Method for the testing of an exhaust gas recirculation system
AssigneeSiemens Aktiengesellschaft
InventorsWolfgang Ludwig, Corinna Pfleger, Hong Zhang
Life of this patent
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Abstract
Method for the testing of the exhaust gas recirculation system of an internal combustion engine that returns exhaust gas at an exhaust gas recirculation rate from the exhaust line to the intake line, in which a specific adjustment of the exhaust gas recirculation rate is set, the NOx concentration in the exhaust gas is measured and in the absence of a differential concentration varying as a function of the adjustment of the exhaust gas recirculation rate, a defect of the exhaust gas recirculation system is diagnosed.
Claims10
A method of testing an exhaust gas recirculation system of an internal combustion engine in which exhaust gas is recirculated from an exhaust line to an intake line, comprising:
- determining a concentration of NOx in the exhaust gas;
- adjusting a rate of circulation of exhaust gas by a predetermined specific rate of recirculation;
- measuring the concentration of NOx in the exhaust gas;
- and
- indicating a defect in the recirculation system if a difference between the NOx concentration before and after changing the rate of circulation does not exceed a threshold value.
Dependencies are inferred from the claim text.