SELECTIVE CATALYTIC REDUCTION STEADY STATE AMMONIA SLIP AND REDUCTANT BREAKTHROUGH DETECTION

    公开(公告)号:US20190010851A1

    公开(公告)日:2019-01-10

    申请号:US15643987

    申请日:2017-07-07

    Abstract: Technical solutions are described for an emissions control system for a motor vehicle including an internal combustion engine. An example emissions control system for treating exhaust gas in a motor vehicle including an internal combustion engine. For example, the emissions control system includes a selective catalytic reduction (SCR) device, an NOx sensor, and a controller that is configured to detect a NH3 slip of the SCR device. The controller detects the NH3 slip by modulating an engine out NOx from an engine, demodulating the engine out NOx from the engine to original state, and measuring NOx upstream and downstream from the SCR device after the modulation. Further, the controller determines the NH3 slip by comparing gradients in the NOx measurement with one or more predetermined thresholds.

    PREDICTIVE CONTROL FOR SLIP AND BREAKTHROUGH DETERMINATION OF SELECTIVE CATALYTIC REDUCTION SYSTEMS

    公开(公告)号:US20180258813A1

    公开(公告)日:2018-09-13

    申请号:US15451447

    申请日:2017-03-07

    Abstract: Disclosed are SCR predictive control systems, methods for using such control systems, and motor vehicles with SCR employing predictive control. A method for regulating operation of an SCR system includes receiving sensor signals indicative of NOx output downstream from an SCR catalyst, and sensor signals indicative of exhaust gas temperature upstream from the SCR catalyst. The method determines if a model error condition has occurred for the NOx output signal and, responsive to such an occurrence, modulating dosing injector output for at least a calibrated designated time period. Upon expiration of the designated time period, the dosing injector is activated and commanded to inject reductant in accordance with a modulated dosing value. After the dosing injector injects the modulated dosing value of reductant, the method determines if the SCR system is underdosing or overdosing based on a response shape of signals received from the outlet NOx content sensor.

    Low temperature diesel aftertreatment regeneration strategy

    公开(公告)号:US12140064B1

    公开(公告)日:2024-11-12

    申请号:US18654370

    申请日:2024-05-03

    Abstract: A method of aftertreatment regeneration includes routing exhaust gases from a diesel engine through an exhaust system and initiating a nitrogen dioxide based aftertreatment regeneration of a diesel particulate filter (DPF) by at least partially de-activating a first DEF injector and an upstream selective catalyst reducer (SCR), increasing levels of Nitric Oxide within exhaust gas from the engine, establishing and maintaining an target exhaust gas temperature at an inlet of the DPF by actively controlling combustion characteristics of the engine, converting, with a diesel oxidation catalyst, (DOC) NO within the exhaust gas entering the DOC to NO2, and converting solid carbon-based particulate matter that has accumulated within the DPF to gaseous carbon dioxide (CO2) and NO by using NO2 as an oxidant.

    Selective catalytic reduction dosing control

    公开(公告)号:US10443471B2

    公开(公告)日:2019-10-15

    申请号:US15586801

    申请日:2017-05-04

    Abstract: Technical solutions are described for an emissions control system for a motor vehicle including an internal combustion engine. The emissions control system includes a reductant injector device, a selective catalytic reduction (SCR) device, and a controller. The controller determines a reductant energizing time for the reductant injector device based on one or more operating conditions of the SCR device. The controller further computes a diagnostic adaptation factor for the reductant energizing time based on an on-board diagnostic signal. The controller further inputs an amount of reductant into the SCR device by adjusting a reductant energizing time of the reductant injector device according to the diagnostic adaptation factor.

    Limiting exposure of zeolite containing aftertreatment components to rich exhaust conditions

    公开(公告)号:US10358966B2

    公开(公告)日:2019-07-23

    申请号:US15711304

    申请日:2017-09-21

    Abstract: Technical solutions are described for limiting exposure of components of an emissions control system to rich exhaust conditions. An example an emissions control system includes an oxygen storage component; and a controller that limits exposure of the oxygen storage component to rich exhaust conditions. The limiting includes determining an air-to-fuel equivalence ratio in exhaust gas in response to an engine receiving a request to generate torque, the request including a displacement of a pedal; determining an amount of oxygen in the exhaust gas based on the air-to-fuel equivalence ratio; determining an oxygen level stored by the oxygen storage component; and if the oxygen level is above a predetermined threshold, lowering a torque generation rate of the engine, which specifies amount of torque generated per unit displacement of the pedal.

    METHODS FOR ASSESSING THE CONDITION OF A SELECTIVE CATALYTIC REDUCTION DEVICES

    公开(公告)号:US20190178129A1

    公开(公告)日:2019-06-13

    申请号:US15834556

    申请日:2017-12-07

    Abstract: Selective catalytic reduction device (SCR) assessment methods include, while communicating exhaust to the SCR, determining a first temperature differential (dT) between a modeled exotherm phase temperature and a measured SCR exotherm outlet exhaust temperature, comparing the first dT to a first threshold, and determining that the SCR performance is suitable if the first dT is below the first threshold, or, if the first dT is above the first threshold, communicating exhaust gas to the SCR during a water endotherm phase, determining a second dT between a modeled endotherm phase temperature and a measured SCR endotherm phase outlet exhaust temperature, comparing the second dT to a second threshold, and determining that the SCR performance is suitable if the second dT is above the second threshold, or determining that the SCR performance is unsuitable if the second dT is below the second threshold. Performance can be SCR reductant storage capacity.

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