Exhaust Treatment System for Internal Combustion Engine

Abstract

An exhaust treatment system for an internal combustion engine comprises an exhaust gas conduit configured to receive an exhaust gas from the internal combustion engine and to deliver the exhaust gas to an exhaust treatment device. A fluid delivery system is located upstream of the exhaust treatment device and is configured to deliver a fluid thereto. It comprises a fluid injector, a fluid tube in fluid communication with the fluid injector and extending radially into the exhaust gas conduit for receipt of fluid from a spray tip of the fluid injector, a controller configured to energize the fluid injector to deliver fluid to the fluid tube, and opening(s) in the tube, disposed beyond the boundary layer of exhaust gas flow in the exhaust gas conduit, for release of the fluid into the exhaust gas flow.

What is claimed is: 
     
         1 . An exhaust treatment system for an internal combustion engine comprising:
 an exhaust gas conduit configured to receive an exhaust gas from the internal combustion engine and to deliver the exhaust gas to an exhaust treatment device;   a fluid delivery system located upstream of the exhaust treatment device and configured to deliver a fluid thereto, the fluid delivery system comprising:
 a fluid injector; 
 a fluid tube in fluid communication with the fluid injector and extending into the exhaust gas conduit for receipt of fluid from a spray tip of the fluid injector; 
 a controller configured to energize the fluid injector to deliver fluid to the fluid tube; and 
 an opening in the tube, centrally disposed within exhaust gas flow in the exhaust gas conduit, for release of the fluid into the exhaust gas flow. 
   
     
     
         2 . The exhaust treatment system of  claim 1 , the exhaust treatment device comprising an oxidation catalyst and the fluid comprising unburned hydrocarbon. 
     
     
         3 . The exhaust treatment system of  claim 1 , the exhaust treatment device comprising an selective catalytic reduction device and the fluid comprising an ammonia (“NH 3 ”) reductant. 
     
     
         4 . The exhaust treatment system of  claim 1 , wherein the fluid tube extends diametrically across the diameter of the exhaust gas conduit having a second end in communication with the exhaust gas conduit. 
     
     
         5 . The exhaust treatment system of  claim 4 , comprising a second fluid injector in communication with the second end of the fluid tube to deliver fluid to the fluid tube. 
     
     
         6 . The exhaust treatment system of  claim 1 , wherein the fluid injector is a fluid vaporizer. 
     
     
         7 . The exhaust treatment system of  claim 1 , further comprising multiple openings located at locations along the length of the tube. 
     
     
         8 . The exhaust treatment system of  claim 7 , further comprising upstream facing openings configured to allow the exhaust gas to enter the fluid tube and entrain the fluid and downstream facing downstream facing openings configured for the flow of fuel and exhaust gas out of the fluid tube. 
     
     
         9 . The exhaust treatment system of  claim 1 , wherein the fluid tube extends radially into the exhaust gas conduit. 
     
     
         10 . The exhaust treatment system of  claim 1 , wherein the opening in the tube is centrally disposed beyond the boundary layer of exhaust gas flow in the exhaust gas conduit. 
     
     
         11 . A fluid delivery system configured to deliver a fluid to an exhaust treatment device via an exhaust gas conduit, the fluid delivery system comprising:
 a fluid injector;   a fluid tube in fluid communication with the fluid injector and extending into the exhaust gas conduit for receipt of fluid from a spray tip of the fluid injector;   a controller configured to energize the fluid injector to deliver fluid to the fluid tube; and   an opening in the tube, centrally disposed within the exhaust gas conduit, for release of the fluid into the exhaust gas conduit.   
     
     
         12 . The fluid delivery system of  claim 11 , wherein the fluid tube extends diametrically across the diameter of the exhaust gas conduit having a second end in communication with the exhaust gas conduit. 
     
     
         13 . The fluid delivery system of  claim 12 , comprising a second fluid injector in communication with the second end of the fluid tube to deliver fluid to the fluid tube. 
     
     
         14 . The fluid delivery system of  claim 11 , wherein the fluid injector is a fluid vaporizer. 
     
     
         15 . The fluid delivery system of  claim 11 , further comprising multiple openings located at locations along the length of the tube. 
     
     
         16 . The fluid delivery system of  claim 15 , further comprising upstream facing openings configured to allow the exhaust gas to enter the fluid tube and entrain the fluid and downstream facing downstream facing openings configured for the flow of fuel and exhaust gas out of the fluid tube. 
     
     
         17 . The fluid delivery system of  claim 11 , wherein the fluid tube extends radially into the exhaust gas conduit. 
     
     
         18 . The fluid delivery system of  claim 11 , wherein the opening in the tube is centrally disposed beyond the boundary layer of exhaust gas flow in the exhaust gas conduit.