Steadystate measurement method based on #br#
NTC microbead thermistor
SHAO Jiayi 1,XU Shen 1,LIN Huan 2,LIU Yongjian 1
1. School of Mechanical and Automotive Engineering, Shanghai University of Engineering Science, Shanghai 201620, China;
2. School of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao 266033, China
Abstract：The principle and mathematical model of steadystate measurement method of thermal conductivity was simple. But the high requirement of heat source temperature uniformity and the long measurement time limit its practical application. A new microsphere method for steadystate thermal measurement of thermal conductivity was proposed. The corresponding physical model and experimental method were established. Grapheneparaffin phase change materials with different mass fractions were prepared by meltblending process. Moreover, the thermal conductivity of prepared samples was measured by the proposed microsphere method. The measured thermal conductivity of grapheneparaffin phase change materials was 0.278 W/(m·K）(0%), 0.330 W/（m·K）(0.5%), 0.402 W/（m·K）(1%), 0.524 W/（m·K）(2%), 0.604 W/（m·K）(3%), 0.654 W/（m·K)(4%) and 0.711 W/(m·K)(5%), respectively. This method had many advantages, such as small volume of microspheres, uniform heat source, fast measurement, and simple sample preparation. It was applicable for the insitu thermal conductivity measurement of phase change materials and liquid in actual engineering.
2021, Vol. 39 
