特殊构型热电腿增强同位素温差电池输出性能

Output performance enhancement of radioisotope thermoelectric generators based on thermoelectric legs with special geometry

为了满足航天器内用电器件对电源的功率需求,本文基于增加热电腿的侧面面积、强化侧面散热提出了2种特殊几何结构的热电腿来提升小型同位素温差电池的输出性能。通过傅里叶热传导定律和欧姆定律证明了2种几何结构改善热电腿输出性能的机理;使用有限元分析的方法计算了热电腿的输出性能随几何参数的变化规律。结果表明:特殊构型热电腿产生了更大的温差并降低了平均温度,降低了高温对Seebeck系数和电阻率的负面影响,从而增加了输出性能。相比于传统的圆柱构型,由特殊构型热电腿组成的热电器件同样表现出更佳的输出功率和功率密度。这种优化热电腿的几何结构、增强散热的设计方法可以为小型同位素温差电池以及其他热电器件的功率提升、改善能量转换效率提供设计参考。

To meet the power requirements of electronic devices in a spacecraft,this study proposes using two thermoelectric legs with special geometrical shapes to improve the output performance of small radioisotope thermoelectric generators by increasing their side surface area and enhancing lateral heat dissipation.The principle of the output performance enhancement of two types of geometries is proved using the Fourier law of heat conduction and Ohm′s law.The variation of the output performance of the thermoelectric legs with geometrical parameters is simulated using the finite element method.Results show that the thermoelectric legs with special geometrical shapes generate a larger temperature difference and lower the average temperature,which reduces the negative effect of high temperature on the Seebeck coefficient and resistivity,increasing the output performance.Compared with the traditional cylindrical shape,the thermoelectric device composed of thermoelectric legs with special geometrical shapes exhibited better output power and power density.This design method of optimizing the geometry of thermoelectric legs to enhance heat dissipation can provide a reference for improving the output power and energy conversion efficiency of small radioisotope thermoelectric generators and other thermoelectric devices.