JPS5862455A - Solar energy collector - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention arranges an inner tube for passing a heat medium inside a light-transmissive outer tube, and makes the space between the inner and outer tubes completely vacuum to collect solar heat. The present invention relates to a solar energy collector in which a solar cell is formed on the outside of an inner tube.

Such an energy collector is capable of efficiently recovering solar energy in the form of both heat and electricity, and one of the present applicants has already filed a patent application in Japanese Patent Application No. 55-59663. The most desirable solar cell in this case is an amorphous silicon (a-8i) solar cell, which is easy to manufacture. However, sunlight that is effective for photovoltaic power generation by A-8I solar cells has a wavelength range of 0.3 μm to 0.7 μm, and the wavelength range of 0.7 μm or more cannot be effectively used for conversion into electrical energy by solar cells. . 0.7μm
Most of the solar energy that cannot be converted into electrical energy in the following wavelength range is converted into heat in the a-8i layer, propagated to a heat collector, and used as thermal energy. - Since the absorption rate of A-8i is low for the outside wires of ten thousand notes, it cannot be expected to be extracted as heat.

The purpose of the present invention is to provide a solar energy collector that utilizes such infrared rays, which cannot be converted into electrical energy, as thermal energy as efficiently as possible. This is achieved by interposing a layer made of a material with a high absorption rate of infrared rays between the outer surface of the inner tube and the solar cell. For silicon solar cells, amorphous germanium, which has a narrower band gap than Si, or a metal compound such as black alumite, iron oxide, or black chromium can be effectively used as the material for such an intervening layer.

The present invention will be described below with reference to all the drawings. In FIG. 1(a), the song Iti111 shows the solar radiation intensity, which has a peak at 0.5 μm. Among these, the energy corresponding to the non-hatched region 12 at a wavelength of about 0.7 μm or less, which corresponds to the forbidden band width of silicon, is a-8i.
It is converted into electrical energy by the solar cell, and the energy corresponding to the hunting area 13 is converted into heat. In order to utilize the remaining sunlight in the infrared region 14 of approximately 0.7 μm or more as effectively as possible, it is absorbed as heat using a heat absorption film having absorption characteristics as shown in FIG. 1(b), for example. . Amorphous germanium (
a-Ge) When the film or base metal is aluminum, black alumite can be used, when it is iron, iron oxide, and when it is copper, black chromium can be used. It shows a high absorption rate in the infrared region compared to The infrared emissivity also has a low value of 0.2 or less. Figures 2 and 3
The figure shows a solar energy collector equipped with such a heat-absorbing film, and the outer surface of the inner tube 2 made of glass or metal provided inside the transparent outer tube 1 absorbs about 0.7μ of sunlight.
The above heat absorbing film 3 that absorbs wavelengths of m or more is deposited, and the solar cell layer 4 made of a-8i is formed on the upper surface.@If the inner tube 2 is made of glass, the heat absorbing film 3 A conductive film is provided thereon, and a solar cell layer 4 is formed thereon.

The a-8i solar cell may be a single solar cell or a plurality of solar cells connected in series or parallel. The outer tube 1 is sealed with the inner tube 2 at the end 6, and the inner tube 2 is evacuated to a degree of vacuum necessary for open sound insulation, and the exhaust lower part is completely vacuum-sealed.

Electricity is generated in the solar cell F@4 by the sunlight that enters this energy collector all the way through the outside.
The output is taken out through the lead wire 8 and the terminal 9. The thermal energy recovered in the solar cell layer 4 and the thermal energy recovered in the heat absorption $3 are transferred to the heat medium flowing inside the inner tube 2 .

A heat absorbing film made of a metal compound is easily formed by plating or thermal oxidation. The a-Ge film is formed on the inner tube by glow discharge decomposition of the Ge compound gas, and the a-8iNIi film can be continuously grown when the reaction gas is changed, making it possible to create a low-cost, high-efficiency energy collector. can be configured.

As described above, the present invention utilizes solar energy in the infrared region, which cannot be converted into electrical energy by solar cells due to the forbidden band width of semiconductors, by using an absorbing film that has a high absorption rate for light in that region. It converts it into thermal energy and extracts it from the heat collecting tube installed under the solar cell.Since solar energy can be used over the entire wavelength range, it can be used as a highly efficient solar energy collector for energy countermeasures. It can be applied very effectively above.

[Brief explanation of the drawing]

Figure 1 (a) shows the solar heat radiation intensity and its utilization by the solar cell, Figure 1 (b) shows the absorption rate of the heat absorbing film according to the present invention, and Figure 1 (C) shows the absorption rate of a-8t. FIG. 2 is a longitudinal cross-sectional view of an embodiment of the solar energy collector according to the present invention, and FIG. 3 is a cross-sectional view thereof. 1... Outer tube, 2... Inner tube, 3... Heat absorption membrane, 4...
...Solar cell layer. 6-

Claims (1)

[Claims] 1) A solar heat collector in which all inner tubes for passing a heat medium are arranged inside a light-transmissive outer tube, and the space between the inner and outer tubes is evacuated. In addition to forming a solar cell on the outside of the inner tube, a layer made of a material having a higher absorption rate of infrared rays than the semiconductor constituting the solar cell is interposed between the outer surface of the inner tube and the solar cell. A solar energy collector featuring: 2. The collector according to claim 1, characterized in that the semiconductor constituting the solar cell is silicon, and the material with a high infrared absorption rate is amorphous germanium, blackened alumite, iron oxide, or black chromium. solar energy collector.