Authors: Jiangfeng Guo; Jun Cai; Huanguang Wang
Addresses: Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100190, China ' Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100190, China ' Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100190, China
Abstract: The influences of the number of heat transfer units distribution, cycle pressure ratio, specific heat ratio, etc. on the performance of an irreversible regenerative closed intercooled Brayton cycle are investigated in terms of thermal efficiency, thermodynamic efficiency, dimensionless power, entropy generation number and Ecological Coefficient Of Performance (ECOP). Different performance criteria correspond to the different optimal number of heat transfer units distribution schemes, generally, the NtuR fraction is the largest, followed by NtuH fraction and NtuL fraction, the NtuI is the smallest in the optimal distribution schemes. There exist the optimal specific heat ratios, the optimal cycle pressure ratios and the optimal intercooling pressure ratios for the maximum thermal efficiency, the maximum thermodynamic efficiency and the maximum ecological coefficient of performance in some situations. In general, the optimal specific heat ratio relatively increases as the cycle pressure ratio decreases and slightly increases as the intercooling pressure ratio increases. The optimal cycle pressure ratio increases and the optimal intercooling pressure ratio slightly decreases as the specific heat ratio decreases.
Keywords: Brayton cycle; heat exchangers; heat transfer; entropy generation; ECOP; ecological coefficient of performance; thermal efficiency; thermodynamic efficiency; dimensionless power; performance evaluation; specific heat ratio; cycle pressure ratio; intercooling pressure ratio; exergy analysis.
International Journal of Exergy, 2012 Vol.11 No.3, pp.271 - 285
Received: 09 Feb 2012
Accepted: 21 Feb 2012
Published online: 05 Nov 2012 *