| 摘要 |
An objection is to provide exhaust gas purification apparatus and method for an internal combustion engine, which can initialize a SCR catalyst by heating the SCR catalyst under predetermined conditions without accompanying troublesome procedures and complicated calculations. With the exhaust gas purification apparatus for an internal combustion engine, arranged on an exhaust-gas passage of the internal combustion engine and including the SCR catalyst for purifying NOx in exhaust gas in the internal combustion engine, the method executes the steps of calculating and accumulating estimate value of the amount of NH 3 adsorption adsorbed on the SCR catalyst, on the basis of the amount of NH 3 injection produced from urea-aqueous solution injected into the exhaust-gas passage from the upstream side of the SCR catalyst and the amount of NH 3 injection for purifying NOx at the upstream side of the SCR catalyst, and initializing the SCR catalyst by heating the SCR catalyst to initialize the estimate value of the amount of NH 3 adsorption. |
