基于传热学的低气压/真空综合环境试验设备校准技术研究

Study on Calibration of Low Pressure/Vacuum Comprehensive Environmental Test Equipment Based on Heat Transfer Theory

目前低气压/真空综合环境试验设备可参照的计量校准依据并不全面。针对不同压力范围的综合环境试验设备对其适用的标准规范进行分析,并通过数值模拟的方式进一步探讨。数值模拟结果表明介质压力大于1kPa的试验设备可参照GB/T5170.10进行温度偏差和温度均匀性校准,在应用中可根据环境试验设备工作空间的增大和介质压力的降低适当放宽容差要求;气压低于1kPa的真空试验设备中辐射传热占据主导,传热效率和内部试件放置位置相关,温度均匀性考察已没有必要,在测量中减小空间热阻和表面热阻是提升测量准确度的关键。

The referenceable calibration basis for low pressure/vacuum integrated environmental test equipment is not comprehensive at present,the analysis of applicable standard specification for low pressure integrated test equipment of different pressure ranges is given and the guiding conclusions are conducted through a numerical simulation.Numerical simulation results show that the test equipment with internal pressure greater than 1 kPa can refer to standard GB/T 5170.10 for the calibration of temperature deviation and temperature uniformity.The tolerance requirement can be appropriately relaxed according to the increase of the working space and the decrease of the internal pressure.Radiation heat transfer occupy a dominant position in test equipment with air pressure less than 1 kPa.The heat transfer efficiency is related to the placement of internal test pieces.It is not necessary to consider the temperature uniformity of the equipment.Reducing the space thermal resistance and surface thermal resistance in the measurement are the key to improving the measurement accuracy.