DEVICE FOR EXHAUST GAS CLEANING DEVICE FAULT DIAGNOSIS Russian patent published in 2017 - IPC F01N3/18 B01D53/94 

FIELD: engines and pumps.

SUBSTANCE: fault diagnosis device comprises an exhaust gas cleaning device positioned in an exhaust passage of internal combustion engine and including a SCR catalyst; a feeding device supplying an additive, such as ammonia, to an exhaust gas cleaning device; EGR device providing recirculation of exhaust gas part from the exhaust passage on the downstream side of the additive feeding position into the inlet channel; obtaining means for obtaining the amount of NO_x inflow in the exhaust gas cleaning device; diagnostic means for calculating a physical quantity correlated with the ability to clean NO_x of exhaust gas cleaning device using the obtained amount of NO_x inflow and diagnosing that the fault occured in the exhaust gas cleaning device, when the physical quantity is less that a threshold quantity; correcting means for correcting the threshold quantity to a smaller quantity, when the additive recirculates together with the exhaust gas part, as opposed to a situation when something different happens.

EFFECT: improved diagnostics reliability and accuracy.

5 cl, 6 dwg