CN-122014441-A - Exhaust gas temperature control

Abstract

A vehicle engine adapted to control an Exhaust Gas Temperature (EGT) at a catalyst inlet includes an EGT sensor in communication with a system controller and adapted to measure the exhaust gas temperature at the catalyst inlet, the system controller adapted to compare the measured EGT to a target EGT and limit gas exchange within cylinders within the engine during an intake stroke when the measured EGT is greater than the target EGT and to increase turbine efficiency of a variable geometry turbocharger of the engine by increasing boost from the variable geometry turbocharger.

Inventors

• J. E. Cottrell
• A. M. Alz
• R.S. McCulpin
• K. Briscoe
• K. M. Luchangsky
• MURTHY PRATAP S

Assignees

• 通用汽车环球科技运作有限责任公司

Dates

Publication Date

20260512

Application Date

20241227

Priority Date

20241111

Claims (10)

1. 1. A method of controlling exhaust gas temperature within a vehicle engine, comprising: measuring an Exhaust Gas Temperature (EGT) at the catalyst inlet with an EGT sensor in communication with the system controller; comparing the measured EGT with a target EGT using the system controller, and When the measured EGT is greater than the target EGT: Limiting gas exchange in a cylinder in the engine during an intake stroke using the system controller, and With the system controller, turbine efficiency of a variable geometry turbocharger of the engine is increased by increasing boost from the turbocharger.
2. 2. The method of claim 1, further comprising adjusting, with the system controller, gas exchange during the intake stroke within the cylinder within the engine to increase the EGT when the measured EGT is less than the target EGT.
3. 3. The method of claim 2, further comprising one of the following when the measured EGT is equal to the target EGT: maintaining a current gas exchange calibration within the cylinder with the system controller, or Limiting gas exchange in the cylinder during the intake stroke with the system controller, and With the system controller, turbine efficiency of a variable geometry turbocharger of the engine is increased by increasing boost from the turbocharger.
4. 4. The method of claim 3, wherein limiting gas exchange within the cylinder during the intake stroke with the system controller further comprises closing an intake valve for the cylinder in advance during the intake stroke with the system controller and reducing a volume of an air-fuel mixture received within the cylinder during the intake stroke.
5. 5. The method of claim 4 wherein closing the intake valve of the cylinder in advance during the intake stroke with the system controller further comprises adjusting a timing of an intake camshaft associated with the intake valve with a cam phaser in communication with the system controller.
6. 6. The method of claim 5, wherein adjusting the timing of the intake cam associated with the intake valve with the cam phaser further comprises adjusting the timing of a short duration intake camshaft associated with the intake valve with the cam phaser.
7. 7. The method of claim 4, further comprising adjusting spark timing based on an advance of the closing of the intake valve.
8. 8. The method of claim 4, wherein increasing boost from the variable geometry turbocharger with the system controller further comprises adjusting an angle of each movable vane of a plurality of movable vanes surrounding the turbine with the system controller, the movable vanes in communication with the system controller and adapted to control the flow of exhaust through the turbine of the variable geometry turbocharger.
9. 9. The method of claim 8, wherein the increasing boost from the variable geometry turbocharger further comprises directing all exhaust from the engine through the turbine of the variable geometry turbocharger.
10. 10. The method of claim 9, wherein the increasing boost from the variable geometry turbocharger further comprises increasing enthalpy extraction from exhaust directed through the turbine of the variable geometry turbocharger.

Description

Exhaust gas temperature control Technical Field The present disclosure relates to an engine for a vehicle adapted to control an Exhaust Gas Temperature (EGT) at a catalyst inlet. Background In an internal combustion engine, as gas passes through an exhaust system, exhaust from cylinders within the engine is directed through a catalyst (catalytic converter). The high EGT at the catalyst affects the performance and durability of the catalyst. Thus, while current systems and methods achieve their intended purpose, there remains a need for a new and improved engine and method for controlling the temperature of exhaust gases from an engine. Disclosure of Invention In accordance with several aspects of the present disclosure, a method of controlling exhaust gas temperature in a vehicle engine includes measuring a temperature of exhaust gas at a catalyst inlet (exhaust gas temperature, EGT) with an EGT sensor in communication with a system controller, comparing the measured EGT with a target EGT with the system controller, and limiting gas exchange in cylinders in the engine during an intake stroke with the system controller when the measured EGT is greater than the target EGT, and increasing turbine efficiency of a variable geometry turbocharger of the engine by increasing boost from the turbocharger with the system controller. According to another aspect, the method further includes adjusting, with the system controller, gas exchange during an intake stroke within a cylinder of the engine to increase the EGT when the measured EGT is less than the target EGT. According to another aspect, the method further includes one of maintaining, by the system controller, a current gas exchange calibration within the cylinder, or limiting, by the system controller, gas exchange within the cylinder during an intake stroke when the measured EGT is equal to the target EGT, and increasing, by the system controller, a turbine efficiency of a variable geometry turbocharger of the engine by increasing boost from the turbocharger. According to another aspect, limiting the exchange of gas within the cylinder during the intake stroke with the system controller further includes closing an intake valve for the cylinder in advance during the intake stroke with the system controller and reducing the volume of the air-fuel mixture received within the cylinder during the intake stroke. According to another aspect, closing the intake valve for the cylinder in advance during the intake stroke with the system controller further includes adjusting a timing of an intake camshaft associated with the intake valve with a cam phaser in communication with the system controller. According to another aspect, adjusting the timing of an intake cam associated with the intake valve with the cam phaser further includes adjusting the timing of a short duration intake camshaft associated with the intake valve with the cam phaser. According to another aspect, the method further includes adjusting spark timing based on advance of intake valve closing. According to another aspect, increasing boost from the variable geometry turbocharger with the system controller further includes adjusting, with the system controller, an angle of each of a plurality of movable vanes surrounding the turbine, the vanes in communication with the system controller and adapted to control exhaust flow through the turbine of the variable geometry turbocharger. According to another aspect, increasing boost from the variable geometry turbocharger further includes directing all exhaust from the engine through a turbine of the variable geometry turbocharger. According to another aspect, increasing the boost from the variable geometry turbocharger further includes increasing enthalpy extraction from exhaust gas directed through a turbine of the variable geometry turbocharger. In accordance with several aspects of the present disclosure, a vehicle engine adapted to control an Exhaust Gas Temperature (EGT) at a catalyst inlet includes an EGT sensor in communication with a system controller and adapted to measure the exhaust gas temperature at the catalyst inlet, the system controller is adapted to compare the measured EGT to a target EGT and to limit gas exchange within cylinders within the engine during an intake stroke when the measured EGT is greater than the target EGT and to increase turbine efficiency of a variable geometry turbocharger of the engine by increasing boost from the variable geometry turbocharger. According to another aspect, the system controller is adapted to adjust gas exchange during an intake stroke in an engine cylinder to increase the EGT when the measured EGT is less than a target EGT. According to another aspect, when the measured EGT is equal to the target EGT, the system controller is adapted to one of maintain a current gas exchange calibration within the cylinder, or limit gas exchange within the cylinder, during an intake stroke and increase turbine efficiency