甲醇/柴油双燃料发动机超低排放集成控制试验研究

在一台非道路共轨柴油机上增设一套甲醇喷射系统，实现了甲醇/柴油双燃料燃烧模式，在非道路国Ⅳ排放法规稳态八工况（NRSC）测试条件下，利用尾气分析仪和FTIR对比研究了纯柴油模式和双燃料模式的排放特性，并系统分析了DOC+DPF+SCR后处理系统对双燃料发动机尾气排放的转化效率。试验结果表明:甲醇/柴油双燃料燃烧模式的NO_x和Soot排放明显低于纯柴油模式，而CO、HC、甲醇和甲醛排放却高于纯柴油模式；经过后处理系统后，对CO和HC排放的转化效率高于99%，同时NO_x和Soot的平均降幅分别为84%和90%，而双燃料模式的甲醇和甲醛排放能够被高效氧化，平均净化效率在90%以上。NRSC测试结果表明双燃料发动机加装DOC+DPF+SCR后CO、HC、NO_x和PM比排放指标均低于非道路国Ⅳ和欧Ⅴ排放法规限值。

Experimental Study on Ultra-low Emissions Integrated Control of Diesel/Methanol Dual-fuel Engine

A methanol injection system is installed on a non-road common-rail diesel engine to realize the methanol/diesel dual-fuel combustion mode. Based on the non-road China-Ⅳ regulation Non-Road Steady Cycle (NRSC) test conditions, the emission characteristics of pure diesel mode and dual-fuel mode were comparative studied by using exhaust gas analyzer and FTIR. And the conversion efficiency of DOC+DPF+SCR post-treatment system on the dual-fuel engine exhaust emissions was systematically analyzed. The results show that the NO_x and Soot emissions of methanol/diesel dual-fuel combustion mode are significantly lower than those of pure diesel mode, while the CO, HC, methanol and formaldehyde emissions are higher than those of pure diesel mode. After the post-treatment system, the conversion efficiency of CO and HC emissions is higher than 99%. Meanwhile, the conversion efficiency of NO_x and Soot emissions is 84% and 90%, respectively. The methanol and formaldehyde emissions of dual-fuel mode can be oxidized efficiently, and the average efficiency is more than 90%. NRSC test results show that the CO, HC, NO_x and PM specific emission indexes of dual-fuel engine equipped with DOC+DPF+SCR are lower than the limits of non-road China-Ⅳ and Euro-V regulations.