JPS5836262B2 - Heat extraction control method for circulating solar water heaters - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides for sending water from the lower part of a hot water storage tank 1 to one end of a solar collector 4 through a circulation pump 2 through an outgoing pipe 3.
In a circulating solar water heater that sends hot water to be heated in the solar collector 4 into the hot water storage tank 1 via the return pipe 5, the temperature A of the hot water to be heated in the solar collector 4 and the temperature of hot water in the lower part of the hot water storage tank 1 are If the difference from B is at least a predetermined level, the operation of the circulation pump 2 is started, and then the temperature C of the hot water at a position near the hot water tank 1 side in the outgoing pipe 3 connected to the lower interior of the hot water storage tank 1, The circulation pump 2 is operated when the difference between the temperature D of the hot water at a position near the hot water tank 1 in the outgoing pipe 5 connected to the hot water storage tank 1 above the connecting position of the outgoing pipe 3 reaches a negative level. The present invention relates to a heat extraction control method for a circulating solar water heater, which is characterized by stopping.

This type of conventional circulating solar water heater has solar collector 1.
A sensor 6 for detecting the temperature A (°C) of the hot water to be heated is provided inside the hot water storage tank 1, and a sensor γ for detecting the temperature B ('C) of the hot water in the hot water storage tank 1 is provided above the bottom of the hot water storage tank 1. The controller 8 compares the detected temperatures of both sensors 6 and 7, and when the difference is A-B≧K [°C] (K is a constant), the circulation pump 2 installed in the middle of the used pipe 3 Start driving and A-B<K
When the temperature reached ('C), heat collection control was performed to stop the operation of the circulation pump 2.

However, in the case of such a conventional example, the piping lengths of the outgoing pipe 3 and return pipe 5 between the solar heat collector 4 and the hot water storage tank 1 vary depending on the place of use, so even if the solar heat collector 4 actually collects heat, the piping loss may occur. There is a drawback that the hot water is cooled immediately before entering the hot water storage tank 1 and cannot collect heat.

Normally, the piping loss was about 6 to 8 times more than the amount of heat collected when the piping length was 16 m, the hot tube was 10 m, IL foamed polyethylene, the pipe material was HT13 vinyl chloride, the outside air was 20°C, and the solar collector outlet temperature was 30 to 40°C.

The present invention has been provided in view of the above-mentioned drawbacks, and its purpose is to adopt a circulating solar water heater with low loss by taking into consideration the heat radiation loss due to piping between the solar collector and the hot water storage tank. Thermal control method is provided.

The present invention will be explained below with reference to examples.

FIG. 2 shows a schematic diagram of one embodiment, in which a sensor 6 for detecting the temperature A C 'C of the hot water to be heated in the solar collector 4 and a sensor 6 provided above the bottom of the hot water tank 1 are installed to detect the hot water in the hot water tank 1. In addition to the sensor 7 for detection, a temperature detection sensor 9 is provided near the inlet of the outgoing pipe 3, which has one end connected to the lower side of the hot water storage tank 1, and has one end connected to the approximately central side of the hot water storage tank 1. A temperature detection sensor 10 is installed near the exit of the return pipe 5.
has been established.

The controller 8 detects 11M degrees A (℃) of the sensor 6 and the sensor 7.
When it is detected that the difference between the detected temperature [℃] becomes A-B≧K (K: constant), the operation of the circulation pump 2 is started, and then the detected mixture temperature C [℃] of the sensor 9 is detected. ] and sensor 1
When it is detected that the difference from the detected temperature D [° C.] of 0 becomes CD<0, a control operation is performed to stop the circulating pump 2 in operation.

Next, the circuit of the controller 8 shown in FIG. 3 will be explained in more detail.

Now, when the solar radiation becomes strong and the temperature difference between temperatures A and B exceeds the set lagoon (K [°C]), an output is generated in the comparator C1, which drives the transistor Tr via the timer contact T1. The relay Ry connected in series with the Tr is energized.

When the relay contact r is closed by the operation of the relay Ry, the timer T and the circulation pump 2 are connected to the power source via the main switch SW, and both start operating.

By operating the circulation pump 2, the hot water in the hot water tank 1 is sent to the solar collector 4 via the outgoing pipe 3, and the heated hot water in the solar collector 4 is sent to the hot water tank 1. .

A few minutes after the timer T starts operating, the timer contact T1
is switched to the broken line side, and the output of the comparator C2 for comparing the detection outputs of the sensors 9 and 10 is connected to the base of the transistor Tr.

At this time, the comparator C2 detects the detected temperature difference C- between the sensors 9 and 10.
At 1, when D is at a negative level, it is set to generate an output, and at 1, when detected temperature difference CD is at a negative level, the above-described operation of the circulation pump 2 is continued.

Next, when the level becomes negative and the output of the comparator C2 disappears, the transistor Tr is turned off and the relay Ry is deenergized.

When the relay contact r is opened, the timer T and the circulation pump 2 are de-energized, the timer T returns to the timer contact T, and the circulation pump 2 stops operating.

Note that the set voltage of the comparator C1 or c2 is set by the resistors R1, R2 or R3 t R4.

The present invention provides a circulation type solar water heater configured as described above, in which the circulation pump is stopped operating if the difference between the temperature of the hot water to be heated in the solar collector and the temperature of the hot water in the lower part of the hot water storage tank is equal to or higher than a predetermined level. After that, the temperature of hot water at a position near the hot water storage tank side in the outgoing pipe connected to the lower interior of the hot water storage tank, and the hot water tank side in the returning pipe connected to the hot water storage tank above the connection position of the outgoing pipe. Since the circulation pump stops operating when the temperature difference between the hot water temperature and the hot water temperature at a nearby location reaches a negative level, the timing for stopping the circulation pump is set when the temperature difference between the hot water in the outbound pipe and the return pipe disappears. Therefore, there is a loss caused by the hot water heated by the solar collector stopping and dissipating heat in the return pipe between the solar collector and the hot water storage tank when the circulation pump stops operating. This has the effect of reducing heat radiation loss even if the pipe length is long, and allowing efficient heat extraction.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a conventional example, Fig. 2 is a schematic diagram of a device using an embodiment of the present invention, and Fig. 3 is a circuit diagram of a controller used in the same. 2 is a circulation pump, 3
is the outgoing pipe, 4 is the solar collector, 5 is the return pipe, A is the mixture of heated hot water in the solar collector, B is the temperature of the hot water in the lower part of the hot water storage tank, and C is the hot water near the entrance of the outgoing pipe. temperature, D
is the temperature of hot water near the outlet in the return pipe.

Claims (1)

[Claims] 1 A circulating solar hot water system in which a circulation pump sends water from the lower part of the hot water storage tank to one end of the solar collector via an outgoing pipe, and also sends water into the heated hot water storage tank in the solar collector via a returning pipe. If the difference between the temperature of the hot water heated by the solar collector and the temperature of the hot water at the bottom of the hot water storage tank is above a predetermined level, the circulation pump starts operating, and then When the difference between the temperature of hot water near the hot water storage tank side and the temperature of hot water near the hot water storage tank side of the return pipe connected to the hot water storage tank above the connection position of the outgoing pipe reaches a negative level. A heat extraction control method for a circulation type solar water heater characterized by stopping operation of a circulation pump.