穿孔管对集成式SCR催化转化消声器性能影响的试验研究

Experimental Study on the Influence of Perforated Pipe on Performance of SCR Convertor Muffler Assembly

穿孔管结构广泛应用于消声器的设计中,SCR催化剂载体前端穿孔管对集成式SCR催化转化消声器的压力损失和SCR的NOx转化效率有较大影响。本研究设计了两种形式的SCR催化剂载体前穿孔管,通过试验研究了其对集成式SCR催化转化消声器性能的影响。采用水银U型管和傅立叶变换红外光谱仪(FTIR)分别测量了压力损失和NOx等浓度。试验结果表明:穿孔率较大的穿孔管和孔部分朝向SCR载体的穿孔管造成的压力损失比较小;穿孔管的不同结构和不同位置布置对SCR的NOx转化效率有明显影响;在某些工况下,差异在10%以上。

Perforated pipe has been widely applied in the design of mufflers. The perforated pipe upstream of SCR catalyst has significant effect on the pressure loss and NOx conversion efficiency of SCR Convertor Muffler Assembly. In the study, two perforated pipes are designed. The effects of the structure and mounting position of the perforated pipes on the performance of SCR Convertor and Muffler Assembly are studied. The pressure loss and NOx concentration are measured separately using mercury U tube and Fourier Transform Infrared （ FTIR） Spectroscopy. The experimental results show that, the pressure loss caused by the perforated pipe with large porosity with holes facing the SCR substrate is low. The structure and mounting position of the perforated pipes have significant effect on the NOx conversion efficiency of SCR Convertor Muffler Assembly. The difference of NOx conversion efficiency is above 10 percent under some operating conditions.