Effect of buckling on the cooling performance of free-standing planar thermoelectric coolers

Abstract

This article investigates the effect of buckling on the cooling performance of planar thermoelectric (TE) coolers (TECs). The TEC is made up of n-type and p-type TE elements with large length-to-thickness ratio. Each TE element is modeled as a fixed–fixed thin plate. Theoretical model for the solutions of temperature and electric potential fields of the TE element after buckling is established. The corresponding coefficient of performance (COP) that indicates the cooling performance of TEC is also given. Influence of Seebeck coefficient, thermal conductivity, temperature difference, and the ratio of length-to-thickness on the cooling performance are discussed. It is found that buckling of TEC will reduce its cooling performance. A bigger Seebeck coefficient and smaller thermal conductivity can both improve the value of COP. It is also found that there is no maximum COP when the temperature difference across the TEC is zero. However, the effect of buckling on the cooling performance of TEC can be ignored if the TEC achieves the maximum COP. The peak value of COP is independent of the ratio of length-to-thickness of the TEC. An optimized value of the electric current corresponding to the maximum COP of the TEC is obtained.