刘旭海^1,2，王军^1,2，张建华^1,2，刘正锐^1,2

（1、内燃机可靠性国家重点实验室，山东 潍坊 261061；2、潍柴动力空气净化科技有限公司，山东 潍坊 261061）

摘要：利用高速摄像技术，对比空气辅助和无空气辅助两种典型的SCR尿素喷射系统尿素喷雾粒径，并且以发动机台架试验为基础，通过排放循环和结晶试验对比来研究空气辅助和无空气辅助SCR系统的性能差异。结果表明，空气辅助喷射系统的喷雾粒径明显小于无空气辅助喷射系统，具有良好的喷雾特性；在相同的试验条件下，空气辅助喷射系统较无空气辅助喷射系统排放结果更好，结晶风险更低。

关键词：柴油机；氮氧化物（NOx）；SCR；尿素溶液喷雾

Abstract：By using high-speed photography, an experimental study was conducted to investigate the urea spray characteristics of two typical SCR injection systems, namely with or without air assistance. On an engine bench test, Comparative emissions and crystallization tests were used to study the performance differences of two SCR injection systems. The results show that, with air assistance, urea spray particle diameter was significantly smaller than without air assistance, which indicated better spray characteristics. Under the same test conditions, with air assistance injection system had better emission results, and lower crystallization risk.

Key words：diesel engine; NOx; selective catalytic reduction(SCR);urea spray