Groove type solar direct steam heat collecting pipe

Abstract

The invention discloses a groove type solar direct stream heat collecting pipe which is used for a solar thermal power generation system. The heat collecting pipe can directly receive solar focusing radiation to heat working medium water in the pipe so as to generate steam and comprises an absorption pipe, a glass casing pipe and connection devices at the two ends of the heat collecting pipe. A heat absorption pipe is composed of a stainless steel pipe, a selective absorption coating on the surface of the outer wall of the heat absorption pipe and a filling structure in the heat absorption pipe. The filling structure is an annular metal foam layer with an axial spiral groove, and the thickness of the layer gradually reduces in the flowing direction of a work medium. A vacuum layer is arranged between the absorption pipe and the glass casing pipe. The connection devices at the two ends of the heat collecting pipe are made of flanges and corrugate pipes. A glass-metal sealing connecting opening is processed in a crumpling mode. According to the groove type solar direct stream heat collecting pipe, on one hand, radial gas-liquid two-phase flow type reconstruction with gas inside and liquid outside in the absorption pipe is achieved, the fact that circumferential heat stress distribution of the absorption pipe is uneven is changed, and the problem of induction invalidation of heat stress is solved; on the other hand, local residual stress in the heat sealed technology can be reduced, and the problem of invalidation of end portion sealing connecting of the glass casing pipe is solved. The groove type solar direct stream heat collecting pipe can obviously improve the reliability and stability of the solar direct stream heat collecting pipe.

Description

technical field [0001] The invention belongs to the technical field of solar light-heat utilization, and in particular relates to a trough-type solar direct steam heat collection tube. Background technique [0002] At present, among the solar thermal power generation technologies, the trough system has the most mature development and the highest degree of commercialization. The trough solar thermal power generation system generally uses heat transfer oil as the heat transfer medium, and generates steam through heat exchange to drive the steam turbine to generate electricity. Since the decomposition temperature of the heat transfer oil limits the improvement of the steam parameters, the power generation efficiency of the steam turbine cannot be further improved. On the other hand, heat transfer oil is expensive, has potential pollution to the environment, and is flammable and toxic. In view of the above deficiencies, the new technology of using trough solar energy to direct...

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Problems solved by technology

[0006] In view of this, the main purpose of the present invention is to provide a trough solar direct steam heat collector to solve the stress-induced failure problem of the trough solar direct steam heat collector in the absorber tube and at the end of the glass sleeve

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