JPS6337638Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a solar water heater having a loop-type heat pipe that collects solar heat to heat water and uses the hot water for hot water supply or air conditioning.

It is generally known that efficient heat exchange can be achieved by using a heat pipe as a heat collecting element in a solar water heater. Furthermore, a structure has been developed in which the heat pipe is made into a closed loop, and a part of the heat pipe is installed in a heat exchange tank for more efficient heat exchange.

FIG. 1 shows the configuration of a solar water heater having a loop-type heat pipe of this kind devised at the development stage of the present invention. side pipe 3
and the inlet pipe 6 of the condensing section 5 housed inside the heat exchange tank 4 located above the solar collector 1 through a gas-liquid separator 7, and the inlet of the evaporating section 2. side pipe 8
and the outlet side pipe 9 of the condensing section 5 are connected by a return pipe 10 to form a loop-shaped heat pipe.

In the solar water heater with this configuration, when the pipe diameter of the evaporator section 2 is small, when the amount of solar radiation is large, or when the temperature inside the heat exchange tank 4 is very low, the amount of evaporation of the working fluid in the evaporator section 2 is small. and a large amount of bubbles are generated. The bubble group acts as a bubble pump, lifts up the liquid-phase working fluid, becomes a two-phase flow, rises, passes through the outlet side pipe 3, and reaches the gas-liquid separator 7. The gas phase and the liquid phase are separated in the gas-liquid separator 7, and the gas phase further advances to the condensation section 5 where it is condensed and liquefied. However, if the intense boiling state continues for a long time, the working fluid will gradually accumulate in the gas-liquid separator 7, and the liquid phase will eventually flow into the condensing section 5, resulting in a decrease in the condensation heat transfer coefficient and effective condensation. It has been found that this has a double negative effect of reducing the area, leading to a significant decrease in heat transfer performance and decreasing the heat collection performance of the solar water heater.

In view of the above-mentioned conventional problems, the present invention has been developed by devising the intermediate path of the loop heat pipe.
The purpose of this invention is to ensure high heat transfer performance even when the amount of solar radiation is large without increasing the volume of the gas-liquid separator, and thus to improve the heat collection performance of a solar water heater.

In order to achieve this purpose, the present invention includes an outlet side pipe of the evaporation section housed in the solar collector,
The inlet side pipe of the condensing section housed inside the heat exchange tank located above the solar collector is communicated via a gas-liquid separator, and the inlet side pipe of the evaporating section and the outlet of the condensing section are communicated with each other via a gas-liquid separator. The side pipes are connected to each other by a return pipe to form an annular loop heat pipe, and the gas-liquid separator and the lower part of the evaporation section are communicated with each other by a drain pipe.

With this configuration, when the pipe diameter of the evaporator is not large or when the amount of solar radiation is very large, boiling and evaporation of the working fluid in the evaporator occurs violently, improving the vitality of the gas-liquid two-phase flow, and increasing the Even if the two-phase flow flows into the gas-liquid separator, the liquid phase after being separated by the gas-liquid separator is immediately returned to the bottom of the evaporator section by the drain pipe, and the working fluid does not flow into the condensing section. Since it is possible to prevent the heat transfer performance from being deteriorated and the heat transfer performance from being deteriorated by deterioration of the heat transfer performance, the heat collection performance of the solar water heater can be improved.

Hereinafter, one embodiment of the present invention will be described based on FIG. 2. In the figure, reference numeral 11 denotes a solar collector, which has a light transmitting body 12 disposed on its front surface, and houses a heat insulating material 13 and an evaporation section 14 of a heat pipe inside. At the upper position of the solar collector 11,
A heat exchange tank 15 is arranged, and a heat medium 1 such as water stored therein is placed in the heat exchange tank 15.
6, the condensing part 17 of the heat pipe is immersed in
is stored. An outlet pipe 18 is connected to one end of the evaporator 14, and an inlet pipe 19 is connected to the other end. Further, an inlet pipe 20 is connected to one end of the condensing section 17, and an outlet pipe 21 is connected to the other end. The outlet side pipe 18 of the evaporating section 14 and the inlet side pipe 20 of the condensing section 17 are communicated via a gas-liquid separator 22, and the inlet side pipe 19 of the evaporating section 14 and the inlet side pipe 20 of the condensing section 17 are connected to each other via a gas-liquid separator 22.
The lower part of the gas-liquid separator 22 and the lower part of the evaporator 14 or the evaporator inlet pipe 1 are communicated with the outlet pipe 21 via the return pipe 23.
9 are connected to each other through a drain pipe 24 to form a loop-type heat pipe 25. Note that the return pipe and the like are not changed in any way even in the configuration in which the return pipe and the like are stored in the box of the solar collector 11.

Next, the operation of the solar water heater having the above configuration will be explained.

Sunlight passes through a light transmitting body 12 disposed in front of the solar collector 11 and is absorbed by the evaporator 14 of the loop heat pipe 25 . and evaporation section 1
The light absorbed by 4 is converted into thermal energy, and the working liquid (not shown) sealed in the evaporator 14 is evaporated by the heat, becoming a gas-liquid two-phase flow and flowing into the gas-liquid separator 22. After being separated into a gas phase and a liquid phase, the steam rises and reaches the condensing section 17, where it is cooled and condensed, giving the latent heat of condensation to the heat medium 16 in the heat exchange tank 15 and converting it into heat. The temperature of the medium 16 is increased. The liquefied working fluid passes through the return pipe 23, returns to the evaporator 14 in the solar collector 11, evaporates again, and repeats the above-described operation.

Here, when the pipe diameter of the evaporator 14 is small or when the amount of solar radiation is large, the pumping action of the vapor bubbles becomes large, and the vapor becomes a two-phase flow in the evaporator 14 and rises rapidly. Although the liquid phase flows into the separator 22 and is separated into a gas phase and a liquid phase, the liquid phase starts to flow out.
Since the water flows down the drain pipe 24 disposed at the bottom of the evaporator 14 and returns to the bottom of the evaporator 14, it does not flow into the condensing part 17, so good condensation heat transfer can be maintained and high heat transfer performance can be ensured. be done.

As described above, according to the present invention, the gas-liquid separator is disposed between the outlet side of the evaporation section and the inlet side of the condensation section, and the lower part of the gas-liquid separator and most of the evaporation section are communicated by a drain pipe. Because of this structure, even when the pipe diameter of the evaporator section is small or when the amount of evaporation is extremely large, the working fluid is prevented from flowing into the condensing section, ensuring high heat transfer performance. It has the excellent feature of improving the heat collection performance of solar water heaters.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of the same water heater devised at the development stage of the present invention, and FIG. 2 is a longitudinal cross-sectional view of a loop type heat pipe type solar water heater showing an embodiment of the present invention. 11... Solar collector, 14... Evaporation section, 1
5... Heat exchange tank, 17... Condensing section, 22...
Gas-liquid separator, 23...Return pipe, 24
...Drain pipe.

Claims (1)

[Scope of utility model registration request] It has an evaporation section housed in a solar collector, and a condensation section housed inside a heat exchange tank located above the solar collector, and an outlet side pipe of the evaporation section and an inlet side pipe of the condensation section. The inlet side pipe of the evaporating section and the outlet side pipe of the condensing section are connected via a return pipe to form a ring, and the gas-liquid separator and the evaporating section are connected through a gas-liquid separator. A loop-type heat pipe type solar water heater that connects the lower part of the water heater with a drain pipe.