Method and system adjusting an exhaust heat recovery valve

Patent metadata

Field	Value
Publication number	US-9441553-B2
Application number	US-201414483047-A
Country	US
Kind code	B2
Filing date	Sep 10, 2014
Priority date	Sep 9, 2010
Publication date	Sep 13, 2016
Grant date	Sep 13, 2016

Abstract

A method for adjusting an exhaust heat recovery valve is presented. In one embodiment, the method may control an amount of boost provided by a turbocharger to an engine.

First claim

The invention claimed is:

1. An engine method, comprising:
during conditions when a turbocharger waste-gate position is not adjustable,
increasing a level of exhaust heat extracted from combusted exhaust gas upstream of a turbocharger turbine by adjusting a position of a heat recovery valve and then flowing the combusted exhaust gas whose heat was extracted through the heat recovery valve and to an exhaust downstream of all cylinders, bypassing the turbocharger's turbine to reduce flow through a turbocharger's compressor.

2. The method of claim 1 , wherein the turbocharger waste-gate is not degraded.

3. The method of claim 2 , wherein the waste-gate position is not adjustable due to one of a low level of boost and a low level of vacuum actuation force.

4. The engine method of claim 3 , where the heat recovery valve is positioned in an exhaust path of an engine, the method further comprising closing an EGR valve while increasing the heat extracted.

5. The method of claim 4 , where the heat recovery valve is at least partially opened and where exhaust flow is diverted from upstream of the turbocharger to an exhaust heat recovery device.

6. The method of claim 4 , where the position of the heat recovery valve is adjusted in response to a pressure ratio of the turbocharger compressor.

7. The method of claim 6 , where the position of the heat recovery valve is further adjusted in response to a flow rate.

8. The method of claim 7 , where closing a turbine shut off valve reduces turbine output when the waste-gate has reduced capacity to limit turbine speed.

9. The method of claim 3 , where an amount of coolant flow to an engine is increased during the conditions when the turbocharger waste-gate position is not adjustable.

10. The method of claim 3 , where an amount of coolant flow to a transmission is increased during the conditions when the turbocharger waste-gate position is not adjustable.

11. An engine system, comprising:
a first exhaust conduit extending from a first exhaust port of a cylinder;
a second exhaust conduit extending from a second exhaust port of the cylinder, the second exhaust port isolated from the first exhaust port by a heat recovery valve and a turbine;
a heat exchanger located in a first branch of the first exhaust conduit, an outlet of the heat exchanger directed to an intake manifold and the second exhaust conduit;
a turbocharger located in a second branch of the first exhaust conduit;
an EGR valve located downstream of the outlet of the heat exchanger and upstream of the intake manifold in the first branch of the first exhaust conduit;
a first catalyst and a second catalyst located along the second exhaust conduit; and
a controller including computer-readable instructions stored on non-transitory memory for:
during an engine cold-start when the heat recovery valve is not stuck closed, closing the EGR valve while opening the heat recovery valve to expedite engine heating; and
during an engine cold-start when the heat recovery valve is stuck closed, increasing an amount of spark retard while holding the EGR valve closed.

12. The system of claim 11 , wherein the controller includes further computer-readable instructions stored on non-transitory memory for:
when the heat recovery valve is not stuck closed, adjusting a position of the heat recovery valve in response to a boost amount in response to a position of a waste-gate of the turbocharger not being adjustable.

13. The system of claim 12 , wherein the position of the waste-gate is not adjustable due to low waste-gate actuation force.

14. The system of claim 12 , wherein the position of the waste-gate is not adjustable due to low boost pressure.

15. The system of claim 12 , wherein the waste-gate is not degraded.

Assignees

• Ford Global Tech Llc

Inventors

• Pursifull Ross Dykstra
• Ulrey Joseph Norman

Classifications

• F02D23/00 Primary

  Controlling engines characterised by their being supercharged · CPC title

• F02D41/0007

  for control of turbo-charged or super-charged engines (control of the pumps per se F02B37/12) · CPC title

• F02D41/005

  according to engine operating conditions · CPC title

• F02M26/05

  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 title

• F02D23/005

  with the supercharger being mechanically driven by the engine (supercharger drives F02B39/00) · CPC title