Power density optimization for an irreversible regenerated closed Brayton cycle

In this paper, the power density, defined as the ratio of power output to t he maximum specific volume in the cycle, is taken as objective for performa nce optimization of an irreversible regenerated closed Brayton cycle couple d to constant-temperature heat reservoirs in the viewpoint of finite time t hermodynamics (FTT) or entropy generation minimization (EGM). The analytica l formulae about the relations between power density and pressure ratio are derived with the heat resistance losses in the hot- and cold-side heat exc hangers and the regenerator, the irreversible compression and expansion los ses in the compressor and turbine, and the pressure drop loss in the piping . The maximum power density optimization is performed by searching the opti mum heat conductance distribution corresponding to the optimum power densit y among the hot- and cold-side heat exchangers and the regenerator for the fixed total heat exchanger inventory The influence of some design parameter s, including the temperature ratio of the heat reservoirs, the total heat e xchanger inventory, the efficiencies of the compressor and the turbine, and the pressure recovery coefficient, on the optimum heat conductance distrib ution and the maximum power density are provided. When the heat transfers b etween the working fluid and the heat reservoirs are carried out ideally, t he analytical results of this paper become those obtained in recent literat ure. The power plant design with optimization leads to smaller size includi ng the compressor, turbine, and the hot- and cold-side heat exchangers and the regenerator.