Method for controlling exhaust gas purification system and exhaust gas purification system

A method for controlling an exhaust gas purification system which includes an exhaust gas purification device provided with an oxidation catalyst device and a diesel particulate filter device provided in order from an upstream side of an exhaust passage of an internal combustion engine, a detector for detecting a temperature of an exhaust gas and an intake temperature, and regeneration controller for carrying out regeneration control for recovering purification capacity of said diesel particulate filter device, accompanied by post injection in in-cylinder fuel injection control based on a detection result of said temperature detector;

• in an exhaust gas temperature rise control at said regeneration control at manual regeneration, comprising:
• when a first exhaust gas temperature of the exhaust gas flowing into said oxidation catalyst device is lower than a predetermined first determining temperature, or when a second exhaust gas temperature of the exhaust gas flowing into said diesel particulate filter device is lower than a predetermined second determining temperature, first exhaust gas temperature rise control, carrying out multi injection in the in-cylinder fuel injection control is executed;
• when said first exhaust gas temperature is higher than said predetermined first determining temperature and said second exhaust gas temperature is higher than said predetermined second determining temperature, and when the intake temperature is lower than a predetermined third determining temperature, second exhaust gas temperature rise control, carrying out post injection in addition to the multi injection in the in-cylinder fuel injection control is executed;
• and
• when said first exhaust gas temperature is higher than said predetermined first determining temperature and said second exhaust gas temperature is higher than said predetermined second determining temperature and when said intake temperature is higher than said predetermined third determining temperature, third exhaust gas temperature rise control, carrying out the post injection in addition to normal injection in the in-cylinder fuel injection control, is executed.