Research Of Structural Design And Fatiguelife Of Thermoelectric Generator

Thermoelectric generation technology is based on the Seebeck effect can convert heat directly into electrical energy,without chemical reaction or fluid medium,the power generation process has the advantages of economy,environmental protection and convenience,can utilize solar energy and industrial waste heat and other low-grade heat source of power.Under the current environmental requirements,thermoelectric power generation technology will play an important role in energy recovery and utilization with its unique advantages.At present,there are many problems such as low power generation performance,short service life,low reliability and so on.In the high temperature environment,the connection between the various components are prone to mass transfer and diffusion of atoms,resulting in decreased performance of thermoelectric materials or failure by the coefficient of thermal expansion between the material and the thermal stress induced by the mismatch is easy to break junction.Therefore,it is necessary to carry out structural design and life analysis of thermoelectric generator by thermal stress analysis.In this paper,four semiconductor thermoelectric couple arm model and two thermoelectric element as the research object,using mature semiconductor materials(PbTe)as galvanic arm materials,design and proper improvement of the semiconductor structure,and analysis of the two thermoelectric element model structure design,through the research of finite element software,the main work done the following:(1)According to the basic principle of thermoelectric power generation and common structure characteristics,determine the basic size of material parameters and structure,improve thermoelectric element model,and the different shape of galvanic arm model analysis,understand the different galvanic arm shape and fixed mode of influence of stress level on power and thermal effect.(2)On the ladder four couple arm model and two thermoelectric element were analyzed,studied the trapezoidal geometry,galvanic couple arm arm spacing and thickness of the ceramic matrix model of the power performance and the effect of thermal stress level;and on the two level model of the lower power even logarithmic ratio on the thermoelectric properties and heat the influence of stress level.(3)According to the working condition of RTG,determine the failure mechanism and fatigue mechanism of thermoelectric generator,fatigue life analysis of different factors on the difference of the four couple arm model and two thermoelectric element effect by using the Workbench software,to provide a basis for improving the reliability of the device.