颗粒物传感器结合DPF的数值模拟研究

Research on numerical simulation of particulate matter sensor combined with DPF

漏电流式颗粒物传感器,在车载诊断(OBD)系统中被用于颗粒物捕集器(DPF)的失效监测,将颗粒物传感器和DPF结合起来进行研究,更具实际意义。利用计算流体力学(CFD)软件Fluent分析了DPF和传感器内部的流场分布,以及传感器内部颗粒物的运动和分布情况,并对DPF入口排气流速对传感器内流场分布的影响进行了探究。模拟结果显示:传感器内部流动性较好,颗粒物分布较为均匀,但迷宫式设计内仍然会有颗粒物沉积,需要定期进行清理;DPF入口流速对传感器内流场分布情况影响较小,主要对传感器内排气流速的大小影响较大。

The leakage current particulate matter（PM） sensor is used to detect malfunctions of diesel particulate filter（DPF） in on-board diagnostics（OBD） system.PM sensor and DPF are studied together by computational fluid dynamics（CFD） software Fluent,which has more practical significance.Flow field distribution inside DPF and PM sensor is analyzed,and movement and distribution condition inside PM sensor are studied.Research on the influence of exhaust flow rate of DPF inlet on flowfield distribution inside PM sensor is performed.The results of simulation reveal good flowability inside the sensor,distribution of PM is uniform but there is still PM deposited in the maze structure design,which need to be cleared up regularly.Velocity of DPF inlet has little influence on flowfield distribution inside the sensor while it has great influence on exhaust velocity magnitude inside the sensor.