一款1.5L缸内直喷汽油机的燃烧系统设计

基于进气道三维流场测试装置、定容弹喷雾试验台和光学单缸机测试系统组成的缸内直喷汽油机燃烧系统可视化开发平台,开发设计了满足设计要求的高性能进气道,并匹配了缸盖燃烧室和活塞,有助于缸内混合气的形成,提高燃烧速率;综合考虑排放与机油稀释量的基础上,优化设计了喷雾靶点。对所设计的燃烧系统进行了光学单缸机试验和热力学多缸机试验验证。结果表明,进气道和燃烧室组织引导的气流在缸内形成高滚流,对喷雾油束有强烈的弯卷作用,极大促进了均质混合气的形成,并减小喷雾碰壁的风险;喷雾靶点的合理设计有效避免喷雾油束与壁面的碰撞,减少了机油稀释率和起燃工况HC排放;所设计的燃烧系统搭载1.5TGDI发动机实现了80kW/L、最大扭矩250N·m、排放较低的性能指标。

Combustion System Design of a 1.5L In-cylinder Direct Injection Gasoline Engine

Based on a visualization platform designed for the development of combustion system of direct injection gasoline engines which including 3 D-PIV technique,constant volume chamber and a transparent single cylinder engine,designed a high performance intake port,combustion chamber and piston,which can improve combustion speed by improving the formation of mixture.The spray target was optimized,considering the emission and oil dilution.Transparent single cylinder engine test and thermodynamic multi-cylinder engine test have been carried out to verify the combustion system design.The present study demonstrated that the high tumble induced by the intake port and combustion chamber can curve the spray,improve the formation of the homogeneous mixture and avoid the impingement of spray.Reasonable design of spray target can reduce oil dilution and emission of HC.The 1.5 L gasoline direct injection engine achieved top level specific power and thermal efficiency in its class.