Exhaust gas processing device

Abstract

An exhaust gas treatment method having a particulate matter (PM) sensor on which a part of PM exhausted from a diesel particulate filter (DPF) may be attached and that generates a signal, may include determining a sensor trap PM model amount that may be trapped on the PM sensor in a condition that the diesel particulate filter may be operated normal according to an engine driving condition and a variation thereof, determining a sensor trap PM real amount that may be attached on the PM sensor by using the signal that may be generated from the PM sensor, and determining a condition of the diesel particulate filter by comparing the sensor trap PM model amount and the sensor trap PM real amount.

What is claimed is: 
     
         1 . An exhaust gas treatment method having a particulate matter (PM) sensor on which a part of PM exhausted from a diesel particulate filter (DPF) is attached and that generates a signal, comprising:
 determining a sensor trap PM model amount that is trapped on the PM sensor in a condition that the diesel particulate filter is operated normal according to an engine driving condition and a variation thereof;   determining a sensor trap PM real amount that is attached on the PM sensor by using the signal that is generated from the PM sensor; and   determining a condition of the diesel particulate filter by comparing the sensor trap PM model amount and the sensor trap PM real amount.   
     
     
         2 . The exhaust gas treatment method of  claim 1 , wherein the diesel particulate filter is determined to be damaged when a difference between the PM trap real amount and the PM trap model is larger than a predetermined value. 
     
     
         3 . The exhaust gas treatment method of  claim 1 , further comprising:
 determining a total PM flow rate that is generated from an engine; and   determining a filter slip PM flow rate by using the total PM flow rate and a trap efficiency of the DPF to determine the sensor trap PM model amount.   
     
     
         4 . The exhaust gas treatment method of  claim 3 , wherein the total PM flow rate is determined by using a rotation speed of the engine, a fuel injection amount, an engine torque, and an Exhaust Gas Recirculation (EGR) rate of the engine. 
     
     
         5 . The exhaust gas treatment method of  claim 3 , wherein the trap efficiency is determined by a PM trap amount that is trapped in the diesel particulate filter, an exhaust gas flow rate of the engine, and a front temperature of the diesel particulate filter. 
     
     
         6 . The exhaust gas treatment method of  claim 3 , wherein the sensor trap PM model amount is determined by a filter slip PM total amount that is determined by the filter slip PM flow rate. 
     
     
         7 . The exhaust gas treatment method of  claim 6 , wherein the filter slip PM total amount is determined after eliminating the PM that is attached to the PM sensor. 
     
     
         8 . The exhaust gas treatment method of  claim 7 , wherein the PM that is attached to the PM sensor is eliminated by a heater that is disposed near the PM sensor. 
     
     
         9 . The exhaust gas treatment method of  claim 1 , wherein the PM sensor includes electrodes that are formed along a predetermined line, and generates the signal according to amount of the PM that is attached between the electrodes.