Resistance-capacitance thermal models as alternatives to finite-element numerical models in the simulation of thermoelectric modules for electric power generation.

• Comparison for the first time of FEM and RC in TEM transient simulation. • RC replicates results of FEM under steady state with deviations lower than 3 % • RC replicates also values, trends and rates of variation under transient conditions. • RC presents negligible computational cost. This paper demonstrates that resistance–capacitance models provide equal results than models based on finite-element software when predicting the performance of a thermoelectric module under transient-state conditions. Previous papers on this topic fall short as comparing finite-element models with simplified versions of resistance–capacitance models. It was confirmed that resistance–capacitance models replicate results of finite-element models in the simulation of a thermoelectric module under steady-state conditions. Deviations lower than 3 % in electric power and efficiency (ratio of electric power to heat input) are obtained for temperature differences between heat source and heat sink as large as 200 K. Similarly, deviations lower than 3 % are obtained for simulation of a thermoelectric module under transient-state conditions. Resistance-capacitance models not only replicate values, trends and rates of variation predicted by finite-element models under step, linear and sinewave variations in the boundary conditions, but they also do this with negligible computational cost. [ABSTRACT FROM AUTHOR]