SCR系统尿素计量装置开发研究

The Development of Urea Level Metering Device for SCR Systems

分析了选择性催化还原(SCR)系统的工作原理,对其中尿素计量装置开发的技术难点进行了归纳,制定了尿素计量装置开发方案,对关键部件进行了详细设计,开发出了尿素计量装置工程样机,并进行了标定、验证和可靠性考核。结果表明,尿素计量装置性能稳定,喷射量与喷射脉宽线性化关系良好,200mg/s以上的尿素喷射量控制精度在3%以内,能够满足对尿素的精确计量要求。

This paper analyzed the working principles of selective catalytic reduction（SCR）system,and summed up the technical difficulties of the development of urea level metering device.The development scheme of urea level metering device was studied and the critical components were designed.The prototype design has been accomplished.The calibration was conducted and reliability was evaluated to optimize the performance.The experimental results showed that urea injection quantity kept quite a good linear relationship with the injection pulse width at different motor speeds.When the urea injection quality was above 200mg/s,the quantity control precision was less than 3%,which could meet the requirement of SCR system.