High-temperature solar heat collecting tube with secondary condenser and trough collector comprising high-temperature solar heat collecting tube

Abstract

The invention relates to a high-temperature solar heat collecting tube with a secondary condenser and a trough collector comprising the high-temperature solar heat collecting tube. The trough collector comprises the high-temperature solar heat collecting tube and a trough condenser; the trough condenser reflects sunlight and focuses the sunlight onto the high-temperature solar collecting tube; a glass outer tube of the high-temperature solar collecting tube sheathes a metal inner tube; the secondary condenser is arranged in an annular vacuum enclosed space between the glass outer tube and themetal inner tube; the secondary condenser is located above the metal inner tube; and the cross section of the secondary condenser is at least one of a parabola, an involute and a straight line. The side, facing towards the metal inner tube, of the secondary condenser has a reflecting mirror surface, and the reflecting mirror surface reflects reflected condensed light of the metal inner tube onto the metal inner tube again, so that the uniformity of energy flux density on the metal inner tube and the concentration ratio are improved, and the radiant heat loss of the metal inner tube is reduced;the other side, back onto the metal inner tube, of the secondary concentrator is provided with a selective absorbing coating, and the selective absorbing coating directly absorbs solar energy and raises temperature, so that radiant heat exchange between the secondary concentrator and the metal inner tube is further reduced.

Description

technical field [0001] The invention relates to a high-temperature solar heat collection tube with a secondary concentrator and a trough heat collector thereof. Background technique [0002] The trough solar thermal power generation technology is currently the most widely used and most stable solar thermal power generation technology in the world. It uses a parabolic trough collector to reflect and focus sunlight onto the high-temperature solar collector tube located on its focal line. Heat the fluid in the tube to realize the conversion of solar energy and heat energy. The trough collector is a key component in the trough solar power generation system from light energy to heat energy conversion, and its light-to-heat conversion efficiency directly determines the power generation efficiency of the system. According to the principle of the trough collector, increasing the opening width of the trough concentrator can not only significantly reduce the system cost, but also has...

AI Technical Summary

Problems solved by technology

However, when the high-temperature solar collector tube works at a high temperature above 400°C, due to the increase in the temperature of the metal inner tube, its external heat radiation loss also increases sharply, especially if the diameter of the metal inner tube increases, the heat loss is significantly increased due to the increase in the heat dissipation area. increase, resulting in a decrease in system power generation efficiency

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