Low loss solar heat-collecting tube

Abstract

A low heat loss solar heat-collecting pipe consists of an inner pipe, a heat-collecting pipe absorbed layer coated on the inner pipe, an outer pipe and a supporting spring located between the heat-collecting pipe absorbed layer and the outer pipe. The outer pipe is coated with the transparent conductive film having spectral selection transmission capacity or clad with plastic film coated with transparent conductive film.

Description

Technical field [0001] The invention relates to a solar heat collecting tube, in particular to a high-efficiency solar heat collecting tube with low heat loss. Background technique [0002] The most commonly used solar collector tube is composed of two glass tubes inside and outside. The inner glass tube is coated with a layer of material with high absorption of solar radiation and low heat radiation (such as gradient aluminum-nitrogen / aluminum or gradient aluminum -Oxygen / aluminum), vacuum is drawn between the inner and outer glass tubes to achieve the purpose of heat preservation. The efficiency of the heat collecting tube is determined by two factors: one is the absorption capacity of the heat collecting tube for solar radiation; the other is the degree of heat dissipation loss of the heat collecting tube. A large part of the heat loss is caused by the heat radiation of the heat collecting tube material. The radiation emitted by an object with a certain temperature obey...

AI Technical Summary

Problems solved by technology

Although the emissivity of the coating material of the inner tube is already very low (<0.1) in the heat collecting tube currently used, it can be seen from formula (1) that the heat radiation loss of the material is still very large under the condition of high temperature, and it continues to decrease. The emissivity of the coating material will greatly increase the cost of the collector

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