DE29518303U1 - Films and coatings with Fresnel lens profiles for glass panes and other translucent covers to concentrate direct sunlight for solar useful heat generation, air conditioning and daylight lighting - Google Patents

Description

Films and coatings with Fresnel lens profiles for glass panes and other translucent covers for concentrating direct sunlight for solar heat generation, air conditioning and daylight lighting

The invention relates to a device according to the preamble of claim 1.

Cast glass panes with rolled-in linear Fresnel cylinder lens profiles as glass coverings for solar applications are state of the art. The Fresnel cylinder lenses achieve a concentration of direct solar radiation in focal lines on the absorber systems below. The absorbers are installed at a sufficiently large distance from each other and only slightly impair the transparency of the glass roof. In order to guarantee the concentration of solar radiation on the absorbers even if the position of the sun deviates from the fixed design, the absorber systems are automatically adjusted to the elevation of the sun using a sensor and a simple mechanism.

Scattering effects on the Fresnel cylinder lenses create diffuse light, which also provides pleasant, glare-free daylight lighting. The entire roof of a building, or just a part of it, can be covered with the glass panes described. The glass panes are used instead of a normal glass covering. Due to the concentration of direct sunlight, a heat transfer medium flowing through the absorbers can be heated in a wide temperature range, from low to process heat temperatures.

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The following advantages can be combined with this technology:

Maintaining the transparency of the glass roof

- Generation of glare-free daylight lighting Air conditioning of the rooms below
no shading system required
no impairment of the exterior view of the glass roof attractive architectural interior design

- Conversion of direct solar radiation into useful heat. Generation of high heat yields through large collector surfaces. Possibility of generating high temperatures through radiation concentration. No weather problems, as all components are inside the room. Simple "switching off" of the collector by moving it out of the focal line.

Particularly promising applications are seen for glass-covered roof structures in public buildings, industrial halls, commercial and office spaces, sports and leisure facilities, exhibition and hotel halls, winter gardens, etc. for domestic water heating or the generation of process heat, heating, air conditioning and daylight lighting. The technology appears particularly interesting for "solar houses" in low-energy construction with underground storage and heat pumps for domestic water heating, heating and cooling. Other interesting applications are seen in the more efficient conversion of concentrated solar energy into electrical current using PV elements.

Figure 1 schematically shows a glass pane 1 with two linear Fresnel cylinder lens profiles embossed on the underside, according to the state of the art, and the resulting radiation concentration 3 on the absorber 2 underneath.

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Figure 2 shows the same arrangement with vacuum tube collectors 2 to generate higher temperatures.

The main claim of the present application relates to translucent films and coatings with Fresnel lens profiles for glass panes and other translucent covers, which serve both as lenses for concentrating direct sunlight and as protection against falling glass shards. Fig. 3 shows schematically various options for applying the films or coatings to single or composite panes, cases 1 to 4, whereby further combinations are conceivable.

An additional protection claim is made for the tool for producing the films or coatings with Fresnel cylinder lens profiles. The required extrusion roller can be advantageously assembled from individual disks, as shown schematically in Fig. 4. The advantages lie in the realization of the smallest curvatures and the precision machining of the flanks of the Fresnel lens profiles. The smallest technically feasible radius in the discontinuities of the lens is only limited by the material properties of the roller and the surface tension of the film or coating material.

Claims (13)

- 5 -Claims 1) Translucent films and coatings with Fresnel lens profiles, linear and non-linear, applied to glass panes and other translucent coverings to concentrate direct solar radiation. 2) Claim under 1) characterized in that adhesive or cling films with Fresnel lens profiles are applied. 3) Claim according to 1), characterized in that the Fresnel lens profiles are applied to the glass panes or other light-permeable covers in a coating process. 4) Claim according to 1) to 3), characterized in that the Fresnel lens concentrates the direct solar radiation in a focal line, a sequence of focal points on a line or in a focal point. 5) Claim according to 1) to 4), characterized in that the glass panes or translucent covers are designed as single or composite panes. 6) Claim according to 1) to 5), characterized in that one or more glass panes or translucent covers are designed in safety, insulation or heat protection quality. 7) Claim according to 1) to 6), characterized in that adjustable absorbers are arranged in the focal lines or in the focal point of the Fresnel lenses. 8) Claim according to 7) characterized in that the absorbers are insulated on one side, with or without selective coatings on the uninsulated side. 9) Claim under 7) characterized in that the absorbers are designed as vacuum tube collectors. 10) Claim under 7) characterized in that PV elements are applied instead of the previously described absorbers. 11) Claim according to 7) characterized in that the absorbers consist of a combination of claims 8), 9) and 10). 12) Claim according to 1) to 3), characterized in that the tool for producing the films or coatings with the Fresnel cylinder lens profiles is composed of individual disks. 13) Claim according to 12) characterized in that films of greater thickness with Fresnel cylinder lens profiles are also produced and used without glass panes and other translucent covers.