A new one-dimensional model of thermoelectric generators

The one-dimensional (1D) theoretical models for thermoelectric generators (TEGs) widely used to interpret experimental results and guide device design have not been subjected to a rigorous re-evaluation. In this work, we examine the foundations of the traditional 1D TEG model and identify the omission of the heat flow induced by the Seebeck effect, and inconsistencies in boundary conditions, both of which can lead to deviations in predicting the origin of thermoelectric power and the energy conversion efficiency. A new 1D model with Seebeck heat flow and four junction temperatures is proposed based on actual thermoelectric generators. In addition, The TEG system is decomposed into a thermal subsystem and an electrical subsystem, which can clarify the energy conservation relation at the interface and inside element. Numerical solutions to the governing equations system of the new 1D model show that compared to traditional 1D models, the new 1D model has three advantages: (1) the temperature at both ends of the thermoelectric element is variable, not fixed; (2) the thermoelectric conversion efficiency can be more accurately predicted; (3) the output electrical power does not come from the conversion of Peltier heat flow, but from the conversion of heat flow provided by the heat reservoir.