【作者】

Alexander Knafl,Stiesch Gunnar,Markus Friebe

【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。With the development of common rail fuel injection systems, variable geometry turbochargers, variable valve timing and combustion feedback systems, medium speed diesel engines offer substantial control flexibility with the potential of significantly improving performance, fuel economy, emissions and thus customer value. Engine performance-traditionally governed solely by the mechanical system-is increasingly dependent on the interaction of the flexible subsystems and their proper control. This paper seeks to demonstrate the benefits offered by variable air-path control in combination with a fully flexible common rail fuel injection system. System interactions and optimization are analyzed and performed with design of experiment(DoE), response surface modeling and constraint merit functions. Above-mentioned methodis applied to design custom tailored medium speedengine maps for constant speed generator, controllable pitch as well as fixed pitch propeller operation. Engine performance data are obtained via enginedynamometer experiments augmented with analytical simulations. With constant speed generator operation, it is shown that through optimizing the engine calibra-tion in accordance to the typical load profile thereof,specific fuel oil consumption is reduced by several grams without related engine-hardware changes. The potential of applying engine-control maps specifically tailored to the mode of operation e.g. fast steam-ing, slow steaming or maneuvering operation is assessed and the potential quantified. This so-calledmulti-mapping approach allows for improved performance and reduced emissions over the entire operating regime of the engine. In addition to steady state operation, benefits in transient response are demonstrated by means of optimized air-and fuel-path con-trol. Particularly load rejection and smoke emissions are substantialy improved over conventional, mechanically rigid systems. Lastly the effect of Tier Ill exhaust gas treatment solutions-selective catalytic reduction(SCR) to reduce oxides of nitrogen (NOx) and /or scrubbers to capture sulfur oxide (SOx)-on engine performance is investigated. It is shown that Tier ll exhaust gas treatment systems may adversely affect engine performance through increased exhaust gas backpressure. By means of optimally adjusting the engine control strategy to the new boundary conditions, it is demonstrated that engine performance and efficiency are restored to Tier ll levels.

【会议名称】

第27届CIMAC会议

【会议地点】

上海

【下载次数】

1

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