Low-temperature solar energy selective absorption coating and preparation method thereof

Abstract

A low temperature solar energy selective absorption coating includes preparing Al or Cu of 0.02-0.06*10<-6>m thick on a glass surface as a substrate, depositing Ge-C of 0.03*10<-6>m-0.15*10<-6>m thick on the substrate as an infrared antireflection layer and preparing an Al-N composite absorbing material layer on the infrared antireflection layer. The invention adds the infrared antireflection layer through the novel solar energy adsorption coating, which is prepared through a multi-target magnetron sputtering technology. The coating is provided with a perfect property of absorbing solar long spectrums within the wavelength range of 0.3-2.5 Mu m. What is more important in that the substrate of the absorption coating is provided with high adsorption rate, good reflection effect on infrared rays which are longer than 8 Mu m and high permeability on infrared rays which are shorter than 8 Mu m. And when the temperature in a vacuum tube rises to 90-100 degree Celsius, the emission rate of the membrane layer can rapidly ascend to increase the heat losses of a heat collector and avoid a system to be overheated.

Description

technical field [0001] The invention relates to a solar energy utilization technology, in particular to a low-temperature solar energy selective absorption coating, and also relates to a preparation method of the coating. Background technique [0002] In 1985, Professor Yin Zhiqiang of Tsinghua University invented a solar selective absorption coating (ZL85100142), and vacuum tube solar water heaters were rapidly popularized in China. In 2006, the installed capacity of solar water heaters in China was 18 million m 2 , with a holding capacity of 90 million m 2 , The installation volume in 2005 was 75.8% of the world's, making China a veritable powerhouse in solar thermal utilization, among which vacuum tube collectors accounted for more than 90% of the Chinese market. However, in the international market (except China), the collectors that account for 90% of the market are flat-plate collectors. Comparing domestic and foreign markets, it can be found that China's vacuum tube ...

AI Technical Summary

Problems solved by technology

1~2m per household 2 , with a water tank, but in foreign countries, most of them are hot water heating composite systems, and each household needs about ten to twenty m 2 The heat collector is used to meet the heating requirements in winter, but in summer, there is no heating demand and the light is good. The energy obtained by the whole system is higher than the required energy. If a vacuum tube collector is used, the absorption rate of the vacuum tube is high. For example, Professor Yin's invention α≈0.93, low emissivity ε≈0.06 (100°C), the whole system is very easy to overheat, causing great hidden dangers to the safety of users and the system

Images