Coherent magneto-caloric effect superconductive heat engine process cycle

Abstract

A heat engine process cycle is proposed in which an armature, composed of a type I superconductor material, is magnetocalorically and magnetodynamically processed in magnetic field-temperature (H-T) space. Provided that the diameter d of the armature is defined by ξ(T) ≥ d ≥ 5λ(T), then a coherent magnetocaloric magnetization process is predicted which refrigerates the armature from a cycle high temperature T ₁ to a cycle low temperature T ₂, and a subsequent coherent magnetocaloric demagnetization process is predicted which heats the armature from T ₂ to an intermediate temperature T ₃, where T ₃ < T ₂. A heat influx from an external high-temperature heat reservoir is required to achieve T ₁ and thereby to complete the cycle. As the temperature changes, the magnetic field is varied between a cycle low magnetic field H ₁ at T ₁ and a cycle high magnetic field H ₂ at T ₂, where the magnetodynamic work output is provided as the magnetic field is decreased from H ₂ to H₁.