Exhaust emission control system of internal combustion engine

An exhaust emission control device of an internal combustion engine, comprising:

• an exhaust emission control device disposed in an exhaust passage of the internal combustion engine and trapping harmful matters in exhaust;
• an exhaust flow rate detecting device that detects a flow rate of the exhaust flowing through the exhaust passage;
• and
• a concentration control device that controls an oxygen concentration of the exhaust passing through said exhaust emission control device according to the flow rate of the exhaust when said exhaust emission control control device is regenerated;
• an engine speed detecting device that detects an engine speed;
• and
• an engine load detecting device that detects an engine load,
• wherein said exhaust flow detecting device detects the flow rate of the exhaust according to the engine speed and the engine load.

A method of burning diesel particulates trapped by a diesel particulate filter provided in an exhaust passage of an engine, comprising:

• detecting a flow rate of exhaust flowing through the exhaust passage;
• reducing an amount of oxygen concentration to increase an amount of unburned hydro-carbon (HC) in the exhaust to burn the trapped diesel particulate:
• and
• adjusting the amount of oxygen concentration thereafter according to the flow rate of the exhaust to prevent said diesel particulate filter from overheating.