真空管吸收涂层的吸收比对全玻璃真空管的热性能影响的试验分析

选择性吸收涂层是全玻璃真空太阳集热管的重要组成部分，其光学性能直接影响着全玻璃真空太阳集热管的热性能。衡量选择性吸收涂层的最主要参数是涂层光学吸收比，而代表全玻璃真空太阳集热管热性能的参数主要是空晒性能参数及闷晒太阳辐照量。文章通过试验研究了涂层的吸收比对全玻璃真空太阳集热管的空晒性能参数和闷晒太阳辐照量的影响。结果表明全玻璃真空太阳集热管涂层吸收比对闷晒太阳辐照量有明显影响，对空晒性能参数也有影响但不明显。

Experimental Study on the Influence of the Absorptance of the Selective Absorbing Coating on the Thermal Performance of All-glass Evacuated Tubes

The selective absorbing coating is one of the key parts of an all-glass evacuated solar tube and its optical properties will have direct influence on the thermal performance of the all-glass evacuated solar tube.The major parameter to represent the optical properties of a selective absorbing coating is its optical absorptance whereas the major parameters to represent the thermal performance of an all-glass evacuated solar tube are the parameter representing the performance of the tube when there is no water in the tube and the solar radiation corresponding to the case when water in the tube is under stagnation conditions.In this paper,the influence of the selective absorbing coating on these two parameters are investigated experimentally for a series of all-glass evacuated tubes.The results show that the absorptance has an apparent influence on the parameter representing the performance of the tube when there is no water in the tube but its influence on the solar radiation corresponding to the case when water in the tube is under stagnation conditions is not significant.