| 摘要 |
A method of operating an aftertreatment system 270 of an internal combustion engine 110, wherein the aftertreatment system comprises a lean nitrogen-oxides (NOx) trap (LNT) 285 and a reductant storage device 290 downstream there from. The reductant storage device may be a selective catalytic reduction (SCR) device, with the reductant being ammonia (NH3). The method comprises the steps of: performing a regeneration of the LNT; measuring, during the regeneration, a reductant concentration between the LNT and the reductant storage device; and calculating an amount of reductant produced by the LNT on the basis of the measured concentration. The reductant concentration may be measured by a NOx sensor with a cross sensitivity for the reductant. The method may include estimating, during the regeneration, a NOx concentration downstream from the LNT, and identifying that an enabling condition for measuring the reductant concentration is fulfilled when the estimated NOx concentration is smaller than a predetermined threshold value. |
