Boosted engine system of a motor vehicle

Patent metadata

Field	Value
Publication number	US-10458317-B2
Application number	US-201715727435-A
Country	US
Kind code	B2
Filing date	Oct 6, 2017
Priority date	Oct 21, 2016
Publication date	Oct 29, 2019
Grant date	Oct 29, 2019

Abstract

Methods and systems are provided for a boosted engine system having an engine arranged to receive boosted air from a variable geometry turbocharger and an electrically powered compressor arranged in parallel with the turbocharger. During temporary high torque demands above a predefined level, the electrically powered compressor may be used to supplement the flow of boosted air from the turbocharger. Additionally, a recirculation circuit around the electrically powered compressor may be provided to build up pressure in the electrically powered compressor before it is connected to the engine so as to minimize fluctuations in engine boost pressure upon start-up of the electrically powered compressor.

First claim

The invention claimed is:

1. A method, comprising:
responsive to a demanded torque being above a threshold while providing boosted air at a first pressure to an engine via a turbocharger compressor, operating an electric compressor via an electronic controller, wherein the electric compressor is arranged in parallel with the turbocharger compressor and wherein the electric compressor is fluidly disconnected from the engine, to increase a second pressure in a recirculation circuit around the electric compressor;
wherein the recirculation circuit comprises an electrically controlled first valve arranged to connect at a position between a shut-off valve and an outlet of the electric compressor; and
responsive to the second pressure reaching the first pressure, fluidly connecting the electric compressor to the engine.

2. The method of claim 1 , wherein operating the electric compressor to increase the second pressure in the recirculation circuit includes operating an electric motor of the electric compressor while maintaining the first valve arranged in a path between the outlet of the electric compressor and an intake manifold of the engine closed and a second valve arranged in the recirculation circuit open.

3. The method of claim 2 , wherein fluidly connecting the electric compressor to the engine includes simultaneously opening the first valve and closing the second valve to flow boosted air at the second pressure from the outlet of the electric compressor to the intake manifold of the engine.

4. The method of claim 1 , wherein operating the electric compressor is further responsive to a bypass valve arranged in a bypass passage around a turbocharger turbine being open.

5. The method of claim 1 , wherein the demanded torque is an operator demanded torque of the engine and wherein the threshold is a torque level corresponding to a maximum boost pressure that the turbocharger compressor is capable of providing to the engine at current operating conditions.

6. A boosted engine system for a motor vehicle, comprising:
an internal combustion engine;
a small capacity variable geometry turbocharger sized to meet demands for boosted air up to a predefined supply level; and
an electrically powered compressor operated by an electronic controller and arranged in parallel to the turbocharger, the engine being arranged to receive a primary supply of boosted air during normal engine running below the predefined supply level from the turbocharger and to receive a supplementary supply of boosted air from the electrically powered compressor when it is required to meet a temporary high demand for boosted air above the predefined supply level and a recirculation circuit to build up pressure when the electrically powered compressor is started before the electrically powered compressor is connected to the engine, the recirculation circuit comprising an electrically controlled recirculation valve to control flow of air through a conduit linking an outlet from the electrically powered compressor to an inlet to the electrically powered compressor, an electrically controlled shut-off valve located between the outlet from the electrically powered compressor and the engine to selectively isolate the outlet from the electrically powered compressor from the engine and a backflow control valve to prevent backflow of air from the inlet to the electrically powered compressor to atmosphere, wherein, upon starting of the electrically powered compressor the electrically controlled recirculation valve is kept open and the electrically controlled shut-off valve is kept closed until a pressure in the recirculation circuit has reached a predefined limit whereupon the electrically controlled shut-off valve is opened and the electrically controlled recirculation valve is closed.

7. The system as claimed in claim 6 , wherein the backflow valve is a non-return valve arranged to prevent air from flowing from the inlet to the electrically powered compressor back to atmosphere.

8. The system as claimed in claim 6 , wherein the backflow valve is an electrically controlled backflow valve arranged to automatically close if a pressure at the inlet to the electrically powered compressor is greater than atmospheric pressure so as to prevent air from flowing from the inlet to the electrically powered compressor back to atmosphere.

9. The system as claimed in claim 6 , wherein there is a first flow path from atmosphere through the turbocharger to the engine and a second flow path from atmosphere through the electrically powered compressor arranged in parallel to the first flow path between a position upstream of the engine and a source of atmospheric air.

10. The system as claimed in claim 9 , wherein the position upstream of the engine is an inlet to an intercooler having an outlet arranged to flow air to the engine, the system further comprising an air filter through which all air for the engine from the source of atmospheric air flows and the first and second air flow paths both have a respective low pressure end connected to an outlet from the air filter.

11. The system as claimed in claim 10 , wherein the first flow path has a first portion connected at one end to the air filter and a second end connected to an inlet of a compressor of the turbocharger and a second portion connected at one end to an outlet of the compressor of the turbocharger and connected at a second end to the inlet of the intercooler and the second air flow path has a first portion including the backflow valve connected at one end to the air filter and a second end connected to the inlet to the electrically powered compressor and a second portion connected at one end to the outlet from the electrically powered compressor and connected at a second end to the inlet of the intercooler and the electrically controlled shut-off valve is arranged to control flow of boosted air through the second portion of the second flow path.

12. The system as claimed in claim 6 , wherein the turbocharger has a turbine having an inlet arranged to receive a supply of exhaust gas from the engine, an outlet to flow exhaust gas to atmosphere, and a bypass passage having a bypass flow control valve that is connected between a position upstream from the inlet to the turbine and a position downstream from the outlet of the turbine, wherein the bypass flow control valve is an electrically controlled valve.

13. The system as claimed in claim 12 , wherein opening and closing of the bypass flow control valve is controlled by the electronic controller of the system and the electronic controller is arranged to open the bypass flow control valve when a predefined exhaust gas pressure limit upstream from the turbine is reached.

14. The system as claimed in claim 12 , wherein opening and closing of the bypass flow control valve is controlled by the electronic controller of the system and the electronic controller is arranged to open the bypass flow control valve when a predefined turbine rotational speed is reached.

15. The system as claimed in claim 6 , wherein opening and closing of the electrically controlled shut-off valve and opening and closing of the electrically controlled recirculation valve are both controlled by the electronic controller.

16. The system as claimed in claim 15 , wherein the electronic controller is arranged to stop use of the electrically powered compressor when a bypass flow control valve is in a closed state.

17. A method of controlling a boosted engine system of a motor vehicle, the system comprising an engine, a variable geometry turbocharger sized to meet demands for boosted ai

Assignees

• Ford Global Tech Llc

Inventors

• Cade Michael John
• Johnson Steve
• Turner Paul Nigel

Classifications

• F05D2220/40

  in turbochargers · CPC title

• F02B39/10

  electric · CPC title

• F04D27/002

  by varying geometry within the pumps, e.g. by adjusting vanes · CPC title

• F02B37/14

  {Control} of the alternation between {or the operation of} exhaust drive and other drive of a pump, e.g. dependent on speed · CPC title

• F04D25/0606

  the electric motor being specially adapted for integration in the pump · CPC title