Exhaust gas post-processing apparatus and regeneration method thereof

Abstract

An exhaust gas post-processing apparatus may include an exhaust pipe through which exhaust gas passes, a particulate material catalyst (PMC) that is mounted in the exhaust pipe, that collects particulate materials included in the exhaust gas, and that is regenerated by NO2, and a control portion that increases amount of NOx supplied from an engine so as to increase amount of NO2 supplied to the PMC to improve regeneration efficiency of the PMC for a predetermined time period according to driving conditions of a vehicle.

1 . An exhaust gas post-processing apparatus, comprising:
 an exhaust pipe through which exhaust gas passes;   a particulate material catalyst (PMC) that is mounted in the exhaust pipe, that collects particulate materials included in the exhaust gas, and that is regenerated by NO2; and   a control portion that increases amount of NOx supplied from an engine so as to increase amount of NO2 supplied to the PMC to improve regeneration efficiency of the PMC for a predetermined time period according to driving conditions of a vehicle.   
   
   
       2 . The exhaust gas post-processing apparatus of  claim 1 , wherein the predetermined time period is approximately ten minutes. 
   
   
       3 . The exhaust gas post-processing apparatus of  claim 1 , further comprising a diesel oxidation catalyst (DOC) that is mounted between the engine and the PMC to purify the exhaust gas and that uses the NOx supplied from the engine to generate the NO2. 
   
   
       4 . The exhaust gas post-processing apparatus of  claim 3 , wherein the DOC includes a ceramic support on which platinum is coated to transform CO, HC, and NO to CO2, H2O, and NO2. 
   
   
       5 . The exhaust gas post-processing apparatus of  claim 3 , wherein the PMC collects soot and the particulate materials and is regenerated by eliminating the collected soot and the particulate materials through reaction with the NO2 supplied from the DOC. 
   
   
       6 . The exhaust gas post-processing apparatus of  claim 1 , wherein the driving conditions of the vehicle is determined to be satisfied and thus the control portion increases the amount of the NOx for the predetermined time period while a total integrated travel distance of the vehicle is larger than a predetermined travel distance and travel time period after the engine is operated elapses a predetermined travel time period. 
   
   
       7 . The exhaust gas post-processing apparatus of  claim 1 , wherein the control portion controls air/fuel ratio, EGR valve opening rate, injection timing retarding rate, and/or vane angle of a turbo charger for the predetermined time period to increase the amount of the NOx. 
   
   
       8 . The exhaust gas post-processing apparatus of  claim 7 , wherein the control portion closes the EGR valve for exhaust gas not to be re-circulated to combustion chamber of the engine to raise temperature in the combustion chamber. 
   
   
       9 . The exhaust gas post-processing apparatus of  claim 7 , wherein the control portion retards the injection timing of fuel to increase the amount of the NOx. 
   
   
       10 . The exhaust gas post-processing apparatus of  claim 7 , wherein the control portion adjusts an opening rate of the vane of the turbocharger to reduce intake air amount so that concentration of fuel as well as that of the NOx are raised to increase temperature of exhaust gas. 
   
   
       11 . The exhaust gas post-processing apparatus of  claim 6 , wherein the predetermined travel distance is approximately 10,000 km. 
   
   
       12 . The exhaust gas post-processing apparatus of  claim 6 , wherein the predetermined travel time period is approximately 100 hours. 
   
   
       13 . A regeneration method of an exhaust gas post-processing apparatus, comprising:
 a determining step in which a total integrated travel distance of a vehicle, a travel distance of the vehicle, and a travel time period after an engine is operated are detected to determine whether a condition of a PMC to be at a regeneration step is satisfied; and   the regeneration step in which the PMC is regenerated by increasing amount of NOx supplied to the PMC, the NOx being generated by the engine for a predetermined time period, while the condition of the PMC to be at the regeneration step is determined to be satisfied.   
   
   
       14 . The exhaust gas post-processing apparatus of  claim 13 , wherein the predetermined time period is approximately ten minutes. 
   
   
       15 . The regeneration method of an exhaust gas post-processing apparatus of  claim 13 , wherein the condition of the PMC to be at the regeneration step is determined to be satisfied when the total integrated travel distance is larger than a predetermined travel distance and the travel time period after the engine is operated elapses a predetermined travel time period. 
   
   
       16 . The regeneration method of an exhaust gas post-processing apparatus of  claim 13 , wherein the predetermined travel distance is approximately 10,000 km and the predetermined travel time period is approximately 100 hours. 
   
   
       17 . The regeneration method of an exhaust gas post-processing apparatus of  claim 13 , wherein the control portion controls air/fuel ratio, EGR valve opening rate, injection timing retarding rate, and/or vane angle of a turbo charger for the predetermined time period to increase the amount of the NOx. 
   
   
       18 . The regeneration method of an exhaust gas post-processing apparatus of  claim 13 , wherein the control portion closes the EGR valve for exhaust gas not to be re-circulated to combustion chamber of the engine to raise temperature in the combustion chamber. 
   
   
       19 . The regeneration method of an exhaust gas post-processing apparatus of  claim 13 , wherein the control portion retards the injection timing of fuel to increase the amount of the NOx. 
   
   
       20 . The regeneration method of an exhaust gas post-processing apparatus of  claim 13 , wherein the control portion adjusts an opening rate of the vane of the turbocharger to reduce intake air amount so that concentration of fuel as well as that of the NOx are raised to increase temperature of exhaust gas.