| 摘要 |
There is provided an apparatus that estimates the NOx adsorption amount, comprising a NOx trap catalyst that is disposed in an exhaust passage of an engine, for adsorbing NOx in exhaust gases during lean operation and releasing and reducing the adsorbed NOx during rich operation, an operation unit that computes an amount of emission from the catalyst during rich operation by using a map or a polynomial equation that reflects emissions from the catalyst based on the exhaust gas temperature and the exhaust gas flow rate of the exhaust passage and the excess-air factor upstream of the catalyst, and an estimating unit that estimates an amount of adsorption in the NOx trap catalyst from the computed emission amount.
|
