Flow controlled electrically assisted dpf regeneration

Abstract

A particulate filter assembly, an exhaust gas treatment system having a particulate filter assembly, and a control method for flow controlled zoned regeneration of the particulate filter assembly are provided. The particulate filter assembly is configured to receive an exhaust gas stream from an internal combustion engine and includes an inlet end configured to receive the exhaust gas stream, a filter configured to remove particulates from the exhaust gas stream, a heating device positioned upstream from the filter having a plurality of zones, each zone of the plurality of zones independently operable to heat a corresponding region of the filter and an exhaust flow valve positioned downstream from the filter configured to selectively restrict flow of the exhaust gas stream through the filter.

What is claimed is: 
     
         1 . A particulate filter assembly configured to receive an exhaust gas stream from an internal combustion engine, the particulate filter assembly comprising:
 an inlet end configured to receive the exhaust gas stream;   a filter configured to remove particulates from the exhaust gas stream;   a heating device positioned upstream from the filter comprising a plurality of zones, each zone of the plurality of zones independently operable to heat a corresponding region of the filter; and   an exhaust flow valve positioned downstream from the filter configured to selectively restrict flow of the exhaust gas stream through the filter.   
     
     
         2 . The particulate filter assembly of  claim 1 , wherein the exhaust flow valve includes a plurality of valve plates, each valve plate of the plurality of valve plates selectively movable between an open position and a closed position. 
     
     
         3 . The particulate filter assembly of  claim 2 , wherein each zone of the plurality of zones of the heating device is configured to heat a respective region of the filter, each region of the filter corresponding to a size, shape and position of a respective zone. 
     
     
         4 . The particulate filter assembly of  claim 3 , wherein to regenerate a particular region of the filter, a zone corresponding to the particular region heats the particular region and a valve plate of the plurality of the valves plates of the exhaust flow valve is closed to restrict flow of the exhaust gas stream through the particular region to be regenerated. 
     
     
         5 . An exhaust gas treatment system for an internal combustion engine, the system comprising:
 an exhaust conduit extending from the engine configured to receive an exhaust gas stream from the engine; and   a particulate filter assembly positioned in fluid communication with the exhaust gas stream comprising:
 an inlet end configured to receive the exhaust gas stream; 
 a filter configured to remove particulates from the exhaust gas stream; 
 a heating device positioned upstream from the filter comprising a plurality of zones, each zone of the plurality of zones independently operable to heat a corresponding region of the filter; and 
 an exhaust flow valve positioned downstream from the filter configured to selectively restrict flow of the exhaust gas stream through the filter. 
   
     
     
         6 . The particulate filter assembly of  claim 5 , wherein the exhaust flow valve includes a plurality of valve plates, each valve plate of the plurality of valve plates selectively movable between an open position and a closed position. 
     
     
         7 . The particulate filter assembly of  claim 6 , wherein each zone of the plurality of zones of the heating device is configured to heat a respective region of the filter, each region of the filter corresponding to a size, shape and position of a respective zone. 
     
     
         8 . The exhaust gas treatment system of  claim 7  further comprising a controller in communication with the heating device and the exhaust flow valve, the controller configured to individually and selectively operate the plurality of zones of the heating device and plurality of valve plates of the exhaust flow valve to control regeneration of a particular region of the filter. 
     
     
         9 . The exhaust gas treatment system of  claim 8 , wherein to regenerate the particular region, the controller operates a zone of the heating device corresponding to the particular region to heat the particular region, and operates a valve plate of the exhaust flow valve to move to a closed position to restrict flow of the exhaust gas stream through the particular region to be regenerated. 
     
     
         10 . The exhaust gas treatment system of  claim 5 , further comprising an oxidation catalyst in fluid communication with the exhaust gas stream disposed in the exhaust gas conduit upstream from the particulate filter assembly. 
     
     
         11 . The exhaust gas treatment system of  claim 10 , further comprising a selective catalyst reduction (SCR) device in fluid communication with the exhaust gas stream disposed in the exhaust gas conduit upstream from the particulate filter assembly and downstream from the oxidation catalyst. 
     
     
         12 . The exhaust gas treatment system of  claim 11 , further comprising an injector disposed in fluid communication with the exhaust gas conduit and positioned between the oxidation catalyst and SCR device, the injector configured to selectively inject a reductant into the exhaust gas conduit 
     
     
         13 . A control method for flow controlled zoned regeneration of a filter of a particulate filter assembly of an internal combustion engine, the method comprising:
 determining whether regeneration of a particular region of the filter is necessary;   activating a zone of a plurality of zones of a heating device to heat the particular region of a plurality of regions of the filter; and   adjusting a position of a valve plate of a plurality of valve plates of an exhaust flow valve to restrict flow of an exhaust gas stream through the particular region of the filter.