A controller for controlling operation of an aftertreatment system that is configured to treat constituents of an exhaust gas produced by an engine, the aftertreatment system including a selective catalytic reduction (SCR) catalyst, the controller configured to: generate a short-term cumulative degradation estimate of the SCR catalyst corresponding to reversible degradation of the SCR catalyst due to sulfur and/or hydrocarbons based on a SCR catalyst temperature parameter; generate a long-term cumulative degradation estimate of the SCR catalyst corresponding to thermal aging of the SCR catalyst based on the SCR catalyst temperature parameter; generate a combined degradation estimate of the SCR catalyst based on the short-term cumulative degradation estimate and the long-term cumulative degradation estimate; and adjust an amount of reductant and/or an amount of hydrocarbons inserted into the aftertreatment system based on the combined degradation estimate of the SCR catalyst.

A controller for controlling operation of an aftertreatment system that is configured to treat constituents of an exhaust gas produced by an engine, the aftertreatment system including a selective catalytic reduction (SCR) catalyst, the controller configured to: generate a short-term cumulative degradation estimate of the SCR catalyst corresponding to reversible degradation of the SCR catalyst due to sulfur and/or hydrocarbons based on a SCR catalyst temperature parameter; generate a long-term cumulative degradation estimate of the SCR catalyst corresponding to thermal aging of the SCR catalyst based on the SCR catalyst temperature parameter; generate a combined degradation estimate of the SCR catalyst based on the short-term cumulative degradation estimate and the long-term cumulative degradation estimate; and adjust an amount of reductant and/or an amount of hydrocarbons inserted into the aftertreatment system based on the combined degradation estimate of the SCR catalyst.

An EHC line leakage diagnosis method can operate a heater of an oxygen detector when satisfying one or more conditions of an engine off time, a coolant temperature, and an outside air temperature by a diagnosis controller upon the key-on of the non-operation of an engine, and then, determine the normality or abnormality of a temperature drop using a change in a temperature value of a signal value and the temperature value detected by the oxygen detector after an air pump is driven, and then confirm the leakage of an exhaust line and a line on the rear end portion of an EHC valve of an air line using the number of times of the occurrence of the abnormality of the temperature drop, and can perform the failure diagnosis without generating the exhaust gas by not operating an engine.

A method for determining a degree of aging of an oxidizing catalytic converter in an exhaust system of an internal combustion engine is provided. The method comprises generating a temporary increase in carbon monoxide levels in an exhaust gas stream, monitoring subsequent oxidizing action and determining a degree of aging of the oxidizing catalytic converter as a function of the measured oxidizing action. The method further comprises measuring a temperature rise during oxidation and correlating the aging of the converter to the speed of temperature rise.

A method of ageing a component of an exhaust gas after-treatment system including the steps of combusting fuel to subject the component to a continuous thermal ageing and simultaneously target loading at least certain sections of the component with ash. The method can be used on a test bench.

Provided is an exhaust gas purification apparatus having a control device that monitors the transition of a detection value of each of an upstream NOx sensor and a downstream NOx sensor, and when the NOx purification rate of the SCR catalyst falls to a value of a first threshold or lower, generates an abnormality detection signal indicating that an over storage state has occurred in an SCR catalyst if the amount of change in the detection value of the upstream NOx sensor per unit time is at least a second threshold and the amount of change in the detection value of the downstream NOx sensor per unit time is at most a third threshold.

Provided is an exhaust gas purification apparatus having a control device that monitors the transition of a detection value of each of an upstream NOx sensor and a downstream NOx sensor, and when the NOx purification rate of the SCR catalyst falls to a value of a first threshold or lower, generates an abnormality detection signal indicating that an over storage state has occurred in an SCR catalyst if the amount of change in the detection value of the upstream NOx sensor per unit time is at least a second threshold and the amount of change in the detection value of the downstream NOx sensor per unit time is at most a third threshold.

An EHC line leakage diagnosis method can operate a heater of an oxygen detector when satisfying one or more conditions of an engine off time, a coolant temperature, and an outside air temperature by a diagnosis controller upon the key-on of the non-operation of an engine, and then, determine the normality or abnormality of a temperature drop using a change in a temperature value of a signal value and the temperature value detected by the oxygen detector after an air pump is driven, and then confirm the leakage of an exhaust line and a line on the rear end portion of an EHC valve of an air line using the number of times of the occurrence of the abnormality of the temperature drop, and can perform the failure diagnosis without generating the exhaust gas by not operating an engine.

Particulate filters are used to remove particulate matter such as soot and ash in the emissions control systems of vehicles, including gasoline direct injection (GDI) engines. Methods are provided to predict the long-term performance and durability of emissions control systems having particulate filters. The methods account for factors such as thermal aging, soot accumulation and regeneration, and ash loading.

A method for desulphurising a nitrogen oxide accumulator catalytic converter of an exhaust gas system that includes the nitrogen oxide accumulator catalytic converter and at least one selective catalytic reduction catalytic converter disposed downstream of the nitrogen oxide accumulator catalytic converter, of an internal combustion engine, where a desulphurisation strategy, on the basis of which the nitrogen oxide accumulator catalytic converter is desulphurised, is adjusted to the ageing of the nitrogen oxide accumulator catalytic converter.