Exhaust Aftertreatment Fault Detection via Storage-Capacity Modeling

The patent introduces an intermediary calculation approach using reaction equations and storage capacity parameters to bridge the gap between upstream exhaust composition and downstream pollutant levels. Instead of directly measuring downstream pollutants with complex sensors, the system uses a chemical model (reaction equation) that incorporates storage capacity as an intermediary parameter to calculate downstream composition from upstream measurements and operating conditions, thereby achieving reliable fault detection with simpler means

The patent replaces direct physical measurement of downstream pollutants with a chemical calculation system. Instead of using complex physical sensing equipment to directly detect pollutant presence downstream, the system substitutes this with a chemical reaction model that calculates downstream composition based on storage capacity changes and reaction kinetics, achieving the same diagnostic goal with a different, more reliable approach

The patent applies preliminary action by pre-determining the storage capacity of the aftertreatment device and incorporating it as a fixed parameter in the reaction equation before actual exhaust gas analysis. This preliminary characterization of the system's storage capacity allows for more accurate real-time calculations without requiring complex dynamic measurements during operation, as the storage capacity serves as a pre-established system property in the calculation model

The patent changes the parameters of the reaction equation by incorporating storage capacity as a key variable that affects reaction kinetics. By adjusting the reaction equation to account for storage capacity variations, the system achieves more accurate predictions of downstream exhaust composition. This parameter change transforms a simple reaction model into a more sophisticated one that captures the actual chemical behavior in the aftertreatment device