【作者】

Federico Millo,Marco Gianoglio Bernardi

【摘要】

论文已在中国上海举行的第27届CIMAC大会上发表。论文的版权归CIMAC所有。 In this work different EGR systems, combined with extreme Miller cycles, were analyzedby means of a one dimensional CFD simulation code for a Wartsila 6 cylinder,4 strokes, medium speed marine diesel engine, to evaluate their potential in order to reach the IMO Tier 3 NOx emissions target. Extreme Miller cycles, with Early Intake Valve Closures(up to100 crank angle degrees before BDC), combined with two stage turbocharging were firstly evaluated and thebest solution in order to reduce NO, emissions without excessive penalties in terms of fuel consumption wasfound to be the adoption of a 90 CA deg EIVC, coupled with a symmetric overlap of 30 CA deg, which allowed a 35% NOxabatement with BSFC values comparable with the reference solution. Afterwards, four different external EGR architectures were evaluated for the assessment of their NO, emissions abatement potentialities. Although all the tested external EGR systems were capable to reduce NO, emissions down to approximately 20% of the reference engine when using the highest EGR rate (20%), the use of an EGR turbocharger(i.e. of an additional small turbocharger used to pump the EGR flow between the exhaust and the intake manifold), allowed maintaining components thermal loads under control, with still acceptable fuel consumption penalties(about 4%). In conclusion, the achievement of IMO Tier 3 NOx emissions levels was proved to be feasible, although further experimental investigation will be needed to confirm the numerical simulation results.

【会议名称】

第27届CIMAC会议

【会议地点】

上海

【下载次数】

2

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