Control system for lean air-fuel ratio NOx catalyst system
AssigneeChrysler Corporation
InventorMark Borland
Life of this patent
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Abstract
A control system is described for optimizing the reduction of nitrogen oxides in exhaust gas produced by an internal combustion engine, especially those internal combustion engines that employ a lean air-fuel ratio. The control system employs a temperature control assembly that is capable of selectively heating the exhaust gas prior to introduction into the NOx catalyst system, thus rapidly bringing the temperature of the NOx catalyst system up to operating temperature.
Claims10
A control system for use in an internal combustion engine automobile having a NOx catalyst system and a urea injection system, comprising:
- a first temperature sensor placed upstream of the NOx catalyst system, the first temperature sensor detecting the temperature of the exhaust gas prior to introduction into the NOx catalyst system;
- a NOx sensor placed upstream of the NOx catalyst system, the NOx sensor sensing the level of NOx in the exhaust gas;
- a temperature control assembly upstream of the first temperature sensor and NOx sensor, the temperature control assembly selectively adjusting the temperature of the exhaust gas prior to the exhaust gas being introduced into the NOx catalyst system;
- and
- a second temperature sensor placed downstream of the NOx catalyst system, the second temperature sensor detecting the temperature of the exhaust gas after exiting the NOx catalyst system,
- wherein the NOx sensor, the second temperature sensor, and the urea injection system are in communication to enhance the removal of NOx from the exhaust gas.
A control system for use in an internal combustion engine automobile having a NOx catalyst system, comprising:
- a temperature control assembly placed upstream of the NOx catalyst system, the temperature control assembly selectively adjusting the temperature of the exhaust gas prior to the exhaust gas being introduced into the NOx catalyst system;
- a first temperature sensor placed downstream of the temperature control assembly and upstream of the NOx catalyst system, the first temperature sensor detecting the temperature of the exhaust gas prior to introduction into the NOx catalyst system;
- a NOx sensor placed downstream of the temperature control assembly and upstream of the NOx catalyst system, the NOx sensor sensing the level of NOx in the exhaust gas;
- and
- a second temperature sensor placed downstream of the NOx catalyst system, the second temperature sensor detecting the temperature of the exhaust gas after exiting the NOx catalyst system;
- wherein the temperature control assembly raises the temperature of the exhaust gas prior to the exhaust gas being introduced into the NOx catalyst system.
A control system for use in an internal combustion engine automobile having a NOx catalyst system, comprising:
- a temperature control assembly placed upstream of the NOx catalyst system, the temperature control assembly selectively adjusting the temperature of the exhaust gas prior to the exhaust gas being introduced into the NOx catalyst system;
- a NOx sensor placed downstream of the temperature control assembly and upstream of the NOx catalyst system, the NOx sensor sensing the level of NOx in the exhaust gas;
- a first temperature sensor placed downstream of the temperature control assembly and upstream of the NOx catalyst system, the first temperature sensor detecting the temperature of the exhaust gas prior to introduction into the NOx catalyst system;
- a second temperature sensor placed downstream of the NOx catalyst system, the second temperature sensor detecting the temperature of the exhaust gas after exiting the NOx catalyst system;
- an actuation assembly being capable of selectively actuating the temperature control assembly;
- and
- an engine control assembly being capable of selectively supplying electrical power to the actuation assembly;
- wherein the engine control assembly selectively supplies electrical power to the actuation assembly in response to at least one sensor selected from the group consisting of the first temperature sensor, the NOx sensor, the second temperature sensor, and combinations thereof;
- wherein the temperature control assembly raises the temperature of the exhaust gas prior to the exhaust gas being introduced into the NOx catalyst system.
Dependencies are inferred from the claim text.