Finite-time thermodynamic performance of an isentropic closed regenerated Brayton refrigeration cycle

Finite-time thermodynamic performance of isentropic closed regenerated Brayton refrigeration cycles coupled to constant- and variable-temperature heat reservoirs has been analyzed in this paper. The relations between cooling load and pressure ratio, and between COP (coefficient of performance) and pressure ratio are derived for the two cases of heat reservoirs. In the analysis, the sole irreversibilities are the heat resistance losses in the heat exchangers between working fluid and the high- and low-temperature heat reservoirs and in the regenerator. A numerical example is also given.