田少雄, 孔令逊, 许敏, 杨杰, 庄瀚洋.缸内涡流比对冷起动燃烧火焰的影响探究[J].内燃机工程,2017,38(3):1-8.
缸内涡流比对冷起动燃烧火焰的影响探究
Study of the Intake Air Swirl Ratio Effect on Flame Propagation of a SIDI Engine under Cold Start Conditions
DOI：
关键词:内燃机  冷起动  涡流比  燃烧火焰  循环波动
Key Words:IC engine  cold start  swirl ratio  combustion flame  cycle-to-cycle variability
基金项目:国家自然科学基金项目（51176115/E060404）；国家自然科学基金项目（51376119/E060502）
作者单位
田少雄, 孔令逊, 许敏, 杨杰, 庄瀚洋 1.上海交通大学 汽车电子控制技术国家工程实验室, 上海 200240
2.上海交通大学 密西根学院, 上海 200240 
摘要点击次数: 5130
全文下载次数: 3016
摘要:针对汽油发动机冷起动存在的燃烧不稳定、燃烧效率低的问题, 基于单缸可视化发动机在冷起动工况下调节进气涡流, 通过分析缸内燃烧火焰特性来探究增强进气涡流对发动机循环波动及输出功率的影响。试验所用发动机为单缸四气门（两进两出）缸内直喷汽油机, 其中一个进气道加装有涡流控制阀, 通过将一个进气道关闭或者开启来改变缸内涡流的强度。利用高速相机从活塞上的光学通道得到发动机缸内的火焰传播图像, 并计算火焰传播面积, 提取火焰边界, 获取火焰中心速度及火焰扩散速度等信息, 同时也利用燃烧分析仪对缸内压力、燃烧放热率等特性进行同步测量和记录, 通过多角度的对比和分析揭示缸内燃烧状况与发动机宏观性能的相关联系, 有效地发掘了在不同涡流强度下缸内火焰的传播特征。研究结果从缸内燃烧火焰的角度解释了提高涡流比能够很好地提高冷起动的燃烧稳定性, 促进发动机缸内燃烧。研究表明, 早期火核分布越集中, 波动越小, 后期循环波动就越小。试验结果还表明, 由缸压计算的瞬时放热率与火焰面积存在很好的线性关系。
Abstract:In view of the problems of combustion instability and low combustion efficiency in the presence of engine cold start, the flame characteristics in an engine cylinder were analyzed to explore the effect of enhanced intake swirl on cycle-to-cycle variability and power output, on the basis of adjusting the intake swirl of a single cylinder visualization engine under cold start conditions. The test engine was of a 4 valve design, including two intake and two exhaust valves, wherein an intake port was provided with a swirl control valve to control swirl ratio. A high speed camera was used to obtain the combustion flame images through an optical window on the piston. With the help of post-processing tools, the flame propagation area flame boundary, flame propagation speed and other information were calculated and analyzed. At the same time, the cylinder pressure, combustion heat release rate and other characteristics were measured and recorded simultaneously by using a combustion analyzer. Though the comparison and analysis from different point of view, the relationship between the combustion flame state and the macro performance of the engine was revealed, and the different flame propagation properties under different swirl intensity were effectively explored. Results explain from the angle of the combustion flame that the increase of swirl ration can improve the combustion stability of cold start and promote the combustion process of the engine. Tests also show that the more concentrated, the late flamer kernel distribution with smaller fluctuation, the less the cycle-to-cycle variability, and the instantaneous heat release rate calculated from the cylinder pressure has a good linear relationship with the flame propagation area.
查看全文  HTML   查看/发表评论