TEMPERATURE CONTROL SYSTEM AND METHOD FOR PARTICULATE FILTER REGENERATION USING A HYDROCARBON INJECTOR

• US 20100076666A1
• Filed: 05/13/2009
• Published: 03/25/2010
• Est. Priority Date: 09/19/2008
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (General Motors Company)
• Inventors: Solbrig, Charles E., Yanakiev, Ognyan N.
• Granted Patent: US 8,265,852 B2
• Time in Patent Office: Days
• US Class Current: 701/103
• CPC Class Codes: F01N 3/023 using means for regenerating the filters, e.g. by burning trapped particles by electrically controlling the supply of combustible mixture or its constituents only F02D41/0235

Abstract

A control system includes a first module, a fuel determination module, a temperature error correction module, and a hydrocarbon injection control module. The first module determines a temperature difference between a desired inlet temperature of a particulate filter (PF) and an outlet temperature of a first catalyst. The fuel determination module determines an uncorrected desired fuel value based on the temperature difference, an ambient temperature, and a mass flow of exhaust gas. The temperature error correction module generates a desired fuel value based on the uncorrected desired fuel value. The hydrocarbon injection control module controls a hydrocarbon injector based on the desired fuel value.

Claims

1. A control system comprising:

a first module that determines a temperature difference between a desired inlet temperature of a particulate filter (PF) and an outlet temperature of a first catalyst;

a fuel determination module that determines an uncorrected desired fuel value based on the temperature difference, an ambient temperature, and a mass flow of exhaust gas;

a temperature error correction module that generates a desired fuel value based on the uncorrected desired fuel value; and

a hydrocarbon injection control module that controls a hydrocarbon injector based on the desired fuel value.

2. The control system of claim 1 wherein the temperature error correction module generates an error value based on a difference between a measured inlet temperature of the PF and the desired inlet temperature.

3. The control system of claim 2 wherein the temperature error correction module generates a correction value based on the error value and generates the desired fuel value based on a sum of the uncorrected desired fuel value and the correction value.

4. The control system of claim 3 wherein the temperature error correction module generates the correction value using one of a proportional, a proportion-integral, and a proportional-integral-derivative approach.

5. The control system of claim 1 wherein the mass airflow of the exhaust gas is based on the desired fuel value and a mass airflow value of intake air.

6. The control system of claim 1 wherein the fuel determination module generates the uncorrected desired fuel value based on:

T_INCR×

N PPM/°

C.×

1E-6×

(MAF_EXH/MW_EXH)×

MW_HC

wherein T_INCR is the temperature difference, N PPM/°

C. is a predetermined number of fuel parts per million (PPM) required to raise the temperature of the exhaust gas by 1°

C., MAF_EXH is the mass airflow of the exhaust gas, MW_EXH is a molecular weight of the exhaust gas, and MW_HC is a molecular weight of hydrocarbon.

7. The control system of claim 6 wherein the fuel determination module comprises a table outputting N PPM/°

C., and wherein the table is indexed by at least one of MAF_EXH and the ambient temperature.

8. The control system of claim 1 wherein the first catalyst is upstream of the PF, wherein a first oxidation catalyst is located between the first catalyst and the PF, and wherein the hydrocarbon injector injects hydrocarbons upstream of the oxidation catalyst.

9. A system comprising the control system of claim 8 and the first catalyst, wherein the first catalyst is one of a selective catalyst reduction (SCR) catalyst and a lean NOx trap.

10. The system of claim 9 further comprising a second oxidation catalyst arranged upstream from the first catalyst.

11. A method comprising:

determining a temperature difference between a desired inlet temperature of a particulate filter (PF) and an outlet temperature of a first catalyst;

determining an uncorrected desired fuel value based on the temperature difference, an ambient temperature, and a mass flow of exhaust gas;

generating a desired fuel value based on the uncorrected desired fuel value; and

controlling a hydrocarbon injector based on the desired fuel value.

12. The method of claim 11 further comprising generating an error value based on a difference between a measured inlet temperature of the PF and the desired inlet temperature.

13. The method of claim 12 further comprising:

generating a correction value based on the error value; and

generating the desired fuel value based on a sum of the uncorrected desired fuel value and the correction value.

14. The method of claim 13 further comprising generating the correction value using one of a proportional, a proportion-integral, and a proportional-integral-derivative approach.

15. The method of claim 11 further comprising determining the mass airflow of the exhaust gas based on the desired fuel value and a mass airflow value of intake air.

16. The method of claim 11 further comprising generating the uncorrected desired fuel value based on:

T_INCR×

N PPM/°

C.×

1E-6×

(MAF_EXH/MW_EXH)×

MW_HC

wherein T_INCR is the temperature difference, N PPM/°

C. is a predetermined number of fuel parts per million (PPM) required to raise the temperature of the exhaust gas by 1°

C., MAF_EXH is the mass airflow of the exhaust gas, MW_EXH is a molecular weight of the exhaust gas, and MW_HC is a molecular weight of hydrocarbon.

17. The method of claim 16 further comprising storing a table outputting N PPM/°

C., wherein the table is indexed by at least one of MAF_EXH and the ambient temperature.

18. The method of claim 11 wherein the first catalyst is upstream of the PF, wherein a first oxidation catalyst is located between the first catalyst and the PF, and wherein the hydrocarbon injector injects hydrocarbons upstream of the oxidation catalyst.

19. The method of claim 18 wherein the first catalyst is one of a selective catalyst reduction (SCR) catalyst and a lean NOx trap.

20. The method of claim 19 wherein a second oxidation catalyst is arranged upstream from the first catalyst.