Emission Characteristics of Off-road Diesel Engines under LLAC
Two non-road diesel engines of different technical routes,respectively 13 L and 3.8 L,meeting the National Ⅳ emission standard,were selected to carry out emission tests based on non-four transient cycle(NRTC)and non-road low load application cycle(LLAC),and the emission characteristics of nitrogen oxides(NOx)under the two cycles were compared and analyzed.The results showed that:The NOx emission of the engines of the two technical routes increased significantly under the LLAC cycle,and there was a risk of excee-ding the non-Ⅳ standard emission limit.However,the effect of LLAC cycle on NOx emission of EGR technolo-gy route engine is significantly smaller than that of SCR technology route engine.The research on the emission test of non-road mobile source should be further strengthened.