Model-Based Temperature Sensor Fault Detection and Fault-Tolerant Control of Urea-Selective Catalyst Reduction Control Systems

• Published in: Energies (Basel) 2018-07, Vol.11 (7), p.1800
• Main Authors: Hu, Jie, Wang, Junliang, Zeng, Jiawei, Zhong, Xianglin
• Format: Article
• Language: English
• Subjects: Ammonia; Control methods; Control systems; diesel engine; Fault detection; Fault diagnosis; Fault tolerance; fault-tolerant control; Nitrogen oxides; Oxides; Photochemicals; Selective catalytic reduction; Sensors; Temperature effects; temperature sensor; Temperature sensors; Temperature tolerance; Urea; urea-selective catalyst reduction (SCR)
• ISSN: 1996-1073; 1996-1073
• DOI: 10.3390/en11071800

This paper aims at investigating the fault diagnosis of the selective catalyst reduction (SCR) outlet temperature sensors and fault-tolerant control methods of the SCR system, and three typical faults of downstream temperature sensors were modeled and analyzed to present influences of different faults on the SCR system performances (such as nitrogen oxides (NOx) emission and conversion efficiency, NH3 slip, urea dosage and ammonia coverage estimation). A temperature model was established to estimate the SCR outlet temperature, and diagnostics were developed based on the differences between model estimates and sensor measurements. Once a downstream temperature sensor fault was detected, the fault-tolerant control will be enabled, and the output of the sensor may be substituted with the estimates of the model. Thus, SCR performances shall be maintained within the acceptable ranges. Moreover, a 0-D SCR model was also established to validate the capability of diagnostics and fault-tolerant control strategy over the European transient cycle (ETC).