Method and apparatus for directing exhaust gas and reductant fluid in an emission abatement system

Abstract

A diverter valve includes a valve member positionable between a number of valve positions to selectively divert both engine exhaust gas and a reductant fluid between a number of emission abatement devices. The valve may be used to divert engine exhaust gas to a first NO X trap while contemporaneously diverting reductant fluid to a second NO X trap. A method of operating a diverter valve of an emission abatement assembly is also disclosed.

1 . A method of operating a diverter valve of an emission abatement assembly, the method comprising the steps of: 
 positioning the diverter valve in a first valve position so as to (i) direct exhaust gas from an internal combustion engine to a first emission abatement device, and (ii) direct a reductant fluid to a second emission abatement device, and    positioning the diverter valve in a second valve position so as to (i) direct exhaust gas from the internal combustion engine to the second emission abatement device, and (ii) direct the reductant fluid to the first emission abatement device.    
     
     
         2 . The method of  claim 1 , wherein: 
 the diverter valve comprises (i) an exhaust gas inlet, (ii) a reductant fluid inlet, (iii) a first outlet fluidly coupled to the first emission abatement device, and (iv) a second outlet fluidly coupled to the second emission abatement device,    the step of positioning the diverter valve in the first valve position comprises fluidly coupling (i) the exhaust gas inlet to the first outlet, and (ii) the reductant fluid inlet to the second outlet, and    the step of positioning the diverter valve in the second valve position comprises fluidly coupling (i) the exhaust gas inlet to the second outlet, and (ii) the reductant fluid inlet to the first outlet.    
     
     
         3 . The method of  claim 2 , wherein: 
 the step of positioning the diverter valve in the first valve position further comprises fluidly isolating (i) the exhaust gas inlet from the second outlet, and (ii) the reductant fluid inlet from the first outlet, and    the step of positioning the diverter valve in the second valve position further comprises fluidly isolating (i) the exhaust gas inlet from the first outlet, and (ii) the reductant fluid inlet from the second outlet.    
     
     
         4 . The method of  claim 1 , wherein: 
 the reductant fluid comprises reformate gas generated by a fuel reformer,    the step of positioning the diverter valve in the first valve position comprises fluidly coupling the fuel reformer to the second emission abatement device so as to direct reformate gas from the fuel reformer to the second emission abatement device, and    the step of positioning the diverter valve in the second valve position comprises fluidly coupling the fuel reformer to the first emission abatement device so as to direct reformate gas from the fuel reformer to the first emission abatement device.    
     
     
         5 . The method of  claim 1 , further comprising moving the diverter valve from the first valve position to the second valve position with a valve actuator.  
     
     
         6 . The method of  claim 5 , wherein: 
 the valve actuator comprises a linear solenoid, and    the moving step comprises moving the solenoid from a first solenoid position to a second solenoid position.    
     
     
         7 . The method of  claim 5 , wherein: 
 the valve actuator comprises a stepper motor, and    the moving step comprises actuating the stepper motor so as to move the diverter valve from the first valve position to the second valve position.    
     
     
         8 . A diverter valve of an emission abatement assembly, the diverter valve comprising: 
 a valve housing defining a valve chamber, the valve housing having (i) an exhaust gas inlet, (ii) a reductant fluid inlet, (iii) a first outlet, and (iv) a second outlet, and    a valve member positioned in the valve chamber, the valve member being positionable between (i) a first valve position in which the exhaust gas inlet is fluidly coupled to the first outlet and the reductant fluid inlet is fluidly coupled to the second outlet, and (ii) a second valve position in which the exhaust gas inlet is fluidly coupled to the second outlet and the reductant fluid inlet is fluidly coupled to the first outlet.    
     
     
         9 . The diverter valve of  claim 8 , wherein 
 when the valve member is positioned in the first valve position (i) the exhaust gas inlet is fluidly isolated from the second outlet, and (ii) the reductant fluid inlet is isolated from the first outlet, and    when the diverter valve is positioned in the second valve position (i) the exhaust gas inlet is fluidly isolated from the first outlet, and (ii) the reductant fluid inlet is fluidly isolated from the second outlet.    
     
     
         10 . The diverter valve of  claim 8 , further comprising a valve actuator coupled to the valve member.  
     
     
         11 . The diverter valve of  claim 10 , wherein the valve actuator comprises a linear solenoid.  
     
     
         12 . The diverter valve of  claim 10 , wherein the valve actuator comprises a stepper motor.  
     
     
         13 . An emission abatement assembly, comprising: 
 a first emission abatement device,    a second emission abatement device,    a source of reductant fluid, and    a diverter valve, the diverter valve being configured to selectively divert both engine exhaust gas and reductant fluid between the first emission abatement device and the second emission abatement device.    
     
     
         14 . The emission abatement assembly of  claim 13 , further comprising a control unit electrically coupled to the diverter valve.  
     
     
         15 . The emission abatement assembly of  claim 13 , wherein the source of reductant fluid comprises a fuel reformer.  
     
     
         16 . An emission abatement assembly, comprising: 
 a first NO X  trap,    a second NO X  trap,    a fuel reformer configured to convert hydrocarbon fuel into a reformate gas, and    a diverter valve having (i) an exhaust gas inlet configured to receive engine exhaust gas, (ii) a reductant fluid inlet fluidly coupled to the fuel reformer, (iii) a first outlet fluidly coupled to an inlet of the first NO X  trap, and (iv) a second outlet fluidly coupled o the inlet of the second NO X  trap.    
     
     
         17 . The emission abatement assembly of  claim 16 , wherein the diverter valve comprises a valve member positionable between (i) a first valve position in which the exhaust gas inlet is fluidly coupled to the first outlet and the reductant fluid inlet is fluidly coupled to the second outlet, and (ii) a second valve position in which the exhaust gas inlet is fluidly coupled to the second outlet and the reductant fluid inlet is fluidly coupled to the first outlet.  
     
     
         18 . The emission abatement assembly of  claim 16 , wherein the diverter valve further comprises a valve actuator coupled to the valve member.  
     
     
         19 . The emission abatement assembly of  claim 16 , wherein the fuel reformer further comprises a plasma fuel reformer.