JPH0250377B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a solar heat collector.
As shown in FIG. 1, a conventional solar heat collector connects an outgoing pipe connection port 2 provided at the bottom of a heat storage tank 1 and an inlet 4 of a heat collector 3 to an outgoing pipe 6 in which a heat collecting pump 5 is interposed. The outlet 7 of the heat collector 3 and the return pipe connection port 8 provided in the middle of the heat storage tank 1 are connected by the return pipe 10 connected to the air vent valve 9 to form a circulation circuit for water as a heat medium. 1
1 is formed. 12 is a water supply pipe that supplies city water to the lower part of the heat storage tank 1; 13 is a hot water outlet pipe that takes out hot water from the upper part of the heat storage tank 1; and 14 and 15 are air vent valves and safety valves connected to the top of the heat storage tank 1. It is.

Reference numeral 16 denotes a control device, and this control device 16 includes a high temperature side heat collection temperature sensor (hereinafter referred to as heat collection sensor) 17 that detects the hot water temperature on the outlet side of the heat collector 3, and a hot water temperature sensor in the lower part of the heat storage tank 1. It is equipped with a low-temperature side heat collection temperature sensor (hereinafter referred to as heat collection sensor) 18 that detects the temperature of the hot water above the return pipe connection port 8 in the heat storage tank, and a boiling prevention temperature sensor 19 that detects the hot water temperature above the return pipe connection port 8 in the heat storage tank. Performs stop control. That is, the control device 16
As shown in FIG. 2, detects the temperature difference between the detected temperatures of both heat collection sensors 17 and 18, and when the temperature difference exceeds a certain value ΔTH, the temperature difference becomes a certain value ΔTL (however, ΔTL<
A heat collection control device 20 consisting of a differential temperature thermostat that closes the output switch 201 until the temperature drops below ΔTH;
When the temperature detected by the temperature sensor 19 exceeds a certain value T1h, the boiling prevention control device 21 closes the output switch 211 until the temperature falls below a certain value T1l (T1l<T1h), and both devices 20 and 21 respectively control the energization. relays 22 and 23, a normally open relay switch 221 of the relay 22, and a normally closed relay switch 231 of the relay 23.
1,231, the heat collection pump 5 is energized and controlled.

Therefore, in the heat collection device described above, the heat collection control device 20
determines whether or not heat collection is possible according to the temperature difference detected by the heat collection sensors 17 and 18, and if the temperature difference is greater than ΔTH, the output switch 201 is closed and the relay 22 is activated.
energize. Therefore, the heat collecting pump 5 is operated by energizing through the relay switches 231 and 221, and the cold and hot water in the lower part of the heat storage tank 1 is pumped from the outgoing pipe connection port 2 to the outgoing pipe 6 to the collector inlet 4 to the collector 3- Heat collector outlet 7-
It circulates in the order of return pipe 10 - return pipe connection port 8, and then the heat collector 3
It is heated by collecting solar heat. Then, the temperature difference between the heat collection sensors 17 and 18 becomes less than ΔTL,
When the heat collection effect can no longer be expected, output switch 2
01 is opened, the relay 22 is de-energized, and the heat collecting pump 5 is stopped.

During the operation of the heat collecting pump 5 described above, the temperature sensor 1
9 detected temperature is T1h (first set temperature, e.g. 95
℃), the output switch 211 of the boiling prevention control device 21 is closed and the relay 23 is energized. Then, by opening the relay switch 231,
The heat collection pump 5 is stopped and the heat collection operation is interrupted to prevent the hot water in the circulation circuit 11 and the heat storage tank 1 from boiling, thereby preventing abnormal vibrations and cavitation of the heat collection pump 5. To ensure safety when using hot water. Then, when the temperature detected by the temperature sensor 19 becomes lower than T1l (second set temperature, for example 90° C.), the output switch 211 is opened to turn off the relay 23 and release the forced stop of the heat collecting pump 5.

The boiling prevention control device 21 generally has a differential between T1h and T1l of 3 to 5 degrees or more.
This is because when the hot water in the heat storage tank 1 circulates through the circulation circuit 11, there is a temperature rise of 5 to 10 degrees when there is a lot of sunlight. This is because the engine will start and stop at the same time. Further, the temperature sensor 19 is installed at a position slightly above and a distance from the return pipe connection port 8 in the heat storage tank 1 so that the boiling state near the collector outlet 7 of the return pipe 10 can also be detected. Therefore, when the heat collection pump 5 is stopped to prevent boiling, the hot water in the heat storage tank 1 will either drop by 3 to 5 degrees or more due to natural cooling, or the water will be supplied from the water supply pipe 12 by hot water supply from the hot water outlet pipe 13, and the temperature The detected temperature of sensor 19 is T1l
Until the following happens, the heat collection pump 5 remains stopped, and since the heat retention of the heat storage tank 1 is good, even though the lower half of the heat storage tank 1 is in a state where it is necessary to collect heat by supplying water. First, there was a drawback that heat collection operation was not performed for several hours.

The present invention has been made to solve the above-mentioned drawbacks, and uses a control device that includes a temperature sensor below the return pipe connection port of the heat storage tank to release the stoppage of the heat collection pump due to boiling prevention. When the heat collection pump is stopped to prevent boiling, operation of the heat collection pump is restarted as soon as the temperature of the heat medium in the lower part of the heat storage tank falls below a certain value, minimizing the time required to prevent boiling. It is an object of the present invention to provide a solar heat collecting device in which the amount of heat collected is reduced to a minimum, and the shortened time is used to increase the amount of heat collected.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings in comparison with a conventional device. FIG. 3 shows a system diagram of this device. Parts corresponding to those in FIG. 1 are given the same symbols, and the difference from that in FIG. Temperature sensors 19 and 24 are provided above and below the mouth 8, and the temperature sensor 24 is installed near the heat collection sensor 18. The control device 16 is as shown in FIG. 4, and is different from the one in FIG. An output switch 212 that opens when T2h or higher is added,
A relay 25 is connected in series with the output switch 212, and a normally open relay switch 251 of the relay 25 is connected in parallel to the relay switch 231. The boiling prevention control device 21 controls the opening/closing temperatures T1h, T1l of the output switch 211 with respect to the temperature detected by the temperature sensor 19 and the opening/closing temperatures T2h, T2l of the output switch 212 with respect to the temperature detected by the temperature sensor 24.
The relationship is selected so that T1h > T1l > T2h > T2l, and (T1h - T2l) is set to be equal to or higher than the maximum temperature rise value (for example, 10 degrees) in the heat collector 3.

According to this embodiment, the heat collection control device 20 starts and stops the heat collection pump 5 in the same way as the conventional one, and when the temperature detected by the temperature sensor 19 is T1h or higher while the heat collection pump 5 is in operation. When the boiling prevention control device 2
The first output switch 211 is closed, the relay 23 is energized, and the relay switch 231 is opened. At this time, if the temperature detected by the temperature sensor 24 is also higher than T2h, the output switch 212 is open, the relay 25 is de-energized, and the relay switch 251 is open, so the heat collection pump 5 is activated by the relay switch 221. Even though the circuit is closed, the power is cut off and it stops. Then, hot water is supplied in this state, and the water supply pipe 1
When water is supplied from 2, the temperature detected by the temperature sensor 24 drops rapidly. When the temperature detected by the temperature sensor 24 drops to T2l, the output switch 212 closes, and the relay 25 is energized to turn the relay switch 2 on.
51 is closed. Of course, the heat collection sensor 13 also senses the temperature of the water supply, and the heat collection sensors 17 and 18
Since there is a sufficient temperature difference between them and the relay switch 221 is closed, the heat collecting pump 5 is energized via the relay switches 251 and 221 and resumes operation. In this way, in this device, when new city water is supplied to the lower part of the heat storage tank 1, even if the temperature detected by the temperature sensor 19 has not fallen to T1l, the heat collecting pump 5
operation can be resumed, and the newly supplied city water can be heated using collected solar heat. Further, the operation of the heat collection pump 5 also stirs the hot water near the return pipe connection port 8 in the heat storage tank 1, and the temperature detected by the temperature sensor 19 also decreases, so that the output switch 211 can be opened quickly.

For example, if T1h is set to 95°C and T1l is set to 90°C, T2l is the temperature rise in collector 1 (maximum approx.
If the temperature sensor 24 is installed near the water supply pipe 12, it may be set to 50 to 60°C. Also, T2h is T2l
It is better to make it higher than T1l and lower than T2h.
The differential of T2l can be set as large as 20 to 30 degrees.

In the above-described embodiment, the temperature sensor 19 is configured to detect the temperature of the heat medium above the return pipe connection port 8 in the heat storage tank 1, but the temperature sensor 19 detects the temperature of the hot water near the heat collector outlet 7 of the return pipe 10. It may also be detected. In this case, the air vent valve is
It is more preferable to install it on the heat storage tank 1 side, and it is better to use it in combination with a delay timer. Further, the temperature sensor 24 may also be used as the heat collection sensor 18.

As described above, the present invention includes a heat collector, a heat storage tank, an outgoing pipe connected between an outgoing pipe connection port provided at the lower part of the heat storage tank and an inlet of the heat collector, and a the heat collection pump, the return pipe connected between the heat collector outlet and the return pipe connection port provided in the middle of the heat storage tank, and the high temperature side heat collection temperature provided on the exit side of the heat collector. Heat collection device that operates the heat collection pump when the temperature difference between the sensor, the low temperature side heat collection temperature sensor provided at the bottom of the heat storage tank, the high temperature side heat collection temperature sensor, and the low temperature side heat collection temperature sensor is greater than a set value. A control device, a boiling prevention temperature sensor installed above the return pipe connection port of the heat storage tank or on the return pipe, and operation of the heat collecting pump when the temperature of the boiling prevention temperature sensor reaches the first set temperature. and the second set temperature is lower than the first set temperature.
In a solar heat collector equipped with a boiling prevention control device that restarts operation of the heat collection pump when the set temperature is reached, the temperature sensor is provided below the return pipe connection port of the heat storage tank, and The heat collection pump is operated when the temperature is below a third set temperature which is lower than the second set temperature, and the temperature difference between the high temperature side heat collection temperature sensor and the low temperature side heat collection temperature sensor is greater than or equal to the set value. Since it is equipped with a control device, if the heat medium temperature in the upper part of the heat storage tank or the return pipe rises and there is a risk of boiling, the heat collecting pump will be stopped, and abnormal vibrations will occur or the heat collecting pump will be stopped. In addition to preventing cavitation of the heat storage tank, it also improves safety when draining liquid, and the drained liquid supplies new heat medium to the bottom of the heat storage tank, reducing the temperature of the heat medium at the bottom of the heat storage tank. Heat collection operation can be resumed at the same time, and the heat collection time can be significantly increased compared to the conventional method that waits for the temperature of the heat medium at the top of the heat storage tank to drop before operating the heat collection pump, which requires time to prevent boiling. This is useful because it can be minimized and the shortened time can be used to increase the amount of heat collected.

[Brief explanation of drawings]

FIG. 1 is a system diagram showing an example of a conventional device, FIG. 2 is an electric circuit diagram showing an example of a control device used in the conventional device, FIG. 3 is a system diagram showing an example of the device of the present invention, and FIG. The figure is an electric circuit diagram showing an example of a control device used in this device. 1... Heat storage tank, 2... Outgoing pipe connection port, 3... Heat collector, 4... Heat collector inlet, 5... Heat collection pump, 6...
... Outgoing pipe, 7... Heat collector outlet, 8... Return pipe connection port,
10... Return pipe, 11... Circulation circuit, 16... Control device, 17, 18... Heat collection sensor, 19, 24...
...Temperature sensor.

Claims (1)

[Claims] 1. A heat collector, a heat storage tank, an outgoing pipe connected between an outgoing pipe connection port provided at the bottom of this heat storage tank and an inlet of the heat collector, and a heat collection pump provided in this outgoing pipe. , a return pipe connected between the heat collector outlet and a return pipe connection port provided in the middle of the heat storage tank, a high-temperature side heat collection temperature sensor provided on the exit side of the heat collector, and a A heat collection control device that operates a heat collection pump when a temperature difference between a low temperature side heat collection temperature sensor provided at a lower part, a high temperature side heat collection temperature sensor, and a low temperature side heat collection temperature sensor is a set value or more, and a heat storage tank. Above the return pipe connection port of
Or a boiling prevention temperature sensor installed in the return pipe,
The operation of the heat collecting pump is stopped when the temperature of the boiling prevention temperature sensor reaches the first set temperature, and the heat collecting pump is started when the temperature of the boiling prevention temperature sensor reaches the second set temperature, which is lower than the first set temperature. In the solar heat collector equipped with a boiling prevention control device for restarting the heat storage tank, the solar heat collecting device includes a temperature sensor provided below the return pipe connection port of the heat storage tank, and a third temperature sensor whose temperature is lower than the second set temperature. and a control device that operates the heat collection pump when the temperature difference between the high temperature side heat collection temperature sensor and the low temperature side heat collection temperature sensor is equal to or higher than the set value. thermal equipment.