Modeling of annular thermoelectric generator considering temperature-dependent material properties and side surface heat convection

An annular thermoelectric generator (ATG) contributes to energy utilization in round structures. An accurate prediction of thermoelectric (TE) performance is key to the design of the ATG. By using the perturbation theory and the equivalent substitution of integrals method, an analytical model is proposed, which can easily deal with the nonlinear heat equation induced by temperature-dependent material properties. The TE performance of the ATG including the Thomson effect is studied by the proposed model, and the effect of structural parameters and operating conditions on the TE behavior is analyzed. The results indicate that if the Thomson effect is neglected, the predicted power output and efficiency will be much higher than the actual cases. Significantly, in both working conditions, the relative error of the predicted temperature field of the proposed model is less than 0.1%, far below the available theoretical models. In addition, the influence of side surface heat convection is also analyzed using a numerical method. Remarkably, the maximum power output may increase as the heat convection coefficient grows.