All-glass vacuum solar heat collecting tube

Abstract

The invention relates to an all-glass vacuum solar heat collecting tube, which is used for solar water heater and solar heating. The all-glass vacuum solar heat collecting tube comprises an outer tube, an inner tube and a clamp. A vacuum space exists between the outer tube and the inner tube. The outer tube and the inner tube are sintered at the tail end and fixed through the clamp. The outer layer of the inner tube is coated with a metal reflection layer. The outer surface of the metal reflection layer is coated with an absorption layer. The coating area of the absorption layer is limited in a sunlight irradiating area under the operation state of the all-glass vacuum solar heat collecting tube. The invention has advantages of reasonable structural design, greatly reduced emittance and low cost.

Description

technical field [0001] The invention relates to an all-glass vacuum solar heat collecting tube, which is used for solar water heaters and solar heating. Background technique [0002] Solar collector tubes, including all-glass vacuum solar collector tubes and glass-metal vacuum solar collector tubes. The vacuum tube we are talking about here refers to the all-glass vacuum solar collector tube. At present, vacuum tubes are mainly used in solar water heaters and solar heating. [0003] The solar absorption ratio and the hemispherical emission ratio are the technical requirements of the all-glass vacuum solar collector tube (hereinafter referred to as the vacuum collector tube) for the solar selective absorption coating. The new national standard stipulates that the solar absorption ratio of the absorbing coating is α≥0.86 (AM1.5), which is the same as the old national standard. The hemispherical emission ratio εh≤0.080 (80°C±5°C), which is 0.01 lower than the old national st...

AI Technical Summary

Problems solved by technology

However, 1. Improving the absorption capacity of the absorbing layer coating can of course improve the energy utilization and conversion when it is illuminated, but the loss is also greater when there is no illumination

2. Utilizing the heat in the area outside the tube will inevitably increase the equipment, increase the complexity and instability of the entire device, and the effects and shortcomings are often not equal

However, the scheme of this patent application is difficult to realize in production, and even if it is realized, its cost is too high. In terms of the benefits it brings, the disadvantages are more prominent and obvious

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