Abstract
Thermionic energy converters, based on the phenomenon of electron thermionic emission, directly convert thermal energy into electrical energy. They are characterized, among other things, by high output power density and potential for integration with high-temperature heat sources. This paper presents a model of a vacuum thermionic energy converter for numerical studies and presents temperature distributions of key components of the converter, including the dispenser cathode, mounting base and ceramic cathode pad, manipulator core, anode, mounting base and ceramic anode pad. The tests were performed in the Ansys 2024 environment in the dispenser cathode temperature range up to 1473,2 K for three electrode mounting base designs made of steel (316L), molybdenum, and copper, respectively. Based on the results obtained, the permissible operating temperature of the cathode mounted on a steel base was determined, at which the emission of toxic vapors from the steel is negligible. The anode temperature values for the three anode mounting base materials and the theoretical limit of energy conversion efficiency were determined. The work emphasizes the need to optimize the selection of materials and mechanical design to improve the durability and efficiency of thermionic energy converters.