Solar vacuum energy exchange thermal-collecting tube

Abstract

The invention relates to a vacuum solar collector, comprising outer glass pipe, inner glass pipe and circular vacuum cavity between them. Transduction diaphragm is bonded with outside wall of the inner glass pipe, Variable diameter barrier step assembling sealing face with certain heat insulation performance is set on the sidewall of outer glass pipe or at the connecting sealing position between inner and outer glass pipe of vacuum solar collector. At least one of variable diameters of outer glass pipe is set at the jointing position between inner and outer glass pipe and is joint with reducing diameter of inner glass pipe. Outer sidewall of vacuum solar collector is possibly combined with condenser lens, whose section is ellipse or free-formed surface of closed line made up of curves andarcs. Through the section of condenser lens, vacuum solar collector makes pipe wall with backlight surface combine reflecting surface so that it condenses by reflecting; or by arc fresnel lens, whichis ray-facing surface of outer glass pipe condensing in refraction is accomplished; or reflecting surface with convex-concave groove compounded on backlight surface of circular glass pipe in longitudinal direction, condensing in reflection is completed.

Description

technical field [0001] The invention relates to a solar heat collecting element, in particular to a solar vacuum energy-converting heat collecting tube. Background technique [0002] During the actual use of the solar vacuum heat collector tube, the selective absorption coating coated on the outer wall of the inner tube mainly absorbs and gathers heat. Since there is a vacuum layer between the inner and outer tubes, there is no air convection between the outer tubes to conduct heat. The problem of heat loss to the outer tube has a better heat collection effect. However, since the vacuum layer between the inner and outer tubes cannot prevent radiation heat transfer, part of the heat absorbed by the inner tube will be lost through thermal radiation, resulting in heat loss. Among them, the radiation heat emissivity of the inner tube is about 5-8%, while that of the outer tube is about 90%. Therefore, most of the heat radiated from the inner tube to the outer tube will be radia...

AI Technical Summary

Problems solved by technology

Although this structure reduces heat loss to a certain extent, it still cannot solve the problem of heat loss caused by heat radiation in the inner and outer tubes. In addition, since the reflector is arranged outside the outer tube, heat will still be lost in the air. Moreover, it is easy to collect dust and dust, which affects the reflection effect. After a period of use, because the reflection plate will be covered by dust, the reflection ...

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