Title: Energy and exergy analyses of a new combined cycle using carbon dioxide as working fluid

Authors: Arash Jamali; Ali Keshavarz

Addresses: School of Mechanical Engineering, K.N. Toosi University of Technology, No. 15, Pardis St, MollaSadra Avenue, Vanak Sq, Tehran 19991-43344, Iran ' School of Mechanical Engineering, K.N. Toosi University of Technology, No. 15, Pardis St, MollaSadra Avenue, Vanak Sq, Tehran 19991-43344, Iran

Abstract: In this study, a new combined cycle based on the Brayton power cycle and the ejector expansion refrigeration cycle is proposed. The proposed cycle can provide simultaneous heating, cooling and power. And be driven by low temperature heat sources. The suggested cycle can save energy around 46% in comparison with a system producing cooling, power and hot water separately. Moreover, the second law efficiency of the combined system is around 30% which can be obtained under the given conditions. Finally, the surface area of the heat exchangers is determined. The suggested cycle can be a promising combined system for buildings and outland regions.

Keywords: combined cycle; CO2; energy analysis; exergy analysis; carbon dioxide; ejector expansion; refrigeration cycle; heat exchangers; size; thermodynamic analysis; Brayton power cycle; energy saving; second law efficiency.

DOI: 10.1504/IJEX.2013.058104

International Journal of Exergy, 2013 Vol.13 No.4, pp.487 - 507

Received: 16 Oct 2012
Accepted: 08 Jan 2013
Published online: 08 Dec 2013 *

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