Power density analysis of an endoreversible, closed, constant-temperature heat reservoir, intercooled regenerative Brayton cycle

Abstract

In this paper, the power density, defined as the ratio of power output to the maximum specific volume in the cycle, is taken as objective for performance analysis of an endoreversible, closed, intercooled regenerated Brayton cycle coupled to constant-temperature heat reservoirs in the viewpoint of finite-time thermodynamics or entropy generation minimization. The analytical formulae about the relations between power density and pressure ratio are derived with the heat resistance losses in the hot- and cold-side heat exchangers, the intercooler and the regenerator. The intercooling pressure ratio is optimized for dimensionless power density. The effects of effectivenesses of the intercooler and the regenerator on the optimal dimensionless power density and its corresponding efficiency are analyzed by detailed numerical examples. The obtained results are compared with those results obtained by using the maximum power criterion, including the cycle efficiencies, the normalized maximum specific volumes and the normalized maximum specific volume differences at two design objectives. The advantages and disadvantages of maximum power density design are obtained via the comparison of the main parameters of cycle at the maximum power and maximum power density conditions. The effects of turbine and compressor losses on the cycle performance are analyzed. Copyright The Author 2010. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oxfordjournals.org, Oxford University Press.