EXHAUST GAS PURIFICATION APPARATUS OF INTERNAL COMBUSTION ENGINE

摘要

An exhaust gas purification apparatus of an internal combustion engine includes: a reducing agent passage that connects a tank and an injection valve; a heater that heats up a hydrolysis catalyst that is provided in the reducing agent passage; and a controller comprising at least one processor configured to control a pump so that a reducing agent located further toward a side of the injection valve than the hydrolysis catalyst flows toward a side of the hydrolysis catalyst after completion of injection of a reducing agent in a state where the hydrolysis catalyst is at a temperature lower than the hydrolysis temperature and before start of injection of a reducing agent in a state where the hydrolysis catalyst is at a temperature equal to or higher than the hydrolysis temperature.

主权项

1. An exhaust gas purification apparatus of an internal combustion engine, comprising:
a selective catalytic reduction NOx catalyst, that is provided in an exhaust passage of the internal combustion engine and that selectively reduces NOx in exhaust gas using a reducing agent; a tank that stores a liquid ammonia precursor, which is a reducing agent; an injection valve that is provided in an exhaust passage on an upstream side of the selective catalytic reduction NOx catalyst and that injects a reducing agent; a reducing agent passage that connects the tank and the injection valve with each other; a hydrolysis catalyst that is provided in the reducing agent passage and that hydrolyzes the ammonia precursor; a heater configured to heat up the hydrolysis catalyst to a temperature equal to or higher than a hydrolysis temperature at which the ammonia precursor hydrolysis is hydrolyzed; a pump that discharges a reducing agent; and a controller comprising at least, one processor configured to control the heater and the pump, wherein the controller comprising at least one processor configured to control the pump so that, when injecting a reducing agent from the injection valve in a state where the hydrolysis catalyst is at a temperature equal to or higher than the hydrolysis temperature after injecting a reducing agent from the injection valve in a state where the hydrolysis catalyst is at a temperature lower than the hydrolysis temperature, a reducing agent located further toward a side of the injection valve than the hydrolysis catalyst flows toward a side of the hydrolysis catalyst after completion of injection of a reducing agent from the injection valve in a state where the hydrolysis catalyst is at a temperature lower than the hydrolysis temperature and before start of injection of a reducing agent from the injection valve in a state where the hydrolysis catalyst is at a temperature equal to or higher than the hydrolysis temperature.