多工况下排气特性对CRT后处理装置的影响规律

The Influence of exhaust characteristics on CRT aftertreatment under different operations

基于GT-Power一维仿真软件,建立连续再生式捕集器(continuously regenerating trap,CRT)装置的仿真模型,通过台架试验验证模型的准确性。基于所建立的仿真模型,在稳态工况下研究排气组分、排气流量、排气温度对CRT装置不同测点温度和压差的影响;在瞬态工况下研究温度突变、排气流量变化、以及不同碳载量对后处理装置温度传递的影响。结果表明:稳态工况下,随着各排气组分浓度增加,CRT测点的压差基本没有影响,但中点和出口温度升高;排气流量增大导致压差线性增加;排气温度升高导致柴油氧化催化器入口和出口温差增大。在瞬态工况下,温度大于700 K时,催化型颗粒物捕集器(catalytic diesel particulate filter,CDPF)前后温差变为负值,CRT装置各轴向测点温度变化时间出现延迟;温度突变对温度变化和稳定时刻延迟时间没有影响;排气流量增加减少了温度变化时刻延迟时间、温度稳定时刻延迟时间和持续时间;CDPF碳载量增加增加了出口温度变化时刻延迟时间和持续时间。

Based on GT-Power one-dimensional simulation software,a continuous regenerative trap CRT device model is established which is verified by bench test.The effect of exhaust component,exhaust flow rate and exhaust temperature on the temperature and the pressure drop for different measuring point of the CRT device are investigated under steady-state conditions.Meanwhile,the effect of temperature change,exhaust flow rate and carbon loading on temperature transfer are studied under transient conditions.The results show that with the increase of exhaust component concentration,the midpoint and outlet temperature increases at the same time,but the pressure drop is almost unchanged.The pressure drop increases linearly with the increase of exhaust flow rate,and the increase of exhaust temperature increases the absolute temperature difference inlet and outlet of DOC.When the temperature is over 700 K,the temperature difference before and after CDPF becomes abnormal,and the temperature change time of different axial measuring points of CRT device will delay.Temperature jump has no effect on time delay.The time delay decreases with the increase of exhaust flow and the higher carbon loading increases the time delay.