空间相机遮光罩的低功耗热设计

Thermal design of space camera baffle with low power

空间相机遮光罩的温度波动直接影响附近光学元件的温度波动，而光学元件的热变形将导致光学成像质量的下降。针对一种高分辨率空间相机的遮光罩，提出了几种不同的热控方案并进行了比对分析。首先，介绍了空间相机遮光罩的一般热控措施及效果并分析了影响空间相机遮光罩温度波动的外热流及传导热阻；然后通过仿真分析得到了三种不同热控方案下的温度数据及主动加热功耗数据，经过比对分析后选用了主动加热功耗少、温度波动范围小的热设计方案。最后，通过热平衡试验及在轨数据验证了选用方案的有效性。空间相机遮光罩的在轨温度范围为4.8～9.2℃，次镜温度范围为17.8～17.9℃，与仿真分析结果一致性良好，热设计合理有效，满足任务需求。

The temperature variety of the outer baffle for space camera directly affects the temperatures of optical components around the baffle. The thermal deformation of optical components would decrease the quality of image. Three different thermal control approaches were stated out for the baffle of a high- resolution space camera and the analysis and comparison among them were accomplished. Firstly, the most common thermal control means of baffle for space camera were introduced. The orbit heat flux and heat resistant between the baffle and the main body of camera, which affect the temperature of the baffle, were calculated and discussed. Then temperatures and powers of active heaters in three cases were obtained via simulation analysis. After comparison, the third design approach was adopted because of the low power of active heater and high temperature stability. Finally, the thermal design was validated in the thermal balance test and temperature test in orbit. The temperature range of the baffle is between 4.8 ℃ to 13.6 ℃ and the second mirror is between 17.8 ℃ to 17.9 ℃. The data in orbit are consistent with the analysis results, which indicate that the thermal design is valid and reasonable which can meet the mission requirements.