针对样品A和样品B两种车用尿素水溶液,在不同储存温度、不同加注方式条件下,对带有SCR系统的发动机进行 ESC 排气污染物测试,测试 SCR 系统 NOx转化效率的变化.经验证,SCR 对于 NOx排放控制效果明显,转化效率可达到 80%,,采用 SCR 技术是柴油车国Ⅴ排放法规达标的主流技术路线.尿素水溶液在不同温度下保存会发生水解,温度越高水解速度越快,但最终会达到某一平衡值;在 1 个月内,30,℃和 20,℃的不同存储温度对 SCR 转化效率影响不明显.在保质期内,30,℃和 20,℃下存储 30,d 对于车用尿素理化特性和 NOx转化效率影响都很小,使用专用加注设备对NOx转化效率的结果影响极小.%Sample A and B,two vehicle-used Aqueous Urea Solutions(AUS 32)were utilized under different storage tem-peratures and by different filling methods.ESC emissions tests were carried out foran engine with a SCR system to measure the system's variation of NOx conversion efficiencies.The results show that using AUS 32 in different conditions and blank tests prove that SCR has an obvious control effect on NOx.The NOx conversion efficiency could reach 80%,.SCR technol-ogy is the mainstream technology roadmap to achieve National V emissions standard of diesel engines.The hydrolysis reac-tion of AUS 32 takes place at different temperatures.The higher the temperature is,the faster the decreasing rate it could be,and finally it could reach a balance value.Within one month,the influence of different storage temperatures at 30,℃and 20,℃ on SCR conversion efficiencies is not obvious.Within the warranty period,storing 30 days both at 30,℃and 20,℃ have little influence on the physical and chemical characteristics of AUS 32 and NOx conversion efficiencies.The use of specialized filling equipment has very little impact on the NOx conversion efficiency.
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