TY - GEN
T1 - Predicting the effect of N2- And CO2-enriched inducted mixture on performance and emissions characteristics of a heavy-duty spark-ignited engine
AU - Papagiannakis, Roussos G.
AU - Zannis, Theodoros C.
AU - Hountalas, Dimitrios T.
AU - Yfantis, Elias A.
PY - 2014
Y1 - 2014
N2 - Modern heavy-duty (HD) spark-ignited (SI) engines, which are burning natural gas indicate higher thermal efficiency (i.e. reduced carbon footprint) compared to other types of thermal engines, which are used for electric power generation. However, despite recent developments, natural gas HD SI engines still remain a major source of gaseous emissions mainly of carbon monoxide (CO) and nitrogen oxides (NOx). Continuously stringent environmental regulations, which have been issued for electric power generation SI engines, have mandated the implementation of various in-cylinder measures besides after-treatment technologies for downplaying NOx emissions. One of the most efficient engine-related NOx curtailing methods is the partial recirculation of exhaust gases (EGR). However, according to the literature, EGR positive effects on NOx emissions are accompanied by negative effects on engine's brake specific fuel consumption (i.e. brake efficiency). An alternative to EGR method for curtailing SI engine NOx emissions is either the nitrogen-enrichment or carbon dioxide-enrichment of the inducted mixture. The aforementioned methodologies could be achieved by using separation membranes, which can recover the specific diluent from the exhaust gases and they have been successfully used in large power plants. Hence, in the present study it is proposed a comparative theoretical examination for the effect of the two EGR-alternative strategies: N2- and CO2-enrichment of the inducted mixture, on performance and emissions characteristics of a SI natural gas engine. For this reason, a comprehensive thermodynamic simulation model, which has been successfully used in the past to predict the operational and environmental performance of a natural gas HD SI engine, has been modified to incorporate the enrichment of intake mixture with either nitrogen or carbon dioxide. The evaluation of the effects of both strategies on performance and emissions characteristics of the engine will be made on a comparative basis under constant boost pressure and reduced in-cylinder oxygen availability. Thus, comparing the theoretical results observed under N2- and CO2-enrichment modes, as against with the respective ones observed under normal composition of the inducted mixture, a considerable effect on engine performance and emission characteristics are revealed. The conclusions of the specific investigation will be extremely valuable for the application of the examined technologies on an existing heavy-duty SI natural gas engine.
AB - Modern heavy-duty (HD) spark-ignited (SI) engines, which are burning natural gas indicate higher thermal efficiency (i.e. reduced carbon footprint) compared to other types of thermal engines, which are used for electric power generation. However, despite recent developments, natural gas HD SI engines still remain a major source of gaseous emissions mainly of carbon monoxide (CO) and nitrogen oxides (NOx). Continuously stringent environmental regulations, which have been issued for electric power generation SI engines, have mandated the implementation of various in-cylinder measures besides after-treatment technologies for downplaying NOx emissions. One of the most efficient engine-related NOx curtailing methods is the partial recirculation of exhaust gases (EGR). However, according to the literature, EGR positive effects on NOx emissions are accompanied by negative effects on engine's brake specific fuel consumption (i.e. brake efficiency). An alternative to EGR method for curtailing SI engine NOx emissions is either the nitrogen-enrichment or carbon dioxide-enrichment of the inducted mixture. The aforementioned methodologies could be achieved by using separation membranes, which can recover the specific diluent from the exhaust gases and they have been successfully used in large power plants. Hence, in the present study it is proposed a comparative theoretical examination for the effect of the two EGR-alternative strategies: N2- and CO2-enrichment of the inducted mixture, on performance and emissions characteristics of a SI natural gas engine. For this reason, a comprehensive thermodynamic simulation model, which has been successfully used in the past to predict the operational and environmental performance of a natural gas HD SI engine, has been modified to incorporate the enrichment of intake mixture with either nitrogen or carbon dioxide. The evaluation of the effects of both strategies on performance and emissions characteristics of the engine will be made on a comparative basis under constant boost pressure and reduced in-cylinder oxygen availability. Thus, comparing the theoretical results observed under N2- and CO2-enrichment modes, as against with the respective ones observed under normal composition of the inducted mixture, a considerable effect on engine performance and emission characteristics are revealed. The conclusions of the specific investigation will be extremely valuable for the application of the examined technologies on an existing heavy-duty SI natural gas engine.
KW - Carbon dioxide
KW - Emissions
KW - Enrichment
KW - Natural gas
KW - Nitrogen
KW - Si engine
UR - http://www.scopus.com/inward/record.url?scp=84915747398&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:84915747398
T3 - Proceedings of the 27th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems, ECOS 2014
BT - Proceedings of the 27th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems, ECOS 2014
A2 - Zevenhoven, Ron
PB - Aabo Akademi University
T2 - 27th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems, ECOS 2014
Y2 - 15 June 2014 through 19 June 2014
ER -