Title: Experimental study on the effects of flame regime on the exergy destruction in premixed low swirl combustion
Authors: Seyyed Iman Pishbin; Mohsen Ghazikhani; Seyyed Mohammad Reza Modarres Razavi
Addresses: Department of Mechanical Engineering, Ferdowsi University of Mashhad, Mashhad 91775-1111, Iran ' Department of Mechanical Engineering, Ferdowsi University of Mashhad, Mashhad 91775-1111, Iran ' Department of Mechanical Engineering, Ferdowsi University of Mashhad, Mashhad 91775-1111, Iran
Abstract: In this paper, the premixed turbulent combustion is experimentally studied from the viewpoint of the second law of Thermodynamics. The low swirl combustion (LSC) concept is employed as the flame stabilisation mechanism in the tests. On the basis of the normalised laminar flame speed (NLFS), two distinguished flame shape regimes are observed: lifted and attached flames. Observations show the significant effect of the flame regime in terms of exergy destruction. The lifted flame that occurs in lower NLFSs considerably demonstrates lower amount of irreversibility production, whereas the attached flame that presents the higher rates of fuel exergy destruction. Besides, the heat transfer from the combustion chamber to the surrounding for the lifted flame condition is 14% more than the attached flame. Analysing the system via the entropy generation approach illuminated the role of temperature distribution in the variations of irreversibility production.
Keywords: flame stabilisation; exergy destruction; premixed combustion; LSC; low swirl combustion; irreversibility; temperature distribution; turbulent combustion; second law; thermodynamics; normalised laminar flame speed; NLFS; flame shape regimes; lifted flames; attached flames; heat transfer; entropy generation.
International Journal of Exergy, 2015 Vol.17 No.3, pp.267 - 286
Received: 17 Feb 2014
Accepted: 17 May 2014
Published online: 08 Jul 2015 *