Parametric Investigation of Methanol Ratio and Diesel Injection Timing for a Marine Diesel–Methanol Dual-Fuel Engine

In the present work, the combustion process of a retrofitted high-speed marine Diesel Methanol Dual Fuel (DMDF) engine is numerically evaluated. This study examines the effects of two important operational parameters, the methanol energy substitution ratio (MESR) and diesel injection timing, with a...

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Main Authors: George Papalambrou, Vasileios Karystinos
Format: Article
Language:English
Published: MDPI AG 2025-03-01
Series:Journal of Marine Science and Engineering
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Online Access:https://www.mdpi.com/2077-1312/13/4/648
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author George Papalambrou
Vasileios Karystinos
author_facet George Papalambrou
Vasileios Karystinos
author_sort George Papalambrou
collection DOAJ
description In the present work, the combustion process of a retrofitted high-speed marine Diesel Methanol Dual Fuel (DMDF) engine is numerically evaluated. This study examines the effects of two important operational parameters, the methanol energy substitution ratio (MESR) and diesel injection timing, with a focus on engine performance and emissions. To perform the analysis, a CFD numerical combustion model was developed, and a mean value model, along with other data-driven models, were employed to estimate the intake cylinder conditions. The numerical models were calibrated and validated using experimental data measured at the DMDF experimental testbed at the Laboratory of Marine Engineering (LME). The models were utilized to conduct a parametric study considering various engine speeds and loads, diesel injection timings, and MESRs up to 75%. The impact of these parameters was quantified with respect to in-cylinder pressure, ignition timing, combustion efficiency, <i>NO<sub>x</sub></i>, soot, and HC emissions. The results revealed that an increased methanol ratio leads to delayed ignition timing, shorter combustion duration, and reduced in-cylinder peak pressure and combustion efficiency. <i>NO<sub>x</sub></i> and soot emissions are also reduced, whereas the concentrations of unburned hydrocarbons in the exhaust gas increase significantly and mainly consist of Volatile Organic Compounds (VOCs). Although advancing injection timing in dual-fuel mode improves combustion efficiency, it increases the maximum in-cylinder pressure and <i>NO<sub>x</sub></i> emissions. The other emissions are either reduced or maintained at the same levels. Moreover, the results suggest that there is a trade-off between <i>NO<sub>x</sub></i> emissions and combustion performance, which must be taken into account when the operational parameters are adjusted for these engines. Finally, the maximum MESRs are estimated to ensure safe combustion within acceptable peak pressure limits and adequate combustion performance.
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spelling doaj-art-50abd1f1fcaf46c09ec8d2dd1f5c58e72025-08-20T02:18:14ZengMDPI AGJournal of Marine Science and Engineering2077-13122025-03-0113464810.3390/jmse13040648Parametric Investigation of Methanol Ratio and Diesel Injection Timing for a Marine Diesel–Methanol Dual-Fuel EngineGeorge Papalambrou0Vasileios Karystinos1Laboratory of Marine Engineering, School of Naval Architecture and Marine Engineering, National Technical University of Athens, 15773 Zografou, GreeceLaboratory of Marine Engineering, School of Naval Architecture and Marine Engineering, National Technical University of Athens, 15773 Zografou, GreeceIn the present work, the combustion process of a retrofitted high-speed marine Diesel Methanol Dual Fuel (DMDF) engine is numerically evaluated. This study examines the effects of two important operational parameters, the methanol energy substitution ratio (MESR) and diesel injection timing, with a focus on engine performance and emissions. To perform the analysis, a CFD numerical combustion model was developed, and a mean value model, along with other data-driven models, were employed to estimate the intake cylinder conditions. The numerical models were calibrated and validated using experimental data measured at the DMDF experimental testbed at the Laboratory of Marine Engineering (LME). The models were utilized to conduct a parametric study considering various engine speeds and loads, diesel injection timings, and MESRs up to 75%. The impact of these parameters was quantified with respect to in-cylinder pressure, ignition timing, combustion efficiency, <i>NO<sub>x</sub></i>, soot, and HC emissions. The results revealed that an increased methanol ratio leads to delayed ignition timing, shorter combustion duration, and reduced in-cylinder peak pressure and combustion efficiency. <i>NO<sub>x</sub></i> and soot emissions are also reduced, whereas the concentrations of unburned hydrocarbons in the exhaust gas increase significantly and mainly consist of Volatile Organic Compounds (VOCs). Although advancing injection timing in dual-fuel mode improves combustion efficiency, it increases the maximum in-cylinder pressure and <i>NO<sub>x</sub></i> emissions. The other emissions are either reduced or maintained at the same levels. Moreover, the results suggest that there is a trade-off between <i>NO<sub>x</sub></i> emissions and combustion performance, which must be taken into account when the operational parameters are adjusted for these engines. Finally, the maximum MESRs are estimated to ensure safe combustion within acceptable peak pressure limits and adequate combustion performance.https://www.mdpi.com/2077-1312/13/4/648diesel–methanol dual fuelmethanol fuelcomputational modelemission reductionmarine engine
spellingShingle George Papalambrou
Vasileios Karystinos
Parametric Investigation of Methanol Ratio and Diesel Injection Timing for a Marine Diesel–Methanol Dual-Fuel Engine
Journal of Marine Science and Engineering
diesel–methanol dual fuel
methanol fuel
computational model
emission reduction
marine engine
title Parametric Investigation of Methanol Ratio and Diesel Injection Timing for a Marine Diesel–Methanol Dual-Fuel Engine
title_full Parametric Investigation of Methanol Ratio and Diesel Injection Timing for a Marine Diesel–Methanol Dual-Fuel Engine
title_fullStr Parametric Investigation of Methanol Ratio and Diesel Injection Timing for a Marine Diesel–Methanol Dual-Fuel Engine
title_full_unstemmed Parametric Investigation of Methanol Ratio and Diesel Injection Timing for a Marine Diesel–Methanol Dual-Fuel Engine
title_short Parametric Investigation of Methanol Ratio and Diesel Injection Timing for a Marine Diesel–Methanol Dual-Fuel Engine
title_sort parametric investigation of methanol ratio and diesel injection timing for a marine diesel methanol dual fuel engine
topic diesel–methanol dual fuel
methanol fuel
computational model
emission reduction
marine engine
url https://www.mdpi.com/2077-1312/13/4/648
work_keys_str_mv AT georgepapalambrou parametricinvestigationofmethanolratioanddieselinjectiontimingforamarinedieselmethanoldualfuelengine
AT vasileioskarystinos parametricinvestigationofmethanolratioanddieselinjectiontimingforamarinedieselmethanoldualfuelengine