Numerical Simulation and Experiment Research on Radioisotope Thermoelectric Generator

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%.