Study On Sr-90Radioisotope Thermoelectric Generator

Radioisotope battery, as a new type of power source, was developed in1960s. There were many different types of radioisotope battery, Sr-90radioisotope thermoelectric generator is one of them which based on the Seebeck effect. When Sr-90decays, it generates heat which is used for power generation. Because of its advantages in terms of long working life, high reliability, flexibility to rugged environment, maintenance free, and high capacity rate, it was applied uniquely in space, isolated terrestrial or ocean spots, deep waters, and medicine.This project is mainly focused on the study about Sr-90radioisotope thermoelectric generator system, including radiation field calculation, calculation and optimization of the thermal insulation structure, and design, simulation, construction, experiments on test platform for thermoelectric conversion efficiency of thermocouple.(1)Modeling and calculating of radiation fields in the vicinity of radioisotope thermoelectric generator was based on the safety analyses using MCNP. Considering the weight and volume of nuclear battery, depleted uranium was selected as the radioprotection material to ensure the shielding effect after comparing several commonly used shielding materials and meanwhile a preliminary design was given. Power distribution was given the after calculation. This result would have a guiding significance for the future radioisotope thermoelectric generator’s structure design, insulation design, and shielding design.(2) The feasibility of the mechanical design was assessed after calculation and optimization of the interior thermal insulation structure with ANSYS Workbench as calculating tool and Solid Edge as modeling tool. By modifying the local structure parameters, different parts of the heat leakage were analyzed for structure optimization. And the temperature of the radioisotope thermoelectric generator system increased significantly after optimizing the design of the RTG structure. This result was believed to give some guidance for the design of the battery insulation structure.(3)Participated in discussions on designing test platform for thermoelectric conversion efficiency of thermocouple. The feasibility of the mechanical design was assessed after calculation and optimization of the thermal insulation structure with ANSYS Workbench as calculating tool and Solid Edge as modeling tool. And the platform was tested after assembling. Although, the tested thermocouple was not the expected but an existing mature one, the feasibility of the test platform can be proved with the gotten result. And I believe that the result can provide a valid reference for design and construction a more advanced, more reliable, and more accurate test platform for thermocouple in the future.