Thermodynamic optimization of regenerators

Abstract

This paper presents a second law of thermodynamics analysis technique for regenerators in single blow operation. Unlike earlier analyses, this technique accounts for the gas and matrix temperature variation along the temporal and spatial coordinates. The results of this study indicate that: 1, well defined optima exist with regard to charging time and number of heat transfer units for maximizing the useful work stored; and 2, whereas in earlier analyses a finite optimum charging time results as Ntu approaches infinity, in the present analysis a square wave of specific irreversibility propagates in the medium. To obtain an appropriate analytical expression, this analysis is approximated to suit a low Ntu regenerator.