Title: Evaluation of cogeneration plant with steam and electricity production based on thermoeconomic and exergoenvironmental analyses

Authors: Eduardo J.C. Cavalcanti; Gabriel F. De Souza; Matheus S.R. Lima

Addresses: Department of Mechanical Engineering, Federal University of Rio Grande do Norte, 59072-970 Natal/RN, Brazil ' Department of Mechanical Engineering, Federal University of Rio Grande do Norte, 59072-970 Natal/RN, Brazil ' Department of Mechanical Engineering, Federal University of Rio Grande do Norte, 59072-970 Natal/RN, Brazil

Abstract: A cogenerative system which produces 83.6 MW of steam and 119 MW of electricity was evaluated. The exergoeconomic and exergo environmental approach were carried out in order to calculate the cost rate and environmental impact per exergy unit of both products. The specific exergy costing (SPECO) approach was used in balance. The results reveal that the specific cost rate of steam and electricity are 66.6 $/GJ and 62.8 $/GJ, respectively. And the specific environmental impact rate of steam and electricity are 15,545 mPt/GJ and 14,350 mPt/GJ, respectively. The lower exergoeconomic factor and exergoenvironmental factor was in the combustor. The effect of air environmental temperature at products (electricity and steam) shown that the increase of air temperature, reduce the electrical power and exergetic efficiency. The increase of air temperature, increase the specific cost rate and the specific environmental impact rate of electricity and steam.

Keywords: cogeneration; gas turbine; HRSG; exergoeconomy; electricity; steam; exergoenvironmental analyses; eco-indicator 99; specific cost rate; specific environmental impact.

DOI: 10.1504/IJEX.2018.090324

International Journal of Exergy, 2018 Vol.25 No.3, pp.203 - 223

Received: 16 May 2017
Accepted: 24 Aug 2017
Published online: 12 Mar 2018 *

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