基于国五发动机满足国六排放标准的技术措施探讨

Discussions on Technical Measures Based on China Ⅴ Engine to Meet China Ⅵ Emission Standard

为了研究现有排放控制技术发动机在国六排放标准下的排放特性,基于一台满足国五排放采用选择性催化还原(SCR)技术路线的发动机,分别进行了国五标准的欧洲稳态测试循环(ESC)、欧洲瞬态测试循环(ETC)和国六标准的世界统一稳态测试循环(WHSC)、世界统一瞬态测试循环(WHTC)测试。结果表明:采用SCR路线的国五发动机颗粒物(PM)、粒子数量(PN)排放均远远超出国六限值,因此,对于国六发动机开发来说,加装柴油颗粒捕集器(DPF)是必要的。与此同时,对于较为苛刻的国六限值,该发动机NO_x排放较高,需进一步改善后处理系统,做好热管理,保证SCR较高的转化效率和反应速率。对于所有的测试循环,总碳氢(THC),CO等排放较低,满足要求。

In order to study the emission characteristics of engine using the existing emission control technology, an engine that meets China Ⅴ emission standard adoption SCR route was selected, and the ESC, ETC,WHTC and WHSC test cycles were carried out respectively. The results show that the PM and PN of the China Ⅴ engine using the SCR route far exceed the China Ⅵ standard limits. Therefore, for the development of the China Ⅵ engine, the addition of DPF is necessary. At the same time, for the more stringent China Ⅵ emission standard, the engine NO_x emissions are higher, the after treatment system needs to be further improved, thermal management is ensured, and the high conversion efficiency and reaction rate of SCR are guaranteed. For all test cycles, the THC, CO emissions are low, meeting the requirements.