A two-stage cuboid-styled thermoelectric cooler with switched polarity

This paper introduces a two-stage cuboid-styled thermoelectric (TE) cooler, which is simply formed by linking two similar single-stage commercial TE modules serially in thermal cascade. Superior to a conventional two-stage pyramid-styled TE cooler, the cuboid-styled cooler has switched polarity, which means that the cooling rate and coefficient of performance (COP) can keep constant when its supplied electric currents are alternated. As an example, a single-stage TE module of MELCOR is chosen for performance comparison between single and two-stage coolers. Practical conditions are accounted for by considering the effect of thermal resistance between stages. The calculations demonstrate that the two-stage cuboid-styled cooler can attain higher temperature differences than those achieved by the single-stage module. Both COP and cooling flux are improved at large temperature difference.