JPH11182941A - Method for operating solar-heat water heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for driving a solar-heat water heater wherein heat-exchange efficiency is improved, pump's working time is relatively shorter, and power consumption is reduced. SOLUTION: The temperature of heating medium at an inlet part of a heat exchanger 30 and the temperature of water in a hot waters storage tank 20 are detected, and a pump 40 is stopped when temperature difference is equal to fixed temperature or below. Temperature sensors S1 and S2 comprise a control unit. 2) The temperature of heating medium at the inlet part of the heat exchanger 30 and the temperature of water in the hot water storage tank 20 are detected, and a time pump 40 is stopped according to its temperature difference. 3) The temperature of heating medium at the inlet part of the heat exchanger 30 and that at an outlet part of the heat exchanger 30 are detected and the time pump 40 is stopped according to its temperature difference. 4) The temperature of heating medium t the outlet part of a solar heat collecting panel 10 is detected, and the pump 40 is operated when rising coefficient of the temperature is equal to a fixed value or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for operating a solar water heater using a heat exchange system.

[0002]

2. Description of the Related Art As a solar water heater, a heat medium heated in a solar heat collecting panel is circulated by a pump through a heat exchanger in a hot water storage tank into the solar heat collecting panel to heat water in the hot water storage tank. A heat exchange type solar water heater using a heat exchange system configured as described above is known (for example, Japanese Patent Application Laid-Open No. 55-727).
No. 59).

[0003] This type of solar water heater utilizes a temperature sensor at the outlet of a solar heat collecting panel to detect the temperature of a heat medium.
Further, the water temperature is detected by a temperature sensor below the hot water storage tank, and when it is detected that the temperature of the heat medium at the outlet of the solar heat collecting panel is higher than the water temperature in the hot water storage tank, the pump is operated. Is operated to be warmed by heat exchange.

[0004]

In the operation of such a conventional solar water heater, if the temperature of the heat medium at the outlet of the solar heat collecting panel is higher than the temperature of the lower water in the hot water storage tank, Since the pump operates even with such a temperature difference, when the temperature difference is very small, there is a problem that heat exchange is small and heat exchange efficiency is deteriorated.

[0005] In addition, since the heat medium passes through the solar heat collecting panel before the heat medium is not sufficiently warmed in the solar heat collecting panel, the efficiency of heat exchange also deteriorates from this point. Moreover,
There is a problem in that the operation time of the pump becomes longer as a whole and power consumption increases.

The solar heat collecting panel is installed at a high place such as a roof of a house, and a temperature sensor must be attached to an outlet of such a solar heat collecting panel. It is inconvenient because the temperature sensor is repaired at a high place.

The present invention solves the above problems,
It is a main object of the present invention to provide a method for operating a solar water heater that can improve the efficiency of heat exchange, reduce the operating time of a pump and reduce power consumption.

[0008]

In order to achieve the above object, according to the first aspect of the present invention, a heat medium heated in a solar heat collecting panel is pumped through a heat exchanger in a hot water storage tank through a heat exchanger. In the operation of a solar water heater that circulates through the heat panel and warms the water in the hot water tank, the temperature of the heat medium at the inlet of the heat exchanger (T ₁ ° C) and the water temperature in the hot water tank (T ₂ ° C)
And the pump is stopped if the temperature difference (T ₁ −T ₂ ) is equal to or lower than a certain temperature.

According to the second aspect of the present invention, the heat medium heated in the solar heat collecting panel is circulated by the pump through the heat exchanger in the hot water storage tank into the solar heat collecting panel, and the water in the hot water storage tank is circulated. In the operation of the solar water heater to be heated, the temperature of the heat medium at the inlet of the heat exchanger (T ₁ ° C) and the temperature of the water in the hot water storage tank (T ₂ ° C) are detected, and the temperature difference (T ₁ -T ₂ ) is detected. The pump is stopped for a time corresponding to the time.

According to the third aspect of the present invention, the heat medium heated in the solar heat collecting panel is circulated by the pump through the heat exchanger in the hot water storing tank to the solar heat collecting panel, and the water in the hot water storing tank is circulated. In the operation of the solar water heater that warms up, the temperature of the heat medium at the inlet of the heat exchanger (T ₁ ° C) and the temperature of the heat medium at the outlet of the heat exchanger (T ₃ ° C) are detected, and the temperature difference (T ₁ −
The pump is stopped for a time corresponding to T ₃ ).

Further, according to the invention of claim 4, the heat medium heated in the solar heat collecting panel is circulated by the pump through the heat exchanger in the hot water storage tank into the solar heat collecting panel, and the water in the hot water storage tank is circulated. In the operation of the solar water heater for warming, the temperature of the heat medium (T ₄ ° C) at the outlet of the solar heat collecting panel is detected,
When the temperature rise rate becomes equal to or less than a certain value, the pump is operated.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for operating a solar water heater according to the first to fourth aspects of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is an explanatory diagram for explaining a method of operating a solar water heater according to the first aspect of the present invention.
Is a solar heat collecting panel, 20 is a hot water storage tank (usually 200 to
30 is a heat exchanger, 40 is a circulation pump, and 50 is a control unit (for example, a microcomputer).

Numeral 11 designates the solar heat collecting panel 10 to the heat exchanger 3
A delivery pipe 12 for sending a heat medium (for example, an antifreeze such as ethylene glycol) to 0, a reflux pipe 12 for refluxing the heat medium from the heat exchanger 30 to the solar heat collecting panel 11, Heat medium storage container (service tank)
13 and a pump 40 are provided. The pump 40 is electrically connected to the control unit 50.

Reference numeral 21 denotes a hot water supply pipe for allowing hot water to flow out of the hot water storage tank 20, reference numeral 22 denotes a water supply pipe for supplying water to the hot water storage tank 20, and reference numeral 23 denotes a drain pipe, which corresponds to the amount of hot water flowing out of the hot water supply pipe 21. From the water supply pipe 22 to the hot water storage tank 20
It is supplied to the inside.

Further, a temperature sensor S 1 for detecting the temperature of the heat medium (T ₁ ° C) at the inlet is attached to the inlet of the heat exchanger 30. temperature sensor S2 for detecting the water temperature in the tank 20 (T ₂ ℃) is attached. Although not shown, these temperature sensors S1 and S2 are electrically connected to the control unit 50.

The temperature difference (T ₁ -T ₂ ) between the heating medium temperature (T ₁ ° C) and the water temperature (T ₂ ° C) is calculated by a comparator provided in the control unit 50. If the value is below a certain temperature, that is, T ₁ −T ₂ ≦ α,
Upon receiving the electric signal, the pump 40 is stopped, and thereafter, after a certain time, that is, an interval time I, the pump 40 is stopped.
Is configured to operate.

Here, the temperature of the heating medium at the inlet of the heat exchanger 30 is generally about 85 ° C. in summer and about 45 ° C. in winter, and the value of α is generally set to about 3 to 9 ° C. You. The interval time I is determined by the flow rate of the heat medium, the diameter and the length of the pipe, and is set to, for example, 10 minutes. These α value and I value are input to the control unit 50 in advance.

If T ₁ −T ₂ > α, the heating medium temperature (T ₁ ° C) and the water temperature (T ₂ ° C) are restored again after a certain period of time, that is, a research time R, after receiving the electric signal. It is configured to be detected. The research time R is also determined by the flow rate of the heat medium and the diameter and length of the pipe, but is set to, for example, one minute. This research time R is also input to the control unit 50 in advance.

In the solar water heater constructed as described above, as shown by a flow sheet in FIG. 2, first, the pump 40 is operated (ON) to remove the heat medium heated in the solar heat collecting panel 10. The water in the hot water storage tank 20 is circulated through the delivery pipe 11, the heat exchanger 30, the reservoir 13, the pump 40, and the reflux pipe 12 into the solar heat collecting panel 10.

At this time, the temperature of the heat medium (T ₁ ° C) at the inlet of the heat exchanger 30 and the temperature of the water (T
₂ ° C.) is detected, and the temperature of the heat medium (T ₁ ° C.) and the water temperature (T ₂
° C) (T ₁ -T ₂ ).

Here, the calculated temperature difference (T₁-T_Two)
Is below a certain temperature, ie, T₁-T _TwoIf ≦ α, then
The pump 40 is stopped (OFF) by an electric signal, and thereafter
After a fixed time, that is, an interval time I, the pump
40 runs. During this interval time I, the heat medium
Is heated in the solar collector panel 10 without circulation
You.

If the calculated temperature difference (T ₁ -T ₂ ) value is higher than a certain temperature, that is, if T ₁ -T ₂ > α, the electric signal is sent to the control unit 50 for a certain time. That is, after the research time R, the heating medium temperature (T ₁
° C.) and the temperature (T ₂ ° C.) is detected again, and the temperature difference (T ₁ -T ₂₎ is calculated. Thus, the pump 40
By repeating the operation and the stop of the water, the water in the hot water storage tank 20 is heated.

According to the above operating method (the invention of claim 1).
If the heating medium temperature (T₁° C) and water temperature (T _Two℃)
(T₁-T_Two) Is only above a certain temperature
The pump is running when the temperature difference is very small.
Therefore, heat exchange is performed efficiently. Moreover, the pump
Uptime is also relatively short.

Further, since the temperature sensor is not installed at a high place such as a roof of a house, construction of wiring and the like and repair of the temperature sensor after installation become easy.

FIG. 3 is an explanatory view for explaining a temperature control method for a solar water heater according to the second aspect of the present invention.
10 is a solar heat collecting panel, 20 is a hot water storage tank (normally, 20
0 to 600 liters), 30 is a heat exchanger, 40 is a circulation pump, and 50 is a control unit (for example, a microcomputer).

Reference numeral 11 denotes the solar heat collecting panel 10 to the heat exchanger 3
A delivery pipe 12 for sending a heat medium (for example, an antifreeze such as ethylene glycol) to 0, a return pipe 12 for returning the heat medium from the heat exchanger 30 to the solar heat collecting panel 11, Heat medium storage container (service tank)
13 and a pump 40 are provided. The pump 40 is electrically connected to the control unit 50.

Reference numeral 21 denotes a hot water supply pipe through which hot water flows out of the hot water storage tank 20, reference numeral 22 denotes a water supply pipe for supplying water to the hot water storage tank 20, and reference numeral 23 denotes a drain pipe, which is water corresponding to the amount of hot water flowing out of the hot water supply pipe 21. From the water supply pipe 22 to the hot water storage tank 20
It is supplied to the inside.

Further, at the inlet of the heat exchanger 30,
Heat medium temperature at inlet (T₁° C) to detect the temperature
S1 is installed, and below the hot water storage tank 20
Is the water temperature in the hot water storage tank 20 (T_Two℃) to detect
Temperature sensor S2 is mounted. The solar collection
At the outlet of the heat panel 10, the heat medium temperature (T _Four
Temperature sensor S4 for detecting
I have.

These temperature sensors S1, S2 and S4
Is electrically connected to the control unit 50 (not shown).
Has been continued. The control unit 50 has
The heating medium temperature (T₁℃) and water temperature
(T_Two℃) and the temperature difference (T₁-T _Two) Is calculated and the
Temperature difference (T₁-T_Two) For a certain period of time S according to
Pump 40 is stopped, and then the pump 40 is operated.
Has been established.

Here, the stop time S of the pump 40 corresponds to the time required for heat transfer in the heat exchanger 30 and is determined by the flow rate of the heat medium and the diameter and length of the pipe.
For example, when the temperature difference is 10 ° C. or less, S is 28 minutes, and the temperature difference is 20 ° C.
In the following, S is 24 minutes, temperature difference is 30 ° C or less, S is 20 minutes, temperature difference is 40 ° C or less, S is 16 minutes, temperature difference is 50 ° C or less, S is 12 minutes, and temperature difference is 60 ° C or less, S is 8 minutes. S is set to 4 minutes when the temperature difference exceeds 60 ° C. The temperature difference and the stop time S are input to the control unit 50 in advance.

The temperature difference between the temperature of the heating medium (T ₄ ° C) at the outlet of the solar heat collecting panel 10 and the temperature of the water (T ₂ ° C) in the hot water storage tank 20 is calculated by a comparator built in the control unit 50. (T ₄ −T ₂ ) is calculated, and if the value is equal to or lower than a predetermined temperature, that is, if T ₄ −T ₂ ≦ β, the pump 40 is operated in response to the electric signal. Here, the value of β is determined by the flow rate of the heat medium and the diameter and length of the pipe, but is generally set to about 3 to 9 ° C., and the value is input to the control unit 50 in advance.

In the solar water heater constructed as described above, first, as shown by the flow sheet in FIG. 4, the heat medium temperature (T ₄ ° C) at the outlet of the solar heat collecting panel 10 and the temperature in the hot water storage tank 20 are measured. The water temperature (T ₂ ° C) is detected and the heat medium temperature (T ₄
Temperature difference ° C.) and the temperature _{(T 2 ℃) (T 4} -T 2) is calculated.

Here, the calculated temperature difference (T ₄ −T ₂ )
If the value is lower than a certain temperature, that is, T ₄ −T ₂ <
If β, the pump 40 is not started by the electric signal, but if T ₄ −T ₂ ≧ β, the pump 40 is operated (ON) by the electric signal, and the pump 40 is operated for a certain period of time to collect solar heat. The heat medium heated in the panel 10 is circulated into the solar heat collecting panel 10 through the delivery pipe 11, the heat exchanger 30, the storage vessel 13, the pump 40, and the reflux pipe 12, and the water in the hot water storage tank 20 is removed. warm. Then, the temperature difference (T ₁ −T ₂ ) between the heat medium temperature (T ₁ ° C) and the water temperature (T ₂ ° C) is calculated by a comparison arithmetic unit built in the control unit 50.
Is calculated.

Then, the calculated temperature difference (T ₁ -T ₂ )
Accordingly, the pump 40 is stopped for the predetermined time S input to the control unit 50 in advance, and the solar heat collecting panel 10 performs heat collection, and then the pump 40 operates. As described above, the operation of the pump 40 is repeated and the operation thereof is stopped, so that the water in the hot water storage tank 20 is heated.

According to the above-mentioned operation method (the invention of claim 2).
If the heating medium temperature (T₁° C) and water temperature (T _Two℃)
(T₁-T_TwoStop the pump for a certain period of time according to)
Heat exchange during this stop time
Can be given to the water in the hot water storage tank 20 through a vessel,
Heat exchange is performed efficiently. Moreover, the operating time of the pump
Is also relatively short.

FIG. 5 is an explanatory diagram for explaining a temperature control method for a solar water heater according to the third aspect of the present invention.
10 is a solar heat collecting panel, 20 is a hot water storage tank (normally, 20
0 to 600 liters), 30 is a heat exchanger, 40 is a circulation pump, and 50 is a control unit (for example, a microcomputer).

Numeral 11 denotes the solar heat collecting panel 10 to the heat exchanger 3
A delivery pipe 12 for sending a heat medium (for example, an antifreeze such as ethylene glycol) to 0, a reflux pipe 12 for refluxing the heat medium from the heat exchanger 30 to the solar heat collecting panel 11, Heat medium storage container (service tank)
13 and a pump 40 are provided. The pump 40 is electrically connected to the control unit 50.

Reference numeral 21 denotes a hot water supply pipe through which hot water flows out of the hot water storage tank 20, 22 denotes a water supply pipe for supplying water to the hot water storage tank 20, and 23 denotes a drain pipe, which is a water equivalent to the amount of hot water flowing out of the hot water supply pipe 21. From the water supply pipe 22 to the hot water storage tank 20
It is supplied to the inside.

Further, a temperature sensor S1 for detecting the temperature of the heat medium (T ₁ ° C) at the inlet is attached to the inlet of the heat exchanger 30, and the outlet of the heat exchanger 30 is connected to the temperature sensor S1. temperature sensor S3 for detecting the inlet of the heat medium temperature (T ₃ ° C.) is mounted. At the outlet of the solar heat collecting panel 10, the temperature of the heat medium in this portion (T ₄ ° C)
A temperature sensor S4 for detecting the water temperature (T ₂ ° C) in the hot water storage tank 20 is mounted below the hot water storage tank 20.

These temperature sensors S1, S2, S3 and S4 are electrically connected to the control unit 50, not shown. Then, a temperature difference (T ₁ −T ₃ ) between the heat medium temperature (T ₁ ° C.) and the heat medium temperature (T ₃ ° C.) is calculated by a comparison arithmetic unit built in the control unit 50, and the temperature is calculated. A certain time S corresponding to the difference (T ₁ −T ₃ )
The pump 40 is stopped only after that, and then the pump 40 is operated.

Here, the stop time S of the pump 40 corresponds to the time required for heat transfer in the heat exchanger 30, and is determined by the flow rate of the heat medium and the diameter and length of the pipe. For example, if the temperature difference is 5 ° C. or less, S is 15 minutes, and the temperature difference is 1
S is 10 minutes at 0 ° C or less, S is 5 minutes at a temperature difference of 15 ° C or less,
It is set to 0 minutes when the temperature difference exceeds 15 ° C. The temperature difference and the stop time S are input to the control unit 50 in advance.

The temperature difference between the temperature of the heating medium (T ₄ ° C) at the outlet of the solar heat collecting panel 10 and the temperature of the water (T ₂ ° C) in the hot water storage tank 20 is calculated by a comparator built in the control unit 50. (T ₄ −T ₂ ) is calculated, and if the value is equal to or higher than a certain temperature, that is, if T ₄ −T ₂ ≧ β, the pump 40 is operated in response to the electric signal. Here, the value of β is determined by the flow rate of the heat medium and the diameter and length of the pipe, but is generally set to about 3 to 9 ° C., and the value is input to the control unit 50 in advance.

In the solar water heater constructed as described above, first, as shown by a flow sheet in FIG. 6, the temperature of the heat medium (T ₄ ° C) at the outlet of the solar heat collecting panel 10 and the temperature in the hot water storage tank 20. The water temperature (T ₂ ° C) is detected and the heat medium temperature (T ₄
Temperature difference ° C.) and the temperature _{(T 2 ℃) (T 4} -T 2) is calculated.

Here, the calculated temperature difference (T ₄ −T ₂ )
If the value is lower than a certain temperature, that is, T ₄ −T ₂ <
If β, the pump 40 is not started by the electric signal, but if T ₄ −T ₂ ≧ β, the pump 40 is operated (ON) by the electric signal, and the pump 40 is operated (ON) for a certain period of time. The heat medium warmed in the solar heat collecting panel 10 is circulated into the solar heat collecting panel 10 through the delivery pipe 11, the heat exchanger 30, the reservoir 13, the pump 40, and the reflux pipe 12, and the hot water is stored in the hot water storage tank 20. Warm the water. Then, a temperature difference (T ₁ −) between the heat medium temperature (T ₁ ° C) and the water temperature (T ₃ ° C) is calculated by a comparison arithmetic unit built in the control unit 50.
T ₃ ) is calculated.

Then, the calculated temperature difference (T ₁ -T ₃ )
Accordingly, the pump 40 is stopped for the predetermined time S input to the control unit 50 in advance, and the solar heat collecting panel 10 performs heat collection, and then the pump 40 operates. As described above, the operation of the pump 40 is repeated and the operation thereof is stopped, so that the water in the hot water storage tank 20 is heated.

According to the above-mentioned operation method (the third aspect of the invention), the temperature difference (T ₁ -T ₃ ) between the temperature of the heat medium (T ₁ ° C) and the temperature of the heat medium (T ₃ ° C) is satisfied. Since the pump is stopped for a fixed time, the heat collected during the stop time can be sufficiently supplied to the water in the hot water storage tank 20 via the heat exchanger, and heat exchange is performed efficiently. In addition, the operating time of the pump is relatively short.

FIG. 7 is an explanatory diagram for explaining the temperature control method of the solar water heater according to the fourth aspect of the present invention.
10 is a solar heat collecting panel, 20 is a hot water storage tank (normally, 20
0 to 600 liters), 30 is a heat exchanger, 40 is a circulation pump, and 50 is a control unit (for example, a microcomputer).

Numeral 11 denotes the solar heat collecting panel 10 to the heat exchanger 3
A delivery pipe 12 for sending a heat medium (for example, an antifreeze such as ethylene glycol) to 0, a reflux pipe 12 for refluxing the heat medium from the heat exchanger 30 to the solar heat collecting panel 11, Heat medium storage container (service tank)
13 and a pump 40 are provided. The pump 40 is electrically connected to the control unit 50.

Reference numeral 21 denotes a hot water supply pipe through which hot water flows out of the hot water storage tank 20, reference numeral 22 denotes a water supply pipe for supplying water to the hot water storage tank 20, and reference numeral 23 denotes a drain pipe, which corresponds to the amount of hot water flowing out of the hot water supply pipe 21. From the water supply pipe 22 to the hot water storage tank 20
It is supplied to the inside.

Further, below the hot water storage tank 20, a temperature sensor S2 for detecting the water temperature (T ₂ ° C) in the hot water storage tank 20 is mounted. A temperature sensor S4 for detecting the temperature (T ₄ ° C) of the heat medium of the portion is attached. Although not shown, these temperature sensors S2 and S4 are electrically connected to the control unit 50.

The rise rate a of the heat medium temperature (T ₄ ° C) is calculated by a comparison arithmetic unit built in the control unit 50.
x ° C./min is calculated, and if the rate of increase ax ° C./min is less than a certain value, the solar heat collecting panel 10 receives the electric signal.
The pump 40 is configured to operate until the heat medium heated inside passes through the heat exchanger 30.

Here, the temperature inside the solar heat collecting panel 10 is:
In general, the temperature is about 85 ° C. in summer and about 45 ° C. in winter, and at the rate of increase of the heating medium temperature (T ₄ ° C.) ax ° C./min, a and x are the flow rate of the heating medium and the diameter and length of the pipe. Is generally 0.1 to 0.6, and x is, for example, 5 ° C.
Is set to These a value and x value are input to the control unit 50 in advance.

The temperature difference between the temperature of the heating medium (T ₄ ° C) at the outlet of the solar heat collecting panel 10 and the temperature of the water (T ₂ ° C) in the hot water storage tank 20 is calculated by a comparator built in the control unit 50. (T ₄ −T ₂ ) is calculated, and its value is equal to or higher than a certain temperature, that is, T ₄ −T ₂ ≧ β and the heating medium temperature (T ₄ ° C.)
Is equal to or lower than a certain temperature, that is, if T ₄ ≦ γ, the pump 40 is operated in response to the electric signal.

Here, the value of β is determined by the flow rate of the heat medium and the diameter and length of the pipe, but is generally set to about 3 to 9 ° C. The value of γ is the safe temperature of the heat medium,
Usually, the temperature is set to be equal to or lower than the boiling point of the heat medium, for example, 100 ° C. These values are input to the control unit 50 in advance.

In the solar water heater utilizing the above-mentioned structure, as shown by a flow sheet in FIG. 8, first, the pump 40 is operated (ON) to heat the heat medium heated in the solar heat collecting panel 10. The water in the hot water storage tank 20 is circulated through the delivery pipe 11, the heat exchanger 30, the reservoir 13, the pump 40, and the reflux pipe 12 into the solar heat collecting panel 10.

At this time, the temperature of the heat medium (T ₄ ° C) at the outlet of the solar heat collecting panel 10 and the temperature of the water (T
₂ ° C.) is detected, and the heat transfer medium temperature (T ₄ ° C.) and the water temperature (T _4
2 ° C.) is calculated (T ₄ −T ₂ ). If the calculated temperature difference (T ₄ −T ₂ ) value is lower than the fixed temperature, that is, if T ₄ −T ₂ <β, the pump 40 is not started by the electric signal.

Here, if T ₄ −T ₂ ≧ β and T ₄ ≦ γ, the rate of increase of the heating medium temperature (T ₄ ° C) ax ° C. / When the rate of increase ax ° C./min is equal to or less than a predetermined value, the pump 40 is operated until the heat medium heated in the solar heat collection panel 10 passes through the heat exchanger 30 in response to the electric signal. Work.

According to the above-described operation method (invention of claim 4), the pump 40 is operated when the rate of increase in the temperature of the heat medium at the outlet of the solar heat collecting panel 10 becomes a certain value or less. The heat of the heat medium temperature close to the maximum obtained by the panel 10 can be sufficiently given to the water in the hot water storage tank 20 via the heat exchanger 30, and the heat exchange is performed efficiently. In addition, the operating time of the pump is relatively short.

[0060]

As described above, according to the method of operating the solar water heater according to the present invention (the inventions of claims 1 to 4), the efficiency of heat exchange is mainly improved, and the operation time of the pump is also compared. The power consumption can be reduced.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram for describing a temperature control method for a solar water heater according to the invention of claim 1;

FIG. 2 is a flow sheet showing a method for controlling the temperature of the solar water heater according to the invention of claim 1;

FIG. 3 is an explanatory diagram for explaining a temperature control method of a solar water heater according to the invention of claim 2;

FIG. 4 is a flow sheet showing a method of controlling the temperature of a solar water heater according to the invention of claim 2;

FIG. 5 is an explanatory diagram for explaining a temperature control method of the solar water heater according to the third aspect of the present invention.

FIG. 6 is a flow sheet showing a temperature control method for a solar water heater according to the third aspect of the present invention.

FIG. 7 is an explanatory diagram for explaining a temperature control method of the solar water heater according to the invention of claim 4;

FIG. 8 is a flow sheet showing a temperature control method for a solar water heater according to the invention of claim 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Solar heat collecting panel 20 Hot water storage tank 30 Heat exchanger 40 Circulation pump 50 Control unit S1 Temperature sensor S2 Temperature sensor S3 Temperature sensor S4 Temperature sensor

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[Procedure amendment]

[Submission date] February 25, 1998

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0031

[Correction method] Change

[Correction contents]

Here, the stop time S of the pump 40 corresponds to the time required for heat transfer in the heat exchanger 30 and is determined by the flow rate of the heat medium and the diameter and length of the pipe. , Temperature difference 10 ° C or less, S is 28 seconds , temperature difference 2
At 0 ° C or less, S is 24 seconds , and at a temperature difference of 30 ° C or less, S is 20
Second , S is 16 seconds at a temperature difference of 40 ° C. or less, S is 12 seconds at a temperature difference of 50 ° C. or less, S is 8 seconds at a temperature difference of 60 ° C. or less, and the temperature difference is 6
Above 0 ° C. S is set as 4 seconds . The temperature difference and the stop time S are input to the control unit 50 in advance.

Claims (4)

[Claims] 1. An operation of a solar water heater that circulates a heat medium heated in a solar heat collecting panel into a solar heat collecting panel through a heat exchanger in a hot water storage tank by a pump to heat water in the hot water storage tank. , The temperature of the heat medium at the inlet of the heat exchanger (T ₁ ° C) and the temperature of the water in the hot water storage tank (T ₂ ° C) are detected, and the temperature difference (T _1-
A method for operating a solar water heater, wherein the pump is stopped if T ₂ ) is equal to or lower than a certain temperature. 2. An operation of a solar water heater that circulates the heat medium heated in the solar heat collecting panel through the heat exchanger in the hot water storage tank into the solar heat collecting panel by a pump and heats the water in the hot water storage tank. , The temperature of the heat medium at the inlet of the heat exchanger (T ₁ ° C) and the temperature of the water in the hot water storage tank (T ₂ ° C) are detected, and the temperature difference (T _1-
A method for operating a solar water heater, wherein the pump is stopped for a time corresponding to T ₂ ). 3. The operation of a solar water heater that circulates the heat medium heated in the solar heat collecting panel through the heat exchanger in the hot water storage tank into the solar heat collecting panel by a pump to heat the water in the hot water storage tank. , The temperature of the heat medium at the inlet of the heat exchanger (T ₁ ° C) and the temperature of the heat medium at the outlet of the heat exchanger (T ₃ ° C) are detected, and the temperature difference (T
The method of operating Solar water heater, characterized in that stopping the time pump according to a ₁ -T _3). 4. An operation of a solar water heater that circulates the heat medium warmed in the solar heat collecting panel through the heat exchanger in the hot water storage tank into the solar heat collecting panel by a pump to heat the water in the hot water storage tank. 3. The method for operating a solar water heater according to claim 1, wherein the temperature of the heat medium (T ₄ ° C) at the outlet of the solar heat collecting panel is detected, and the pump is operated when the temperature rise rate becomes equal to or lower than a predetermined value.