加速度场中环路热管温度波动现象分析

Investigation of temperature fluctuation in loop heat pipe under acceleration fields

基于离心机系统,搭建了双储液器环路热管(DCCLHP)工作特性实验台,实验研究了环路热管在地面重力场和过载加速度场中的运行性能,热载荷范围为25~300 W,过载加速度大小为3g^9g,分析了不同热载荷、加速度方向、大小对环路热管温度波动的影响。结果表明,过载加速度会改变环路热管的启动模式和运行性能,可抑制或激发冷凝器出口温度波动甚至整个环路的波动,但相同热载荷下蒸发器运行温度基本一致。回路中气液两相流动自身固有的不稳定性在过载加速度效应下更易受到激发,加剧回路中流动不稳定,进而加剧蒸发器向储液器漏热的不稳定。冷凝器的冷却作用可以有效削弱冷凝器段的温度波动。

Based on the centrifugal machine system,a test apparatus was set up to investigate the operating characteristics of dual compensation chambers loop heat pipe（ DCCLHP） under both gravity and acceleration fields. The ranges of the heat load and the magnitude of acceleration are 25- 300 W and 3g- 9g,respectively. The influences of different heat loads,acceleration directions and magnitudes on temperature fluctuations of loop heat pipe were analyzed. The results indicate that the effect of the acceleration can change the start mode and operating performance of the DCCLHP. The temperature fluctuation at the outlet of the condenser and even around the whole loop can be restrained or wakened. But the operating temperature of the evaporator is nearly the same under the same heat load conditions. The inherent flow instability of the gas-liquid two phase flow can be enhanced by the acceleration effect which reinforces this unstable flow in reverse.Furthermore,the instability of the heat leak from the evaporator to the compensation chamber is enhanced. In addition,the cooling effect of the condenser can weaken the temperature fluctuation of the condensing pipe line.