温差同位素电源数字仿真与模拟试验研究

Numerical Simulation and Experiment Research on Radioisotope Thermoelectric Generator

温差同位素电源是一种将放射性同位素衰变产生的热能转换为电能的装置,涉及热-电物理场强耦合,如何准确仿真分析是一大难点。本文基于一款90Sr温差同位素电源样机,首先建立了样机整机热-电物理场直接耦合的数字仿真模型,结合试验数据对模型参数进行优化,然后通过模拟试验验证了电源样机稳态和动态运行下模型仿真的准确性。最后利用模型开展了电源样机整机热-电物理场分析,以及外接不同负载时的输出功率研究。结果表明,在给定工况下,样机系统漏热占比26%,电路电能损耗占比10%;在最佳匹配负载下,整机最大输出功率可达96mW,热电转换效率2%。

Radioisotope thermoelectric generator is a device that converts the thermal energy produced by the decay of radioactive isotopes into electric energy.It involves the strong coupling of thermal-electric physical fields and is difficult to simulate accurately.In this paper,based on a 90Sr Radioisotope thermoelectric generator prototype,firstly,the digital simulation model of the direct coupling of thermal-electric physical fields of the prototype is established,and the model parameters are optimized by combining the experimental data.Then,the accuracy of the model simulation under the steady and dynamic operation of the prototype is verified by simulation tests.Finally,the thermal-electric field analysis of the whole prototype and the output power research with different load resistance are carried out by using the model.The results show that the heat leakage of the prototype system accounts for 26%and the electric energy loss of the circuit is 10%under given operating conditions.Under the best matching load resistance,the maximum output power of the whole prototype can reach 96 mW,and the thermoelectric conversion efficiency is 2%.