Exhaust gas post processing system and control method thereof

Abstract

An exhaust gas post processing method, may include detecting driving conditions of an engine, determining a ratio of soluble organic matter and carbon particles trapped in a diesel particulate filter according to the detected driving conditions, selecting a first predetermined temperature and a first maintain time for eliminating the soluble organic matter according to the ratio of the soluble organic matter and the carbon particles, and controlling a temperature of the diesel particulate filter according thereto, and eliminating the soluble organic matter by sustaining the first predetermined temperature for the first maintain time, selecting a second predetermined temperature for eliminating the carbon particles, and controlling a temperature of the diesel particulate filter according thereto.

1 . An exhaust gas post processing method, comprising:
 detecting driving conditions of an engine;   determining a ratio of soluble organic matter and carbon particles trapped in a diesel particulate filter according to the detected driving conditions;   selecting a first predetermined temperature and a first maintain time for eliminating the soluble organic matter according to the ratio of the soluble organic matter and the carbon particles, and controlling a temperature of the diesel particulate filter according thereto; and   eliminating the soluble organic matter by sustaining the first predetermined temperature for the first maintain time, selecting a second predetermined temperature for eliminating the carbon particles, and controlling a temperature of the diesel particulate filter according thereto.   
     
     
         2 . The exhaust gas post processing method of  claim 1 , further comprising determining regeneration timing of the diesel particulate filter based on the detected driving conditions. 
     
     
         3 . The exhaust gas post processing method of  claim 2 , wherein the regeneration timing is determined based on pressure difference and travel distance. 
     
     
         4 . The exhaust gas post processing method of  claim 1 , further comprising using a front/rear pressure difference of the diesel particulate filter to determine a regeneration ending time. 
     
     
         5 . The exhaust gas post processing method of  claim 1 , further comprising raising the temperature of the diesel particulate filter to the second predetermined temperature to eliminate the carbon particles. 
     
     
         6 . The exhaust gas post processing method of  claim 1 , wherein the driving conditions of the engine include engine speed, fuel injection amount, a front/rear pressure difference of the diesel particulate filter, internal temperature of the diesel particulate filter, or exhaust gas temperature. 
     
     
         7 . The exhaust gas post processing method of  claim 1 , wherein the ratio of the soluble organic matter and the carbon particles trapped in the diesel particulate filter is selected from map data according to the detected driving conditions. 
     
     
         8 . The exhaust gas post processing method of  claim 7 , wherein the map data includes a relationship between the rotation speed and fuel injection amount of the engine. 
     
     
         9 . The exhaust gas post processing method of  claim 1 , wherein the detected driving conditions have a map of internal temperature according to engine speed and load (fuel injection amount) during the regeneration of the diesel particulate filter. 
     
     
         10 . The exhaust gas post processing method of  claim 1 , wherein the detected driving conditions have an elimination rate map of the soluble organic matter (SOF) according to engine speed and load (fuel injection amount). 
     
     
         11 . An exhaust gas post processing system, comprising:
 a diesel particulate filter trapping PM (particulate matter) that is included in exhaust gas of an engine; and   a control portion that performs a predetermined program so as to eliminate the PM trapped in the diesel particulate filter according to driving conditions of the engine, wherein the predetermined program includes instructions for performing the method of  claims 1  to  10  at least once.