【作者】

Morteza Fathi,Rahim Khoshbakhti Saray

【摘要】

论文已在上海2013年CIMAC大会上发表，论文版权归CIMAC所有。 Homogeneous charge compression ignition (HCCI) combustion is a spontaneous multi-point combustion of a highly diluted premixed fuel-air mixture. This combustion mode is an ultra-low in-cylinder NOx formation strategy which has also benefits in terms of efficiency. The high efficiency is due to the ability of operating with high compression ratios, lack of throttling losses at part load, lean combustion, and close to constant volume ideal Otto cycle heat release. There are some deficiencies intrinsic to HCCI combustion which should be overcome: The lack of any direct control method for combustion timing; producing high levels of HC and CO emissions; obtaining an appropriate fueling rate for achieving high engine loads under mechanical limitations of engine. In order to make the HCCI engine a feasible alternative to the conventional engines, several items must be elucidated. Control of the combustion timing is one of the most important of these items to be resolved. Combustion timing should be controlled in order that heat is released at the best time in the engine cycle. HCCI combustion is a form of natural auto-ignition. Thus it is highly sensitive to the mixtures thermal, physical and chemical proper-ties. The intake temperature, pressure, air/fuel ratio, auto-ignitability, and EGR rate are the most influential parameters. This study investigates the effect of intake charge temperature on dual fuel HCCI combustion of n-heptane and natural gas to control the combustion. The experimental investigations are based on a modified first law apparent heat release model developed by the authors. This heat release model is a detailed one which produces more reliable results. Seven cases in two data sets were experimented on a Waukesha CFR single cylinder research engine. The results indicate that intake charge temperature has profound effects on in-cylinder charge pressure and temperature. It alters heat release rate magnitude and phasing. This parameter also affects indicated power and fuel consumption. Measured emissions have also shown changes due to variations of this initial condition..

【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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