ing. A method of controlling the hot water supply temperature using such a solar water heater will be described with reference to the flowchart of the conventional example of FIG. When the operation switch is turned on, first, the water flow is detected by the water flow detector arranged in the hot water supply path. “Water flow present” is, in other words, “hot water supply starts (during hot water supply)”. During hot water supply, the hot water temperature (Th) of the hot water storage tank is constantly monitored via a thermometer.
Therefore, when the hot water temperature (Th) of the hot water storage tank is equal to or higher than the desired hot water supply temperature (set temperature; Tset), the mixing device on the solar water heater (main body) side is used to remove hot water from the hot water storage tank and branch pipes. Water is mixed so that the mixed hot water temperature (Tmix) becomes the desired hot water supply temperature (set temperature; Tset). At this time,
No additional heating with the auxiliary heat source. When the hot water temperature (Th) of the hot water storage tank is lower than the desired hot water supply temperature (set temperature; Tset), the mixing device mixes the hot water from the hot water storage tank with the water from the branch pipe to lower the lower limit capacity of the auxiliary heat source device. Once the temperature is lowered to a low level (TLset) that does not exceed, then additional heating is performed with the auxiliary heat source device, and hot water is adjusted to the desired hot water temperature.

[0003]

When the hot water temperature is controlled by such a method, when the hot water temperature (Th) of the hot water storage tank, which was initially less than Tset, fluctuates to exceed Tset during hot water supply, The temperature of the mixed hot water to the auxiliary heat source device is transferred from TLset to Tset, and the additional heating of the auxiliary heat source device is also controlled from operation to stop. At this time, the temperature of the mixed hot water passing through the hot water supply path connecting the mixing device and the auxiliary heat source device is TLset, and the hot water is supplied without additional heating. Also, initially
When the hot water temperature (Th) of the hot water storage tank, which was the same as or higher than Tset, fluctuated below Tset, the mixed hot water temperature to the auxiliary heat source device moved from Tset to TLset, and the auxiliary heat source device operated from forced stop. It becomes control. In this case, the temperature of the hot water passing through the inside of the pipe connecting the mixing device and the auxiliary heat source device is Tset, and if this is additionally heated, the amount of heating by the auxiliary heat source device is temporarily higher than the desired hot water supply temperature. Only hot water is supplied. In order to avoid this superheated hot water supply, another control method (control to detect the water temperature on the water input side of the auxiliary heat source device or the hot water supply side to stop heating) can be performed.
The hot water supply temperature becomes unstable with a delay in control. The object of the present invention is to solve the above problems, namely,
It is an object of the present invention to provide a hot water supply temperature control method capable of supplying hot water at a stable temperature even if the hot water temperature (Th) of the hot water storage tank fluctuates to some extent.

[0004]

In order to achieve the above object, the control method of the present invention has the following configuration. That is, in the present invention, the solar water heater (main body) 1 including the solar heat collector 11 and the auxiliary heat source device 4 connected to the downstream thereof by piping.
When controlling the hot water supply temperature (at the end) of the solar water heater 20 configured by and when the hot water temperature (Th) of the hot water storage tank 15 is less than the desired hot water supply temperature (set temperature; Tset) at the start of hot water supply, No matter how the hot water temperature (Th) of the hot water storage tank 15 changes until the hot water supply is stopped (that is, the water flow is stopped), including the start of hot water supply, the hot water from the hot water storage tank 15 is removed from the hot water storage tank 15 on the solar water heater (main body) side. Is adjusted to a low level temperature (TLset) that does not exceed the lower limit capacity of the auxiliary heat source device 4, and is then additionally heated on the auxiliary heat source device side to adjust to the desired hot water supply temperature. on the other hand,
At the start of hot water supply, if the hot water temperature (Th) of the hot water storage tank 15 is equal to or higher than the desired hot water temperature (set temperature; Tset), the hot water at the outlet end of the hot water supply is provided on condition that the auxiliary heat source device 4 does not heat the hot water. In order for the temperature to reach the desired hot water supply temperature (set temperature; Tset),
On the solar water heater (main body) side, the hot water in the hot water storage tank 15 is diluted with water via the control unit 8 to adjust it to a desired hot water supply temperature. If the hot water temperature (Th) of the hot water storage tank 15 becomes lower than the desired hot water supply temperature after the hot water supply is started, the hot water temperature of the hot water storage tank 15 is stopped from that point until the hot water supply is stopped (that is, the water flow is stopped). No matter how the (Th) changes, on the solar water heater (main body) side, the hot water from the hot water storage tank 15 does not exceed the lower limit capacity of the auxiliary heat source device 4 at a low level temperature (TLse
After adjusting to t), additional heating is performed on the auxiliary heat source side to adjust to the desired hot water supply temperature.

In the above control method, as the solar water heater (main body) 1, a solar heat collector 11, a hot water storage tank 15 for storing hot water heated via the solar heat collector 11, and a hot water temperature of the hot water storage tank 15 are stored. A solar water heater (main body) including a thermometer 5 for measuring (Th) and a mixing device 3 for mixing hot water from the hot water storage tank 15 and water from the branch pipe 2 can be used. In that case, when the hot water temperature (Th) of the hot water storage tank 15 is equal to or higher than the desired hot water supply temperature (set temperature; Tset), the hot water temperature of the hot water storage tank 15 is the hot water at the outlet side (of the mixing device 3). It can be adjusted by diluting and mixing with water in the mixing device 3 so that the temperature becomes the desired hot water supply temperature.
Here, the diluting and mixing in the mixing device 3 is usually
The mixing ratio of hot and cold water is adjusted according to the opening degree of the built-in mixing valve.

[0006]

[Function] If the hot water temperature (Th) of the hot water storage tank at the start of hot water supply is lower than the desired hot water supply temperature (set temperature; Tset), then the auxiliary heat source is in operation until the hot water supply is stopped (that is, the water flow is stopped). Is. On the other hand, when the hot water temperature (Th) of the hot water storage tank at the start of hot water supply is equal to or higher than the desired hot water supply temperature (set temperature), the auxiliary heat source device is normally in the stopped state. However,
If the hot water temperature (Th) of the hot water storage tank changes to exceed the desired hot water supply temperature (set temperature) during hot water supply, the auxiliary heat source device changes from the stopped state to the operating state, but this is only once. After that, the auxiliary heat source is in the operating state until the hot water supply is stopped. In any case, the auxiliary heat source unit (heating and combustion unit) will not be turned on or off during hot water supply,
Hot water can be supplied at a stable temperature.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be described more specifically with reference to the drawings. Before describing the method for controlling the hot water supply temperature of the present invention, first, the solar water heater used will be described with reference to FIG. The solar water heater 20 is mainly composed of a solar water heater (main body) 1 including a solar heat collector 11 and an auxiliary heat source device 4 having a combustion heating unit. In the casing of the solar water heater (main body) 1, there is a hot water storage tank 15 having a heat exchanger 10, and in a circulation pipe (forward pipe and return pipe) 12 connecting the heat exchanger 10 and the solar heat collector 11. Is filled with a heat medium and forcedly circulated by the circulation pump 13 to warm the water in the hot water storage tank 15. The temperature (Th) of the hot water in the hot water storage tank 15 is monitored via the thermometer 5. In the hot water flow path (hot water supply pipe) on the solar water heater (main body) side, there are a hot water tank outlet pipe 14 for supplying hot water from the hot water tank 15, and a branch pipe 2 for branching water at the hot water tank inlet side to supply water. There is a hot and cold water mixing pipe after these two pipes have joined, and a mixing device 3 for mixing hot and cold water is arranged at the joining portion, and the hot and cold water mixing ratio is determined by the opening degree of a built-in mixing valve. Further, a water flow detector 9 is arranged in the middle of the water supply pipe on the upstream side of the hot water storage tank. Then, the hot water from the hot and cold water mixing pipe flows into the auxiliary heat source device side, and is additionally (auxiliarily) heated by the auxiliary heat source device 4 if necessary, and then supplied to each hot water supply terminal.

Regarding the control section of the solar water heater 20, the first control section 8 is arranged on the solar water heater (main body) side, and the second control section 16 is arranged on the auxiliary heat source side. The control unit 8 and the second control unit 16 are electrically connected via a communication cord. A remote control unit (remote control) 6 is connected to the first control unit 8, and a desired hot water supply temperature (set temperature; Tset) can be input and set using this. The desired hot water supply temperature (set temperature; Tset) set by the remote controller 6 is transmitted not only to the first control unit 8 on the solar water heater side but also to the second control unit 16 on the auxiliary heat source side. As a result, the user can recognize the desired hot water supply temperature (that is, the set temperature: Tset) on both the solar water heater side and the auxiliary heat source side. Data communication from the remote controller 6 to the second control unit 16 via the first control unit 8
A method of connecting the cords on the same communication line and directly receiving the data may be used.

Next, the method for controlling the hot water supply temperature of the present invention will be described with reference to the flow chart of FIG. When the operation switch is turned on, first, the water flow detector 9 arranged in the hot water supply path
To detect water flow. "There is a water flow" means "starting hot water supply (during hot water supply)".

When the hot water temperature (Th) of the hot water storage tank 15 is equal to or higher than the desired hot water supply temperature (set temperature; Tset), the hot water storage tank 15 is heated by the mixing device 3 on the solar water heater (main body) side.
The hot water is cooled with water from the branch pipe 2 and the hot water temperature (Tm
Adjust so that ix) becomes the desired hot water supply temperature (set temperature; Tset). At this time, additional heating by the auxiliary heat source device 4 is not performed.

When the hot water temperature (Th) of the hot water storage tank is lower than the desired hot water supply temperature (set temperature; Tset), the mixing device 3 mixes the hot water from the hot water storage tank 15 with the water from the branch pipe 2 to generate an auxiliary heat source. After lowering the temperature to a low level temperature (TLset) that does not exceed the lower limit capacity of the heater 4, additional heating is performed by the auxiliary heat source device 4 and then hot water is adjusted to the desired hot water temperature. Here, while the water flow detector 9 arranged in the hot water supply path is detecting the water flow, that is, while the hot water supply is not stopped midway, this cycle (Fig. The middle part of the cycle) will spin around.

When the hot water storage tank hot water temperature (Th) is equal to or higher than the desired hot water supply temperature (Tset) at the start of hot water supply, the tank hot water temperature (Th) is then changed to the desired hot water supply temperature (Tse).
When it changes to fall below t), the cycle of the central portion in FIG. 1 is entered. That is, the mixing device 3 mixes the hot water from the hot water storage tank 15 with the water from the branch pipe 2 to lower the temperature to a low level temperature (TLset) that does not exceed the lower limit capacity of the auxiliary heat source device 4, and then In addition, the auxiliary heat source device 4 performs additional heating to adjust the temperature to the desired hot water supply temperature and supply hot water. Once in this cycle, the water flow stop (ie
It goes around the cycle regardless of the hot water temperature (Th) in the hot water storage tank until the hot water is stopped.

When the water flow detector 9 detects the water flow stop, that is, when the hot water supply is stopped (including a temporary stop), the above cycle (the cycle at the central portion in FIG. 1) is canceled and the initial operation is started. Return to the switch ON state.

In the above example, the water flow detector 9 is provided on the upstream side of the hot water storage tank 15, but this is not limited to this.
It may be provided on the downstream side of. Further, although the water flow detector is used as a means for detecting the start or end of the hot water supply operation, a pressure switch (usually arranged downstream of the hot water storage tank) may be used instead.

[0015]

According to the control method of the present invention using the solar water heater, even if the hot water temperature (Th) of the hot water storage tank fluctuates during hot water supply, the auxiliary heat source device (the combustion heating section thereof) is turned on or off. Is avoided. Therefore, hot water can be stably supplied at the user's desired hot water supply temperature (or set temperature).

[Brief description of drawings]

FIG. 1 is an example of a flowchart of a method for controlling hot water supply temperature according to the present invention.

FIG. 2 is an example of a solar water heater used in the present invention.

FIG. 3 is a flowchart of a conventional hot water supply temperature control method.

[Explanation of symbols]

1: Solar water heater (main body) 2: Branch pipe 3: Mixing device 4: Auxiliary heat source device 5: Thermometer 6: Remote control unit (remote control) 7: Thermometer 8: Control unit (first control unit) 9: Water flow detector 10: Heat exchanger 11: Solar heat collector 12: Circulation piping (outgoing pipe and return pipe) 13: Circulation pump 14: Hot water storage tank outlet pipe 15: Hot water storage tank 16: Control unit (second control unit) 20: Solar water heater

Claims (2)

[Claims] 1. A solar water heater (main body) including a solar heat collector.
When controlling the hot water supply temperature of the solar hot water supply device, which is composed of an auxiliary heat source device connected to the downstream of the hot water supply device, if the hot water temperature (Th) of the hot water storage tank is less than the desired hot water supply temperature at the start of hot water supply, No matter how the hot water temperature (Th) of the hot water storage tank changes until the hot water supply is stopped, including the start of hot water supply, the hot water from the hot water storage tank does not exceed the lower limit capacity of the auxiliary heat source device (TLset). ), Adjust with additional heating by the auxiliary heat source device, and when the hot water temperature (Th) of the hot water storage tank is equal to or higher than the desired hot water temperature at the start of hot water supply, do not heat with the auxiliary heat source device. As conditions, dilute the hot water in the hot water storage tank with water through the control unit so that the hot water temperature at the hot water supply terminal outlet side becomes the desired hot water temperature.
After that, if the hot water temperature (Th) of the hot water storage tank falls below the desired hot water supply temperature, from that point until the hot water supply is stopped,
No matter how the hot water temperature (Th) of the hot water tank changes, after adjusting the hot water from the hot water tank to the temperature (TLset),
A method of controlling the hot water supply temperature by additionally heating with an auxiliary heat source. 2. A solar water collector (main body), a solar heat collector, a hot water storage tank for storing hot water heated through the solar heat collector, and a thermometer for measuring the hot water temperature (Th) of the hot water storage tank. Using a solar water heater (main body) equipped with a mixing device that mixes the hot water from the hot water tank and the water from the branch pipe, the hot water temperature (Th) of the hot water tank at the start of hot water is the same as or higher than the desired hot water temperature. In the case of adjusting the hot water temperature, the control method according to claim 1, wherein the hot water in the hot water storage tank is diluted with water by the mixing device so that the hot water temperature on the outlet side of the mixing device becomes a desired hot water supply temperature.