Patent ID: 11946400
Assignee: PACCAR INC
Field: Environmental technology (Chemistry)
Classification: CPC F  Y | IPC F

Claim 8:
9. A vehicle system, comprising:
a lean-burn internal combustion engine;
an exhaust aftertreatment system fluidly coupled to the internal combustion engine, the exhaust aftertreatment system including an oxidation catalyst;
a first temperature sensor arranged to monitor an exhaust gas feedstream upstream of the oxidation catalyst;
a second temperature sensor arranged to monitor the exhaust gas feedstream downstream of the oxidation catalyst;
a controller, in communication with the internal combustion engine and the first and second temperature sensors; the controller including an instruction set that is executable to:
determine a fueling rate and a mass flowrate of the exhaust gas feedstream;
determine, via the first temperature sensor, an inlet temperature of the exhaust gas feedstream upstream of the oxidation catalyst and determine, via the second temperature sensor, an in-use outlet temperature of the exhaust gas feedstream downstream of the oxidation catalyst;
determine an expected outlet temperature from the oxidation catalyst based upon the inlet temperature, the fueling rate, and the mass flowrate of the exhaust gas feedstream; and
evaluate the oxidation catalyst based upon the expected outlet temperature and the in-use outlet temperature,
wherein the instruction set being executable to determine the expected outlet temperature from the oxidation catalyst based upon the inlet temperature, the fueling rate, and the mass flowrate of the exhaust gas feedstream comprises the instruction set being executable to determine a temperature differential based upon the following relationship:, Δ
   ⁢
   
    T
    
     e
     ⁢
     x
     ⁢
     h
    
   
  
  =
  
   (
   
    
     
      
       m
       ˙
      
      
       H
       ⁢
       C
      
     
     *
     L
     ⁢
     H
     ⁢
     
      V
      
       H
       ⁢
       C
      
     
    
    
     C
     ⁢
     
      p
      
       e
       ⁢
       x
       ⁢
       h
      
     
     *
     
      
       m
       ˙
      
      
       e
       ⁢
       x
       ⁢
       h
      
     
    
   
   )
  
 

 wherein:
ΔTexh represents the temperature differential,
{dot over (m)}HC represents a mass flow rate of HC that is determined based upon the fueling rate,
LHVHC represents a lower heating value of fuel,
Cpexh represents a specific heat of the exhaust gas feedstream at a constant pressure, and
{dot over (m)}exh represents the mass flowrate of the exhaust gas feedstream, and
wherein the instruction set being executable to determine the expected outlet temperature from the oxidation catalyst based upon the temperature differential and the inlet temperature of the exhaust gas feedstream upstream of the oxidation catalyst.