Research Of The Rmalstress And Fatiguelife Of High-temperature Thermorlectric Generator

Nowadays, energy and environment issues become increasingly prominent, so promoting the development and utilization of green sustainable energy has become the choice for many countries, and the technology of thermoelectric power generation is a kind of typical environment-friendly energy technology, which is based on the Seebeck effect of thermoelectric materials and could transform heat directly into electricity. It can use various forms of heat sources, such as solar, isotopes fission energy, low-grade heat, heat of combustion of hydrocarbon fuels, etc.. Moreover, Thermoelectric Generator is safe, easy to carry, work statically, no pollution, etc., which make its development and application in the civilian areas more and more attentive to people.Thermoelectric Generator consists of three parts: heat source, heat sink and thermoelectric element, while the thermoelectric element is the core component of Thermoelectric Generator, so recently the main object of most of the researches on Thermoelectric Generator is thermoelectric element. Thermoelectric element is composed of one or more thermoelectric monomers, and thermoelectric monomer is the basic structural unit, which is composed of galvanic arm(P-type and N-type), deflector electrode and the ceramic matrix.In this paper, thermoelectric monomer and thermoelectric element are the main targets of study, and we use a kind of mature semiconductor material(silicon-germanium alloy) as galvanic arm material, and design and appropriately improve the structure of thermoelectric monomer. With finite element software, we study their performance under the condition of high temperature, and mainly complete the following tasks:(1) Determine the used materials’ parameters and the size of structure, and complete the modeling of thermoelectric monomer and thermoelectric element. Make the analysis of thermoelectric conversion, and compare the effects of the traditional structure and improved structure.(2) Make the coupling thermal analysis of thermoelectric monomer and element with the finite element software of ANSYS, and analyze the situation of thermal stress of thermoelectric monomer and thermoelectric element influenced by boundary conditions, galvanic arm sizes, galvanic arm cross-sectional shape and solder layer.(3) Determine the mechanism of fatigue damage according to the thermoelectric generator operating condition. Use the software of FE-SAFE to make fatigue life analysis of thermoelectric monomer and thermoelectric element, and analyze the situation of the fatigue life of thermoelectric generator by different external boundary conditions.