The solar covering light guide structure
Technical field
The present invention relates to a kind of at the lip-deep special light guide structure of solar covering.
Background technology
The raising of the demand for development solar components electricity conversion of heliotechnics, and limited the lifting of solar components power as the light transmittance of the solar energy glass of encapsulating material.Be by improving light transmittance at present mostly in embossing on glass and the low iron of realization ultrawhite.
The patterned structure of existing solar energy glass is a lot, but all be shallow embossing decorative pattern, and embossing face contacts with the EVA layer during encapsulation, and EVA understands glass-filled embossing space during lamination.The refractive index of EVA and the refractive index of glass are approaching, so have reflection loss hardly at glass-EVA interface.Yet the front surface of glass is a shiny surface, and air-glass light sliding surface interface reflection loss can take place, is about 4% light.Prior art has no idea to reduce the reflection loss of air-glass surface, unless plate one deck antireflection layer on the surface of glass, but glass cost can be increased like this.
Summary of the invention
Additionally do not increase the cost of cover plate again in order to increase light transmittance, the invention provides a kind of solar covering light guide structure, this structure makes light can produce reflection loss hardly at air-cover plate interface.
For achieving the above object, the present invention adopts following technical scheme:
The solar covering light guide structure, it is characterized in that, the dark patterned structure that the front of described cover plate is provided with evenly and arranges continuously, its back side is smooth flat, described dark patterned structure is positive truncated rectangular pyramids, the bottom surface length of side of described terrace with edge is 0.3-0.4mm, and the upper bottom surface length of side is 0.08mm, highly is 0.85-1.14mm.
Described dark patterned structure can be arranged in the periodic array of four directions or triangle.When forming cubic array, the spacing between the described dark patterned structure is 0.03-0.04mm.
The present invention adds dark embossing light guide structure at the front surface of cover plate, can revise the direction of propagation of reflection ray, makes reflection ray can penetrate the surface that cover plate arrives the battery sheet, significantly increases the light transmittance of cover plate, does not additionally increase the cost of cover plate again.In addition this structure can also with from the light of battery sheet surface reflection again total reflection return, further improved the utilance of light, thereby promoted the electricity conversion of photovoltaic module.
Description of drawings
Fig. 1 is the side view and the light path schematic diagram of solar covering light guide structure of the present invention.
Fig. 2 is the light path schematic diagram that passes through light guide structure of the present invention from the light that the surface reflection of battery sheet is come out.
Embodiment
Below in conjunction with the drawings and specific embodiments the present invention is done explanation in further detail.
Solar covering is selected glass material for use, its front is provided with the patterned structure that is shaped as positive truncated rectangular pyramids of periodic arrangement, spaced apart formation groove between terrace with edge and the terrace with edge, the bottom surface length of side of its positive truncated rectangular pyramids is 0.3-0.4mm, the upper bottom surface length of side is 0.08mm, highly be 0.85-1.14mm, highly be almost 2.8 times of the bottom surface length of side, be a kind of dark patterned structure.Shiny surface with cover plate during encapsulation contacts with the EVA layer, the dark patterned structure in cover plate front can be brought up to light transmittance more than 99% when light incident, reduce the reflection loss of glass, optical phenomenas such as total reflection, reflection and refraction take place in the light that should reflect away by this glass light guide structure the time, change the direction of propagation of reflection ray, make it finally can reduce reflection loss, thereby reach the purpose that improves the solar energy glass light transmittance all through glass.Structure of the present invention can promote the light transmittance of photovoltaic module.
As shown in Figure 1, refraction and anacamptics phenomenon take place for being incident in the light of solar energy glass cover plate front surface at air-glass surface in light 1, produce refracted ray 2 and reflection ray 3 respectively.Total reflection takes place and produces light 21 and light 22 in refracted ray 2 in glass medium, light 22 arrives the surface of battery sheet by glass and EVA.Reflection ray 3 enters in the adjacent patterned structure through air layer, produces refracted ray 31, produces light 32 by total reflection then, and light 32 arrives the surface of battery sheet by glass and EVA.In whole optical path, light 22 accounts for 96%, and light 32 accounts for 3.07%, and light transmittance reaches as high as 99.07%.
In the present embodiment, the positive truncated rectangular pyramids of patterned structure is arranged in the periodic array in four directions, and the spacing of terrace with edge bottom surface base between vertical and horizontal is 0.03-0.04mm.Size of the present invention, at interval can reduce the reflection loss at EVA-battery sheet interface effectively, as shown in Figure 2, the light 1 that comes out from the surface reflection of battery sheet is through this structure, again with the surface of light total reflection telegram in reply pond sheet.