Tank type solar vacuum heat collecting tube with one-sided inner fin

Abstract

The invention relates to a tank type solar vacuum heat collecting tube with a one-sided inner fin, comprising a glass outer tube and a metal inner tube with a one-sided inner fin enhanced heat transfer structure, wherein two ends of the glass outer tube are sealed with the metal inner tube through corrugated tubes; the space between the glass outer tube and the metal inner tube is vacuum; the external surface of the metal inner tube is coated with a selective sunlight absorption coating; the inner fin is arranged on the inner surface of one side of the metal inner tube which absorbs focalized solar energy; and the inner fin and the metal tube are integrated. The inner fin introduces heat to the center of the metal inner tube, increases the heat convection area, reduces the temperature difference between the metal inner tube and a heat-conducting fluid, and improves the cooperation degree between the velocity field of the heat-conducting fluid in the heat collecting tube and the temperature field of the heat collecting tube. Furthermore, the inner fin also increases the strength and reliability of the heat collecting tube.

Description

technical field [0001] The invention relates to a trough solar vacuum heat collecting tube. Background technique [0002] In solar heat utilization, the metal tubes of trough and linear Fresnel solar collectors are heated non-uniformly on one side, and the energy flow density distribution in the circumferential direction is extremely uneven, and the energy density is up to 5×10 4 Watts per square meter, the lowest is only on the order of hundreds of watts per square meter. More importantly, the heat collecting tube is always heated on one side during its life cycle, and the heated surface faces the earth's surface. On the one hand, the extremely uneven distribution of energy flow causes a large temperature difference in the circumferential and axial directions of the metal tube of the collector, and the resulting thermal expansion will adversely affect the performance of the collector. Therefore, higher requirements are put forward for the design, installation and operatio...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to overcome the shortcomings of low system reliability and high cost in the prior art, and propose a trough-type solar vacuum heat collection tube with single-side inner fins to enhance heat transfer

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