Optimum design of a thermoelectric device

The design goal of a thermoelectric (TE) device is to determine the optimum structure of the semiconductor thermoelements so as to meet the required specifications with a minimum cost. The cost usually consists of the construction costs of semiconductor materials and heat exchangers and the running cost of supplied electricity. A real TE cooler with a finite-rate heat transfer between the surroundings is investigated in this paper. A set of theoretical performance formulae is derived from the thermal network model, based on which a general expression for the total cost of a TE cooler is presented. A practical procedure for optimizing a TE cooler in order to minimize its total cost is described. Furthermore, the optimum design parameters are calculated at some practical operative conditions, for example, maximum cooling power density and maximum benefit of semiconductor materials, etc. The results obtained in this paper could be useful for the designers of TE coolers as well as designers of power generators.