JPS5820853Y2 - solar heat collector - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a solar heat collector using a heat pipe, and is designed to prevent damage to the heat pipe due to freezing of the working fluid.

Generally, a heat pipe is a heat transporter that uses the latent heat of the working fluid by reducing the pressure inside the metal tube and sealing the working fluid in it.
As shown in FIG. 1, a solar heat collector A using this heat pipe is constructed.

That is, heat collecting fins 2 are placed inside a transparent outer tube 1 made of glass or the like.
Insert the heat pipe 3 thermally connected to the outer tube 1, close the opening of the outer tube 1 with the stem 4, lead out the upper part of the heat pipe 3 from the stem 4, create a vacuum inside the outer tube 1, and A required amount of working fluid is sealed inside the vacuum heat pipe 3.

As a solar heat collecting device, as shown in Figs. 2 to 4.

A plurality of solar heat collectors A are arranged in parallel, and the upper condensing part from which each heat pipe 3 is led out is located in the circulating heat medium 5,
Solar heat is received by the heat collection fins 2, the temperature of the heating part of the heat pipe 3 is raised, the working fluid 6 of the heat pipe 3 is heated and evaporated, the vapor moves to the condensing part, and the latent heat is circulated. The liquid is discharged into the medium 5 and condensed, and the condensed liquid returns to the original heating part due to gravity, and the same cycle is repeated.

By the way, when water is used as the working fluid 6, when the water as the working fluid 6 freezes due to a drop in outside temperature, the volume increases by about 9%, and the metal tube that makes up the heat pipe 3 is deformed due to expansion from the inside. If the deformation limit is exceeded, the metal tube will break.

Therefore, there is a restriction that only a working fluid that does not freeze even in winter must be used, and water with excellent operating characteristics cannot be used as the working fluid 6 of the heat pipe 3.

This invention was developed by taking the above points into consideration and preventing the heat pipe from being damaged even if the working fluid freezes. This will be explained in detail with reference to the drawings.

First, in FIG. 5 a and l) showing one embodiment, a cylindrical liquid reservoir 7 is formed at the lower end of the heating part of the heat pipe 3,
The volume of the liquid reservoir 7 is approximately twice or more the volume of the hydraulic fluid 6 made of water.

Therefore, even if the hydraulic fluid 6 freezes and expands in volume, the fluid reservoir 7 will not be deformed at all, and the heat pipe 3 will not be damaged.

Furthermore, if the container of the liquid reservoir 7 is made of copper with a thickness of 1 m/m, for example, the strength of the container is greater than that of the ice, and there is no possibility of breakage.

Next, in FIGS. 6a and 6l), the shape of the liquid reservoir 8 is made spherical, and furthermore, a capillary structure 9 such as mesh or fiber is immersed in the liquid reservoir 8.

In this case, even if the working fluid 6 is unevenly distributed in the locally provided liquid reservoir 8 and the evaporation surface area becomes small, the capillary structure 9 promotes evaporation of the working fluid 6 in the liquid reservoir 8.

Furthermore, FIGS. 7a and 7l) show examples in which the cylindrical liquid reservoir 10 is attached to the heat pipe 3 in different directions.

Note that the liquid reservoirs 7 and 10 shown in FIGS. 5 and 7 are arranged horizontally when the heat pipe 3 is installed.
It is attached to heat pipe 3.

As described above, according to the solar heat collector of this invention, a reservoir of working fluid made of water is formed at the lower end of the heating section of the heat pipe, and the volume of the reservoir is approximately 2 times the volume of the working fluid. By more than doubling the volume, it is only necessary to take antifreeze measures for the liquid reservoir, and water with excellent operating characteristics can be used as the hydraulic fluid, and even if the hydraulic fluid freezes, Since no pressure is applied to the wall surface of the heat pipe, the heat pipe will not be damaged and its lifespan can be extended, and the heat pipe does not necessarily have to be highly resistant to pressure.

Furthermore, by immersing the capillary structure in the liquid pool,
It can promote evaporation of the working fluid and increase the function of the heat pipe.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a solar heat collector using a normal roof pipe, Fig. 2 is a perspective view of a solar heat collector using the solar heat collector of Fig. 1, and Fig. 3 is a perspective view of a solar heat collector using the solar heat collector of Fig. 2. A cutaway plan view of a part of
Figure 4 is a cutaway side view of Figure 2, Figures 5 and below show the main parts of an embodiment of the solar heat collector of this invention, and Figures 5, 6, and 7 show each embodiment. A for each country is a cutaway side view, and B for each country is a perspective view. A...Solar heat collector, 1...Outer tube, 2
... Heat collection fin, 3 ... Heat pipe, 6 ... Working fluid, 7, 8.10 ... Liquid reservoir, 9 ... ...Capillary structure.

Claims (1)

[Scope of utility model registration request] In a solar heat collector using a heat pipe, a pool of working fluid made of water is formed at the lower end of the heating part of the heat pipe, and the volume of the pool is approximately twice or more the volume of the working fluid. solar heat collector.