Solar selective absorption coating and preparing method thereof

Abstract

The invention relates to a solar selectivity absorbing coating which can prevent diffusion and have stable structure, belonging to the technical field of photothermal conversion utilization of solar energy; the absorbing coating, from top to bottom, sequentially comprises a metal substrate, an absorbing layer and a reflection reduction layer; the metal substrate is deposited by a first heat resistance diffusion layer which comprises TiC, TiN and TiCN; and the absorbing layer is deposited by a second heat resistance diffusion layer comprising TiN and Ti. The selectivity absorbing coating is generated by the spattering of a metal target in the gas. The solar selectivity absorbing coating has the beneficial effects that the thermal diffusion effect between coatings is effectively prevented, the structure is stable, the high-temperature resistance performance is good, the thermal efficiency is improved, the preparation method is simple and the production cost is low.

Description

technical field [0001] The invention relates to a solar selective absorption coating with anti-diffusion and stable structure prepared by magnetron sputtering coating technology, and belongs to the field of solar photothermal conversion and utilization. Background technique [0002] With the development of human science and technology and the improvement of productivity level, the problem of energy shortage is gradually exposed. The increasing depletion of traditional energy sources such as oil and natural gas restricts the continued development and progress of human beings. Under the new situation of global energy shortage, the development of solar energy is both economical and environmentally friendly, and is a new way to relieve energy shortage. [0003] Solar selective absorbing coatings are used to absorb incoming solar radiation and convert it into thermal energy. The current solar thermal utilization is mainly used in low temperature applications with a temperature ...

AI Technical Summary

Problems solved by technology

However, when the working temperature is high, the activity of aluminum ions in the coating increases, the thermal diffusion of metal ions and insulating medium is strengthened, the structure of the coating is disordered, and the performance of the coating decreases, which affects the heat collection efficiency and life of the vacuum tube.

[0005] Chinese invention patent CN 1360084A discloses a solar spectrum selective absorption coating, which is aluminum nitrogen + titanium nitrogen - aluminum titanium film and aluminum nitrogen oxide + Titanium oxynitride-aluminum titanium film, the absorptivity of the coating can reach above α≈0.93, the emissivity ε≈0.06~0.10 (80°C), the stability of the coating has been enhanced, but it still cannot prevent the metal layer in the coating from Diffusion between absorption layers, while the overall performance of the coating is low, and the deposition rate of the coating with oxygen is very low, the deposition of the film layer needs to consume enough process time, and the production cost is high

[0006] The solar selective absorbing coatings currently used in the solar thermal utilization industry are mostly interference film structures with two absorbing layers. The two layers of films interfere with each other due to the different ratios of metal components. With high absorption ratio and lower emission ratio, the high temperature resistance performance has also been greatly improved, but due to the low melting point of the commonly used Al-AlN or SS-AlN metal-ceramic composite film itself, the influence of thermal diffusion is still large

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