Exhaust throttle valve system and method for diesel particulate filter regeneration

Abstract

An exhaust gas aftertreatment system ( 10 ) for a vehicle having an engine ( 14 ) includes a fluid passageway ( 20 ) extending from the engine to an ambient ( 18 ) for fluidly communicating exhaust gas (F). A diesel particulate filter ( 24 ) is disposed on the fluid passageway ( 20 ) downstream of the engine ( 14 ). At least one exhaust throttle valve ( 30 A- 30 D) is located downstream of the engine ( 14 ) on the fluid passageway ( 20 ). When the exhaust throttle valve ( 30 A- 30 D) is actuated, the valve obstructs the flow of exhaust gas (F) and increases the temperature of the exhaust gas. The heated exhaust gas (F) causes regeneration at the diesel particulate filter ( 24 ).

1 ) An exhaust gas aftertreatment system for a vehicle having an engine, the aftertreatment system comprising:
 a fluid passageway extending from the engine to an ambient for fluidly communicating exhaust gas;   a diesel particulate filter disposed on the fluid passageway downstream of the engine; and   at least one exhaust throttle valve located downstream of the engine on the fluid passageway, wherein actuation of the valve obstructs the flow of exhaust gas through the exhaust throttle valve and increases the temperature of the exhaust gas, wherein the heated exhaust gas effects regeneration at the diesel particulate filter.   
     
     
         2 ) The aftertreatment system of  claim 1  further comprising an actuator for actuating the at least one exhaust throttle valve to at least partially obstruct the fluid passageway. 
     
     
         3 ) The aftertreatment system of  claim 1  wherein the at least one exhaust throttle valve is a butterfly valve. 
     
     
         4 ) The aftertreatment system of  claim 1  wherein the at least one exhaust throttle valve is disposed upstream of the diesel particulate filter on the fluid passageway. 
     
     
         5 ) The aftertreatment system of  claim 1  wherein the at least one exhaust throttle valve is disposed downstream of the diesel particulate filter on the fluid passageway. 
     
     
         6 ) The aftertreatment system of  claim 1  wherein the at least one exhaust throttle valve comprises two exhaust throttle valves, wherein a first exhaust throttle valve is disposed downstream of the diesel particulate filter on the fluid passageway, and a second exhaust throttle valve is disposed upstream of the diesel particulate filter on the fluid passageway. 
     
     
         7 ) The aftertreatment system of  claim 1  further comprising at least one of a temperature sensor for sensing the temperature at the aftertreatment system and a back pressure sensor for sensing the pressure at the aftertreatment system, wherein at least one of the temperature sensor and the back pressure sensor communicate at least one of the temperature and the back pressure to an engine control module on the engine. 
     
     
         8 ) The aftertreatment system of  claim 7  wherein when at least one of a predetermined amount of back pressure and a predetermined temperature is communicated to the engine control module, the engine control module actuates the at least one exhaust throttle valve. 
     
     
         9 ) The aftertreatment system of  claim 1  wherein when the actuator is actuated, the engine injects additional fuel into a cylinder of the engine. 
     
     
         10 ) A method of regenerating an exhaust aftertreatment system of an engine having a diesel particulate filter, the method comprising:
 providing a fluid passageway from the engine to an ambient;   providing an exhaust throttle valve downstream of the engine on the fluid passageway;   actuating the exhaust throttle valve to at least partially obstruct the flow of exhaust gas through the fluid passageway;   compressing and heating the exhaust gas upstream of the exhaust throttle valve on the fluid passageway; and   delivering the heated exhaust gas to the diesel particulate filter to initiate regeneration.   
     
     
         11 ) The method of  claim 11  further comprising the step of locating the exhaust throttle valve one of upstream of the diesel particulate filter and downstream of the diesel particulate filter. 
     
     
         12 ) The method of  claim 11  wherein the exhaust throttle valve comprises two exhaust throttle valves, the method further comprising the step of locating a first exhaust throttle valve upstream of the diesel particulate filter and locating a second exhaust throttle valve downstream of the diesel particulate filter. 
     
     
         13 ) The method of  claim 11  further comprising the step of sensing and communicating at least one of a back pressure of the aftertreatment system and a temperature of the aftertreatment system to an engine control module, and comparing at least one of the back pressure and the temperature to a predetermined back pressure and a predetermined temperature, wherein on the basis of the comparison, the engine control module actuates the exhaust throttle valve. 
     
     
         14 ) The method of  claim 11  further comprising the step of actuating the exhaust throttle valve with an actuator. 
     
     
         15 ) The method of  claim 11  further comprising the step of injecting an increased amount of fuel into the cylinders when the exhaust throttle valve is actuated. 
     
     
         16 ) An exhaust gas aftertreatment system for a vehicle having an engine, the aftertreatment system comprising:
 an engine control module associated with the engine;   a fluid passageway extending from the engine to an ambient for fluidly communicating exhaust gas;   a diesel particulate filter disposed on the fluid passageway downstream of the engine;   at least one exhaust throttle valve located downstream of the diesel particulate filter on the fluid passageway;   an actuator for actuating the at least one exhaust throttle valve; and   at least one of a temperature sensor for sensing the temperature at the aftertreatment system and a back pressure sensor for sensing the pressure at the aftertreatment system, wherein at least one of the temperature sensor and the back pressure sensor communicate at least one of the temperature and the back pressure to an engine control module on the engine.   
     
     
         17 ) The exhaust gas aftertreatment system of  claim 16  wherein when at least one of a predetermined amount of back pressure and a predetermined temperature is communicated to the engine control module, the engine control module actuates the at least one exhaust throttle valve with the actuator. 
     
     
         18 ) The exhaust gas aftertreatment system of  claim 16  further comprising at least one second exhaust throttle valve located on the fluid passageway between the engine and the diesel particulate filter. 
     
     
         19 ) The exhaust gas aftertreatment system of  claim 16  wherein the exhaust throttle valve is a butterfly valve. 
     
     
         20 ) The exhaust gas aftertreatment system of  claim 16  wherein the exhaust throttle valve closes about 80 to 96% of the fluid passageway to obstruct the flow of exhaust gas through the exhaust throttle valve.