Design,Optimization And Experiments Of Radioisotope Thermoelectric Generator Based On Finite Element Analysis

With the development of aerospace industry,the ever-complicating space missions pose a challenge to not only the spacecraft but also to the power supply.Comparing to the fuel battery or solar cells,the radioisotope thermoelectric generator has no internal moving parts,and it can provide stable electricity for more than ten years.More importantly,due to the spontaneity decay of radioactive elements,radioisotope thermoelectric generator is barely influenced by the exterior environment.Therefore,radioisotope thermoelectric generator plays a more and more important role in space missions.So far,a lot of valid work has been done domestically,yet comprehensive research and demonstration on the design,optimization,and experiments of radioisotope thermoelectric generator is still short-handed based on the available papers.Hence,this dissertation demonstrated the design process of a watt-power bismuth telluride-based radioisotope thermoelectric generator and conducted relevant experiments and optimization of its output performance.In the design part,finite element analysis was adopted to simulate the temperature field of the radioisotope heater and the heat-sinking capacity of the fin-shaped radiator.Based on the simulation results,the manufactured substituted electric heater has a higher surface temperature and a better temperature uniformity,which can transfer the heat more efficiently.Also,the manufactured radiator possesses the best heat-sinking capacity upon a certain heat transfer area.In the experiment part,the influence of thermal resistance,the temperature of the thermoelectric module's hot end and thermoelectric module's electric connection had been studied separately,several useful conclusions of how to reach thermoelectric module's optimal performance had been drawn from the experiment.In the optimization part,a simulation model of the bismuth telluride-based radioisotope thermoelectric generator was built first,the optimal geometry and number of P-N thermocouple within one thermoelectric module had been determined by simulating the output performanceunder different thermocouple geometry.After that,the obtained finite element optimization method was employed to optimize the skutterudite-based radioisotope thermoelectric generator model,with the same model structure,similar results were simulated from it and the output performance was further enhanced.Throughout this dissertation,a complete research scheme of how to balance every factor that influences the output performance,during design,optimization,and application of radioisotope thermoelectric generator,had been proposed.