Modeling of Spark Ignition and Aftertreatment Systems for SI Combustion Engines

SI 内燃机火花点火和后处理系统建模

• 批准号: 537431-2018
• 负责人: Zheng, Ming
• 金额: $ 6.8万
• 依托单位: University of Windsor
• 依托单位国家: 加拿大
• 项目类别: Collaborative Research and Development Grants
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=720318
• 关键词: Modeling; Spark; Ignition; Aftertreatment; Systems

Developing engines with better fuel economy has become the main focus for the automotive industry to counter global warming and meet government regulations. Lean/diluted spark ignition engines have been proven to improve fuel economy and reduce pollutant emissions, but the unfavorable air/fuel stoichiometry results in more prominent cycle-to-cycle variation which limits the extension of lean-burn and EGR-diluted high efficiency operations. A critical part to optimize the lean/diluted gasoline engines is to improve the spark ignition and flame kernel development processes, especially for the engines that utilize strong cylinder flow to accelerate the combustion for better efficiency. Spark initiated flame propagation involves complex phenomena such as plasma channel stretching as well as multiple restrikes in a strong cross flow field. Energy transfer from the spark plasma to the combustible gas is a key factor to enable stable flame kernel formation thereby reducing the cycle-to-cycle variation of high efficiency diluted gasoline engines. Currently, there is still a lack of accuracy in combustion modeling to predict the spark plasma channel because of the complex phenomenon of spark stretching and restrike under strong turbulent flow. As for the lean/diluted operation of gasoline engines, the nitrogen oxides aftertreatment is challenging due to the lower exhaust temperature and the oxygen abundance in the exhaust stream. Thus, the low temperature light-off characteristics and oxygen storage capability of the three-way-catalyst (TWC) are of critical importance in TWC modeling for lean/diluted SI engines for industrial needs. The proposed research will focus on: 1) building an empirical spark ignition model which can better predict the spark stretching and the restrike phenomenon; 2) quantitatively determining the energy distribution of the spark channel and the spark-to-gas energy transfer; 3) investigating the low temperature light-off of TWC for lean/diluted SI engines. The proposed research will utilize the established expertise and advantages in measurement and control resources at the Clean Combustion Engine Laboratory (CCEL), directed by Dr. Zheng with supports from FCA.

开发燃油经济性更好的发动机已成为汽车业应对全球变暖和满足政府法规的主要重点。稀薄/稀薄火花点火发动机已被证明可以改善燃油经济性和减少污染物排放，但不利的空气/燃料化学计量比导致更显著的循环变化，限制了稀燃和EGR稀释型高效运行的推广。优化稀薄汽油机的关键是改进火花点火和火焰发展过程，特别是对于那些利用强气缸流动加速燃烧以获得更高效率的发动机。火花引发的火焰传播涉及等离子体通道拉伸以及强交叉流场中的多次重击等复杂现象。火花等离子体到可燃气体的能量传递是使高效稀释型汽油机能够稳定形成火核，从而减小循环间波动的关键因素。目前，由于强湍流下火花拉伸和重击的复杂现象，燃烧模型对火花等离子体通道的预测仍然缺乏准确性。对于汽油机的稀薄运行，由于排气温度较低，排气气流中的氧气含量较高，氮氧化物后处理具有挑战性。因此，三效催化剂(TWC)的低温起燃特性和储氧能力对于工业需要的稀薄/稀薄汽油机的TWC建模至关重要。本文的研究重点是：1)建立能够更好地预测火花拉伸和重击现象的火花点火经验模型；2)定量确定火花通道的能量分布和火花到气体的能量传递；3)研究稀薄/稀薄汽油机TWC的低温起燃。拟议的研究将利用清洁内燃机实验室(CCEL)在测量和控制资源方面的成熟专业知识和优势，该实验室由郑博士指导，并得到FCA的支持。