马腾飞, 李树鹏, 吴儒亮, 等. 温度循环试验中试件表面结霜/露现象及舱内水分来源的实验研究[J]. 航天器环境工程, 2019, 36(5): 468-474 DOI: 10.12126/see.2019.05.010
引用本文: 马腾飞, 李树鹏, 吴儒亮, 等. 温度循环试验中试件表面结霜/露现象及舱内水分来源的实验研究[J]. 航天器环境工程, 2019, 36(5): 468-474 DOI: 10.12126/see.2019.05.010
MA T F, LI S P, WU R L, et al. Experimental study of the condensation and identifiation of the moisture source during thermal cycling test[J]. Spacecraft Environment Engineering, 2019, 36(5): 468-474 DOI: 10.12126/see.2019.05.010
Citation: MA T F, LI S P, WU R L, et al. Experimental study of the condensation and identifiation of the moisture source during thermal cycling test[J]. Spacecraft Environment Engineering, 2019, 36(5): 468-474 DOI: 10.12126/see.2019.05.010

温度循环试验中试件表面结霜/露现象及舱内水分来源的实验研究

Experimental study of the condensation and identifiation of the moisture source during thermal cycling test

  • 摘要: 温度循环试验中试件表面出现结露,会对试件造成损害。文章对典型温度循环舱内大热惯性试件的表面结露现象进行了实验研究:分析了舱内水分来源,并测量了舱内压力在空间和时间上的分布特征。结果表明:舱内压力随着温度的降低而降低,风机进风口的负压造成了舱外湿空气侵入舱内;而试验前舱内蒸发器表面存有的霜层,也是造成低温向高温的切换过程中舱内空气露点温度升高的重要原因。采用氮气流量控制,可有效维持舱内的正压,同时抑制升温阶段舱内空气露点温度的快速升高,规避试件表面结露的风险。

     

    Abstract: The condensation of the water vapor on the product surface in the thermal cycling test may cause irreversible damages in the electrical products. In this paper, the condensation is observed on the test sample with a large thermal inertia in a typical thermal cycling test chamber, and the source of the moisture is analyzed. It is shown that the pressure in the chamber drops with the decrease of the air temperature. The negative pressure at the fan inlet results in the infiltrating of the outside moist air into the test chamber. In addition, the frost layer on the evaporator in the air handling unit before the test is also an essential factor that levels up the dew point of the air in the test chamber during the temperature rise period. The nitrogen flow control can help maintain a positive pressure within the test chamber and effectively bring down the dew point temperature during the temperature rise period.

     

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