基于储氨停喷响应特性的SCR系统氨泄漏识别  

NH_(3) Slip Detection Based on NH_(3) Coverage Changing Behavior of SCR System Under Dosing Stopped Status

作　　者：王天田 黄自增 曾敏 任继文 王均刚 Wang Tiantian;Huang Zizeng;Zeng Min;Ren Jiwen;Wang Jungang(Key Laboratory of Conveyance and Equipment,Ministry of Education,East China Jiaotong University,Nanchang 330013,China;Power Transmission Development Department,Jiangling Automobile Company Limited,Nanchang 330100,China;Texas Emission Solution(Wuxi)Limited,Wuxi 214037,China)

机构地区：[1]华东交通大学载运工具与装备教育部重点实验室,江西南昌330013 [2]江铃汽车股份有限公司动力总成研究院,江西南昌330100 [3]得州排放控制技术(无锡)有限公司,江苏无锡214037

出　　处：《内燃机学报》2024年第4期376-383,共8页Transactions of Csice

基　　金：中国博士后科学基金资助项目(2022M711353);江西省自然科学基金资助项目(20232BABL314037);南昌市新能源汽车动力电池安全重点实验室资助项目(2021-NCZDSY-004)。

摘　　要：有效识别出氨(NH_(3))泄漏是柴油机NO_(x)转化(De NO_(x))系统实现精确闭环控制与自适应修正的基础.针对NO_(x)传感器对排气中的NH_(3)和NO_(x)存在交叉敏感这一情况,提出了一种基于停喷状态下选择性催化还原(SCR)系统储氨响应特性的NH_(3)泄漏识别方法.在工况条件合适时,持续将NO_(x)转化效率的传感器测量值和预测值的比值与标定限值进行对比,超过限值时则触发停喷诊断动作,并在停喷过程中通过对比催化器的储氨消耗超过限值的时间与转化效率低于限值的时间先后,实现对NH_(3)泄漏状态的准确识别.结果表明:该方法能够有效识别出SCR系统的NH_(3)泄漏,并能够在NO_(x)排放超过车载故障诊断(OBD)限值时准确识别出NO_(x)排放超标.Identification of ammonia(NH_(3))slip is important for accurate closed-loop control and self-adaptation of DeNO_(x) systems.A NH_(3) slip detection function based on NH_(3) coverage changing behavior of selective catalytic reduction(SCR)system under dosing stopped status was proposed based on NO_(x) sensors’cross-sensitivity between NH_(3) and NO_(x).Under suitable operating conditions,once the ratio of the DeNO_(x) efficiency calculated by the sensor to that calculated by model was over the calibrated limit,the NH_(3) slip detection function would be triggered.The NH_(3) slip could also be detected if the ammonia consumption became over a limit at the time earlier than the DeNO_(x) efficiency below a limit.Validation tests results show that this NH_(3) slip detection function can effectively detect the NH_(3) slip of the SCR system,and can immediately send out a NO_(x) slip result when NO_(x) emission exceeds the onboard diagnostics(OBD)limit.

关 键 词：柴油机 选择性催化还原系统 氨泄漏识别 

分 类 号：TK421.5[动力工程及工程热物理—动力机械及工程]