Heat generation system for determining a selective catalytic reduction device efficiency

Patent metadata

Field	Value
Publication number	US-9415345-B2
Application number	US-201313760558-A
Country	US
Kind code	B2
Filing date	Feb 6, 2013
Priority date	Feb 6, 2013
Publication date	Aug 16, 2016
Grant date	Aug 16, 2016

Abstract

A control method and system for monitoring a selective catalytic reduction (“SCR”) device of an exhaust gas treatment system is disclosed. The method includes monitoring a plurality of operating conditions related to determining an efficiency of the SCR device and a SCR temperature. The method includes determining if each of the operating conditions are within a respective predetermined range and if the SCR temperature is below an operating temperature range. The method includes activating a hydrocarbon supply based on if each of the operating conditions are within the respective predetermined range and if the SCR temperature is below the operating temperature range. The hydrocarbon supply is located upstream of the SCR device to generate heat if activated. The method includes monitoring the SCR temperature to determine if the SCR device is operating within the operating temperature range.

First claim

What is claimed is:

1. A control method for monitoring a selective catalytic reduction (“SCR”) device of an exhaust gas treatment system included in a vehicle, the control method comprising:
monitoring a plurality of operating conditions existing during a current driving condition controlled by an engine of the vehicle, and an SCR temperature by an electronic control module including a hardware processor with electronic circuitry configured to execute operative circuit logic, the plurality of operating conditions related to determining an efficiency of the SCR device;
determining if each of the operating conditions are operating within a respective predetermined range, and if the SCR temperature is below an operating temperature range;
activating a hydrocarbon supply including an injector configured to inject unburned hydrocarbon based on each of the plurality of operating conditions operating within the respective predetermined range regardless of the current driving condition controlled by the engine, and the SCR temperature being below the operating temperature range, the hydrocarbon supply located upstream of the SCR device to generate heat if activated;
monitoring the SCR temperature to determine if the SCR device is operating within the operating temperature range after the hydrocarbon supply is activated; and
when the SCR temperature is below the operating temperature range within a predetermined amount of time, setting a diagnostic code and disabling the hydrocarbon supply.

2. The control method of claim 1 , further comprising selectively determining the efficiency of the SCR device within a predetermined amount of time if the SCR device is operating within the operating temperature range.

3. The control method of claim 1 , further comprising deactivating the hydrocarbon supply if the efficiency of the SCR device is not determined within a predetermined amount of time, and wherein the SCR device is operating within the operating temperature range.

4. The control method of claim 1 , wherein the efficiency of the SCR device is based on an upstream NO x concentration value and a downstream NO x concentration value.

5. The control method in claim 4 , wherein the efficiency is calculated using the following equation:
Eff=1−NO x _ DWN/NO x _ UP

wherein Eff is the efficiency, NO x _ DWN is a measured concentration of the downstream NO x concentration value, and NO x _ UP is a measured concentration of the upstream NO x concentration value.

6. The control method of claim 1 , wherein the plurality of operating conditions include a vehicle speed, an exhaust flow rate, and a pedal position.

7. The control method of claim 1 , wherein the operating temperature range is above a light-off temperature of the SCR device.

8. The control method of claim 1 , wherein the hydrocarbon supply comprises one of a hydrocarbon injector and an internal combustion engine.

9. A control system for monitoring a selective catalytic reduction (“SCR”) device of an exhaust gas treatment system in a vehicle, the control system comprising:
a hydrocarbon supply located upstream of the SCR device, the hydrocarbon supply including an injector configured to be selectively activated to inject unburned hydrocarbons for generating heat to the SCR device; and
an electronic control module including a hardware process having electronic circuitry configured to execute operative logic, the electronic control module in communication with the hydrocarbon supply, the electronic control module comprising:
an activation module comprising a hardware processor including operative logic that, when executing computer-readable instructions, performs monitoring a plurality of operating conditions existing during a current driving condition controlled by an engine of the vehicle and an SCR temperature, the activation module determining if each the plurality of operating conditions are within a respective predetermined range and the SCR temperature is below an operating temperature range, the plurality of operating conditions related to determining an efficiency of the SCR device;
a hydrocarbon activation module comprising a hardware processor including operative logic that, when executing computer-readable instructions, is configured to activate the hydrocarbon supply if each of the plurality of operating conditions are operating within the respective predetermined range regardless of the current driving condition controlled by an engine of the vehicle, and if the SCR temperature is below the operating temperature range; and
an SCR temperature timer module comprising a hardware processor including operative circuit logic that, when executing computer-readable instructions, is configured to monitor the SCR temperature to determine if the SCR device is operating within the operating temperature range after the hydrocarbon supply is activated, wherein
when the SCR temperature is below the operating temperature range within a predetermined amount of time, setting a diagnostic code and disabling the hydrocarbon supply.

10. The control system of claim 9 , wherein the electronic control module includes an SCR efficiency calculation module that selectively determines the efficiency of the SCR device within a predetermined amount of time if the SCR device is operating within the operating temperature range.

11. The control system of claim 9 , wherein the electronic control module includes an SCR efficiency calculation module that deactivates the hydrocarbon supply if the efficiency of the SCR device is not determined within a predetermined amount of time, and wherein the SCR device is operating within operating temperature range.

12. The control system of claim 9 , wherein the efficiency is based on an upstream NO x concentration value and a downstream NO x concentration value.

13. The control system of claim 12 , wherein the efficiency is calculated using the following equation:
Eff=1−NO x _ DWN/NO x _ UP

wherein Eff is the efficiency, NO x _ DWN is a measured concentration of the downstream NO x concentration value, and NO x _ UP is a measured concentration of the upstream NO x concentration value.

14. The control system of claim 9 , wherein the plurality of operating conditions include at least a vehicle speed, an exhaust flow rate, and a pedal position.

15. The control system of claim 9 , wherein the operating temperature range is above a light-off temperature of the SCR device.

16. The control system of claim 9 , wherein the hydrocarbon supply comprises one of a hydrocarbon injector and an internal combustion engine.

Assignees

• Gm Global Tech Operations Llc

Inventors

• Holbert Timothy J
• Sisco Eric M
• Kowalkowski Janean E

Classifications

• Y02T10/12

  Improving ICE efficiencies · CPC title

• F01N11/00

  Monitoring or diagnostic devices for exhaust-gas treatment apparatus · CPC title

• F01N3/208

  Control of selective catalytic reduction [SCR], e.g. by adjusting the dosing of reducing agent · CPC title

• B01D53/9459

  Removing one or more of nitrogen oxides, carbon monoxide, or hydrocarbons by multiple successive catalytic functions; systems with more than one different function, e.g. zone coated catalysts (layered catalysts with only one function B01D53/9413, B01D53/944 or B01D53/945) · CPC title

• F01N2610/02

  the substance being ammonia or urea · CPC title