高温集热管真空寿命预测研究

VACUUM LIFE PREDICTION STUDY OF PARABOLIC TROUGH RECEIVER

针对高温真空集热管真空老化性能展开真空度预测和寿命评价研究。模拟电站高温集热管运行环境,在400℃进行热循环模拟和热损测试,在450℃进行过热加速循环试验。结果表明:集热管封离后,室温条件下其内初始真空度达4.7×10^(-4)Pa,在400和450℃经过400次循环后,管内真空度分别为5×10^(-3)Pa和6×10^(-2)Pa。室温状态下集热管在吸收涂层法向发射比为0.08,真空度为10^(-3)Pa时,400℃下热损为216 W/m,显示出良好的热性能。拟合结果表明在400℃条件下集热管使用寿命满足25年要求。

This study aims at obtaining vacuum aging mechanism in the annulus of the receiver. Simulating the parabolic trough receiver operation environment,the receivers are heat-treated at 400 ℃ and 450 ℃ to get the variative regulation of the vacuum. The initial vacuum level of the receiver after the degassing process is 4.7×10^(-4)Pa at room temperature. After 400 cycles at 400 ℃ and 450 ℃,the pressure of the receiver is 5×10^(-3)Pa and 6×10^(-2)Pa,respectively. At room temperature,when the normal emission ratio of the absorption coating is 0.08 and the vacuum degree is 10^(-3)Pa,the heat loss of the receiver tube is 216 W/m at 400 ℃,showing good thermal performance. The life time of the receiver is about 25 years according to the accelerated aging experiment.