DPF regeneration monitoring method
View Patent ↗A method for operating an internal combustion engine ( 100 ) and exhaust system therefor includes the step of initiating a regeneration event in a diesel particulate filter (DPF 109 ) ( 401 ). A first oxygen concentration ( 213 ) of a gas upstream of the DPF 109, and a second oxygen concentration ( 215 ) of the gas downstream of the DPF 109 are sensed ( 403 ) to infer a rate of combustion of material in the DPF ( 405 ) based on the difference between the first ( 213 ) and the second ( 215 ) oxygen concentrations. The rate of combustion is compared to a threshold value ( 409 ) and the regeneration event in the DPF 109 is terminated ( 411 ) if the rate of combustion is above the threshold.
1. A method comprising the steps of:
initiating a regeneration event in a diesel particulate filter (DPF);
sensing a first oxygen concentration of a gas upstream of the DPF, and a second oxygen concentration of the gas downstream of the DPF;
inferring a rate of combustion of material in the DPF based on a difference between the first and the second oxygen concentrations;
comparing the rate of combustion with a predetermined rate of combustion;
terminating the regeneration event in the DPF if the rate of combustion is above the predetermined rate of combustion.
2. The method of claim 1 , further comprising the step of determining whether the regeneration event is complete.
3. The method of claim 1 , further comprising the step of repeating the sensing step if the rate of combustion is below the predetermined rate of combustion.
4. The method of claim 1 , further comprising the step of calculating a gas velocIty for the gas passing through the DPF.
5. The method of claim 1 , further comprising the step of estimating a loading of the DPF.
6. The method of claim 1 , further comprising the step of computing a temperature of a filter disposed in the DPF.
7. A method comprising the steps of:
sensing a first oxygen concentration upstream of a diesel particulate filter (DPF);
sensing a second oxygen concentration downstream of the DPF;
determining an exhaust gas velocity for exhaust gas passing through the DPF;
estimating a total carbon mass deposit on a filter; and
calculating a parameter of the filter based on the first oxygen concentration, the second oxygen concentration, the exhaust gas velocity, the total carbon mass deposit, and a constant value, wherein the constant value is at least one of a bulk material density of the filter and a bulk heat capacity of the filter, and wherein the calculated parameter of the filter is at least one of a temperature of the filter and a rate of combustion in the filter.
8. The method of claim 7 , wherein the step of sensing a first oxygen concentration upstream of a diesel particulate filter (DPF) comprises measuring the first oxygen concentration in an exhaust system of an engine.
9. The method of claim 7 , wherein the step of sensing a first oxygen concentration upstream of a diesel particulate filter (DPF) comprises measuring the first oxygen concentration in an intake system of an engine.
10. The method of claim 7 , wherein the determining, estimating, and calculating steps are performed by at least one algorithm in an electronic control unit.
11. The method of claim 7 , further comprising the step of comparing the calculated parameter of the filter to a threshold parameter.