Method for controlling a turbocharger arrangement of an internal combustion engine, and control device

Patent metadata

Field	Value
Publication number	US-9777653-B2
Application number	US-201213536938-A
Country	US
Kind code	B2
Filing date	Jun 28, 2012
Priority date	Jun 29, 2011
Publication date	Oct 3, 2017
Grant date	Oct 3, 2017

Abstract

Embodiments for controlling exhaust gas turbines are provided. In one embodiment, a method for controlling a turbocharger arrangement of an internal combustion engine, the turbocharger arrangement having at least a first exhaust-gas turbine and a second exhaust-gas turbine arranged downstream of the first, and an exhaust-gas aftertreatment system being arranged downstream of the second exhaust-gas turbine comprises, in a warm-up mode, controlling at least one exhaust-gas turbine so as to increase an inlet temperature of an exhaust-gas flow at the inlet into the exhaust-gas aftertreatment system. In this way, the exhaust-gas aftertreatment system may be rapidly heated.

First claim

The invention claimed is:

1. A method for controlling a turbocharger arrangement of an internal combustion engine, the turbocharger arrangement having at least a first exhaust-gas turbine and a second exhaust-gas turbine arranged downstream of the first, and an exhaust-gas aftertreatment system being arranged downstream of the second exhaust-gas turbine, comprising:
in a warm-up mode, controlling the first exhaust-gas turbine to attain a setpoint charge pressure of the internal combustion engine, including controlling an amount of exhaust gas through the first exhaust-gas turbine and an amount of exhaust gas through a first bypass of the first exhaust-gas turbine, and further including controlling an amount of intake air through a compressor coupled to the first exhaust-gas turbine as a function of an engine system pressure;
during the warm-up mode, controlling the second exhaust-gas turbine so as to increase an inlet temperature of an exhaust-gas flow at an inlet into the exhaust-gas aftertreatment system, including controlling the amount of exhaust gas from the first exhaust-gas turbine and the first bypass through the second exhaust-gas turbine and through a second bypass of the second exhaust-gas turbine, the second bypass having an inlet downstream of an outlet of the first bypass and downstream of an outlet of the first exhaust-gas turbine;
during a normal mode, controlling the first exhaust-gas turbine and the second exhaust-gas turbine as a function of an amount of intake air bypassing the compressor; and
flowing exhaust-gas recirculation (EGR) through an EGR passage having an inlet upstream of the first exhaust-gas turbine, and in the warm-up mode, the first exhaust-gas turbine is further controlled so as to attain a setpoint EGR flow, the exhaust gas through the first bypass also bypassing the EGR passage.

2. The method as claimed in claim 1 , wherein controlling the second exhaust-gas turbine to increase the inlet temperature in the warm-up mode further comprises superimposing a disturbance variable on a control signal of the second exhaust-gas turbine.

3. The method as claimed in claim 1 , wherein the first bypass of the first exhaust-gas turbine includes a first bypass valve for controlling the first exhaust-gas turbine, and the second bypass of the second exhaust-gas turbine includes a second bypass valve for controlling the second exhaust-gas turbine, and wherein in the warm-up mode, the second bypass valve is controlled so as to increase the inlet temperature.

4. The method as claimed in claim 3 , wherein the second bypass valve is opened further or completely in order to increase the inlet temperature.

5. The method as claimed in claim 1 , wherein the warm-up mode is started on the basis of a cold start signal and is ended on the basis of a temperature signal or a time signal.

6. The method as claimed in claim 3 , wherein the compressor includes a third bypass controlled by a third bypass valve, and wherein controlling the first exhaust-gas turbine and the second exhaust-gas turbine as a function of the amount of intake air bypassing the compressor comprises controlling the first exhaust-gas turbine and the second exhaust-gas turbine as a function of a position of the third bypass valve.

7. The method as claimed in claim 6 , wherein controlling the first exhaust-gas turbine and the second exhaust-gas turbine as a function of the position of the third bypass valve comprises:
determining a first position of the first bypass valve and a second position of the second bypass valve as a function of engine speed and load;
responsive to the third bypass valve being fully closed, adjusting the first position of the first bypass valve using a first correction value determined as a function of charge pressure; and
responsive to the third bypass valve being open, adjusting the second position of the second bypass valve using a second correction value determined as a function of charge pressure.

8. A control device for a turbocharger arrangement of an internal combustion engine, wherein the control device is set up for carrying out the method according to claim 1 .

9. A method, comprising:
during a first condition, controlling a first bypass valve of a high-pressure turbine based on engine speed and load, controlling a second bypass valve of a low-pressure turbine based on catalyst temperature, and actuating a third bypass valve of a high-pressure compressor as a function of an engine system pressure;
during a second condition and responsive to the third bypass valve fully closing, controlling the first bypass valve based on boost pressure and controlling the second bypass valve based on engine speed and load; and
flowing exhaust-gas recirculation (EGR) through an EGR passage having an inlet upstream of the high-pressure turbine, and during the first condition, the first bypass valve is further controlled so as to attain a setpoint EGR flow, exhaust gas bypassing the high-pressure turbine via the first bypass valve also bypassing the EGR passage.

10. The method of claim 9 , wherein the first condition comprises catalyst temperature below a threshold and the second condition comprises catalyst temperature above the threshold, and wherein controlling the first bypass valve based on boost pressure comprises adjusting the first bypass valve away from a setpoint position based on a difference between desired boost pressure and measured boost pressure.

11. The method of claim 9 , further comprising, during the second condition and responsive to the third bypass valve opening, controlling the second bypass valve based on boost pressure and controlling the first bypass valve based on engine speed and load, and wherein controlling the second bypass valve based on boost pressure comprises adjusting the second bypass valve away from a setpoint position based on a difference between desired boost pressure and measured boost pressure.

12. A turbocharger method, comprising:
determining respective set positions of a first bypass valve of a high-pressure turbine and a second bypass valve of a low-pressure turbine;
under a first condition, adjusting a position of the second bypass valve away from the set position to increase catalyst temperature;
under a second condition and responsive to a third bypass valve of a high-pressure compressor being closed, adjusting a position of the first bypass valve away from the set position to maintain charge pressure and engine load while maintaining the second bypass valve at the set position for the second bypass valve;
responsive to a third condition including the third bypass valve being open, adjusting a position of the second bypass valve away from the set position by an amount based on charge pressure and engine load while maintaining the first bypass valve at the set position for the first bypass valve; and
flowing exhaust-gas recirculation (EGR) through an EGR passage having an inlet upstream of the high-pressure turbine, and under the first condition, the position of the first bypass valve is controlled so as to attain a setpoint EGR flow, exhaust gas bypassing the high-pressure turbine via the first bypass valve also bypassing the EGR passage.

13. The method of claim 12 , wherein the first condition comprises catalyst temperature below a threshold.

14. The method of claim 12 , wherein the third bypass valve is open during high speed and high load conditions and is closed during low speed and low load conditions.

15. The method of claim 12 , wherein the set positions of the first and second bypass valves are determined as a function of engine speed and load.

16.

Assignees

• Petrovic Simon
• Ford Global Tech Llc

Inventors

• Petrovic Simon

Classifications

• Y02T10/26

  Cross-Sectional Technologies · mapped topic

• F02D41/024 Primary

  to increase temperature of the exhaust gas treating apparatus · CPC title

• Y02T10/144

  Cross-Sectional Technologies · mapped topic

• F02D23/00

  Controlling engines characterised by their being supercharged · CPC title

• F02B37/004

  with exhaust drives arranged in series · CPC title