Parametric analysis of a gas turbine cycle coupled to a Brayton refrigeration cycle

Abstract

Performance analysis and optimization of an endoreversible Brayton cycle coupled to a Brayton refrigeration cycle has been performed using finite-time thermodynamics. The analy-tical formulae are derived with respect to power, efficiency, optimal extracted pressure ratio of air refrigeration cycle corresponding to optimal power, optimal power and the corresponding efficiency. The influences of various parameters on the cycle performances are analysed by numerical examples. The results show that there exists one optimal pressure ratio of the compressor corresponding to maximum power and another optimal pressure ratio of the compressor corresponding to maximum efficiency; the compressor inlet temperature is reduced by mixing the chilled working fluid from the Brayton refrigeration cycle and the main intake working fluid streams; the intake working fluid temperature could be controlled even below the temperature of the heat sink and the gas turbine performance can be improved.