US 12,392,269 B2
Control device and method for deriving engine-out NOx concentration
Christer Lundberg, Rönninge (SE)
Assigned to Scania CV AB, Södertälje (SE)
Appl. No. 18/710,232
Filed by Scania CV AB, Södertälje (SE)
PCT Filed Nov. 18, 2022, PCT No. PCT/SE2022/051075
§ 371(c)(1), (2) Date May 15, 2024,
PCT Pub. No. WO2023/091071, PCT Pub. Date May 25, 2023.
Claims priority of application No. 21209443 (EP), filed on Nov. 22, 2021.
Prior Publication US 2025/0035024 A1, Jan. 30, 2025
Int. Cl. F01N 3/20 (2006.01); F01N 9/00 (2006.01); F01N 11/00 (2006.01)
CPC F01N 3/2066 (2013.01) [F01N 9/00 (2013.01); F01N 11/00 (2013.01); F01N 2560/026 (2013.01); F01N 2900/1402 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A method, performed by a control device, for deriving an engine-out NOx concentration of an exhaust gas stream in an exhaust system configured to treat exhaust gas from a combustion engine,
wherein the exhaust system comprises:
a turbocharger;
a selective catalytic reduction catalyst arranged downstream of the turbocharger;
a dosing device adapted for injecting a reductant either towards or in the turbocharger, such that the reductant is dispersed in the exhaust gas stream by usage of a rotational motion of a turbine of the turbocharger;
a first NOx sensor arranged downstream of the dosing device but upstream of the selective catalytic reduction catalyst; and
a second NOx sensor arranged downstream of the selective catalytic reduction catalyst,
wherein the method comprises:
deriving engine-out NOx concentration based on both a first concentration reading obtained from the first NOx sensor and a second concentration reading obtained from the second NOx sensor, said first concentration reading being obtained while the dosing device is in operation so as to introduce reductant into the exhaust gas stream, wherein the first concentration reading is obtained from the first NOx sensor at a first point in time, and the second concentration reading is obtained from the second NOx sensor at a second point in time, and wherein the second point in time is after a time, corresponding to an estimated time for the exhaust gas stream to travel from the first NOx sensor to the second NOx sensor, has elapsed since the first point in time; and
controlling a dosage of reductant injected into the exhaust treatment system using the derived engine-out NOx concentration.