不凝气体对环路热管工作性能的不利影响

Adverse effect of non-condensable gas on the operating performance of loop heat pipe

通过向环路热管内充装定量氮气来模拟实际不凝气体的生成,考察了不同不凝气体含量、热载荷和热沉温度条件下,环路热管工作性能的变化.结果显示不凝气体对工作性能造成的不利影响体现在：取决于热载荷和热沉温度,可导致稳态工作温度升高2~10℃;在小于60W的热载荷区间或者-5℃的热沉温度条件下,不凝气体导致的不利影响更加显著;改变控温性能,产生一个故障热载荷区间;启动时间、启动温度、启动温升增大;引发温度波动现象和系统运行失效.基于特征点温度的变化特性,分析并讨论了不凝气体影响环路热管工作性能的物理机理.

Nitrogen was injected into the loop heat pipe （LHP） as non-condensable gas （NCG）, and the operating performance of the LHP with NCG was studied for different NCG inventories, while heat loads were applied to the evaporator and heat sink temperatures. Under the adverse effects of NCG： the operating temperature of the evaporator was elevated by 2-10℃ depending on the heat load and heat sink temperature; such effect was notable for a smaller heat load （less than 60 W） or at lower heat sink temperature （--5 ℃）; the temperature controlling performance varied, leading to a corresponding failure range for the heat load; the startup temperature and super tup overshooting increased, and the startup time was prolonged; the temperature oscillation phenomenon and operating failure could be triggered. According to the temperature variations of the characteristic points along the loop, the physical mechanism of the effect of NCG on the operating performance was ana- lyzed and discussed.