DIRECT INJECTION OF DILUENTS OR SECONDARY FUELS IN GASEOUS FUEL ENGINES

• US 20140331668A1
• Filed: 05/07/2013
• Published: 11/13/2014
• Est. Priority Date: 05/07/2013
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Bidner, David Karl, Dearth, Mark Allen
• Granted Patent: US 9,453,465 B2
• Time in Patent Office: Days
• US Class Current: 60/605.2
• CPC Class Codes: F02D 19/027 Determining the fuel pressure, temperature or volume flow, the fuel tank fill level or a valve position
• CPC Class Codes: F02M 26/36 with means for adding fluids other than exhaust gas to the recirculation passage; with reformers
• CPC Class Codes: Y02T 10/30 Use of alternative fuels, e.g. biofuels

Abstract

An engine system, comprising a first gaseous fuel source with a first gaseous fuel located therein coupled to one or more engine cylinders and an exhaust gas recirculation (EGR) system with a reform catalyst located therein, the reform catalyst reforming natural gas into a gas with a wider AFR operating range. The engine may thus operate at an AFR that may be outside of that available during natural gas combustion alone to allow for cooler engine operation.

Claims

1. An engine system, comprising:

a first gaseous fuel source with a first gaseous fuel located therein coupled to one or more engine cylinders;

an exhaust gas recirculation (EGR) system coupling an exhaust system to an intake system and including a reform catalyst therein; and

a natural gas inlet coupling a natural gas source with natural gas located therein to the EGR system.

2. The engine system of claim 1, wherein the natural gas inlet couples the natural gas source to the reform catalyst or to a location within the EGR system upstream of the reform catalyst.

3. The engine system of claim 2, wherein the reform catalyst is a steam reform catalyst and includes a plate or substrate with a reactive coating.

4. The engine system of claim 3, wherein the reactive coating includes a metallic oxide comprising one or more of nickel oxide, copper oxide, zinc oxide, manganese oxide, molybdenum, chromium oxide, vanadium oxide, titanium oxide, iron oxide, cobalt oxide, tungsten oxide, zirconium oxide, aluminum oxide, cerium oxide, praseodymium oxide, neodymium oxide, or another transition metal oxide.

5. The engine system of claim 3, wherein the plate or substrate includes one or more of platinum, palladium, rhodium, ruthenium, gold, silver or another precious metal.

6. The engine system of claim 1, wherein the engine system is turbocharged and the EGR system is a low pressure EGR system.

7. The engine system of claim 1, wherein the first gaseous fuel is one or more of CNG and methane.

8. The engine system of claim 1, wherein first gaseous fuel source includes the natural gas source and the first gaseous fuel includes the natural gas.

9. The engine system of claim 1, wherein the natural gas source includes methane.

10. The engine system of claim 1, including a first exhaust system coupled to a first cylinder bank and a second exhaust system coupled to a second cylinder bank, wherein a first EGR system coupled to the first exhaust system includes the reform catalyst and a second EGR system coupled to the second exhaust system does not include a reform catalyst.

11. The engine system of claim 10, wherein a first intake system includes a first compressor coupled to a first turbine located within the first exhaust system;

and a second intake system includes a second compressor coupled to a second turbine located within the second exhaust system.

12. A method for operating an engine system including;

port injecting a first quantity of a first gaseous fuel; and

injecting a second quantity of the first gaseous fuel into an EGR system that includes a reform catalyst therein, the second quantity a function of a desired AFR, the desired AFR based on temperature of an engine exhaust valve.

13. The method of claim 12, further comprising reforming the first gaseous fuel within the reform catalyst to form a secondary gaseous fuel.

14. The method of claim 13, further comprising reforming methane and water within the first gaseous fuel source to hydrogen gas and carbon monoxide within the second gaseous fuel source.

15. The method of claim 13, further comprising determining the desired AFR as a function of a current AFR and an additional AFR available from injecting the secondary gaseous fuel into an intake system.

16. The method of claim 12, further comprising fluidically coupling an exhaust system to the reform catalyst when a temperature of exhaust gas is between a threshold minimum and maximum.

17. The method of claim 12, further comprising increasing the second amount of the first gaseous fuel injected into the EGR system when an AFR is below a richness threshold;

and decreasing the second amount of the first gaseous fuel injected into the EGR system when the AFR is above a richness threshold.

18. A method for operating an engine system, comprising:

injecting a first quantity of a first gaseous fuel;

determining a desired AFR, an AFR achievable via the first quantity of the first gaseous fuel, and an additional AFR desired from a secondary injectant;

determining a percent of secondary injectant desired within an EGR system in response to the additional AFR desired from the secondary injectant; and

in response to the percent of secondary injectant desired, injecting a third amount of a third gaseous fuel source.

19. The method of claim 18, including reforming the third gaseous fuel source and EGR gas into the secondary injectant via a reform catalyst located within the EGR system.

20. The method of claim 18, including injecting the secondary injectant into an intake system of the engine system.