Title: Energy and exergy analyses of a spark-ignition engine

Authors: M. Ameri, F. Kiaahmadi, M. Khanaki, M. Nazoktabar

Addresses: Combined Heat & Power Specialized Unit (CHP), Energy Engineering Department, Power and Water University of Technology, P.O. Box 16765-1719, Tehran, Iran. ' Combined Heat & Power Specialized Unit (CHP), Energy Engineering Department, Power and Water University of Technology, P.O. Box 16765-1719, Tehran, Iran. ' Department of Mechanical Engineering, Imam Khomeini International University, P.O. Box 34149-16818, Gazvin, Iran. ' Department of Mechanical Engineering, Sharif University of Technology, P.O. Box 14858-67544, Tehran, Iran

Abstract: In this paper, the performance of an internal combustion engine is evaluated at the steady-state condition by application of energy and exergy analysis using the experimental test results. The energy and exergy balances are calculated at different engine speeds. The results show that the heat rejection of energy and exergy flow increases with increasing engine speed. The exergy efficiencies are slightly higher than the corresponding energy efficiencies. The results of this study have revealed that the most important source of the system inefficiency is the destruction of exergy by irreversible processes, mostly by the combustion. One can conclude that the use of a combined energy and exergy analysis provides better criteria for the performance assessment of a thermal system.

Keywords: SI engines; spark inition engines; energy analysis; exergy analysis; energy efficiency; exergy efficiency; irreversibility; engine performance; internal combustion engines.

DOI: 10.1504/IJEX.2010.034928

International Journal of Exergy, 2010 Vol.7 No.5, pp.547 - 563

Published online: 31 Aug 2010 *

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