Parameter analysis and optimal design for two-stage thermoelectric cooler

The objective of this work is to examine the parameter sensitivity and optimize the cooling performance of two-stage thermoelectric cooler (TEC). Firstly, a multiphysics model is used to investigate the effects of geometry parameters and applied currents on the performance of a two-stage TEC. Specially, cross-sectional area ratio of the p-type leg to the leg pair χ and height ratio of the cold stage leg to the two stage legs δ are explored, which have never been investigated in previous studies. Secondly, a simplified conjugated-gradient method is coupled into the multiphysics model to optimize the four key geometric parameters and two applied currents supplied to hold and cold stages, for seeking the maximum cooling capacity. The results of individual parameter analysis mainly show that the optimal χ does not depend on the geometric structure and applied currents of TEC, while it is only determined by the p-type and n-type semiconductor materials. The height ratio δ always plays the role to adjust the temperature between the cold and hot stages, resulting in that the both stages could operate at the proper temperature differences matching with their respective applied current. The optimization results show that the maximum cooling capacity Q_c,c at δT=0, 20, 40, and 60K is enhanced by 19.62%, 21.30%, 25.49%, and 43.83%, respectively, as compared with the initial design. When δT increases from 0K to 40K, the change for each parameter in the optimal set is not larger than 1.8%, indicating that once the optimal design is obtained at a specific δT, it can be safely used at any other δT.