JPS59134459A - Solar heat collector - Google Patents

Abstract

PURPOSE:To maintain the liquid level in a solar heat collector in a predetermined range, constantly collect heat mainly through exchange of latent heat and contrive to enhance heat-collecting performance, by providing a liquid-reserving tank in which a ball tap is provided. CONSTITUTION:When collection of heat by evaporation of a latent heat type heat-transmitting medium in the solar heat collector 1 progresses, the liquid level is lowered, and the liquid level in the liquid-reserving tank 12 is also lowered correspondingly, resulting in that the ball tap 11 is opened. At this time, the pressure in a pipe provided between a pump 4 and the ball tap 11 is lowered below that in the condition wherein the tap 11 is closed. Then lowering of the pressure is detected by a pressure switch 10, and an electric current is passed to the pump 4 to start operation through a controller 13. When the liquid level is raised to a certain level, and the ball tap 12 is closed, the pressure in the pipe is raised by the pump 4. By these operations, the medium in a liquid state is fed in accordance with the quantity of the medium evaporated in the collector 1. Accordingly, heat is constantly collected mainly through exchange of latent heat, irrespectively of variations in the intensity of solar radiation, namely, variations in the quantity of the medium evaporated.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention 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.

Structure of conventional example and its problems As shown in FIG. 1, this type of conventional solar heat collector includes a solar heat collector 1, a heat exchanger 3 housed in a hot water storage tank 2, and a pump 4. The pipes were connected in a closed circuit, and at the same time, a latent heat medium such as fluorocarbon was sealed inside the pipes. Furthermore, to start and stop the pump 4, a low-temperature side thermostat 5 is installed inside the hot water storage tank 2, a high-temperature side thermostat 6 is installed at the outlet of the solar heat collector 1, and the signals from both are input to the controller 7. The temperatures of the thermostat 6 and the high-temperature thermostat 6 are compared, and only when the temperature of the thermostat 〇 on the high-temperature side is higher than the temperature of the thermostat 5 on the low-temperature side, the pump 5 is energized and the latent heat medium liquid is transferred to the solar heat collector 1.
t/? : 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 latent heat medium in the solar heat collector 1 is heated by solar heat and evaporates, becoming steam and passing through the heat exchanger 3.
It condenses and radiates heat, heating the water in the hot water storage tank 2 and storing the heat. In this case, if the amount of evaporation of the latent heat medium in the solar heat collector 1 is the same as the amount conveyed by the pump 4, latent heat exchange is always performed. The amount of evaporation of the medium is not constant because the intensity of sunlight is unstable. In other words, the sunlight intensity is large and the hot water tank 2
The lower the temperature inside the hot water storage tank 2, the greater the amount of evaporation. On the other hand, the lower the intensity of sunlight and the higher the temperature inside the hot water storage tank 2, the smaller the amount of evaporation. 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 intensity of sunlight is low, the latent heat medium in the solar heat collector 1 becomes 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. In addition, 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 solar intensity and the temperature inside the hot water storage tank, but this requires a complicated and expensive control mechanism. , had not been 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 provides a liquid storage tank with a ball tap inside before the inlet of the solar collector, and also provides a check valve on the inlet side of the pump and a pressure switch on the outlet side. The pump is configured to start and stop in response to the signal from the pressure switch. With this configuration, the liquid storage tank is replenished according to the amount of latent heat medium evaporated in the solar heat collector, and when the liquid level in the liquid storage tank further drops, the ball tap opens and reduces the pressure drop at the pump outlet. The latent heat medium is transported by detecting it by Kasuinochi and energizing the pump. Therefore, the liquid level of the latent heat medium in the solar heat collector is maintained within a certain range, and heat collection is performed mainly through latent heat exchange from liquid to steam.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. In FIG. 2, an intermediate tank 8 for storing condensate and a check valve 9 are provided after the heat exchanger 3, and a liquid reservoir in which a ball tap 11 is installed is provided after the pump 4 via a pressure switch 1o. A tank 12 is provided. Furthermore, the above
A controller 13 is provided for starting and stopping the pump 4 in response to a signal from the pressure gauge inch 10. Note that the same members as in FIG. 1 are given the same numbers.

In the above configuration, when sunlight hits the solar heat collector 1, the latent heat medium liquid inside evaporates, becomes steam, flows into the heat exchanger 3 housed in the hot water storage tank 2, condenses and liquefies, The heat of condensation is stored in the hot water storage tank 2. On the other hand, the condensate will accumulate in the intermediate tank 8. Further, as the heat collection due to evaporation of the latent heat medium in the solar heat collector 1 progresses, the liquid level decreases, and correspondingly, the liquid level in the liquid storage tank 12 also decreases, and the ball tap 11 becomes open. At this time, the internal pressure of the pipe between the pump 4 and the ball tap 11 will be lower than the internal pressure when the ball tap 11 is in the open state, compared to when the ball tap 11 is in the closed state. The pressure switch 10 detects the above pressure drop, and the pump 4 is energized via the controller 13 to start operation. As a result, the latent heat medium in the intermediate tank 8 is transferred to the liquid storage tank 12 and the liquid level is raised. When the liquid level rises to a certain position, the ball tap 12 is closed and the pressure inside the pipe is increased by the pump 4. When the pressure inside the piping reaches a certain pressure value, the pressure gas 5 inochi 1o detects the pressure increase, stops powering the pump 4, and stops operation. However, a check valve is installed in front of the pump 4. Because
The pressure inside the pipe is maintained. To explain the above relationship using FIG. 3, if the setting of the pressure switch 10 is to stop the operation of the pump 4 when the pressure is 21 or more,
1 is in the closed state, the inside of the pipe is maintained at Pl, and the sump pump 4 is in a stopped state. Heat collection progresses further and the liquid level decreases, and when the ball tap 12 opens at time t1, the pressure inside the pipe increases. The pressure decreases rapidly and becomes below P1, so the pressure filter 10 is activated and sends a signal to the controller 13 to operate the pump 4. While the pump 4 is in operation, the pressure is maintained at P2, but as the latent heat medium is transported +C, the liquid level rises, and eventually the ball tap 12 becomes closed at time t2.

Even when the ball tap 12 is in the closed state, the pump 4 continues to operate, and when the internal pressure of the pipe increases and reaches Pl, the pressure inlet 1o is cut off, and the operation of the pump 4 is stopped via the controller 13. Due to the above action, the liquid of the latent heat medium is transported according to the amount of evaporation of the latent heat medium in the solar heat collector 1. Since heat collection is always performed mainly through latent heat exchange, it has the effect of improving the performance of the solar heat collection device.

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

(1) By installing a dripping liquid storage tank with a ball tap inside, the liquid level inside the solar heat collector can be maintained within a certain range, that is, the amount of liquid depending on the amount of evaporation of the latent heat medium is supplied. However, heat collection performance is improved by always collecting heat mainly through latent heat exchange.

(2) Check valves and pressure switches are installed before and after the pump, and a ball tap is connected to the internal drainage tank to detect pressure fluctuations in the piping and start and stop the pump. 1, there is no need to wire the solar heat collector installed on the roof as in the past, and control parts can be placed around the pump on the ground, improving reliability and reducing maintenance. It also becomes easier.

[Brief explanation of the drawing]

@Figure 1 is a system diagram of a conventional solar heat collector, and Figure 2 is a system diagram showing an embodiment of the solar heat collector of the present invention.
FIG. 3 is a diagram showing temporal fluctuations in the pressure inside the piping, that is, the pressure detected by the pressure filter in an embodiment of the solar heat collecting device of the present invention. 1...Solar heat collector, 3...Heat exchanger,
4...Pump, 9...Check valve, 10...
・・・・Pressure inch, 11 ・・・・Ball tap,
12...Liquid storage tank. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3 Entrance gate

Claims (1)

[Claims] A solar heat collector that evaporates the liquid latent heat medium, a heat exchanger that condenses the vapor of the latent heat medium, a check valve, a pump, a pressure filter, and a liquid storage tank that includes a ball tap are connected in order in a closed circuit. A solar heat collection device that is connected to the solar heat collector by piping and controls the operation of the pump according to the signal from the pressure filter.