System and method for improving operation of an engine combusting liquefied petroleum gas

Patent metadata

Field	Value
Publication number	US-9322355-B2
Application number	US-201313970510-A
Country	US
Kind code	B2
Filing date	Aug 19, 2013
Priority date	Aug 19, 2013
Publication date	Apr 26, 2016
Grant date	Apr 26, 2016

Abstract

A method and system for improving operation of an engine that is supplied a fuel having a low super critical temperature is presented. In one example, the method supplies fuel to cool a direct injection fuel pump and participate in combustion in an engine cylinder after the fuel is vaporized. The method also provides for injecting a liquid fuel to the engine cylinder via the direct injection fuel pump.

First claim

The invention claimed is:

1. A method for operating an engine, comprising:
cooling a direct injection fuel pump with a liquid fuel, the liquid fuel not pumped via the direct injection fuel pump; and
reducing an amount of fuel pumped through the direct injection fuel pump in response to the direct injection fuel pump exceeding a threshold temperature.

2. The method of claim 1 , where the direct injection fuel pump is mechanically coupled to the engine.

3. The method of claim 1 , where the liquid fuel is vaporized into a gaseous fuel.

4. The method of claim 3 , further comprising port injecting the gaseous fuel to the engine.

5. The method of claim 4 , where a port fuel injector pulse width is adjusted in response to a pressure of the gaseous fuel.

6. The method of claim 1 , further comprising adjusting boost in response to injecting the gaseous fuel to the engine.

7. The method of claim 1 , where the direct injection fuel pump is enclosed in an evaporator.

8. The method of claim 1 , wherein reducing the amount of fuel pumped through the direct injection fuel pump includes stopping direct injection of the fuel.

9. The method of claim 8 , wherein reducing the amount of fuel pumped through the direct injection fuel pump includes reducing the amount of fuel pumped to near zero.

10. A method for operating an engine, comprising:
cooling a direct injection fuel pump with a first liquid fuel, the first liquid fuel not pumped via the direct injection fuel pump;
vaporizing the first liquid fuel via an evaporator to form a gaseous fuel;
injecting the gaseous fuel from the evaporator to the engine via a conduit; and
injecting a second liquid fuel pumped through the direct injection fuel pump to the engine.

11. The method of claim 10 , where the first liquid fuel and the second liquid fuel are a same type of fuel.

12. The method of claim 10 , further comprising adjusting boost in response to injecting the gaseous fuel to the engine.

13. The method of claim 10 , where the first fuel vaporized to form the gaseous fuel is injected to the engine via port injection.

14. The method of claim 12 , further comprising adjusting a pulse width of a port fuel injector in response to a pressure of the gaseous fuel.

15. The method of claim 10 , further comprising returning gases formed from the second liquid fuel to a fuel tank via a condenser.

Assignees

• Ford Global Tech Llc

Inventors

• Pursifull Ross Dykstra

Classifications

• F02D41/0027

  the fuel being gaseous (non-electrical control F02D19/02) · CPC title

• F02D41/0025

  Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures · CPC title

• F02D41/065

  at hot start or restart (F02D41/067 takes precedence) · CPC title

• F02D41/042

  for stopping the engine · CPC title

• Y02T10/30

  Use of alternative fuels, e.g. biofuels · CPC title