JPS59134458A - Solar heat collector - Google Patents

Abstract

PURPOSE:To enhance the efficiency of a solar heat collector, by a heat-collecting system wherein heat exchange at a solar heat collector is effected mainly by exchange of latent heat. CONSTITUTION:A reserving tank 9 is provided with an upper liquid level detecting means 10 and a lower liquid level detecting means 11 which are provided at heights intermediate between the uppermost part and the lowermost part of the solar heat collector 1. When the liquid level in the tank 9 reaches a preset lower liquid level, the detecting means 11 detects the liquid level, a pump 4 is started to operate by passing an electric current thereto through a controller 7, and a latent heat type heat-transmitting medium condensed in a heat exchanger 3 is fed to the tank 9. When the liquid level in the tank 9 reaches to a preset upper liquid level, the detecting means 10 detects the liquid level, the passing of the electric current to the pump 4 is stopped through the controller 7, thereby stopping the operation of the pump 4. Accordingly, the liquid level of the medium in the solar heat collector 1 is maintained at the level preset in the tank 9, and in the collector 1, heat is collected at a high efficency mainly through exchange of latent heat accompanied by conversion of the medium from a liquid to a vapor.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a solar heat collector using solar heat as a heat source and a latent heat medium as a working medium. As shown in Fig. 1, the heat collecting device connects a solar heat collector 1, a thermal heat exchanger 3 installed in a hot water storage tank 2, and a pump 4 through piping in order in a closed circuit. For example, a latent heat medium such as fluorocarbon was sealed. Furthermore, to start and stop the pump 4, a low-temperature side thermostat 6 is installed inside the hot water storage tank 2, a high-temperature side thermostat is installed at the outlet of the solar heat collector 1, and the signals from both are taken into the controller 7. The temperatures of the side thermostat 6 and the high-temperature side thermostat 6 are compared, and only when the temperature of the high-temperature side thermostat 6 becomes higher than the temperature of the low-temperature side thermostat 5, the pump 6 is energized and the latent heat medium liquid is transferred to the solar heat collector at 1Vc. It was being transported. In the above configuration, when sunlight hits the solar heat collector 1, the temperature of the latent heat medium inside rises, making the temperature of the high temperature side thermostat 6 higher than the low temperature side thermostat 5. As a result, the pump 4 is energized, and the latent heat medium The liquid is conveyed to the solar collector 1. The heat medium A in the solar heat collector 1 is heated by solar heat, evaporates, becomes steam, is conveyed to the heat exchanger 3, condenses, radiates heat, heats the water in the hot water storage tank 2, and is stored. In this case, if the amount of latent heat medium in the solar heat collector 1 is the same as the amount conveyed by the evaporation pump 4, latent heat exchange is always performed, but generally the amount conveyed by the pump 4 is constant; The amount of evaporation of the heat medium is not constant because the intensity of sunlight is unstable. That is, the greater the sunlight intensity and the lower the temperature in the hot water storage tank 2, the greater the amount of evaporation.On the other hand, in the case where the sunlight intensity is low and the temperature in the hot water storage tank 2 is high, the amount of evaporation becomes smaller. Therefore, when the pump 4 has an intermediate capacity, the liquid level of the latent heat medium in the solar heat collector 1 drops significantly when the intensity of sunlight is high, and the steam is often heated. On the other hand, when the sunlight intensity is low, the latent heat medium in the solar heat collector 1 becomes only liquid. In both steam heating and liquid heating of the latent heat medium, the heat exchange capacity is significantly lower than in the case of latent heat exchange, and the above-mentioned conventional solar heat collectors have the disadvantage of low performance. Still, in order to improve the performance of the solar heat collecting device, it is necessary to change the conveyance amount of the pump 4 according to the intensity of sunlight and the temperature inside the hot water storage tank, but this requires a complicated and expensive control mechanism. Therefore, it was not realized.

Purpose of the Invention The present invention solves such conventional problems, and aims to improve the efficiency of a solar heat collector by changing the heat exchange in the solar heat collector to a heat collection method that mainly uses latent heat exchange. purpose.

Structure of the invention - To achieve this object, the present invention sequentially connects a solar heat collector, a heat exchanger, a pump, a check valve, and a storage tank with a liquid level detection means in a closed circuit. It is connected to a pipe and controls the operation of the pump according to the signal from the liquid level detection means. With this configuration, the liquid level of the latent heat medium in the storage tank installed at a height between the highest and lowest parts of the solar collector is always kept within a certain range, and accordingly,
The liquid level of the latent heat body in the solar heat collector is also kept within a certain range even when the sunlight intensity fluctuates.

Therefore, even if the amount of evaporation of the latent heat medium in the solar heat collector fluctuates, the corresponding amount of latent heat medium is supplied from the storage tank to the solar heat collector. Heat collection is performed mainly through latent heat exchange between the liquid medium and the vapor Ic.

Description of examples An embodiment of the present invention will be described below with reference to FIG.

In FIG. 2, a storage tank 9 is provided between the pump 4 and the solar heat collector 1 via a check valve 8. The storage tank 9 is provided at a height between the highest and lowest parts of the solar heat collector 1, and is provided with an upper liquid level detection means 1o and a lower liquid level detection means 11. As the liquid level detection means, for example, a float is provided. etc. can be used. The same numbers are given to the same parts in Fig. 1.

In the above configuration, when sunlight hits the solar heat collector 1, the latent heat medium inside is heated and becomes steam, which is conveyed to the heat exchanger 3, where it is condensed and liquefied, and the heat is radiated and stored in the hot water storage tank 2. As heat collection progresses further, the latent heat medium liquid evaporates,
As the liquid level in the solar heat collector 1 decreases, the evaporated portion of the latent heat medium liquid flows into the solar heat collector 1 from the storage tank 9 and is replenished. Lower the liquid level. At this time, when the liquid level in the storage tank 9 reaches a preset lower liquid level position, the lower liquid level detection means 11 detects the liquid level, and via the controller 7,
The pump 4 is energized and starts operating, and the latent heat medium liquid condensed in the heat exchanger 3 is transferred to the storage tank 9.

The latent heat medium liquid transported by the pump 4 is stored in a storage tank 9.
When the liquid level within the pump reaches a preset upper liquid level position, the upper liquid level detection means 10 detects the liquid level and stops energizing the pump 4 via controller No. 7. , stop operation. As a result, the liquid level of the latent heat medium in the solar heat collector 1 is maintained at a level corresponding to the liquid level between the preset upper liquid level position and lower liquid level position in the storage tank 9. At the same time, high-efficiency heat collection is performed in the solar heat collector 1 mainly through latent heat exchange in which the latent heat medium converts from liquid to steam, resulting in improved performance.

Next, another embodiment of the present invention will be described with reference to FIG. The difference in FIG. 3 from the above embodiment is that a liquid storage tank 12 is provided in a part of the piping between the heat exchanger 3 and the pump 4 and at a position below the heat exchanger 3. According to this configuration, the latent heat medium liquid condensed and liquefied in the heat exchanger 3 is temporarily stored in the liquid storage tank 12, so that the pump 4 can be operated continuously for a certain period of time. That is, when the intensity of sunlight fluctuates and condensation exceeds the conveying capacity of the pump 4, liquid accumulates in the heat exchanger 3 in the device shown in FIG. 2, reducing heat exchange performance. But the third
In the device shown in the figure, the condensate is introduced into the liquid storage tank 12, which has the effect of enabling stable operation of the heat exchanger 3 without degrading its performance.

Effect of the invention According to the solar heat collector of the present invention, the following effects can be obtained.

(1) A storage tank with a liquid level detection means is installed between the pump and the solar heat collector via a check valve, so the liquid level inside the solar heat collector is maintained within a certain range and latent heat is generated. In response to the evaporation of the medium, the latent heat medium is supplied to the solar heat collector, and the heat exchange within the solar heat collector mainly involves the latent heat exchange from the liquid of the latent heat medium to the steam. This has the effect of improving heat collection performance.

(2) In the embodiment, the storage tank installed at a height partially between the highest and lowest parts of the solar heat collector has two positions by providing an upper liquid level detection means and a lower liquid level detection means. Since the pump is configured to be able to detect the liquid level, the pump will operate from the lower liquid level position until it reaches the upper liquid level position, and will not repeatedly start and stop, and will be able to detect fluctuations in sunlight intensity. Nevertheless, the operation is carried out for an arbitrary fixed period of time, which has the effect of maintaining the reliability of the pump.

(3) In the example, part of the piping between the heat exchanger and the pump,
In addition, by providing a liquid storage tank below the heat exchanger, the latent heat medium liquid condensed in the heat exchanger is guided to the liquid storage tank, so the amount of condensed liquid that accumulates in the heat exchanger is reduced. This has the effect of enabling stable heat exchange without deteriorating the performance of the heat exchanger.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of a conventional solar heat collecting device, and FIG. 2 is a system diagram showing an embodiment of the solar heat collecting device of the present invention.
FIG. 3 is a system diagram of another embodiment of the solar heat collecting device of the present invention. 1...Solar heat collector, 3...Heat exchanger, 4-...
...Pump, 8...Check valve, 9...Storage tank, 1°...Upper liquid level detection means, 11...
. . . Lower liquid level detection means, 12 . . . Liquid storage tank. Name of agent: Patent attorney Toshio Nakao and 1 other person-2
ε Figure 1 6 Figure 2 Figure 3

Claims (3)

[Claims] (1)'! A solar heat collector that evaporates the liquid M medium, a heat exchanger that condenses the vapor of the latent heat medium and radiates heat, a pump that circulates and conveys the latent heat medium, a check valve, and a storage tank that stores the liquid latent heat medium. and a solar heat collecting device which is connected in a closed circuit via piping in order and controls the operation of the pump in response to a signal from a liquid level detection means provided in the storage tank. (2) The storage tank is installed at a height located in a part between the highest and lowest parts of the solar heat collector, and at the same time, the liquid level detection means of the storage tank is located at a lower liquid level at which the pump starts operating. The solar heat collector according to claim 1, which is configured to detect two positions of the detection means and the upper liquid level detection means for stopping the operation of the pump. (3) The solar heat collection device according to claim 1, wherein a liquid storage tank is provided in a part of the piping between the heat exchanger and the pump and at a position below the heat exchanger.