Research Of Semiconductor Thermoelectric Generator In Low-grade Heat Energy And Small Temperature Difference

This thesis introduces the related principle, history, as well as current research progress and application of thermoelectric generation (TEG). The thermoelectric effect which is the rationale of semiconductor TEG is carried on detailed showing in the thesis, specially the process. In this foundation, in view of the former research which almost all take material parameter (Seebeck coefficient α,conductivity σ,heat conductivity λ) simply as constant, the thesis mensurates the parameter values of Bi₂Te₃ material which is most commonly used nearby the present room temperature from 0℃ to 200℃ nearby, and obtains fitting formulae along with the temperature change. That's a beneficial exploration of further theory studies.As one of main parts, the thesis designs and builds experimental platform using the low-grade heat source of small temperature difference according to the basic principle of TEG. And completes generator's performance research under multi-operating modes and different temperature differences, obtains the reliable empirical datum, and summarizes a series of movement rules. The thesis embarks from the non-equilibrium state thermodynamics theory, programs with MATLab to confirm these rules according to the module (commercial refrigeration module TEC1-12703). In the process of simulation, the thesis also considers the module both sides potsherd part (there are no related reports in domestic and foreign), uses methods of finite difference and iteration to obtain the temperature field distribution and electricity generation performance quantitative relations under certain working condition. Finally contrasts the experimental result with the simulation result on typical temperature operating instance, results indicate that they fit fairly good.The thesis summarizes rules that the electricity generation performance parameters such as electromotive force, interface resistance, power and so on change along with factors of external circuit, temperature operating, geometrical size through the performance research of low-grade heat source semiconductor TEG, then summarizes performance of multi-module which is significant to the project practical application, obtains a series of useful conclusions, provides some practicable methods in the low-grade heat source directly using by the TEG.