船用低速柴油机排气含硫、温度较低，更适合采用涡轮前布置的高压SCR系统。但是，高压SCR系统的船舶应用仍存在硫酸腐蚀、盐类堵塞以及切换延迟等实际问题，且相关理论基础研究有所欠缺。针对高压SCR系统实船应用技术问题及难点，本项目采用理论研究与试验验证相结合的方法，拟开展船用低速柴油机高压SCR系统铵盐钝化机理及主机调制策略研究，详细分析极限条件下SCR系统催化反应动力学，解析高压、高硫废气条件下SCR系统铵盐结晶钝化特性及反应机理；在此基础上，构建船用低速柴油机高压SCR系统Engine+SCR全机模型，探索船用低速柴油机高压SCR系统瞬态性能预测方法，并详细分析变工况条件下主机调制方法及影响规律，解析高压SCR系统、主机及涡轮运行匹配方法及协同控制机制，制定变工况及主机调制模式下多系统协同控制策略及方案，提高船用低速柴油机高压SCR系统的船舶应用效果，应对国内外船舶废气污染物排放法规要求。

With low temperature and high sulfur oxides content of the discharged exhaust gas, marine low-speed diesel engine is more suitable to install a high-pressure SCR system in front of the turbine. However, the marine applications of high-pressure SCR systems still have practical problems such as sulfuric acid corrosion, ammonium-salt blockage and response delay, and lacking the related theoretical basic research. In order to solve these technical problems and difficulties of high-pressure SCR system, studies on ammonium-salt passivation mechanism of high-pressure SCR system and engine turning strategy of its matched marine low-speed diesel engine will be carried out in the project, using the combination of theoretical research and experimental verification. In this project, catalytic kinetics of SCR system under extreme conditions will be analyzed in detail, and the passivation characteristics and formation mechanism of ammonium-salt deposited in SCR system under high pressure and high sulfur oxides content conditions will be clarified. On this basis, the Engine+SCR full-engine model will be built, which is used to explore performance predicting methods of the high-pressure SCR system for marine low-speed diesel engine. And then, main engine turning methods and its affecting regularities under variable working conditions and loads will be studied in detail, operation matching methods and coordination controlling mechanism among the high-pressure SCR system, the engine and the turbine will also be clarified. Consequently, the multi-system cooperative controlling method and scheme under variable working conditions and main engine turning modes can be developed by this project, which can improve the application performance of high-pressure SCR system, and make its matched marine low-speed diesel engine meet the requirements of marine exhaust emission regulations at home and abroad.