Exhaust gas purification system for internal combustion engine and exhaust gas purification method

摘要

An exhaust gas purification system for an internal combustion engine including: a filter (22) that is disposed in an exhaust passage of an internal combustion engine (1) to trap particulate matters in exhaust gas; and means for starting filter regeneration that starts the filter regeneration to remove the particulate matters deposited on the filter when a deposition amount of the particulate matters on the filter reaches a determination value for start-up of the filter regeneration. The exhaust gas purification system further including: means for determining
termination of the filter regeneration based on an exhaust gas temperature (37;38), an air-fuel ratio of the exhaust gas, and an exhaust gas flow rate of the internal combustion engine.