柴油机SCR系统控制研究现状与技术挑战

Current Research and Future Technical Challenges of Diesel Engine SCR Control

介绍了柴油机典型的后处理系统结构和催化剂对SCR系统性能的影响;通过SCR催化还原机理、催化器内部反应过程的分析阐述了SCR系统的建模及标定方法;对采用开环控制、闭环控制、自适应控制、模型预测控制等方法的SCR系统控制策略和应用现状进行详细总结和分析。结合SCR系统运行特点,从SCR的低温性能、氨覆盖率的计算、NOx传感器的交叉感应现象、催化剂的老化、SCR与其它后处理部件及发动机的协同优化控制五个方面提出了未来柴油机SCR系统的技术发展方向。

The typical structure of aftertreatment system of diesel engine and the catalyst of SCR on the performance of SCR system are introduced.By analyzing the catalytic reduction mechanism of SCR,the modeling and calibration methods of the internal dynamics and chemical reaction process of the catalyst is then described.The SCR system control strategy and application status using open-loop control,closed-loop control,adaptive control,model predictive control and other methods are summarized and analyzed in detail.Finally,according to the operating characteristics,the future of SCR control research is discussed from the low temperature performance of SCR,the calculation of ammonia coverage,the cross-sensitivity of NOx sensor,the aging of catalyst,multi-system collaborative optimization control of SCR with engine and other aftertreatment components.