Medium-and-high-temperature solar selective absorption coating and preparation method thereof

Abstract

The invention discloses a preparation method for a medium-and-high-temperature solar selective absorption coating. The coating consists of an infrared reflection layer, an absorption layer and a reflection reduction layer from a base body to a surface; the infrared reflection layer consists of a Mo film, and the thickness of the infrared reflection layer is 50 to 200mm; the absorption layer comprises a first sub layer and a second sub layer; the first sub layer and the second sub layer consist of a Mo+AlN film respectively, and the thickness of the first sub layer and the second sub layer is 30 to 150mm; the reflection reduction layer consists of a AlN film, and the thickness of the reflection reduction layer is 30 to 100mm; according to the method, the infrared reflection layer is deposited on the base body by a Mo target direct current magnetron sputtering method; the absorption layer is deposited on the infrared reflection layer by Mo target direct current magnetron sputtering and Al target medium-frequency magnetron sputtering; the reflection reduction layer is deposited on the absorption layer by Al target medium-frequency magnetron sputtering; and the preparation method is simple, convenient to operate, easy to control, and high in sputtering velocity and can shorten a production cycle.

Description

technical field [0001] The invention relates to the technical field of solar energy utilization, in particular to a method for preparing a medium-high temperature solar selective absorption coating. Background technique [0002] Solar thermal power generation is an important technical approach for large-scale development and utilization of solar energy. At present, there are tower, trough, and dish systems, among which trough and tower systems are more commercially used, especially trough solar thermal power generation, which is the most popular so far. So far, it is the only mature technology in the world that has been commercialized for 20 years, and its cost is much lower than that of photovoltaic power generation. In the trough-type concentrating thermal power generation system, its energy storage system or combustion system can realize 24-hour operation. With the increase of scale, the cost per unit of electricity is also very competitive. [0003] The key technology i...

AI Technical Summary

Problems solved by technology

In a near-vacuum environment, when the absorbing coating is used below 100°C, its absorption rate is greater than 92%, and its thermal emissivity is less than 8%. At a higher temperature (above 200°C), due to the enhanced diffusion of metal and medium between coatings, the coating structure is destroyed and the overall performance of the coating changes. The thermal emissivity of this absorbing coating will be as high as 18%.

Medium and high temperature solar selective absorption coating is a frontier topic in solar thermal utilization. Medium and high temperature selective absorption coating requires the coating to be able to withstand high temperatures above 200°C and work stably for a long time. In the solar spectrum range (wavelength 0.3 ~2.5um) has a high absorption ratio, while maintaining a low emission ratio in the infrared spectrum range (wavelength 2.5~5.0um), but the process is relatively complicated and the cost is high

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