Systems and methods for air assisted injection of a reductant into an aftertreatment system

Abstract

An aftertreatment system structured to decompose constituents of an exhaust produced by an engine having a turbocharger including a turbine and a compressor coupled thereto, includes: a selective catalytic reduction system; an injector fluidly coupled to the selective catalytic reduction system and structured to selectively insert a reductant into the selective catalytic reduction system; an intake conduit fluidly coupled to a compressor outlet of the compressor and structured to deliver a compressed air from the compressor to the engine; and an air delivery line fluidly coupling the intake conduit to the injector, the air delivery line structured to deliver a portion of the compressed air to the injector.

What is claimed is: 
     
         1 . An aftertreatment system, structured to decompose constituents of an exhaust produced by an engine having a turbocharger including a turbine and a compressor coupled thereto, the aftertreatment system comprising:
 a selective catalytic reduction system;   an injector fluidly coupled to the selective catalytic reduction system and structured to selectively insert a reductant into the selective catalytic reduction system;   an intake conduit fluidly coupled to a compressor outlet of the compressor and structured to deliver a compressed air from the compressor to the engine; and   an air delivery line fluidly coupling the intake conduit to the injector, the air delivery line being structured to deliver a portion of the compressed air to the injector so as to facilitate air-assisted insertion of the reductant by the injector.   
     
     
         2 . The aftertreatment system of  claim 1 , further comprising:
 a booster pump positioned in the air delivery line upstream of the injector;   wherein the air delivery line is structured to deliver the portion of the compressed air within the air delivery line upstream of the booster pump at a first pressure; and   wherein the booster pump is structured to pressurize the portion of the compressed air, so as to generate pressurized air having a second pressure greater than the first pressure, and deliver the pressurized air to the injector.   
     
     
         3 . The aftertreatment system of  claim 2 , wherein the injector comprises a nozzle structured to shear the reductant into reductant droplets using the pressurized air at the second pressure. 
     
     
         4 . The aftertreatment system of  claim 2 , further comprising a flow valve positioned in the air delivery line upstream of the booster pump, the flow valve operable between a first state and a second state, the flow valve structured to facilitate fluid communication between the intake conduit and the booster pump in the first state and to prohibit fluid communication between the intake conduit and the booster pump in the second state. 
     
     
         5 . The aftertreatment system of  claim 1 , wherein the injector comprises a nozzle structured to shear the reductant into reductant droplets. 
     
     
         6 . The aftertreatment system of  claim 1 , wherein the portion of the compressed air has a volume in a range of 0.01-8% of a total volume of the compressed air flowing through the intake conduit. 
     
     
         7 . The aftertreatment system of  claim 1 , further comprising:
 an exhaust conduit fluidly coupled to a turbine inlet of the turbine, structured to receive exhaust from the engine, and structured to provide the exhaust from the engine to the turbine; and   an inlet conduit fluidly coupled to a turbine outlet of the turbine, fluidly coupled to the selective catalytic reduction system separate from the injector, structured to receive the exhaust from the turbine, and structured to provide the exhaust from the turbine to the selective catalytic reduction system.   
     
     
         8 . The aftertreatment system of  claim 1 , further comprising:
 a reductant tank structured to store the reductant prior to insertion of the reductant into the selective catalytic reduction system by the injector; and   a reductant insertion assembly fluidly coupled to the reductant tank and the injector, the reductant insertion assembly structured to draw the reductant from the reductant tank and provide the reductant to the injector.   
     
     
         9 . An aftertreatment system for an internal combustion engine, the aftertreatment system comprising:
 a turbocharger comprising:
 a compressor configured to receive air from an air source; and 
 a turbine configured to receive exhaust from the internal combustion engine; 
   an intake conduit configured to receive compressed air from compressor;   an intake manifold configured to receive a first portion of the compressed air from the intake conduit and to provide the first portion of the compressed air to the internal combustion engine;   an air delivery line configured to receive a second portion of the compressed air from the intake conduit separate from the intake manifold; and   a housing configured to receive the second portion of compressed air from the air delivery line and to receive the exhaust from the turbine.   
     
     
         10 . The aftertreatment system of  claim 9 , further comprising:
 a reductant insertion assembly; and   an injector coupled to the housing and configured to receive the second portion of compressed air from the air delivery line, receive reductant from the reductant insertion assembly, mix the second portion of compressed air and the reductant into an air-reductant mixture, and deliver the air-reductant mixture into the housing.   
     
     
         11 . The aftertreatment system of  claim 10 , wherein the injector comprises a nozzle configured to shear the reductant into reductant droplets using the second portion of the compressed air. 
     
     
         12 . The aftertreatment system of  claim 9 , further comprising:
 a booster pump positioned in the air delivery line between the intake conduit and the housing;   wherein the air delivery line is structured to deliver the first portion of the compressed air at a first pressure; and   wherein the booster pump is configured to pressurize the second portion of the compressed air to a second pressure greater than the first pressure.   
     
     
         13 . The aftertreatment system of  claim 12 , further comprising a flow valve positioned in the air delivery line upstream of the booster pump, the flow valve operable between a first state and a second state, the flow valve structured to facilitate fluid communication between the intake conduit and the booster pump in the first state and to prohibit fluid communication between the intake conduit and the booster pump in the second state. 
     
     
         14 . The aftertreatment system of  claim 9 , wherein:
 the first portion of the compressed air accounts for a first volume of compressed air over a period of time;   the second portion of the compressed air accounts for a second volume of compressed air over the period of time;   a sum of the first volume of compressed air and the second volume of compressed air results in a total volume of compressed air over the period of time; and   the second volume of compressed air is in a range of 0.01-1% of the total volume of compressed air over the period of time.   
     
     
         15 . An aftertreatment system for an internal combustion engine having a turbocharger with a compressor and a turbine, the aftertreatment system comprising:
 an intake conduit configured to receive compressed air;   an air delivery line coupled to the intake conduit and structured such that a first portion of the compressed air bypasses the air delivery line and a second portion of the compressed air is diverted into the air delivery line; and   a housing structured to receive the second portion of compressed air from the air delivery line and to separately receive exhaust.   
     
     
         16 . The aftertreatment system of  claim 15 , further comprising:
 a reductant insertion assembly; and   an injector structured to receive the second portion of compressed air from the air delivery line, receive reductant from the reductant insertion assembly, mix the second portion of compressed air and the reductant into an air-reductant mixture, and deliver the air-reductant mixture into the housing.   
     
     
         17 . The aftertreatment system of  claim 16 , further comprising a booster pump positioned in the air delivery line between the intake conduit and the housing;
 wherein the air delivery line is structured to deliver the first portion of the compressed air at a first pressure; and   wherein the booster pump is structured to pressurize the second portion of the compressed air to a second pressure greater than the first pressure.   
     
     
         18 . The aftertreatment system of  claim 17 , further comprising a flow valve positioned in the air delivery line between the intake conduit and the booster pump, the flow valve operable between a first state and a second state, the flow valve structured to facilitate fluid communication between the intake conduit and the booster pump in the first state and to prohibit fluid communication between the intake conduit and the booster pump in the second state. 
     
     
         19 . The aftertreatment system of  claim 18 , wherein the injector comprises a nozzle configured to shear the reductant into reductant droplets using the second portion of the compressed air. 
     
     
         20 . The aftertreatment system of  claim 19 , wherein, over a period of time:
 the first portion of the compressed air accounts for a first volume of compressed air;   the second portion of the compressed air accounts for a second volume of compressed air;   a sum of the first volume of compressed air and the second volume of compressed air results in a total volume of compressed air; and   the second volume of compressed air is in a range of 0.01-1% of the total volume of compressed air or is in a range of 1-8% of the total volume of compressed air.