柴油机双SCR系统结构参数优化试验研究

Experimental Research on Structural Parameters Optimization of Dual SCR System of Diesel Engine

为了研究国六重型柴油机选择性催化还原(SCR)系统性能影响因素,文章运用实验方式对催化器的长度、孔的数目以及壁厚进行了试验验证。结果表明:在相同的横截面积下,催化器的长度越短,SCR系统性能较好;孔数目的多少取决于排气背压增加的限值,它的变化使NOx转化效率及压力损失相互矛盾,相互制约。载体壁厚越薄,发动机性能越优秀,但壁厚的减小必需使催化器载体满足强度、热应力及制造工艺的要求。

In order to study the influencing factors of the performance of the selective catalytic reduction(SCR) system of the National Six Heavy Diesel Engine, the length of the catalyst, the number of holes, and the wall thickness were experimentally verified by experiments. The results show that: under the same cross-sectional area, the shorter the length of the catalyst, the better the performance of the SCR system;the number of holes depends on the limit of the increase in exhaust back pressure, and its changes make the NOxconversion efficiency and pressure loss mutually Contradictions and mutual constraints. The thinner the carrier wall thickness, the better the engine performance, but the reduction of the wall thickness must make the catalyst carrier meet the requirements of strength, thermal stress and manufacturing process.