Generation of combustion irreversibilities in a spark ignition engine under biogas-hydrogen mixtures fueling

Rakopoulos, CD; Michos, CN

dc.contributor.author	Rakopoulos, CD	en
dc.contributor.author	Michos, CN	en
dc.date.accessioned	2014-03-01T01:30:48Z
dc.date.available	2014-03-01T01:30:48Z
dc.date.issued	2009	en
dc.identifier.issn	0360-3199	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/19632
dc.subject	Hydrogen	en
dc.subject	Biogas	en
dc.subject	Spark ignition engine	en
dc.subject	Availability analysis	en
dc.subject	Combustion irreversibilities	en
dc.subject	Spatial distribution	en
dc.subject	Multi-zone thermodynamic model	en
dc.subject	Quasi-dimensional combustion model	en
dc.subject.classification	Chemistry, Physical	en
dc.subject.classification	Energy & Fuels	en
dc.subject.classification	Environmental Sciences	en
dc.subject.classification	Physics, Atomic, Molecular & Chemical	en
dc.subject.other	LAMINAR-BURNING VELOCITY	en
dc.subject.other	AVAILABILITY ANALYSIS	en
dc.subject.other	2ND-LAW ANALYSIS	en
dc.subject.other	OXIDE FORMATION	en
dc.subject.other	NATURAL-GAS	en
dc.subject.other	MODEL	en
dc.subject.other	PERFORMANCE	en
dc.subject.other	DIESEL	en
dc.subject.other	VALIDATION	en
dc.subject.other	OPERATION	en
dc.title	Generation of combustion irreversibilities in a spark ignition engine under biogas-hydrogen mixtures fueling	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/j.ijhydene.2009.02.087	en
heal.identifier.secondary	http://dx.doi.org/10.1016/j.ijhydene.2009.02.087	en
heal.language	English	en
heal.publicationDate	2009	en
heal.abstract	Availability analysis is applied to the cylinder of a spark ignition engine during the closed part of the engine cycle when biogas-hydrogen blends, with volumetric fractions of hydrogen up to 15%, are used as fuel. The focal point is on the demonstration of the spatial distribution inside the burned gas of the combustion-generated irreversibilities for the various hydrogen concentration cases examined, which constitute one of the major sources for the defective exploitation of fuel into useful mechanical work that cannot be identified by the traditional first-law analysis. For this reason, an experimentally validated closed cycle simulation code is used, based on a multi-zone thermodynamic model of the cylinder content, applied in conjunction with a quasi-dimensional combustion model for burn rate predictions. After presenting global availability-balance-related results, pointing out the increase in the second-law efficiency of engine operation with the hydrogen enrichment of biogas, detailed information is provided regarding the spatial development of the combustion irreversibilities throughout the thermodynamically inhomogeneous burned gas, along with their link with the developed temperature field, as determined during combustion at each hydrogen fraction. It is revealed that the addition of increasing amounts of hydrogen in biogas promotes the degree of reversibility of the burning process mainly during the combustion of the later burning gas, due to the incurred increase in its combustion temperatures. On the contrary, the contribution of the early burning gas to the decrease in combustion irreversibilities with hydrogen addition seems to be less prominent. (C) 2009 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.	en
heal.publisher	PERGAMON-ELSEVIER SCIENCE LTD	en
heal.journalName	INTERNATIONAL JOURNAL OF HYDROGEN ENERGY	en
dc.identifier.doi	10.1016/j.ijhydene.2009.02.087	en
dc.identifier.isi	ISI:000267173700021	en
dc.identifier.volume	34	en
dc.identifier.issue	10	en
dc.identifier.spage	4422	en
dc.identifier.epage	4437	en