Exergoeconomic performance analyses of an endoreversible intercooled regenerative Brayton cogeneration-type model

Abstract

The exergoeconomic performance of an endoreversible intercooled regenerative Brayton cogeneration plant coupled to variable-temperature heat reservoirs is investigated using finite-time thermodynamics. The analytical formulae for the dimensionless profit rate and exergy efficiency of the cogeneration plant are deduced. The two cases with fixed and variable total pressure ratios are discussed. When the total pressure ratio is variable, by means of numerical calculations, the optimal intercooling pressure ratios corresponding to the optimal profit rate and exergy efficiency are obtained, respectively. The maximum profit rate, the maximum exergy efficiency and the corresponding optimal total pressure ratios are obtained. The effects of the design parameters on the exergoeconomic performance of the cogeneration plant are analysed. The results show that there exist two optimal consumer-side temperatures which lead to a double-maximum profit rate and a double-maximum exergy efficiency.