接触热阻对相变耦合温差发电系统的影响

Effect of Thermal Contact Resistance on the Performance of Thermoelectric Generation System with Phase Change Material

在汽车尾气温差发电系统中,热量在传递的过程中通常要经过若干个接触界面。而界面间的接触热阻影响着热量的传递效率和热电器件冷热两侧的实际温差,进而影响到系统的发电性能。利用工业热风机模拟汽车运行实际工况,使用装载有相变材料(phase change material,PCM)的温差发电系统,通过涂抹不同导热系数的导热硅脂来调节热电器件与系统间的接触热阻,研究了接触热阻对PCM以及系统输出电压的影响。研究发现,同时减小热电器件两侧与系统间的接触热阻会削弱PCM的储热能力;相较于减小热电器件热面与系统间的接触热阻,减小热电器件冷面与冷端换热器间接触热阻,对温差发电系统输出电压的提升效果更为显著。

In the automotive exhaust thermoelectric generator,the heat passes through several interfaces.The thermal contact resistance of contact surface would affect the efficiency of heat transfer and the actual temperature difference between the hot and cold sides of thermoelectric devices,that would affect the electricity generation performance of the thermoelectric generator.A thermoelectric power generation system with heat storage phase change materials(PCM)was heated by an industrial hot air blower to imitate a practical automobile exhaust situation.The thermal contact resistance was altered by using conductive silicone grease with different thermal conductivity to investigate the effect on the PCM and system output voltage.The results showed that the heat storage ability of PCM would be weakened when the thermal contact resistances of both the hot and cold surfaces were decreased.Moreover,the output voltage of thermoelectric power generation system was enhanced by reducing the thermal contact resistance of cooling surface more obviously compared with that of hot surface.