【摘要】 CAI燃烧具有高效节能和低NOx的优点,但CAI燃烧也存在燃烧始点和放热率难以控制的难点。通过添加火花点火的方法,在缸内制造热点,产生有助于CAI燃烧的着火条件,从而达到了控制CAI燃烧始点的目的。试验表明,在添加火花点火后,着火滞燃期明显缩短,CAI着火及燃烧更稳定,并对经济性有一定改善。火化辅助点火也有利于CAI运行范围向更低负荷方向拓展。因此,火花点火可以作为控制CAI燃烧的一种辅助手段。更多还原

【Abstract】 Controlled Auto-ignition (CAI) combustion was facilitated in a Ricardo single cylinder engine using special camshafts with modified valve lift and cam profile in order to trap enough internal EGR. In order to investigate the influence of spark ignition on CAI combustion using the internal EGR and valve timings strategies, the operation regions and other detailed combustion characteristics of the CAI engine operation were analyzed and compared between the pure CAI mode and the CAI mode with the aid of spark ignition. The results showed that spark ignition would play a key role in controlling CAI combustion ignition timing. Meanwhile, short ignition delay, stable combustion, low fuel consumption and cycle-to-cycle variations can be achieved with the aid of spark ignition. Spark ignition can be used as an assisted control method for CAI operation.更多还原