TRANSIENT COMPENSATION FOR VARIABLE GEOMETRY COMPRESSOR

• US 20190024576A1
• Filed: 07/18/2017
• Published: 01/24/2019
• Est. Priority Date: 07/18/2017
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Van Nieuwstadt, Michiel J., Upadhyay, Devesh, Hanna, David R.
• Granted Patent: US 10,494,991 B2
• Time in Patent Office: Days
• CPC Class Codes: F02B 2037/125 Control for avoiding pump stall or surge
• CPC Class Codes: F02B 37/004 with exhaust drives arranged in series
• CPC Class Codes: F02B 37/04 Engines with exhaust drive and other drive of pumps, e.g. with exhaust-driven pump and mechanically-driven second pump
• CPC Class Codes: F02B 37/18 by bypassing exhaust from the inlet to the outlet of turbine or to the atmosphere
• CPC Class Codes: F02B 37/24 by using pumps or turbines with adjustable guide vanes
• CPC Class Codes: F02D 2041/0017 by simultaneous control of throttle and exhaust gas recirculation
• CPC Class Codes: F02D 2041/0075 by using flow sensors
• CPC Class Codes: F02D 2200/0406 Intake manifold pressure
• CPC Class Codes: F02D 2200/606 Driving style, e.g. sporty or economic driving
• CPC Class Codes: F02D 2200/701 Information about vehicle position, e.g. from navigation system or GPS signal
• CPC Class Codes: F02D 41/0007 for control of turbo-charged or super-charged engines control of the pumps per se F02B37/12
• CPC Class Codes: F02D 41/0072 Estimating, calculating or determining the EGR rate, amount or flow sensors in EGR systems F02M26/45
• CPC Class Codes: F02D 41/1445 the characteristics being related to the exhaust flow
• CPC Class Codes: F02M 26/05 High pressure loops, i.e. wherein recirculated exhaust gas is taken out from the exhaust system upstream of the turbine and reintroduced into the intake system downstream of the compressor
• CPC Class Codes: F02M 26/06 Low pressure loops, i.e. wherein recirculated exhaust gas is taken out from the exhaust downstream of the turbocharger turbine and reintroduced into the intake system upstream of the compressor
• CPC Class Codes: F04D 29/4213 suction ports
• CPC Class Codes: F04D 29/685 Inducing localised fluid recirculation in the stator-rotor interface
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

Methods and systems are provided for controlling a turbocharged engine. In one example, a method may include concurrently adjusting an exhaust recirculation gas flow and a turbine flow while adjusting geometry of a compressor to compensate for disturbance caused by the compressor adjustment.

Claims

1. A method for an engine comprising:

adjusting an exhaust gas recirculation (EGR) flow via a first actuator and a turbine flow via a second actuator while adjusting a geometry of a compressor, wherein the EGR flow and the turbine flow are adjusted based on the adjustment of the compressor geometry.

2. The method of claim 1, wherein the EGR flow and the turbine flow are adjusted to maintain a substantially constant gas flow and a substantially constant pressure during the compressor geometry adjustment.

3. The method of claim 2, wherein the gas flow includes a mass air flow, and the first actuator includes a throttle.

4. The method of claim 2, wherein the gas flow includes the EGR flow, and the first actuator includes an EGR valve.

5. The method of claim 4, wherein the first actuator further includes a throttle.

6. The method of claim 2, wherein the pressure is an exhaust pressure or a boost pressure.

7. The method of claim 2, wherein the second actuator is a wastegate or a variable geometry turbine.

8. The method of claim 2, further comprising measuring the gas flow and the pressure, and adjusting the gas flow and the pressure based on the measured gas flow and the measured pressure without adjusting the geometry of the compressor.

9. The method of claim 1, wherein the geometry of the compressor is adjusted via a third actuator, and a change in the position of the third actuator determined based on an amount of the compressor geometry adjustment.

10. The method of claim 9, further comprising adjusting the EGR flow and the turbine flow based on the change in the position of the third actuator, a sensitivity of the EGR flow with respective to the first actuator, a sensitivity of the EGR flow with respective to the second actuator, a sensitivity of the pressure with respective to the second actuator, a sensitivity of the pressure with respective to the first actuator, a sensitivity of the EGR flow with respective to the third actuator, and a sensitivity of the pressure with respective to the third actuator.

11. A method for a turbocharged engine comprising:

adjusting an EGR flow and a turbine flow responsive to EGR rates and a boost pressure;

determining a first amount of compressor geometry adjustment;

determining a second amount of EGR flow adjustment and a third amount of turbine flow adjustment based on the first amount of compressor geometry adjustment; and

concurrently adjusting a compressor geometry with the first amount, the EGR flow with the second amount, and the turbine flow with the third amount.

12. The method of claim 11, wherein the EGR rates and the boost pressure remain substantially constant while adjusting the compressor geometry.

13. The method of claim 11, wherein the EGR flow is adjusted by actuating an EGR valve and a throttle.

14. The method of claim 11, further comprising after adjusting the compressor geometry, adjusting the EGR flow and the turbine flow responsive to the EGR rates and the boost pressure.

15. The method of claim 11, further comprising adjusting the EGR flow and the turbine flow based on the EGR rates and the boost pressure while adjusting the compressor geometry.

16. An engine system, comprising:

a compressor for supplying a boosted air to an engine, wherein a geometry of the compressor adjustable by actuating a compressor actuator;

a turbine coupled to the compressor;

an EGR passage for circulating an exhaust gas from engine output to engine intake;

an EGR valve coupled to the EGR passage for controlling an EGR flow;

a first sensor coupled to the engine for measuring a gas flow;

a second sensor coupled to the engine for measuring a manifold pressure; and

a controller with computer readable instructions stored on non-transitory memory configured for;

adjusting the gas flow and the manifold pressure based on outputs of the first sensor and the second sensor;

determining an amount of adjustment in the compressor actuator;

determining an expected change in the gas flow and an expected change in the manifold pressure based on the amount of adjustment in the compressor actuator;

actuating the compressor actuator by the determined amount of adjustment; and

while actuating the compressor actuator, adjusting the EGR flow and a turbine flow to compensate for the expected change in gas flow and the expected change in manifold pressure.

17. The engine system of claim 16, wherein the controller is further configured for adjusting the gas flow and the manifold pressure based on outputs of the first sensor and the second sensor after actuating the compressor actuator.

18. The engine system of claim 16, wherein a pressure ratio across the compressor remains substantially constant while actuating the compressor actuator.

19. The engine system of claim 16, wherein the compressor is an active casing compressor, the amount of change in the actuator is a first amount when the compressor is adjusted from a norminal position to a surge position, and amount of change in the actuator is a second amount when the compressor is adjusted from a norminal position to a choke position.

20. The engine system of claim 16, wherein the EGR passage includes low pressure EGR passage and high pressure EGR passage, and adjusting the EGR flow further comprises allocating EGR flow between a low pressure EGR passage and a high pressure EGR passage.