Exhaust system and control method of amount of urea supply

Abstract

An exhaust system according to an exemplary embodiment of the present invention includes a nitrogen oxide storing catalytic collector connected to an exhaust line and collecting a nitrogen oxide included an exhaust gas in a first temperature or less; a first selective catalytic reducer disposed at a rear portion of the nitrogen oxide storing catalytic collector and reducing a nitrogen oxide included in the exhaust gas; and a first urea injector disposed at the front side of the nitrogen oxide storing catalytic collector and supplying a urea solution when a temperature of the nitrogen oxide exceeds the first temperature.

What is claimed is: 
     
         1 . An exhaust system comprising:
 a nitrogen oxide storing catalytic collector connected to an exhaust line, the nitrogen oxide storing catalytic collector collecting a nitrogen oxide included an exhaust gas in a first temperature or less;   a first selective catalytic reducer disposed at a rear portion of the nitrogen oxide storing catalytic collector, the first selective catalytic reducer reducing the nitrogen oxide included in the exhaust gas; and   a first urea injector disposed at a front portion of the nitrogen oxide storing catalytic collector, the first urea injector supplying a urea solution when a temperature of the nitrogen oxide exceeds the first temperature.   
     
     
         2 . The exhaust system of  claim 1 , further comprising:
 a second selective catalytic reducer disposed at a rear portion of the first selective catalytic reducer device, the second selective catalytic reducer reducing the nitrogen oxide included in the exhaust gas.   
     
     
         3 . The exhaust system of  claim 2 , further comprising:
 a second urea injector disposed between the first selective catalytic reducer and the second selective catalytic reducer, the second urea injector supplying the urea solution to the exhaust line when the temperature of the nitrogen oxide exceeds a second temperature.   
     
     
         4 . The exhaust system of  claim 3 , wherein:
 the first selective catalytic reducer includes a low temperature selective catalytic reduction catalyst activated in the second temperature or less, and   the second selective catalytic reducer includes a high temperature selective catalytic reduction catalyst activated when the temperature of the nitrogen oxide the second temperature.   
     
     
         5 . The exhaust system of  claim 1 , wherein:
 the first temperature is about 300 degrees (° C.).   
     
     
         6 . The exhaust system of  claim 3 , wherein:
 the second temperature is about 500 degrees (° C.).   
     
     
         7 . The exhaust system of  claim 4 , wherein:
 the low temperature selective catalytic reduction catalyst includes a component of zeolite and copper (Cu).   
     
     
         8 . The exhaust system of  claim 4 , wherein:
 the high temperature selective catalytic reduction catalyst includes one component of zeolite and iron (Fe) or manganese (Mn).   
     
     
         9 . The exhaust system of  claim 1 , wherein:
 the nitrogen oxide storing catalytic collector collects the nitrogen oxide in the temperature of 0 degree or more and 200 degrees or less.   
     
     
         10 . The exhaust system of  claim 4 , wherein:
 the low temperature selective catalytic reducer is activated in the temperature of the first temperature or more and the second temperature or less.   
     
     
         11 . The exhaust system of  claim 4 , wherein:
 the high temperature selective catalytic reduction catalyst is activated in the temperature of 400 degrees or more.