Process for checking the operability of an exhaust gas purification catalyst
First Claim
1. A process for checking the operability of a catalyst for purification of the exhaust gases of a combustion engine during operation of the engine, wherein the catalyst comprises a light-off temperature TCO,50% and a conversion ratio rCO for carbon monoxide and the combustion engine is equipped with an electronic control system comprising engine electronics and OBD electronics and wherein a malfunction of the catalyst exists at an operation point of the engine if the conversion ratio rCO for carbon monoxide is below a limit value rCO, L while simultaneously the exhaust gas temperature TE is by an amount Δ
- TL larger than the light-off temperature TCO,50%, new of the new catalyst.
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Abstract
A process for checking the operability of an exhaust gas purification catalyst for diesel engines, which has a light-off temperature and a degree of conversion rCO for carbon monoxide (CO), by direct measurement of the carbon monoxide concentration in combination with a temperature measurement. To evaluate the remaining catalytic activity of the catalyst the difference ΔT between the current catalyst exit temperature TE of the exhaust gas and the light-off temperature TCO,50%,fresh of the fresh catalyst for carbon monoxide stored as a function of the speed and load
is determined and the degree of conversion rCO for carbon monoxide is ascertained.
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Citations
8 Claims
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1. A process for checking the operability of a catalyst for purification of the exhaust gases of a combustion engine during operation of the engine, wherein the catalyst comprises a light-off temperature TCO,50% and a conversion ratio rCO for carbon monoxide and the combustion engine is equipped with an electronic control system comprising engine electronics and OBD electronics and wherein a malfunction of the catalyst exists at an operation point of the engine if the conversion ratio rCO for carbon monoxide is below a limit value rCO, L while simultaneously the exhaust gas temperature TE is by an amount Δ
- TL larger than the light-off temperature TCO,50%, new of the new catalyst.
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
Specification