刘辰朋，桂勇，刘腾，屠丹红
中船动力研究院有限公司, 上海200129
摘要：应用三维计算流体动力学软件对某船用低速柴油机的缸内燃烧进行研究，分析喷油器结构参数对缸内燃烧的影响。结果表明：喷油器喷嘴深入燃烧室内的长度较短时，缸内燃烧较差，导致缸盖过热；随着喷嘴伸入燃烧室内的长度增加，缸内燃烧情况得到改善，燃烧持续期逐渐缩短，NOx排放逐渐增加。随喷孔逆缸内涡流的径向角度增加，缸内燃烧情况逐步改善，燃烧室壁面传热减少；随喷孔倾斜角度增加，活塞表面受热增加。对新开发机型燃烧系统的研究发现：喷嘴的喷孔倾斜角度保持不变，将喷嘴长度增加10 mm，径向角度沿喷嘴轴线逆时针旋转10°或15°，缸内燃烧性能得到明显提升。
关键词：喷嘴长度；喷孔方向；径向角度；倾斜角度；燃烧持续期；NOx排放
Abstract:Three dimensional CFD software is used to study the incylinder combustion of one low speed marine diesel engine. The influence of different injector structure parameters for cylinder combustion is analyzed. The results show that when the length of the nozzle tip penetrating into combustion chamber is short, the combustion is poor, and the cylinder head is usually overheated. With the increase of nozzle tip length, the combustion duration is gradually shortened and the NOx emission is gradually increased. With the increase of the radial angle of the injector hole in the opposite direction against the swirl, heat transfer on the wall of the combustion chamber decreases. With the increase of the inclination angle of the injector hole, the heat transfer on the piston surface increases. For the nozzle designed for a new developed combustion system, if the length of the nozzle is increased by 10 mm, the inclination angle of the nozzle hole remains unchanged, and the radial angle rotates counterclockwise along the axis of the nozzle by 10° or 15°, the incylinder combustion performance will be improved obviously.
Keywords:nozzle tip length; injector hole direction; radial angle; inclination angle; combustion duration; NOx emission
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