Filter regeneration system for eliminating particulate matter generated in a diesel engine

Abstract

A filter regeneration system for eliminating particulate matter generated in a diesel engine is disclosed. The filter generation system is adapted to determine a time to regenerate a filter to eliminate particulate matter discharged from the diesel engine and collected by the filter. The particulate matter is incinerated by increasing the exhaust gas temperature via an injection of fuel. The system comprises a collected amount detecting unit for detecting the amount of particulate matter collected by the filter; a control unit for determining a time to regenerate the filter based on the amount of collected particulate matter and for controlling the injection of fuel for incinerating the particulate matter; and a fuel supply unit mounted on an exhaust system for injecting the fuel in response to the control of the control unit.

What is claimed is:  
     
         1 . A regeneration system for eliminating particulate matter generated in a diesel engine from a filter, the system comprising: 
 a collected amount detecting unit for detecting the amount of particulate matter collected by a filter disposed in an exhaust system;    a control unit for determining the time to regenerate the filter based on the amount of collected particulate matter detected by said collected amount detecting unit and for controlling an injection of fuel for incinerating the particulate matter; and    a fuel injection unit mounted on the exhaust system for injecting the fuel into the exhaust system in response to the control of said control unit.    
     
     
         2 . The system as defined in  claim 1  further comprising a temperature detecting unit for detecting the temperature of exhaust in said exhaust system, wherein said control unit controls the injection of fuel for incinerating the particulate matter collected by the filter based on the temperature of the exhaust gas.  
     
     
         3 . The system as defined in  claim 1 , wherein said collected amount detecting unit includes pressure sensors mounted downstream of the filter and upstream of an oxidation catalyst of the exhaust system.  
     
     
         4 . The system as defined in  claim 2 , wherein said temperature detecting unit is a temperature sensor disposed on said exhaust pipe.  
     
     
         5 . The system as defined in  claim 1 , wherein said fuel injection unit comprises: 
 a fuel pump mounted in a fuel tank; and    an injector connected via a supply pipe to the fuel pump and mounted at the fore end of said oxidation catalyst on said exhaust pipe.    
     
     
         6 . A method for regenerating a filter in an exhaust system of an engine, comprising: 
 determining when to regenerate the filter;    measuring the temperature of the exhaust; and    increasing the temperature of the exhaust to regenerate the filter.    
     
     
         7 . The method of  claim 6 , wherein the determining comprises: 
 measuring a first exhaust pressure from a point upstream of the filter;    measuring a second exhaust pressure from a point downstream of the filter;    calculating a pressure difference between the first and second pressures;    comparing the pressure difference to a threshold pressure difference; and    deciding to regenerate the filter if the pressure difference is greater than the threshold pressure difference.    
     
     
         8 . The method of  claim 7 , wherein the threshold pressure difference corresponds to the filter holding excessive particulate matter.  
     
     
         9 . The method of  claim 6 , wherein the measuring comprises measuring the temperature of the exhaust at a point upstream of the filter.  
     
     
         10 . The method of  claim 6 , wherein the increasing comprises injecting fuel into the exhaust to bring the exhaust near a desired temperature for a desired time.  
     
     
         11 . The method of  claim 10 , wherein the desired temperature and the desired time are a temperature and a time that result in incinerating substantially all a particulate matter from the filter.  
     
     
         12 . A system for regenerating a filter in an exhaust system of an engine, comprising: 
 a detection system for detecting filter blockage and for determining when to regenerate the filter including a pressure sensor or a flow sensor; and    an exhaust temperature increasing system, including an injector for injecting a combustible material into the exhaust system.    
     
     
         13 . The system of  claim 12 , the detection system further comprising: 
 a first pressure sensor disposed in the exhaust upstream from the filter;    a second pressure sensor disposed in the exhaust downstream from the filter;    a control unit in communication with the first and second pressure sensors and programmed with instructions for: 
 measuring a first exhaust pressure from a the first pressure sensor;  
 measuring a second exhaust pressure from a the second pressure sensor;  
 calculating a pressure difference between the first and second pressures;  
 comparing the pressure difference to a threshold pressure difference; and  
 deciding to regenerate the filter ifs the pressure difference is greater than the threshold pressure difference.  
   
     
     
         14 . The system of  claim 12 , the exhaust temperature increasing system further comprising a fuel injector for injecting engine fuel into the exhaust and a control unit in communication with the fuel injector, the control unit programmed with instructions for injecting fuel into the exhaust to bring the exhaust to a desired temperature for a desired time.