Regenerative Thermomagnetic Power

Abstract

Thermomagnetic power devices utilize the temperature dependence of magnetic moment to convert heat into organized energy. In an analogous manner thermoelectrostatic devices would utilize changes of electric moment to perform the same function and the analysis of each can be given in a single treatment. This paper, which analytically explores new considerations relevant to these energy conversion methods, is motivated by a search for increased performance. To begin, a basis for the treatment of the thermodynamics of polarizable substances is developed in a manner that stresses material parameters. Explicit thermodynamic functions are then derived corresponding to both a simple and a realistic equation of state. With this information power cycles are devised and evaluation is made of their thermodynamic efficiencies. An optimum regenerative cycle emerges and criteria for its attainment are considered. Finally, a power estimate accounting for thermal irreversibilities predicts the possibility of low specific weight. Using more general conversion techniques than were admitted in the past, the prospect for thermomagnetic and thermoelectrostatic energy conversion is greatly improved.