不同路线国V车用柴油机非常规排放对比研究

在AVL全流采样(CVS)发动机台架上,对2台国V柴油机进行了ESC、ETC测试循环,并利用FTIR气体分析仪对非常规气体排放进行了测试。通过对比不同技术路线(增压中冷+共轨+EGR+DOC+DPF和增压中冷+共轨+SCR)发动机的NO2、SO2、NH3、HCHO和NOx排放,对它们的排放特性进行了试验研究;同时还分析了两种路线的CO2排放和油耗情况。研究结果表明DOC+DPF可以使NOx中NO2的比例升高,ESC循环达到了24.3%;两种路线都可以使车用柴油机满足国V排放标准要求,但前者THC、CO、HCHO、NH3排放明显低于后者,后者NO2排放及NO2在NOx排放中的比例明显低于前者。SCR路线在油耗和CO2排放方面相对具有优势。

Contrast of Unregulated Emissions of Chinese V Light-duty Diesel Engines Using Different Technology Routes

Two Chinese V engines were tested by running ESC and ETC cycles on an AVL engine test bench with Constant Volume Sample System （CVS） in this paper, and unregulated emissions were measured by FFIR equipment. The exhaust characteristic was studied by comparing the NO2, SO2, NH3, HCHO and NOx emissions of the two engines using different technology routes： turbocharger ＋ common rail injection ＋ EGR ＋ DOC ＋ DPF and turboeharger ＋ common rail injection ＋ SCR. The CO2 emission and fuel consumption were studied too. It was found that DOC ＋ DPF can increase the fraction of NO2 in NOx, which reached 24.3% in ESC cycle. Both the two technology routes can make the light -duty engines meet the Chinese V Emission standard. But the THC, CO, HCHO, NH3 emissions of the former route was remarkably lower than those of the latter route, and in contrast the NO2 and the fraction of NO2 in NOx of the latter route was obviously less than those of the former route. The latter route has advantages in CO2 emission and fuel consumption relatively.