Method of monitoring hydrocarbon levels in a diesel particulate filter
View Patent ↗In a method of determining hydrocarbon slip through a diesel oxidation catalyst for an engine having an electronic control module and an exhaust system having a diesel oxidation catalyst and a diesel particulate filter, the electronic control module receives data indicative of a temperature of a diesel oxidation catalyst input, a temperature of a diesel oxidation catalyst output, and a temperature of a diesel particulate filter output. An energy conversion ratio is calculated with the electronic control module using the data indicative of the temperature of the diesel oxidation catalyst input, the temperature of the diesel oxidation catalyst output, and the temperature of the diesel particulate filter output. The calculated energy conversion ratio is compared to stored energy conversion ratio in a memory accessed by the electronic control module. An estimate of hydrocarbon slip through the diesel oxidation catalyst is generated with the electronic control module based upon the comparison of the calculated energy conversion ratio to stored energy conversion ratio.
1. A method of monitoring hydrocarbon levels in a diesel particulate filter for an engine having an electronic control module and an exhaust system having a diesel oxidation catalyst and a diesel particulate filter, method comprising:
receiving in an electronic control module data indicative of a temperature of a diesel oxidation catalyst input, a temperature of a diesel oxidation catalyst output, and a temperature of a diesel particulate filter output;
calculating an energy conversion ratio with the electronic control module using the data indicative of the temperature of the diesel oxidation catalyst input, the temperature of the diesel oxidation catalyst output, and the temperature of the diesel particulate filter output;
comparing the calculated energy conversion ratio to a stored energy conversion ratio in a memory accessible by the electronic control module; and
generating an estimate of hydrocarbon slip through the diesel oxidation catalyst based upon the comparison of the calculated energy conversion ratio to the stored energy conversion ratio wherein the calculated energy conversion ratio is generated using the following formula:
Energy
Conversion
Ratio
=
T
2
-
T
1
T
3
-
T
1
wherein T1 is a temperature at the diesel oxidation catalyst input, T2 is a temperature at the diesel oxidation catalyst output, and T3 is a temperature at the diesel particulate filter output.
2. The method of claim 1 , wherein the data indicative of the temperature of the diesel oxidation catalyst input, the temperature of the diesel oxidation catalyst output, and the temperature of the diesel particulate filter output received are averaged for a period of time before calculating the energy conversion ratio.
3. The method of claim 1 further comprising:
receiving in the electronic control module data indicative of an exhaust flow rate of the engine; and
determining whether the engine is operating in one of either a transient manner or a steady-state manner based upon the exhaust flow rate data.
4. The method of claim 1 , wherein the memory accessible by the electronic control module is disposed within the electronic control module.
5. The method of claim 1 , further comprising:
comparing the data indicative of the temperature of the diesel oxidation catalyst input, the temperature of the diesel oxidation catalyst output, and the temperature of the diesel particulate filter output to stored calibration data ranges.
6. A method of estimating hydrocarbon levels in a diesel particulate filter during a diesel particulate filter regeneration, the diesel engine having an electronic control module, a diesel oxidation catalyst, and a diesel particulate filter, the method comprising:
initiating a diesel particulate filter regeneration cycle;
calculating an energy conversion ratio with the electronic control module using data indicative of a temperature of the diesel oxidation catalyst input, a temperature of the diesel oxidation catalyst output, and a temperature of the diesel particulate filter output;
generating an estimate of hydrocarbon slip through the diesel oxidation catalyst with the electronic control module based upon the energy conversion ratio; and
disabling the diesel particulate filter regeneration cycle when the estimate of hydrocarbon slip through the diesel oxidation catalyst exceeds a threshold value wherein the calculated energy conversion ratio is generated using the following formula:
Energy
Conversion
Ratio
=
T
2
-
T
1
T
3
-
T
1
wherein T1 is a temperature at the diesel oxidation catalyst input, T2 is a temperature at the diesel oxidation catalyst output, and T3 is a temperature at the diesel particulate filter output.
7. The method of claim 6 further comprising:
receiving in the electronic control module data indicative of a temperature of a diesel oxidation catalyst input, a temperature of a diesel oxidation catalyst output, and a temperature of a diesel particulate filter output.
8. The method of claim 6 further comprising:
reducing engine power output when the estimate of hydrocarbon slip through the diesel oxidation catalyst exceeds the threshold value.
9. The method of claim 6 further comprising:
receiving in the electronic control module data indicative of an exhaust flow rate of the engine; and
determining whether the engine is operating in a transient manner or a steady-state manner based upon the exhaust flow rate data, wherein the calculating the energy conversion ratio with the electronic control module is performed only when the engine is operating in a steady-state manner.
10. The method of claim 6 further comprising:
setting a fault code in the electronic control module when the estimate of hydrocarbon slip through the diesel oxidation catalyst exceeds a threshold value.
11. The method of claim 6 , wherein the estimate of hydrocarbon slip through the diesel oxidation catalyst is generated by comparing the calculated energy conversion ratio to stored energy conversion ratios in a memory accessed by the electronic control module.
12. A method for calculating an energy conversion ratio of a diesel oxidation catalyst and a diesel particulate filter for a diesel engine having the diesel oxidation catalyst, the diesel particulate filter, and an electronic control module, the method comprising:
presenting a temperature of an inlet of the diesel oxidation catalyst to the electronic control module;
providing a temperature of an outlet of the diesel oxidation catalyst to the electronic control module;
delivering a temperature of an outlet of the diesel particulate filter to the electronic control module; and
calculating an energy conversion ratio with the electronic control module using the following formula:
Energy
Conversion
Ratio
=
T
2
-
T
1
T
3
-
T
1
wherein T1 is a temperature at the diesel oxidation catalyst input, T2 is a temperature at the diesel oxidation catalyst output, and T3 is a temperature at the diesel particulate filter output.
13. The method of claim 12 further comprising:
receiving in the electronic control module data indicative of an exhaust flow rate of the engine; and
determining whether the engine is operating in a transient manner or a steady-state manner based upon the exhaust flow rate data, wherein the calculating the energy conversion ratio is performed when the engine is operating in the steady-state manner.
14. The method of claim 12 further comprising:
averaging the data indicative of the temperature of the diesel oxidation catalyst input, the temperature of the diesel oxidation catalyst output, and the temperature of the diesel particulate filter output received for a period of time before calculating the energy conversion ratio.