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In order to solve the problem of slow flame propagation in a spark-ignition engine fueled with compressed natural gas (CNG), the influence of in-cylinder flows on combustion process was investigated in CA6SE3-21E4N CNG-engine by means of numerical simulation and experiment. The status of in-cylinder flows from intake to expansion stroke was described by computational fluid dynamic tool, which revealed that the in-cylinder flows were one of the main reasons of slow burning rate. Therefore, a special-shaped combustion chamber called Cross was used to improve the in-cylinder flows. The results showed that peak turbulent kinetic energy of Cross was 43.9% higher than that of original combustion chamber called Cylinder during the late compression period at 1450 rpm 100% load. The combustion parameters, brake specific fuel consumption (BSFC) and regulated emissions were obtained by means of experiment. At 1450rpm 25%, 50%, 75% and 100% load conditions, the ignition delay of Cross was longer than that of Cylinder, moreover, the Cross produced averagely 5.75°CA shorter combustion duration. The BSFC of Cross was on an average of 4.3% reduction at 1450 rpm as well as the HC and CO emissions were reduced whereas the NOx emissions were significantly increased. 相似文献
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介绍油改电技术的发展,分析、比较几种低架油改电插拔取电技术的优缺点,说明电动自动插拔式轮胎吊低架油改电系统通过开发和应用全新的结构,从根本上解决了传统低架油改电系统存在的许多问题,具有很好的推广应用效果。 相似文献
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基于D-S证据理论和BP算法的直流电机故障诊断研究 总被引:3,自引:0,他引:3
提出一种基于D-S证据理论和BP算法的故障诊断方法,通过分析直流电机的故障机理,得到电机在不同故障情况下表现的信号特征,给出了基于BP神经网络和D-S证据理论的多传感器数据融合技术的直流电机故障诊断方法,利用多源信息间的冗余性和互补性,有效提取故障特征信息,提高了诊断的可靠性和灵敏度. 相似文献
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