A medium-high temperature cavity type heat collecting tube used in a trough heat collecting system

Abstract

The invention discloses a medium-high temperature cavity heat collection tube in a trough type heat collection system. The medium-high temperature cavity heat collection tube comprises a round glass cavity, triangular reflection plates and a metal absorption tube. The outer surface of the round glass cavity is coated with a thermal insulation layer, a certain gap is reserved between the triangular plates and serves as a light incidence opening, the inner surface of the round glass cavity is plated with a reflection film, and the outer surface of the absorption tube is plated with a selective absorption coating. Sun light is reflected through a parabolic reflection surface, one part of the light directly irradiates in the round glass cavity, other light enters the cavity after being reflected by the triangular reflection plates, one part of the light which irradiates in the cavity directly irradiates the absorption tube, and the other part of the light is absorbed by the absorption tube after being reflected by the round glass cavity. Strict vacuum requirements of a traditional vacuum tube are met, and the medium-high temperature cavity heat collection tube has the advantages of being good in heat collection effect, simple in structure, low in requirement for a tracking system and the like, cost is lower than the cost of a traditional medium-high temperature heat collection tube, maintaining is convenient, service life is longer, and the medium-high temperature cavity heat collection tube has good market development prospects.

Description

technical field [0001] The invention relates to a solar heat collection tube, in particular to a medium-high temperature cavity type heat collection tube in a trough heat collection system. Background technique [0002] As a kind of medium and high temperature heat collecting tube, the trough-type focused solar heat collecting tube can obtain a higher heat collecting temperature, and can be used in production and living fields such as power generation, refrigeration and air conditioning, heating, and seawater desalination. At present, the traditional trough-type solar heat collector mainly adopts metal-glass structure. Although the high-vacuum interlayer greatly reduces heat loss, there is also the problem of air leakage after long-term work due to the sealing of metal and glass. The principle-based cavity absorber can effectively avoid the above problems, improve the reliability of system operation, and reduce the difficulty and cost of research and production. The absorbe...

AI Technical Summary

Problems solved by technology

Its disadvantages are: complicated process, high cost, inability to maintain long-term high vacuum and selective coating stability, and under long-term high-temperature working conditions, due to the different expansion coefficients of glass and metal seals, it will cause metal and glass seals There is an air leak at the place, it is difficult to maintain the vacuum, which reduces the working efficiency and system stability of the entire trough solar system

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