Theory of the infinite stage Nernst-Ettingshausen refrigerator

Abstract

It is shown that an infinite stage Nernst-Ettingshausen refrigerator can be constructed by proper shaping of the material. Expressions for the coefficient of performance, maximum temperature difference and the shaping function z(x) are given in general and for the special case where the product of the Nernst figure of merit Z and temperature T is independent of T. Some theoretical results of interest are depicted in graphical form. Preliminary experiments have verified the usefulness of the theory. Cooling from ice water to dry ice temperatures has been achieved with a Nernst-Ettingshausen refrigerator using pure bismuth for the material.