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DE-102024139855-A1 - EXHAUST GAS TEMPERATURE CONTROL

DE102024139855A1DE 102024139855 A1DE102024139855 A1DE 102024139855A1DE-102024139855-A1

Abstract

A vehicle engine designed to control the exhaust gas temperature (EGT) at a catalyst inlet includes an EGT sensor that communicates with a system controller and is designed to measure the exhaust gas temperature at the catalyst inlet, the system controller being designed to compare the measured EGT with a target EGT and then, if the measured EGT is greater than the target EGT, to limit the gas exchange in a cylinder in the engine during an intake stroke and to increase the turbine efficiency of a variable geometry turbocharger of the engine by increasing the pressure boost from the variable geometry turbocharger.

Inventors

  • Justin Edward Ketterer
  • Andrew Michael Aerts
  • Robert S. McAlpine
  • Kenneth Briscoe
  • Kevin M. Luchansky
  • Pratap Srinivasa Murthy

Assignees

  • GM Global Technology Operations LLC

Dates

Publication Date
20260513
Application Date
20241230
Priority Date
20241111

Claims (10)

  1. A method for controlling the exhaust gas temperature in a vehicle engine, comprising: Measuring the exhaust gas temperature (EGT) at a catalytic converter inlet using an EGT sensor in communication with a system controller; Comparing the measured EGT with a target EGT using the system controller; and then, if the measured EGT is greater than the target EGT: Limiting the gas exchange in a cylinder of the engine during an intake stroke using the system controller; and Increasing the turbine efficiency of a variable-geometry turbocharger of the engine by increasing the boost pressure from the turbocharger using the system controller.
  2. Procedure according to Claim 1 , which furthermore includes, if the measured EGT is smaller than the target EGT, an adjustment with the system controller of the gas exchange during the intake stroke in the cylinder in the engine to increase the EGT.
  3. Procedure according to Claim 2 , which furthermore includes, if the measured EGT is equal to the target EGT, one of the following: maintaining the current gas exchange calibration in the cylinder using the system controller; or limiting the gas exchange in the cylinder during the intake stroke using the system controller; and increasing the turbine efficiency of the variable geometry turbocharger using the system controller by increasing the pressure boost from the turbocharger.
  4. Procedure according to Claim 3 , wherein limiting the gas exchange in the cylinder during the intake stroke with the system controller further comprises advancing the closing of an intake valve for the cylinder during the intake stroke with the system controller and reducing the volume of an air/fuel mixture that is taken into the cylinder during the intake stroke.
  5. Procedure according to Claim 4 , wherein the advancement with the system controller of the closing of the intake valve for the cylinder during the intake stroke further includes an adjustment with a cam phaser in communication with the system controller of the timing of an intake camshaft assigned to the intake valve.
  6. Procedure according to Claim 5 , wherein the adjustment with the cam phaser of the timing of the intake cam assigned to the intake valve further includes an adjustment with the cam phaser of the timing of a short intake duration camshaft assigned to the intake valve.
  7. Procedure according to Claim 4 , which further includes an adjustment of the ignition timing sequence based on the advance of the closing of the intake valve.
  8. Procedure according to Claim 4 , wherein increasing the pressure increase from the variable geometry turbocharger with the system controller further includes adjusting with the system controller an angle of each of several movable blades around the turbine, which are in communication with the system controller and are designed to control the exhaust gas flow through the turbine of the variable geometry turbocharger.
  9. Procedure according to Claim 8 , wherein increasing the pressure increase from the variable geometry turbocharger further includes directing all exhaust gas from the engine through the turbine of the variable geometry turbocharger.
  10. Procedure according to Claim 9 , wherein increasing the pressure increase from the variable geometry turbocharger further comprises increasing the enthalpy extraction from exhaust gas passed through the turbine of the variable geometry turbocharger.

Description

INTRODUCTION The present disclosure relates to a power engine for a vehicle designed to control the exhaust gas temperature (EGT) at a catalyst inlet. In an internal combustion engine, exhaust gas from the cylinders is passed through a catalytic converter (exhaust gas catalyst) as it travels through an exhaust system. A high exhaust gas temperature (EGT) at the catalyst impairs its performance and lifespan. Thus, while current systems and procedures achieve their intended purpose, there is a need for a new and improved engine and a new and improved method for controlling the temperature of exhaust gases from the engine. SUMMARY According to several aspects of the present disclosure, a method for controlling the exhaust gas temperature in a vehicle engine comprises measuring an exhaust gas temperature (EGT) at a catalyst inlet with an EGT sensor in communication with a system controller, comparing the measured EGT with a target EGT using the system controller, and then, if the measured EGT is greater than the target EGT, limiting the gas exchange in a cylinder in the engine during an intake stroke using the system controller, and increasing the turbine efficiency of a variable-geometry turbocharger of the engine by increasing the pressure boost from the turbocharger using the system controller. According to another aspect, the procedure also includes, if the measured EGT is smaller than the target EGT, an adjustment with the system controller of the gas exchange during the intake stroke in the cylinder in the engine in order to increase the EGT. According to another aspect, the procedure further includes, if the measured EGT is equal to the target EGT, either maintaining the current gas exchange calibration in the cylinder with the system controller or limiting the gas exchange in the cylinder during the intake stroke with the system controller, and increasing the turbine efficiency of the turbocharger with variable geometry of the engine by increasing the pressure boost from the turbocharger. According to another aspect, limiting the gas exchange in the cylinder during the intake stroke with the system controller also includes advancing the closing of an intake valve for the cylinder during the intake stroke with the system controller and reducing the volume of an air/fuel mixture that is taken into the cylinder during the intake stroke. According to another aspect, advancing with the system controller of closing the intake valve for the cylinder during the intake stroke also includes adjusting with a cam phaser in communication with the system controller of the timing of an intake camshaft assigned to the intake valve. According to another aspect, adjusting the timing of the intake cam associated with the intake valve using the cam phaser also includes adjusting the timing of a short intake duration camshaft associated with the intake valve using the cam phaser. According to another aspect, the procedure also includes adjusting an ignition timing sequence based on the advancement of the intake valve closing. According to another aspect, increasing the pressure increase from the variable geometry turbocharger with the system controller also includes adjusting with the system controller an angle of each of several movable blades around the turbine, which are in communication with the system controller and are designed to control the exhaust gas flow through the turbine of the variable geometry turbocharger. According to another aspect, increasing the pressure boost from the variable geometry turbocharger also includes directing all exhaust gas from the engine through the turbine of the variable geometry turbocharger. According to another aspect, increasing the pressure increase from the variable geometry turbocharger also includes increasing the enthalpy extraction from exhaust gas that is passed through the turbine of the variable geometry turbocharger. According to several aspects of the present disclosure, a vehicle engine designed to control the exhaust gas temperature (EGT) at a catalyst inlet includes an EGT sensor that communicates with a system controller and is designed to measure the temperature to measure the exhaust gas temperature at the catalyst inlet, wherein the system controller is designed to compare the measured EGT with a target EGT and then, if the measured EGT is greater than the target EGT, to limit the gas exchange in a cylinder in the engine during an intake stroke and to increase the turbine efficiency of a variable geometry turbocharger of the engine by increasing the pressure increase from the variable geometry turbocharger. According to another aspect, if the measured EGT is smaller than the target EGT, the system controller is designed to adjust gas exchange during the intake stroke in the cylinder of the engine in order to increase the EGT. According to another aspect, if the measured EGT is equal to the target EGT, the system controller is designed to either maintain the curre