热电偶臂构型尺寸对环形热电发电器性能的影响

Effect of configuration size of thermoelectric couple on performance of annular thermoelectric generator

基于一维稳态热传导理论提出环形热电发电器(ATEG)的数学物理模型,考虑P型和N型热电偶臂的构型尺寸、材料热电性质不对称性以及界面接触阻力对其输出性能的影响.针对理想的环形热电发电器,基于最大能量转换效率原则建立P型和N型热电偶臂构型尺寸与材料性质间的最优定量关系.考虑界面接触热阻和界面接触电阻效应的影响,给出相对于精确解更方便实用的电流线性简化解,确定环形热电发电器最大输出功率、最大能量转换效率对应的P型、N型热电偶臂圆周角度比.发现界面接触对小尺寸器件的热电偶臂圆周角度比影响显著,但随着器件构型尺寸的增大,比值逐渐趋近于理想器件的结果.当器件尺寸参数sr>2时,可以基于理想模型指导环形热电发电器的设计计算.

A theoretical model was provided for the annular thermoelectric generator(ATEG)based on the onedimensional steady heat transport theory.Effects of configuration size of P-type and N-type thermoelectric couple,asymmetry of material properties of thermoelectric couple and interface contact resistance on the output performance of ATEG were considered.The relationship between configuration size of P-type and N-type thermoelectric couple and their material properties was determined for the ideal ATEG based on the principle of maximum energy conversion efficiency.The influence of interface contact heat resistance and electrical resistance was considered,and the linear simplified solution which is more convenient to use than exact solution was obtained.The optimized angle ratio of N-type to P-type thermoelectric legs in the direction of circumference was also determined when the maximum output power and maximum conversion efficiency of ATEG attained.The interface contact resistance has a significant effect on the optimized anlge ratio for the short ATEG,and this ratio approaches to the ideal solution gradually as the configuration size of ATEG increases.Resluts obtained based on the ideal model can be used to guide the design of the realistic ATEG device when the size parameter sr is greater than 2.