JPS58102059A - Solar-heat water heater - Google Patents

Abstract

PURPOSE:To enhance thermal conductance at a part of contact between a condensing part of a heat pipe and a container, by a method wherein a condensing part of a heat pipe is covered by a covering container made of a material having a coeffient of thermal expansion lower than that of a material for the condensing part, and the container and a hot water storing tank are sealed. CONSTITUTION:The water heater is comprised of a heat collector which consists of heat-collecting plates and an evaporating part of the heat pipe 1, and the hot water storing tank 3 which is placed in the direction of an upper part of the heat collector and through which the condensing part 1a of the heat pipe 1 is passed. The condensing part 1a is covered by the covering container 2 made of a material (e.g., copper) having a coefficient of thermal expansion lower than that of the material (e.g., Al) for the part 1a, and the container 2 and the tank 3 are sealed. Initially, an appropriate gap is present between the container 2 and the condensing part 1a, so that the part 1a can be easily fitted into or detached from the container 2. On the other hand, when the heat collector receives sunshine, the temperature of the pipe 1 becomes higher than that of the container 2, and the part 1a and the container 2 are snugly connected to each other, whereby the thermal conductance can be enhanced, and heat-collecting efficiency can be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a solar water heater comprising a heat collector having a heat pipe and a hot water storage tank.

The conventional device of this type (Japanese Patent Application Laid-Open No. 1999-119097) is as follows:
As shown in FIG. 3, the heat pipe 8
The condensing part 8a is formed into a screw shape, and the hot water storage tank 9
The liquid 11 in the hot water storage tank 9 is sealed between the screw container 1o and the hot water storage tank 9.

Note that 12 in the figure is a heat insulating material that covers the hot water storage tank 9.

Here, since the heat pipe 8 is inserted into the screw container 10, the screw-shaped condensation part 81 of the heat pipe 8 and the screw container 10 are in local contact.
Since the thermal conductance becomes smaller, it will not have a negative effect on the heat collecting performance.Furthermore, if the heat collecting plate provided in the evaporation part of the heat pipe 8 is large or if multiple heat pipes 8 are connected, , it had a serious drawback that it was impossible to screw the heat pipe 8 into the screw container 1o while turning it.

The present invention eliminates these conventional drawbacks, and allows the condensing section of the heat pipe to be easily inserted into the heat exchange container that is firmly sealed to the hot water storage tank without turning it. A container for protection against corrosion etc. can be easily attached.
Furthermore, the purpose is to increase the thermal condensation at the contact portion between the condensing portion of the heat pipe and the container.

In order to achieve the above object, the present invention covers the condensing part of the heat pipe with a covering container made of a material having a smaller coefficient of thermal expansion than the material of the condensing part of the heat pipe, and seals the covering container and the hot water storage tank. It is.

With this configuration, when solar radiation hits the heat collector, the temperature of the heat pipe becomes higher than the temperature of the covered container that is in contact with the liquid in the hot water storage tank, and the heat pipe condensation part also has a higher coefficient of thermal expansion. Since it is thicker than the covering container, due to the difference in thermal expansion, even though it was possible to insert and attach it easily due to the appropriate gap between the covering container and the heat pipe condensing part in the beginning, when collecting heat, The condensing part and the covering container are in close contact with each other, increasing thermal conductance and, in turn, improving heat collection efficiency.

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. Figure 1 shows a cross section of the main part of a solar water heater in which the condensing part of the heat pipe is inserted into the hot water storage tank. 1a is formed, and a covering container 2 having fins 2a and made of a material having a coefficient of thermal expansion smaller than that of the condensing part 1a is disposed in the condensing part 11L in a loose fit, and one end of the covering container 2 is The heat pipe 1 is closed and has a sealing cylinder 2b formed at the other end, and is inserted into a connecting cylinder 4 provided in the hot water storage tank 3.
and the hot water storage tank 4, and the sealing cylinder 2b and the connecting cylinder 4.
A sealing member 6 made of a removable material connects both the liquid 6 and the liquid 6 to prevent the liquid 6 from leaking. 7
is a heat insulating material that covers the hot water storage tank 3.

Next, the operation of the solar water heater with the above configuration will be explained.
When the evaporator (not shown) is irradiated and the heat is absorbed,
The absorbed heat is transferred to the condensing section 1a, and the temperature of the condensing section 1a increases. Thermal expansion also occurs as the temperature rises, and the condensing part 1a, which has a higher coefficient of thermal expansion than the covering container 2, eventually fits tightly into the covering container 2, which was initially loosely fitted and easy to attach and detach. This increases the thermal conductance of the contact area and improves heat collection performance.

The material of the condensing part 1a is aluminum, and the covering container 2
When the material of is copper, the linear expansion coefficient β of each is aluminum (β=23.9X10 liter) copper
(β = 16.5 x 10 1/C) (20℃
The temperature is higher in the condensing part 1& of the heat pipe 7, where the heat absorbed by the heat collecting plate (not shown) is transferred, than in the covered container 2, which is in direct contact with the liquid 6 in the hot water storage tank 3. Coupled with the increased height, the condensing portion 1a and the covering container 2 can be brought into close contact with each other.

In this way, when the covering container 2 and the condensing part 1a come into close contact with each other, not only does the thermal conductance of the contact part increase and the heat collecting performance improves, but also when the material of the condensing part of the heat pipe 1 is aluminum, Hot water storage tank 3 due to corrosion caused by water
However, by attaching the copper coated container 2 as a protective container as in the present invention, the condensing portion 1a can be protected from corrosion.

As described above, according to the solar water heater of the present invention, the condensing part is covered with a covering container made of a material whose thermal expansion coefficient is smaller than that of the material of the condensing part of the heat pipe, and the covering container and the hot water storage tank are sealed. Therefore, it is easy to insert and attach the heat pipe and the covering container, and the thermal conductance of the contact portion is increased, so that the heat collection performance can be improved.

Furthermore, if the coated container is configured to have an increased surface area as shown in Figure 2, the increased heat transfer area will increase the thermal conductance during heat collection, resulting in improved heat collection performance. Effects can be obtained.

[Brief explanation of the drawing]

FIG. 1 is an enlarged sectional view of essential parts of a solar water heater showing an embodiment of the present invention, FIG. 2 is a sectional view of the Moom of FIG.
The figure is an enlarged sectional view of the main parts of a conventional solar water heater. 1...Heat pipe, 1a...Condensing section, 2...Coating container, 3...Hot water storage tank. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2

Claims (1)

[Claims] 0) A heat collector consisting of a heat collecting plate and an evaporating part of a beat pipe;
The heat is collected in a covered container made of a material with a smaller coefficient of thermal expansion than the material of the condensing part of the heat pipe, which is disposed in the upper direction of the heat collector and into which the condensing part of the heat pipe is inserted. A solar water heater characterized in that a condensing part of a pipe is covered, and the covering container and a hot water storage tank are sealed. ? 2. The solar water heater according to claim 1, wherein the material of the condensing part of the heat pipe is aluminum and the material of the covering container is copper.