Temperature Stability Analysis of Adjustable Operating Temperature Loop Heat Pipe

Loop heat pipes are widely applied in thermal management field of spacecraft payload, owing to the advantages of high temperature controlling accuracy, high heat transfer capability, long heat transfer distance and minimal vibration. For the thermal control of spacecraft payload working intermittently with heat dissipation changing dramatically, the adjustable operating temperature loop heat pipe was proposed and analyzed in this paper. The adjustable operating temperature loop heat pipe was found to save preservation heating power enormously when payload was turned off. To decrease the temperature overshoot when temperature setpoint was adjusted, the influence of temperature controlling point's location and heating mode were investigated. A heat leak model was established to predict compensation chamber heating power. High temperature controlling accuracy was realized by using double heating loops and double temperature setpoints. The on-orbit data showed that the temperature controlling accuracy was higher than ±0.5 oC with preservation heating power reducing from 318 W to 47 W.