固态铵SCR系统铵盐热解反应及NOx低温还原特性研究

项目名称： 固态铵SCR系统铵盐热解反应及NOx低温还原特性研究

项目编号： No.51306070

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 能源与动力工程

项目作者： 曲大为

作者单位： 吉林大学

项目金额： 24万元

中文摘要： 现有尿素SCR技术需要在高排温条件下将尿素热解水解生成氨气，无法有效降低发动机低排温工况下的NOx排放。固态铵SCR（SSCR）技术能够拓宽NOx催化还原的工作温度范围，提高发动机低徘温工况下的NOx转化效率，是应对欧Ⅵ及更高排放法规的有效技术手段。本项目针对SSCR系统氨气直接喷射及NOx低温还原的特点，结合实验测量及计算模拟开展SSCR系统铵盐热解正逆反应特性的研究，阐明氨气生成及逆反应结晶的主要影响因素和特点；分析空速、排温及氨气尾气混合度等边界条件对SCR箱内氨分布的影响规律；研究NOx低温还原化学反应动力学特性及发动机全工况范围（特别是低排温工况）NOx转化效率，确定影响SSCR系统NOx还原能力的关键因素。通过开展以上研究工作，揭示SSCR系统铵盐反应特性、氨混合氨分布特性及NOx低温还原特性，为SSCR系统实际应用及降低发动机全工况范围内的NOx排放奠定理论基础。

中文关键词： 柴油机；固态选择性催化还原；分解特性；重结晶；反应特性

英文摘要： Urea need to be hydrolyzed into generate ammonia in high exhaust temperature conditions with urea SCR technology, thus unable to effectively reduce the engine NOx emission in low exhaust temperature conditions. Solid ammonium SCR (SSCR) technology can broaden the range of NOx catalytic reduction's operating temperature, improve NOx conversion efficiency in the low exhaust temperature of engine. SSCR technology is an effective technology to deal with the Europe Ⅵ and higher emission regulations. This project will aim at the characteristics of ammonia direct injection and low temperature reduction of NOx, combines with the experimental measurement and numerical simulation to carry out the study of SSCR system's forward and inverse reaction characteristics of the ammonium salt pyrolysis reaction, clarify the main influencing factors and characteristics of ammonia's generation and crystallization of the reverse reaction; analyse the law about how the boundary condition such as airspeed、exhaust temperature and ammonia gas mixed degree effect the ammonia distribution of the SCR box; research the low temperature reduction chemical kinetics of NOx and its conversion efficiency under the full working conditions of the engine(especially the low exhaust temperature conditions), determine the key factors that affect the SSC

英文关键词： Diesel engine；Solid selective catalytic reduction；Decomposition characteristics；Recrystallization；Reaction characteristics