Heat-collecting tube with solar energy selective absorption coating and manufacturing method thereof

Abstract

The invention provides a heat-collecting tube with a solar energy selective absorbing coating and the manufacturing method thereof. The solar energy selective absorbing coating is deposited on the outer surface of the basis material steel tube, the two ends of the steel tube have a non-film area, the inner cavity is filled with flowing working substance, and the coating is formed by the following steps: forming a transition layer and an adhesion layer on the basis material, depositing a metal infrared reflection layer, sputtering a protective layer and a cermet absorbing layer and finally an antireflection layer. The manufacturing method is provided with the following steps: (1) the transition layer is formed on the basis by firing; (2) the adhesion layer and the infrared reflection layer are sputtered; (3) the proactive layer is coated by the magnetron sputtering method; (4) the cermet absorbing layer is deposited by the double-target sputtering method; (5) the antireflection layer is sputtered; and (6) the heat-collecting tube with the coating is subjected to vacuum treatment at 200-350 DEG C to enable the film coating to be compacter. The heat-collecting tube is applied to high temperature air, each performance is stable and realizable, and the service life is long.

Description

technical field [0001] The invention relates to a heat-collecting tube with a solar selective absorption coating and a manufacturing method thereof. The coating makes the heat-collecting element suitable for high-temperature air, and belongs to the technical field of solar water heaters. Background technique [0002] Due to the poor oxidation resistance and poor stability of the heat collecting tube of the solar water heater, the solar selective coating can only be used in vacuum or protective gas. Domestically produced heat collectors are used in a vacuum to ensure their lifespan. Foreign Solel companies (metal and glass-sealed vacuum heat collectors produced by Luz, Israel) and Schott’s products can operate at high temperatures around 40°C. However, its coating must be used in vacuum or protective gas, otherwise its performance will rapidly decay and it cannot be applied. In addition, the manufacturing process of these products is complicated and the cost is high. Conten...

AI Technical Summary

Problems solved by technology

[0002] Due to the poor oxidation resistance and poor stability of the heat collector tube of the solar water heater, the solar selective coating can only be used in a vacuum or in a protective gas.

Domestically produced heat collectors are used in a vacuum to ensure their lifespan. Foreign Solel companies (metal and glass-sealed vacuum heat collectors produced by Luz, Israel) and Schott’s products can operate at high temperatures around 40°C. However, its coating must be used in vacuum or protective gas, otherwise its performance will rapidly decay and make it impossible to apply. In addition, the manufacturing process of these products is complicated and the cost is high

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