本文首先针对船用低压SCR系统设计新型旋流板式混合器，与某船用柴油SCR系统折流板式混合器对比，对它们管路内部流体的流动特性和混合效果进行数值模拟分析。结果显示，新型旋流板混合器管路内部流体混合效果有所提升，但管路的压力损失增大。对新型混合器进行结构参数优化，包括空间布置方式、双层混合器设置、混合叶片倾角及混合器管路尺寸等，仿真结果表明：混合器布置在尿素喷射点后比布置在喷射点混合效果略有提升，但压损增大；双层旋流板能引起更大的旋流，管内流体混合性能明显提升，但压力损失也随之增大，改变旋流片的位置和角度能够改善混合性能及压力损失，但压力损失与混合性能协同改善不良；增大混合器管路管径和长度能有效协同改善混合效果和压力损失，混合器管为530 mm双层旋流板式混合器叶片倾角50°时效果最佳。
In this paper, a new type of swirl plate mixer is designed for the marine low-pressure SCR system. Compared with a baffle mixer of a marine diesel SCR system, the flow characteristics and mixing effect of the fluid in their pipelines are numerically simulated and analyzed. The results show that the fluid mixing effect in the pipeline of the new type swirl plate mixer has been improved, but the pressure loss of the pipeline has increased. Then optimize the structural parameters of the new mixer, including the spatial arrangement, the setting of the double-layer mixer, the inclination angle of the mixing blades, and the size of the mixer pipe. The simulation results show that the mixer is arranged after the urea injection point to mix than when it is arranged at the injection point. The effect is slightly improved, but the pressure loss is increased; the double-layer swirl plate can cause greater swirl, and the mixing performance of the fluid in the tube is obviously improved, but the pressure loss also increases. Changing the position and angle of the swirl plate can improve Mixing performance and pressure loss, but the pressure loss and mixing performance are not improved synergistically; increasing the pipe diameter and length of the mixer pipe can effectively improve the mixing effect and pressure loss, the mixer pipe with 530 mm double-layer swirl plate mixer and 50 degree blade inclination angle type works best.
2022,44(21): 106-112 收稿日期：2021-03-23
DOI：10.3404/j.issn.1672-7649.2022.21.022
分类号：U664.1
作者简介：李长熊(1982-),男,讲师,研究方向为船用动力装置节能减排及防污染技术
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