Ammonia Cross-Sensitivity Eliminatin Method of NO_x Sensor for UREA-SCR (Selective Catalytic Reduction) System

摘要

This paper reports an ammonia cross-sensitivity elimination filter for SCR systems. Since NO_X sensors are cross sensitive to NH_3, a reading of NO_X sensor could not be accurate. As the reading is inaccurate, the closed-loop SCR systems is unpredictable. The proposed filter can be applied to any kinds of NO_X sensors and effectively remove the cross-sensitivity. Single gas and mixed exhaust gas tests are conducted. The results show the evident removal of NH_3 in both single gas and mixed gases experiments. The experiments show the filtering method can considerably improve the accuracy of NO_X concentration measurement in Urea-SCR systems.