Near-Field Radiative Heat Exchange Analysis of a Spacecraft Waste Heat Converter Design

Abstract

This paper presents a new design to convert spacecraft waste heat to electrical energy. The proposed device utilizes near-field radiative heat transfer incorporated with pyroelectric materials. To generate electricity, the pyroelectric materials are cyclically heated using spacecraft waste heat and cooled by the thermal environment of deep space (∼2.7 K). Near-field plane-to-plane radiative heat exchange within the device is calculated using a modified sphere-to-plane asymptotic approximation. This method is superimposed on multiple spheres to approximate a plane-to-plane environment. Silica and lithium fluoride coatings are considered in this study to maximize the near-field heat exchange. The efficiency of the device is 17% and 32% when compared to the Carnot cycle efficiency and the Curzon-Ahlborn efficiency, respectively. Initial results indicate that the device is promising but requires further development before it is manufactured for operational use. Suggestions for possible future developments to enhance the design are presented.