Keywords: closed regenerated Brayton cycle, irreversible cycles, finite heat capacity, heat reservoirs, power output, performance optimisation, heat exchangers, thermal capacitance rate matching, pressure ratio, heat resistance losses, heat exchanger inventory
Optimum distribution of heat exchanger inventory and optimum thermal capacitance rate matching for power optimisation of a regenerated closed Brayton cycle
The power output of the cycle is taken as objective for performance analysis and optimisation of an irreversible regenerated closed Brayton cycle coupled to variable-temperature heat reservoirs. The analytical formulae about the relations between power output and pressure ratio are derived with the heat resistance losses in three heat exchangers, the irreversible losses in the compressor and turbine, the pressure drop losses in the piping and system, and the effect of the finite thermal capacity rate of the heat reservoirs. The power output optimisation is performed by searching the optimum heat conductance distribution among the three heat exchangers for the fixed total heat exchanger inventory, and by searching the optimum thermal capacitance rate matching between the working fluid and the heat reservoir.