柴油机SCR系统控制策略研究与软件设计

为有效地降低柴油机排气污染物NO_x,结合模块化设计思想,在Matlab/Simulink环境下完成SCR控制软件的开发。软件主要包括数据管理模块、SCR状态模块、尿素量计算模块和任务模块,其中尿素量计算模块采用基本尿素喷射量计算、尿素量修正和闭环反馈调节的组合方式提高尿素量计算精度。软件经代码生成后刷写至SCR控制器DCU中,在试验台架上完成ESC和WHTC循环测试。试验结果表明:在ESC和WHTC试验循环下,NO_x转换效率分别高于79.09%和72.35%,经催化还原后排放值分别低于1.836g/(kW·h)和2.147g/(kW·h),满足国Ⅴ法规的限值要求。

Control Strategy Research and Software Design of Diesel Engine SCR System

In order to reduce NO xemission of diesel engine effectively ,the SCR control software was developed under the Matlab/Simulink environment combined with the modular design idea .The software mainly included data management module , SCR state module ,urea calculation module and task module and wherein the urea calculation module used the mixed methods of fundamental urea injection calculation , urea injection correction and close loop feedback to improve the urea calculation accuracy .The software codes were generated and written into the SCR controller DCU and tested through the ESC and WHTC cycle tests on the test bench .The results showed that NO xconversion efficiency in ESC and WHTC tests was more than 79.09% and 72 .35% respectively .Their NO xemissions were lower than 1 .836 g/(kW· h) and 2 .147 g/(kW· h) after the catalytic reduction ,which meet the limit requirement of China Ⅴ regulations .