Performance comparison of an endoreversible closed variable temperature heat reservoir Brayton cycle under maximum power density and maximum power conditions

In this paper, the power density, defined as the ratio of power output to m aximum specific volume in the cycle, is taken as the objective for performa nce analysis of an endoreversible closed Brayton cycle coupled to variable temperature heat reservoirs in the viewpoint of finite time thermodynamics or entropy generation minimization. The analytical formulae about the relat ions between power density and pressure ratio are derived with heat resista nce losses in the hot and cold side heat exchangers. The obtained results a re compared with those results obtained by using the maximum power criterio n. The influences of some design parameters on the maximum power density ar e provided by numerical examples, and the advantages and disadvantages of m aximum power density design are analyzed. The power plant design with maxim um power density leads to a higher efficiency and smaller size. When the he at transfer is effected ideally and the thermal capacity rates of the two h eat reservoirs are infinite, the results of this paper become those obtaine d in recent literature. (C) 2001 Elsevier Science Ltd. All rights reserved.