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Item type:Publication, Access status: with files , Investigation of oil emission mechanisms in a marine medium-speed dual-fuel engine(Sage Publications, 2024-05); ; ; ; Pilot-ignition Otto marine engines are known for greatly reduced emissions of air pollutants (sulphur oxides, nitrogen oxide, particulates) compared to marine diesel engines. However, lubricating oil emissions still are about one order of magnitude higher than in land-based systems. To identify reduction potentials, a better understanding of oil emission mechanisms has to be gained. For this purpose, mass spectrometric oil emission measurements and fluorescence lubricating film thickness measurements were performed on a medium-speed marine engine. With the fluorescence measuring system, the varying lubricating oil film on the cylinder wall can be visualised and analysed in sub-crank-angle resolution. By applying the developed calibration method to the measurement data, the oil film thickness can be determined in µm. It is shown that the oil film left by the piston rings on the liner as it moves down is almost halved after ignition compared to during intake stroke. The authors have further been able to detect and time operating point dependent ring rotation and investigations show a connection between ring rotation and cylinder liner temperature distribution. Aligning ring gaps allow blow-by to happen. This and other high intensity events such as engine knock, load shedding or the transition from diesel-mode to gas-mode, heavily disturb the oil layer and cause peaking oil emissions.Publicationtype: Journal Article84 24 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Investigation of oil emission mechanisms in a marine medium-speed dual-fuel enginePilot-ignition otto marine engines are known for greatly reduced emissions of air pollutants (sulphur, nitrogen oxide, particulates) compared to marine diesel engines. However, lubricating oil emissions still are about one order of magnitude higher than in land-based systems. To identify reduction potentials, a better understanding of oil emission mechanisms has to be gained. For this purpose, mass spectrometric oil emission measurements and fluorescence lubricating film thickness measurements were performed on a medium-speed marine engine. With the fluorescence measuring system, the varying lubricating oil film on the cylinder wall can be visualised and analysed in sub-crank-angle resolution. This enables ring rotation detection and investigations show a connection between ring rotation and cylinder liner temperature distribution. Aligning ring gaps allow blow-by to happen. This and other high intensity events such as engine knock, load shedding or the transition from diesel-mode to gas-mode, heavily disturb the oil layer and cause peaking oil emissions.Publicationtype: Conference Paper50 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Lubrication large bore engines(Forschungsvereinigung Verbrennungskraftmaschinen e.V., 2019-09); ; ; ; Publicationtype: Conference Poster not in Proceedings97 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Lubrication large bore engines(Forschungsvereinigung Verbrennungskraftmaschinen e.V., 2019-03); ; ; ; The three main air pollutants produced by marine traffic are sulphur oxides, nitrogen oxides and particulate matter (PM). Due to the fact that marine traffic near shores and even in urban areas is on the rise, while on the other hand air quality is a major political and social concern, special account needs to be taken of the environmental impact of ships operating in these regions. While strict restrictions for the first two mentioned pollutants exist, there are currently none for PM emissions in shipping. Since it is only a matter of time before threshold values will be set, the gaining of knowledge in the field of PM is of exceptional importance. The target of the project is an evaluation of measures that are expected to reduce the lubricating oil-originated PM emissions with respect to their results and impact on engine operation. Additional goals are the classification of PM emissions in medium speed engines and to describe the correlation between these emissions and the lubricating oil film thickness.Publicationtype: Conference Poster not in Proceedings46