Dual-fuel engine system and method having the same

Patent metadata

Field	Value
Publication number	US-9903284-B1
Application number	US-201615338941-A
Country	US
Kind code	B1
Filing date	Oct 31, 2016
Priority date	Oct 31, 2016
Publication date	Feb 27, 2018
Grant date	Feb 27, 2018

Abstract

Dual-fuel engine system includes cylinders in which the cylinders have an intake valve and an exhaust valve that control a flow of fluid into and out of a combustion chamber of the corresponding cylinder. The intake valve is configured to have an intake valve closure (IVC) timing. The dual-fuel engine system is configured to operate in a single-fuel mode and a dual-fuel mode. The combustion chamber and a piston are designed to provide a compression ratio. The dual-fuel engine system also includes one or more processors that are operably coupled to and configured to control operation of the first fuel injector. The compression ratio and the IVC timing are selected to achieve a target pre-combustion temperature. The target pre-combustion temperature permits the dual-fuel engine system to operate at a high substitution rate in the dual-fuel mode and at a sufficient fuel efficiency in the single-fuel mode.

First claim

What is claimed is:

1. A dual-fuel engine system comprising:
a plurality of cylinders in which the cylinders of said plurality have an intake valve and an exhaust valve that control a flow of fluid into and out of a combustion chamber of the corresponding cylinder, the intake valve configured to have an intake valve closure (IVC) timing;
first and second fuel injectors configured to inject first and second fuels into the combustion chamber, wherein the dual-fuel engine system is configured to operate in a single-fuel mode in which only the second fuel is provided to the combustion chamber and a dual-fuel mode in which the first and second fuels are provided to the combustion chamber, the first fuel injector configured to inject the first fuel at a substitution rate;
a piston configured to move within the combustion chamber, wherein the combustion chamber and the piston are designed to provide a compression ratio; and
one or more processors operably coupled to and configured to control operation of the first fuel injector, wherein the compression ratio and the IVC timing are selected to achieve a target pre-combustion temperature, the target pre-combustion temperature permitting the dual-fuel engine system to operate at a high substitution rate in the dual-fuel mode and at a sufficient fuel efficiency in the single-fuel mode.

2. The dual-fuel engine system of claim 1 , further comprising a heat exchanger and an exhaust gas recirculation (EGR) manifold that receives exhaust from the dual-fuel engine system, the heat exchanger cooling the exhaust to provide recirculated gas, wherein the recirculated gas is mixed with air from outside of the dual-fuel engine system and provided to the plurality of cylinders.

3. The dual-fuel engine system of claim 2 , wherein the recirculated gas is provided to the plurality of cylinders at an EGR rate selected by the one or more processors.

4. The dual-fuel engine system of claim 3 , wherein the first fuel injector is configured to control the substitution rate of the first fuel based on an operating pre-combustion temperature during operation.

5. The dual-fuel engine system of claim 4 , wherein the one or more processors are configured to determine the operating pre-combustion temperature within the cylinders based on at least one of a temperature sensor at the air manifold, a temperature sensor in one of the one or more cylinders, or a temperature sensor at an exhaust gas recirculating manifold.

6. The dual-fuel engine system of claim 1 , wherein the compression ratio is between 11 and 15.

7. The dual-fuel engine system of claim 1 , wherein the intake valve is configured to close between 515-540 crank angle degrees of a 720 degree crank cycle or 620-645 crank angle degrees of a 720 degree crank cycle.

8. The dual-fuel engine system of claim 1 , wherein a maximum percentage of the substitution rate is configured to be at least 75% for predetermined baseline conditions and the fuel efficiency in the single-fuel mode is at least 40% for predetermined baseline conditions.

9. The dual-fuel engine system of claim 1 , wherein the compression ratio is a geometric compression ratio, the IVC timing and the geometric compression ratio being fixed based on hardware used to manufacture the dual-fuel engine system.

10. The dual-fuel engine system of claim 1 , wherein at least one of the IVC timing and the compression ratio may be selected by the one or more processors during operation of the dual-fuel engine system.

11. A method of designing a dual-fuel engine, the method comprising:
providing a plurality of cylinders in which the cylinders of said plurality have an intake valve and an exhaust valve that are configured to control a flow of fluid into and out of a combustion chamber of the cylinder;
operably coupling first and second fuel injectors to the cylinders, the first and second fuel injectors configured to inject first and second fuels into the combustion chamber, wherein the dual-fuel engine system is configured to operate in a single-fuel mode in which only the second fuel is provided to the combustion chamber and a dual-fuel mode in which the first and second fuels are provided to the combustion chamber, the first fuel injector configured to inject the first fuel at a substitution rate;
providing a piston configured to move within the combustion chamber; and
selecting a compression ratio and an intake valve closure (IVC) timing relative to each other to achieve a target pre-combustion temperature, the target pre-combustion temperature permitting the dual-fuel engine system to operate at a high substitution rate in the dual-fuel mode and at a sufficient fuel efficiency in the single-fuel mode.

12. The method of claim 11 , further comprising operably coupling a heat exchanger and an exhaust gas recirculation (EGR) manifold that receives exhaust from the dual-fuel engine system, the heat exchanger configured to cool the exhaust from the dual-fuel engine system to provide recirculated gas such that the recirculated gas is mixed with air from outside of the engine and provided to the plurality of cylinders.

13. The method of claim 11 , wherein the compression ratio is between 11 and 15.

14. The method of claim 11 , wherein the intake valve is configured to close between 515-540 crank angle degrees of a 720 degree crank cycle or 620-645 crank angle degrees of a 720 degree crank cycle.

15. The method of claim 11 , wherein the compression ratio is between 11 and 15, a maximum percentage of the substitution rate is configured to be at least 75%, and the fuel efficiency in the single-fuel mode is at least 40%.

16. The method of claim 11 , wherein one or more processors are configured to select at least one of the IVC timing and the compression ratio during operation of the dual-fuel engine system.

17. The method of claim 11 , wherein the first fuel injector is configured to control the substitution rate of the first fuel based on an operating pre-combustion temperature during operation.

18. A method of operating a dual-fuel engine comprising:
providing a dual-fuel engine system that includes a plurality of cylinders in which the cylinders have an intake valve and an exhaust valve that control a flow of fluid into and out of a combustion chamber of the cylinder, the dual-fuel engine system also including first and second fuel injectors configured to inject first and second fuels into the combustion chamber, the first fuel injector configured to inject the first fuel at a substitution rate, the dual-fuel engine system also including a piston configured to move within the combustion chamber; and
operating the dual-fuel engine system in a single-fuel mode in which only a second fuel is provided to the combustion chamber and a dual-fuel mode in which the first and second fuels are provided to the combustion chamber;
wherein the cylinders have a compression ratio and the intake valves have an intake valve closure (IVC) timing that are selected to achieve a target pre-combustion temperature, the target pre-combustion temperature permitting the dual-fuel engine system to operate at a high substitution rate in the dual-fuel mode and at a sufficient fuel efficiency in the single-fuel mode.

19. The method of claim 18 , wherein operating the dual-fuel engine system includes controlling an exhaust gas recirculation (EGR) rate of recirculated gas that is provided to the dual-fuel engine and controlling the substitution rate of the first fuel based on an operating pre-combustion temperature during operation.

20. The

Assignees

• Gen Electric

Inventors

• Lavertu Thomas Michael
• Primus Roy James
• Gupta Venu Gummadavelli
• Freund Sebastian Walter
• Akinyemi Omowoleola Chukwuemeka
• Klingbeil Adam Edgar
• Salazar Victor Manuel

Classifications

• F02D41/0027

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

• F02D2041/389

  for injecting directly into the cylinder · CPC title

• F02M26/47 Primary

  the characteristics being temperatures, pressures or flow rates · CPC title

• F02D41/005

  according to engine operating conditions · CPC title

• F02D41/38

  of the high pressure type · CPC title