Standalone thermal energy recycling device for engine after-treatment systems

Abstract

A standalone thermal energy recycling device in which exhaust air emitted from an internal combustion engine exchanges heat with that being heated during regeneration of after-treatment devices. By using the thermal energy recycling device, heat generated for regeneration is used to compensate energy loss during heat exchange rather than provide the overall energy needed for boosting exhaust flow temperature to target. Inside the thermal energy recycling device, heat exchanger is bypassed during normal engine operations for decreasing back pressure.

1 . An internal combustion engine after-treatment system comprising:
 a filter that traps PM (Particulate Matter) in exhaust air;   a heat generation device that generates heat for the regeneration of said filter;   an energy exchange device in which exhaust air emitted from said internal combustion engine exchanges heat with that heated with said heat generation device;   said filter and said heat generation device are outside said energy exchange device.   
   
   
       2 . A system as in  claim 1 , wherein said heat generation device includes a DOC (Diesel Oxidation Catalyst) device; 
   
   
       3 . A system as in  claim 2 , wherein said heat generation device includes an external doser for fuel injection; 
   
   
       4 . A system as in  claim 2 , wherein said external doser is placed in between said heat exchange device and said DOC; 
   
   
       5 . A system as in  claim 2 , wherein said heat generation device uses in-cylinder post fuel injection; 
   
   
       6 . A system as in  claim 1 , wherein said heat generation device includes a fuel burner; 
   
   
       7 . A system as in  claim 6 , wherein said fuel burner includes a fuel pump and an ignition device; 
   
   
       8 . A system as in  claim 1 , wherein said heat generation device includes an electrical resistive heating device; 
   
   
       9 . A system as in  claim 1 , wherein said energy exchange device includes a heat exchanger through which two air flows exchange heat; 
   
   
       10 . A system as in  claim 9 , wherein said energy exchange device includes an exhaust air bypass apparatus that is controlled to bypass said heat exchanger; 
   
   
       11 . A system as in  claim 1 , wherein said after-treatment system further includes a SCR (Selective Catalytic Reduction) device; 
   
   
       12 . A system as in  claim 1 , wherein said after-treatment system further includes an LNT (Lean NOx Trap) device; 
   
   
       13 . A system as in  claim 1 , wherein said after-treatment system further includes an LNC (Lean NOx Catalyst) device; 
   
   
       14 . An internal combustion engine after-treatment system comprising:
 an LNT device;   a heat generation device that generates heat for the regeneration of said LNT device;   an energy exchange device in which exhaust air emitted from said internal combustion engine exchanges heat with that heated with said heat generation device;   said filter and said heat generation device are outside said energy exchange device.   
   
   
       15 . A system as in  claim 14 , wherein said heat generation device includes a DOC; 
   
   
       16 . A system as in  claim 15 , wherein said heat generation device includes an external doser for fuel injection; 
   
   
       17 . A system as in  claim 16 , wherein said external doser is placed in between said heat exchange device and said DOC; 
   
   
       18 . A system as in  claim 14 , wherein said energy exchange device includes a heat exchanger through which two air flows exchange heat; 
   
   
       19 . A system as in  claim 18 , wherein said energy exchange device includes an exhaust air bypass apparatus that is controlled to bypass said heat exchanger; 
   
   
       20 . A system as in  claim 14 , wherein said after-treatment system further includes a DPF;