农用发动机SCR系统内尿素分解特性研究  

Research of urea decomposition characteristics in agricultural engine SCR system

作　　者：杨朔 杜慧勇 李可 王站成 李民 范晨阳 Yang Shuo;Du Huiyong;Li Ke;Wang Zhancheng;Li Min;Fan Chenyang(College of Vehicle and Traffic Engineering,Henan University of Science and Technology,Luoyang,471003,China;Gu'an Denox Environmental Protection Equipment Manufacturing Co.,Ltd.,Langfang,065000,China)

机构地区：[1]河南科技大学车辆与交通工程学院,河南洛阳471003 [2]固安迪诺斯环保设备制造有限公司,河北廊坊065000

出　　处：《中国农机化学报》2023年第9期131-136,264,共7页Journal of Chinese Agricultural Mechanization

基　　金：国家自然科学基金项目(52006054)。

摘　　要：以某型号非道路发动机为试验发动机,反应段为直径7寸、目数200、长度25 mm和50 mm规格的钒基挤出式催化剂各两段组合而成的SCR催化反应器,研究催化剂内部氨的生成特性,探究结构参数与工况条件对催化剂内部尿素分解率和氨分布的影响。结果表明:随着排气温度的升高和流量的减小,使得催化剂径向测量截面氨分布均匀性提高,SCR反应效率提高。在各试验工况和结构条件下,尿素分解主要发生在催化剂的前100 mm,在此长度内分解速率较快,后逐渐变慢。在催化剂长度为150 mm时,各个工况下催化剂出口处尿素平均分解率均大于80%,可满足标准SCR反应所需。通过台架试验对尿素分解特性及氨分布的研究,为提高车用尿素利用效率和优化后处理系统催化剂设计提供一定的参考。Taking a model of off-road engine as the test engine,and the reaction section was a SCR catalyst with two sections of vanadium-based extruded catalysts of 7″diameter,200 mesh,25 mm and 50 mm in length.The ammonia generation characteristics inside the catalyst were investigated,and explored the effects of structural parameters and operating conditions on the urea decomposition rate and ammonia distribution inside the catalyst.The results showed that with the increase of exhaust gas temperature and the decrease of flow rate,the uniformity of ammonia distribution in the radial measurement cross-section of the catalyst and the efficiency of SCR reaction was increased.Under each test condition and structural condition,urea decomposition mainly occurred in the first 100 mm of the catalyst,and the decomposition rate was faster in this length and gradually slowed down.At 150 mm catalyst length,the average decomposition rate of urea at the catalyst outlet was more than 80% under all conditions,which could meet the requirements of standard SCR reaction.In this paper,the study of urea decomposition characteristics and ammonia distribution through bench test can provide some reference for improving the efficiency of urea utilization and optimizing the catalyst design of after-treatment system.

关 键 词：农用发动机 催化剂 氨分布 尿素分解 分解率 车辆与动力 

分 类 号：S218.5[农业科学—农业机械化工程] TK421.5[农业科学—农业工程]