柴油机TR燃烧系统的数值模拟  

Numerical Simulation of Diesel TR Combustion System

作　　者：何旭[1] 刘卫国[1] 高希彦[1] 廖春明[1] 杨德胜[1] 

机构地区：[1]大连理工大学内燃机研究所,大连116023

出　　处：《内燃机工程》2006年第4期4-8,共5页Chinese Internal Combustion Engine Engineering

基　　金：国家重点基础研究发展规划资助项目(2001CB209202)

摘　　要：为了改善柴油机的油气混合过程,开发了TR燃烧系统。该系统在原机ω型燃烧室的基础上增加壁面导向圆弧,配合锥面4×Φ0．36十垂直中心喷孔1×Φ0．20喷油器。以对TR燃烧系统的可视化研究为依据,应用STAR-CD软件对其喷雾混合过程进行三维数值模拟。结果表明导向圆弧形成的二次射流增加了空气卷吸和油气混合空间。中孔油束与中心凸台碰撞形成的盘状喷注同样也增加了中心处的油气混合；TR燃烧系统具有较少的燃油附壁质量并存在多处大小不同方向各异的漩涡,加速了油气混合。台架试验表明：TR燃烧系统在中低负荷时排放烟度低于0．1 BSU,全负荷时低于0．4 BSU。推迟供油提前角至11℃A时,NO_x排放大幅度降低,浓度为203×10^(-6)～776×10^(-6),烟度在0．3～0．6BSU之间。试验表明TR燃烧系统在降低柴油机排放方面具有较大的潜力和应用前景。A new combustion system, named TR（three-rapidity） was developed to improve the air-fuel mixture formation in diesel engines. It was modified from co combustion chamber with an oriented arc at the chamber wall, specially and perfectly fit in a nozzle with 4 ×Ф 0.36 orifices in the conic section plus 1×Ф 1.20 orifice in the center. The mixture formation process was simulated by STAR-CD. The result shows that the secondary jet formed by the oriented arc increases air entrainment and fuel-air mixture space. The fuel injected from central orifice impinges on the plane convex at the bottom, forming discal spray, which improves the mixture in the center. TR deposited less fuel on the chamber wall and an amount of eddy with different scales and directions generated in TR chamber significantly contributed to the transient mixture formation. In the test study TR demonstrated an excellent performance with 0. 1 BUS smoke emission in the part load condition and 0.4 BUS in the full load condition and retarding fuel delivery timing to 11℃A BTDC, NOx decreases greatly. The concentration of NOx is 203 × 10^-6～ 776 × 10^-6 and the smoke is 0.3-0.6 BSU in the whole load condition. It is proved that TR combustion system has great potential to improve emissions and promising the application to diesel engines.

关 键 词：内燃机 柴油机 TR燃烧系统 数值模拟 喷雾 

分 类 号：TK421[动力工程及工程热物理—动力机械及工程]