Research On Heat-electric-stress Performance Of Thermoelectric Device Under The Conditions Of Transient Non-uniform Heat Flux

Thermoelectric power generation technology, as a kind of new energy technology, has been researched for more than a century both in theories and engineering applications. Thermoelectric power generation technology can be used as an effective means to alleviate the energy crisis. At the same time, thermoelectric power devices have the advantages of no noise, no media leaks, zero emissions, and very friendly to environment. In addition, thermoelectric generators also have the advantages of mobile convenience, long life, low maintenance cost, light weight, no wear, small size, and so on. And due to the above advantages, this technology has attracted worldwide attention in recent years. We advanced a mathematical model for the thermoelectric generator coupling the mechanism of heat-electricity–stress in this thesis. Then we analyzed the power output and thermal stress characteristics in different conditions, and we also analyzed the influencing factors on the thermoelectric generator output and stress characteristic.Firstly, we built the thermoelectric mathematical model coupled with the mechanism of heat-electricity–stress, and we analyzed on the influences of thermoelectric material parameters with temperature and thermal radiation on the system power output. The impact on the output characteristic by the non-uniform heat flux has been analyzed. At the same time, the system temperature contours are presented by choosing a serial of cross-sections. Later, we analyzed the start-stop characteristics of thermoelectric devices. In addition, we researched on the transient output characteristics, observing the process of the influence on temperature and voltage effects of thermal radiation and variable physical parameters.After researching on heat-electric performance, the thermal stress performance has been analyzed. From the result of thermal stress distributions, the maximum value position has been obtained. The results showed that the maximum thermal stress position locates at the right angle in contact of thermoelectric materials and the copper plate. Tracking this position by transient analysis, the thermal stress changing process in thermal stress from the beginning to end is presented. And by tracking a series of cross sections chosen in the module, the thermal strain and displacement contours have been observed. The locations which are most likely to damage are obtained. Then the influence of the thickness of the copper plate and the heat layer thickness on the magnitude of the thermal stress, as well as for power generation stability, stress stability, heat flux, temperature, and the thermal stress' s phase relationship have been analyzed.