JP2002022284A - Reflecting face member for heat collecting apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reflecting face member capable of being easily manufactured and efficiently reflecting the solar rays to a heat collecting body. SOLUTION: The reflecting face member partially surrounding the tubular heat collecting body so as to reflect the solar rays to the heat collecting body is manufactured by molding a resin molded product and mirror-finishing a reflecting face. The reflecting face member having thermal insulation properties and capable of efficiently reflecting the solar rays to the heat collecting body is easily manufactured only by molding by use of a mold and coating at low costs. Its shape stability and reproducibility in manufacturing are also good.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat collector for converting sunlight into heat, and more particularly to a tubular heat collector having a fluid passage defined therein for raising a temperature of a fluid such as water by sunlight. The present invention relates to a reflecting surface member that intensively reflects sunlight.

[0002]

2. Description of the Related Art Conventionally, a tubular heat collector for flowing water or the like therein and raising the temperature by sunlight is provided, and a reflector for reflecting the sunlight intensively to the heat collector is provided. Heat collectors are used in solar water heaters and the like.

Further, a compound parabolic surface (CPC: Comp) having a cross section formed by combining a reflecting surface of the above-mentioned reflecting plate with a pair of radiation inclined at an angle θ and an involute curve is used.
sound Parabolic Concentrat
The heat collecting apparatus described in US Pat. No. 4,002,4 has attracted attention because of its high light-collecting (heat collecting) efficiency.
No. 99 or JP-A-11-287521). Such a reflecting plate has a reflecting surface mirror-finished to further improve its reflection efficiency.

[0004]

However, in order to manufacture the above-mentioned reflector, conventionally, a flat plate is formed into a curved surface as described above, and then the reflection surface is processed (mirror surface). Since the curved surface has a complicated shape, plastic processing is troublesome, and the mirror surface processing of the reflective surface is also extremely troublesome, and it is necessary to stably obtain a reflector that can efficiently collect light to the heat collector. Could not.

On the other hand, in the above-described heat collecting device, it is necessary to suppress heat radiation as much as possible in order to increase the heat collecting efficiency. Generally, simply closing the casing still releases a large amount of heat, so that the heat collection efficiency cannot always be increased. In particular, for example, the heat radiation is large in an extremely cold region or in winter.

SUMMARY OF THE INVENTION The present invention has been devised to solve the above-mentioned problems of the prior art, is easy to manufacture, and allows a solar collector to be mounted on a heat collector without impairing the light collection (heat collecting) efficiency. It is an object of the present invention to provide a reflecting surface member capable of efficiently reflecting light.

[0007]

In order to achieve the above object, the present invention provides a tubular heat collector having a passage for the fluid therein for receiving sunlight, converting the heat into heat, and raising the temperature of the fluid. A body, and a heat collecting unit reflecting surface member provided with one or more heat collecting units including a reflecting surface member partially surrounding the heat collector to reflect sunlight to reflect sunlight,
The reflection surface was a mirror-finished resin molded product. This makes it possible to manufacture a highly accurate reflective surface member having high heat retention by only molding and coating with a mold.

[0008]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a perspective view showing the overall configuration of a heat collecting device used for a solar water heater according to a first embodiment of the present invention. This heat collecting apparatus includes a box-shaped casing 1 that opens upward, and a number of heat collecting units 2 that are arranged in parallel inside the casing. Each heat collecting unit 2 includes a tubular heat collector 3 and a reflecting surface member 4 for intensively reflecting sunlight on the heat collector 3. The heat collectors 3 of the heat collecting units 2 are connected in series, one end of which is connected to a cold water supply source via a pump or the like, and the other end of which has a heated water storage tank or a direct heater. Connected to the destination of hot water. Actually, the heat elements 3 may be connected in parallel, a plurality of heat collectors 3 connected in series may be connected in parallel, or a plurality of heat collectors 3 connected in parallel may be connected in series. Further, the opening of the casing 1 is closed by a cover 5 made of one or a plurality of transparent glasses that transmit light, and the inside of the casing 1 is sealed.

As shown in FIG. 2, the reflecting surface member 4 of the heat collecting unit 2 is formed by molding a highly heat-insulating resin material such as urethane foam in a mold (not shown). The surface (reflective surface) 4a is coated with a reflective layer 6 made of metal. As a coating method, a known physical film forming method represented by plating or ion plating, a chemical film forming method, coating, or the like may be used. The reflection surface formed by this molding and coating has better shape stability, better molding reproducibility, and lower cost compared to the case of processing a plate material.

Here, the surface (reflection surface) 4a is processed so as to be a composite paraboloid (CPC). As described above, the composite paraboloid has a cross section formed by combining a pair of identical parabolas (side portions 4b) forming an angle θ and an involute curve (bottom portion 4c). Is provided with a ridge 4d. This is a shape in which light incident from the opening of the reflecting surface member 4 is reflected most efficiently toward the heat collector 3 near the bottom surface (for example, see US Pat. No. 4,002,499). Ideally, the ridge 4d at the center is in contact with the heat collector 3, but the tip is lowered and slightly separated (gap) to prevent heat dissipation and heat loss by contact.

By receiving the heat collecting unit 2 as described above in the casing 1, the heat retaining effect is enhanced as in the case where the casing 1 is filled with a heat insulating material, and the heat collecting efficiency is improved.

In the above construction, a plurality of heat collecting units 2 are received in the casing 1. For example, if a light-transmitting unit cover is provided at the opening of the heat collecting unit 2 and the inside is closed, the heat collecting unit 2 can be formed as a single unit. Can also be used as a device,
A plurality of heat collecting units 2 can be connected in series or in parallel to be used as a heat collecting device.

[0014]

As is apparent from the above description, according to the reflecting surface member for a heat collecting device according to the present invention, the reflecting surface member partially surrounding the tubular heat collector so as to reflect sunlight. Is a resin molded product with a mirror-finished reflection surface, which has high heat retention only by molding and coating with a mold, and a highly accurate reflection surface capable of efficiently reflecting sunlight on a heat collector. The member can be manufactured easily and at low cost, and its shape stability and reproducibility at the time of manufacture are good.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the overall configuration of a heat collecting device used for a solar water heater to which the present invention is applied.

FIG. 2 is a cross-sectional view of the heat collecting unit of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Casing 2 Heat collection unit 3 Heat collector 4 Reflection surface member 4a Reflection surface 4b Side surface part 4c Bottom part 4d Projection 4e Flange part 5 Cover 6 Reflection layer

Claims (2)

[Claims] 1. A tubular heat collector having a passage for the fluid therein for receiving sunlight and converting it to heat to increase the temperature of the fluid, and a heat collector for reflecting the sunlight to the heat collector. A heat collecting unit reflecting surface member provided with one or a plurality of heat collecting units each including a partially surrounding reflecting surface member, wherein the reflecting surface member is made of a resin molded product whose mirror surface is mirror-finished. Reflecting surface member for a heat collector. 2. A reflection surface of the reflection surface member extends along the heat collector and surrounds the heat collector, forming a pair of parabolas of the same shape on the side surface, and forming an involute curve on the bottom surface. And a compound parabolic surface (CPC: Compound Parabolic) having a cross section having a ridge at the center of the bottom portion.
The reflecting surface member for a heat collecting apparatus according to claim 1, wherein the reflecting surface member is a concentrator.