Cryogenic Heat Engine Experiment

Abstract

Experimental results on the operation of a “cryogenic heat engine” are presented. A cryogenic heat engine employs a cryogenic medium as a heat sink and the atmosphere as a heat source. Cold thermal storage by refrigeration to produce the cryogenic medium is thus equivalent to energy storage. Using liquid nitrogen as the cryogenic medium, a small cryogenic heat engine which utilizes a simple gas expansion process has been evaluated to experimentally provide 19 kJ of mechanical energy per kilogram of nitrogen exhausted. Theoretical modeling indicates that larger specific energy values are readily possible using more advanced cryogenic heat engine processes. Cryogenic heat engines are potentially suitable as power systems for zero emission vehicles. In order to prove that this is possible, an automobile has been converted for operation using liquid nitrogen as its fuel. In addition, a study has been conducted to assess the feasibility of using a cryogenic heat engine as a zero emission vehicle power system.