Method and apparatus for activating a diesel particulate filter with engine heat

Abstract

An apparatus, including a diesel particulate filter, at least one sensor for sensing information associated with operation of an engine, an engine brake configured to brake the engine, and a controller electrically coupled to the at least one sensor and the engine brake, to determine if the engine is operating in a manner that does not generate enough engine heat to activate the diesel particulate filter, and if the engine is so operating, operate the engine brake so as to brake the engine to cause the engine to generate enough engine heat to activate the diesel particulate filter. An associated method is disclosed.

1 . A method of regenerating a diesel particulate filter, the method comprising the steps of:
 determining if the diesel particulate filter is in need of regeneration,   determining if an engine is operating in a manner that produces insufficient engine heat to regenerate the diesel particulate filter, and   if the engine is so operating, braking one or more cylinders of the engine while allowing at least one cylinder to combust fuel.   
     
     
         2 . The method of  claim 1 , wherein the determining step comprises determining if the engine is operating below a predetermined engine speed. 
     
     
         3 . The method of  claim 2 , wherein the determining step comprises monitoring output from an engine speed sensor. 
     
     
         4 . The method of  claim 1 , wherein the determining step comprises determining if the engine is operating below a predetermined engine load. 
     
     
         5 . The method of  claim 4 , wherein the determining step comprises querying an engine load map. 
     
     
         6 . The method of  claim 1 , wherein the braking step comprises elevating the temperature of the diesel particulate filter to at least an activation temperature of the diesel particulate filter with the engine heat. 
     
     
         7 . The method of  claim 6 , comprising regenerating the diesel particulate filter by use of the engine heat. 
     
     
         8 . The method of  claim 7 , wherein the regenerating step comprises (i) activating an oxidation catalyst by use of the engine heat, and (ii) regenerating a diesel particulate filter with heat generated by the activated oxidation catalyst. 
     
     
         9 . The method of  claim 7 , wherein the regenerating step comprises regenerating a catalyzed particulate filter by use of the engine heat. 
     
     
         10 . The method of  claim 7 , wherein the regenerating step comprises regenerating a NOx trap by use of the engine heat. 
     
     
         11 . The method of  claim 1 , wherein the braking step comprises braking at least one engine cylinder of the engine while operating at least one engine cylinder of the engine so as to generate power by combustion therein. 
     
     
         12 . An apparatus, comprising:
 a diesel particulate filter,   at least one sensor for sensing information associated with operation of an engine,   an engine brake configured to brake the engine, and   a controller electrically coupled to the at least one sensor and the engine brake, the controller comprising (i) a processor, and (ii) a memory device electrically coupled to the processor, the memory device having stored therein a plurality of instructions which, when executed by the processor, cause the processor to:   determine if the diesel particulate filter is in need of regeneration,   determine if the engine is operating in a manner that produces insufficient engine heat to regenerate the diesel particulate filter, and   if the engine is so operating, operate the engine brake so as to brake one or more cylinders of the engine while allowing at least one cylinder to combust fuel to cause the engine to generate enough engine heat to regenerate the diesel particulate filter.   
     
     
         13 . The apparatus of  claim 12 , wherein the plurality of instructions, when executed by the processor, further cause the processor to:
 determine if the engine speed of the engine is within a predetermined engine speed range, and   operate the engine brake if the engine speed is within the predetermined engine speed range.   
     
     
         14 . The apparatus of  claim 13 , wherein the at least one sensor comprises an engine speed sensor, and the plurality of instructions, when executed by the processor, further cause the processor to monitor output from the engine speed sensor. 
     
     
         15 . The apparatus of  claim 12 , wherein the plurality of instructions, when executed by the processor, further cause the processor to:
 determine if engine load of the engine is within a predetermined engine load range, and   operate the engine brake if the engine load of the engine is within the predetermined engine load range.   
     
     
         16 . The apparatus of  claim 12 , wherein the plurality of instructions, when executed by the processor, further cause the processor to query an engine load map. 
     
     
         17 . The apparatus of  claim 12 , wherein the plurality of instructions, when executed by the processor, further cause the processor to:
 determine if the temperature of exhaust gas from the engine is within a predetermined temperature range, and   operating the engine brake if the temperature of the exhaust gas from the engine is within the predetermined temperature range.   
     
     
         18 . The apparatus of  claim 17 , wherein the at least one sensor comprises an exhaust gas temperature sensor, and the plurality of instructions, when executed by the processor, further cause the processor to monitor output from the exhaust gas temperature sensor. 
     
     
         19 . The apparatus of  claim 12 , wherein the plurality of instructions, when executed by the processor, further cause the processor to operate the engine brake so as to brake a first engine cylinder of the engine and to operate the engine such that a second engine cylinder of the engine remains active while the engine brake brakes the first engine cylinder. 
     
     
         20 . The apparatus of  claim 12 , wherein the diesel particulate filter comprises a NOx trap.