Theory of thermoelectric refrigeration and generation

Abstract

The electrical and thermal conductivities are defined. It is then shown how the cooling effect from a thermoelectric refrigerator can be related to the electric current and the thermoelectric coefficients. The coefficient of performance is defined and it is shown that it can be expressed in terms of a materials parameter that is known as the figure of merit. The conditions for the optimisation of the figure of merit for a given pair of positive and negative thermoelements are derived. It is shown how the same figure of merit applies when thermocouples are used for generation of electricity from heat. The performance of multi-stage Peltier coolers is discussed. Energy conversion devices based on the transverse thermomagnetic effects are also considered.