热电制冷模块热物性参数理论获取方法及精度分析

Theoretical methods and accuracy analysis for extracting thermophysical parameters of thermoelectric cooling module

获取精确的热电模块的热物性参数值是热电制冷系统性能分析的关键。制冷量是衡量热电制冷性能的参数,根据厂商数据单以及半导体材料与温度相关的热物性经验公式,绘制了采用常物性参数法、变物性参数法分析制冷量的性能曲线图,并提出通过热电臂内热平衡的微分表达式获得不同工况下制冷量的准确值及标准性能曲线图;通过数值对比分析发现,常物性参数法在计算热电制冷量时有最大约6 W的绝对误差,但可以通过改善常物性参数获取精度减小计算误差;而变物性参数法最大绝对误差仅为1.5 W,该热物性参数获取方法精度较高,适用于分析热电制冷性能。

For exact analysis of cooling ability of thermoelectric cooling system, accurate extraction of thermophysical parameters is of vital importance. Cooling capacity is the measure of system＇s cooling ability. Based on the datasheet of thermoelectric module and empirical formulas evaluating temperature- dependent parameters, performance curves assuming constant and temperature-dependent material properties were plotted respectively. The standard value of cooling capacity and performance curve were obtained with differential equations for energy conservation along the TE element. Through numerical comparison and analysis, it was found that the maximum absolute error of cooling capacity was 6 W for constant parameters estimated from the datasheet and could be minimized by applying a proper set of constant parameters. The maximum absolute error of cooling capacity was 1.5 W for temperature- dependent parameters calculated with empirical formulas. The accuracy of the numerical model assuming temperature-dependent material peoperties was confn＇med and it could be used to accutately evaluate thermoelectric cooling performance.