Modeling of Ammonia Combustion Emissions
in a Dual-Fuel Engine

Ποντικάκος, Γεώργιος; Pontikakos, Georgios

dc.contributor.author	Ποντικάκος, Γεώργιος	el
dc.contributor.author	Pontikakos, Georgios	el
dc.date.accessioned	2023-04-06T07:22:56Z
dc.date.available	2023-04-06T07:22:56Z
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/57489
dc.identifier.uri	http://dx.doi.org/10.26240/heal.ntua.25186
dc.rights	Αναφορά Δημιουργού - Παρόμοια Διανομή 3.0 Ελλάδα	*
dc.rights.uri	http://creativecommons.org/licenses/by-sa/3.0/gr/	*
dc.subject	Αμμωνία	el
dc.subject	Μηχανές Διπλού Καυσίμου	el
dc.subject	Θερμοδυναμική μοντελοποίηση	el
dc.subject	Εναλλακτικά Καύσιμα	el
dc.subject	Χημική Κινητική	el
dc.title	Modeling of Ammonia Combustion Emissions in a Dual-Fuel Engine	en
heal.type	bachelorThesis
heal.classification	Μ.Ε.Κ.	el
heal.classification	Θερμοδυναμική μοντελοποίηση	el
heal.classification	Εναλλακτικά Καύσιμα	el
heal.classification	Θερμοδυναμική	el
heal.classification	Μηχανολογία	el
heal.language	en
heal.access	free
heal.recordProvider	ntua	el
heal.publicationDate	2023-03-06
heal.abstract	The strict regulations dictated by the International Maritime Organization (IMO) regarding the decarbonization of the shipping sector have initiated worldwide research and development for using alternative fuels for ship propulsion. Among them, ammonia (NH3) is an attractive candidate, due to its wide availability and the potential of being produced by means of renewable energies, its non-explosive character, as well as its good thermophysical properties, which include a volumetric energy density in the range of other alternative fuels. Potential challenges associated with the adoption of ammonia for marine propulsion include its resistance to autoignition, its corrosive and toxic characteristics, the potential for nitrogen oxides (NOx) formation due to fuel bound nitrogen, as well as the production of nitrous oxide (N2O), associated with a very high global warming potential. The main objective of the present study is to develop and validate a computational tool for assessing the production of emissions from ammonia combustion in dual-fuel engines. To this end, a thermodynamic model is developed in the frame of the GT-POWER computational tool, and is coupled with a Detailed Chemical Kinetics Mechanism (DCKM). The latter consists of a detailed mechanism for n-dodecane (C12H26) combustion, assembled with a mechanism for NOx-NH3 chemistry; it includes approximately 190 species and 2800 elementary reactions. The computational tool developed has been tested for the case of a heavy- duty four-stroke dual-fuel engine, for which experimental data are available in the open literature. The engine can operate (i) in the diesel mode, and (ii) using simultaneously diesel fuel and ammonia, with the former directly injected and the latter introduced upstream the intake manifold. The present computational results were compared against experimental data for a ”Constant Power - Constant Speed” operation stencil; as the percentage of ammonia in the fuel mixture increases, the engine operation transitions from a diesel mode to a lean premixed ammonia combustion mode. The parameters of the thermodynamic tool developed were properly adapted to match the experimental pressure traces, yielding an overall good comparison for all cases considered. Further, predictions of emitted carbon dioxide (CO2) were also in good agreement with experiments. Predicted nitric oxide (NO) emissions were in reasonably good agreement with experiments for high and intermediate percentage of diesel in the diesel-ammonia mixture, and less so for low contribution of diesel fuel (high percentage of ammonia), suggesting that the chemical kinetics mechanism should be further tested in the corresponding operation range. Low exhaust concentration was predicted for nitrogen dioxide (NO2) and N2O. Overall, the present development forms a solid basis towards characterizing ammonia combustion and predicting associated emissions in marine engines operating with ammonia, in an effective manner.	en
heal.sponsor	WinGD	el
heal.advisorName	Καϊκτσής Λάμπρος	el
heal.advisorName	Kaiktsis, Lambros	en
heal.committeeMemberName	Kaiktsis, Lambros	en
heal.committeeMemberName	Papadakis, Georgios	en
heal.committeeMemberName	Papadopoulos, Christos	en
heal.academicPublisher	Εθνικό Μετσόβιο Πολυτεχνείο. Σχολή Ναυπηγών Μηχανολόγων Μηχανικών	el
heal.academicPublisherID	ntua
heal.numberOfPages	85 p.	en
heal.fullTextAvailability	false