Medium-high temperature solar photothermal selective-absorbing coat

Abstract

The invention relates to a solar energy selective-absorbing coat. The coat is deposited on a metal substrate, and the coat sequentially comprises a bonding transition layer, an infrared high-reflecting layer, a high-metal-content metal-ceramic composite film, a low-metal-content metal-ceramic composite film and a dereflection film which are arranged on the surface of the substrate from bottom to top. The infrared high-reflecting layer is a metallic compound film, the compound film has a high reflectivity in an infrared band and a high absorptivity in a sunlight band, and the compound film has a high hardness and a high oxidation resistance. The metal adopted by the metallic compound film is same to metals adopted by the bonding transition layer and the above metal-ceramic composite films, so the mutual pollution problem among materials is reduced, and the making of the coat is simple. The coat has an absorptivity of above 95% and a hemispherical emittance of below 10% when the atmospheric quality factor AM is 1.5, and the coat also has a good thermal stability.

Description

technical field [0001] The invention relates to a novel solar photothermal selective absorption coating, which is one of the key technologies in solar photothermal utilization such as solar trough photothermal power generation, solar air conditioning, and seawater desalination. It belongs to the technical field of solar thermal utilization. Background technique [0002] At present, the medium and high temperature photothermal utilization of solar energy has attracted more and more attention. Its utilization methods include solar thermal power generation, solar seawater desalination, solar heating and drying, and solar air conditioning. The trough solar thermal power generation is a typical representative of high temperature solar thermal utilization of solar energy. It has begun commercial application in foreign countries, but it is in its infancy in China, and its commercial application has broad prospects. The medium and high temperature solar photothermal selective absor...

AI Technical Summary

Problems solved by technology

[0003] At present, the medium and high temperature solar light and heat selective absorption coatings that have been researched and developed are mainly made of Au, Cu, Mo and other high-temperature relatively stable metal materials with high reflectivity. Diffusion and oxidation are easy to occur under the environment, so that the incidence rate increases; the absorption layer is a cermet film in which refractory metal particle clusters are dispersed in the ceramic dielectric layer, and the refractory metal materials selected are mainly W, Mo, Au, SS, Pt, etc., the same refractory metal particle clusters are prone to oxidation and diffusion at high temperature, which will cause the absorption performance of the selective absorbing coating to decrease or even fail after long-term service at high temperature; in addition, the general solar selective absorbing coating Composed of more than three materials, strict requirements are put forward for the coating manufacturing equipment and preparation process

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