Modeling and parametric analysis of a Korean small radioisotope thermoelectric generator

Radioisotope thermoelectric generators (RTGs) have served as essential sources of both electrical and thermal power for space probes and rovers over the past several decades. This is because RTGs are robust power generation systems capable of operating reliably under the challenging conditions of space, including extremely low temperatures and dark regions where sunlight is either completely or seasonally blocked. Korea Atomic Energy Research Institute (KAERI) has been developing small RTGs over the past 10 years. Here, we develop a three-dimensional RTG model incorporating a heat source module, a thermoelectric device, and a passive thermal control system, and conduct a comprehensive parametric analysis. The electrical and thermal performance of the RTG is evaluated by varying key design parameters, including the dimensions of the thermoelectric device, contact resistance, thermal conductivity of insulators, and surface emissivity of the RTG. Our RTG system achieves an output power of 550 mW and a conversion efficiency of 5.5% from a 10 W th heat source. This design strategy offers substantial insights for enhancing and optimizing RTG systems.