EXHAUST GAS PURIFICATION SYSTEM AND EXHAUST GAS PURIFICATION METHOD

摘要

Exhaust gas of an internal combustion engine is made to pass through an exhaust gas purification device after passing through a pre-oxidation catalyst. When a first temperature of the exhaust gas on an upstream side of the device is lower than a first set temperature, multistage temperature rise injection is performed. When the first temperature becomes the first set temperature or more, post injection is performed in addition to the multistage temperature rise injection, and feedback control of the post injection is executed so that a second temperature of the exhaust gas on a downstream side of the exhaust gas purification device becomes a second set temperature.

主权项

1. An exhaust gas purification system comprising:
an exhaust gas purification device including a pre-stage oxidation catalyst and at least one of an NOx purification catalyst and a diesel particulate filter provided in an exhaust passage of an internal combustion engine; and a control device configured to control an operation of the internal combustion engine; a first exhaust gas temperature sensor, a pre-oxidation catalyst, and a second exhaust gas temperature sensor are arranged in order from an upstream side in the exhaust passage on the upstream side of the exhaust gas purification device; and the control device is configured to execute first control to perform multistage temperature rise injection by in-cylinder combustion control when a first temperature detected by the first exhaust gas temperature sensor is lower than a first set temperature set in advance, perform post injection in addition to the multistage temperature rise injection when the first temperature rises to the first set temperature or more, and feedback control the post injection so that a second temperature detected by the second exhaust gas temperature sensor becomes a second set temperature set in advance.