Analytical Analysis of Temperature-Dependent Thermoelectric Generator and Optimization Based on Functionally Graded Materials

Based on the concept of functionally graded, a thermoelectric device is optimized in this study to obtain higher energy difference. By deriving basic thermoelectric equations, the thermoelectric coupling governing equation considering the temperature dependence is obtained under a rectangular coordinate system. Analytical method is used to solve the governing equation in which the material parameters vary in a general law, the maximum energy difference expression with gradient parameters is obtained, and then the optimal gradient parameters under certain working conditions are solved . The results show that, compared with the power series iteration approximation (PSIA) solution , the analytical solution is accurate and has less calculation. When the volume fraction of materials varied in a power function gradient, the maximum energy difference obtained by using the analytical method is better than that obtained by using the PSIA method when the volume fraction varied in general linear and exponential functions. The appropriate gradient distribution could improve the energy difference of thermoelectric generators effectively