Pressure regulating mass flow system for multipoint gaseous fuel injection

Patent metadata

Field	Value
Publication number	US-11092091-B2
Application number	US-201815925534-A
Country	US
Kind code	B2
Filing date	Mar 19, 2018
Priority date	Mar 19, 2018
Publication date	Aug 17, 2021
Grant date	Aug 17, 2021

Abstract

Embodiments of a gaseous or dual fuel electronic pressure regulation system (EPRS) for a multipoint fuel injection engine are described herein. Additionally, embodiments of a method for controlling the EPRS are provided. In particular, the EPRS employs an electronic pressure regulator (EPR) capable of accurately determining and controlling the mass flow of gaseous fuel into a fuel rail so as to avoid pressure droop and over- and under-pressurization of the gas admission valves (GAVs). By using the EPRS described above, mass flow is able to be distributed to the downstream manifold or engine cylinders very accurately, and the GAVs are able to be driven simultaneously in a pressure/pulse duration that is optimal for accurate and repeatable operation.

First claim

What is claimed is:

1. A method of regulating flow of a gaseous fuel in a multipoint fuel injection system in which a fuel rail provides the gaseous fuel to a plurality of gas admission valves, the method comprising the steps of:
determining a first mass flow of the gaseous fuel entering the fuel rail using an electronic pressure regulator;
determining a second mass flow of the gaseous fuel exiting the fuel rail;
calculating a rate of pressure change in the fuel rail as a function of a difference between the second mass flow and the first mass flow; and
adjusting at least one of a first effective area of an electronic pressure regulator or a second effective area of the plurality of gas admission valves in response to the calculated rate of pressure change.

2. The method of claim 1 , further comprising a step of creating a negative rate of pressure change when a pressure in the fuel rail trends toward a predetermined upper limit.

3. The method of claim 2 , wherein the step of creating a negative rate of pressure change further comprises executing a temporary reduction in the first mass flow such that the second mass flow is greater than the first mass flow.

4. The method of claim 1 , further comprising a step of creating a positive rate of pressure change when a pressure in the fuel rail trends toward a predetermined lower limit.

5. The method of claim 4 , wherein the step of creating a positive rate of pressure change further comprises executing a temporary increase in the first mass flow such that the first mass flow is greater than the second mass flow.

6. The method of claim 1 , wherein the step of calculating a rate of pressure change comprises numerically differentiating a pressure set point.

7. The method of claim 1 , wherein the step of calculating a rate of pressure change comprises filtering a pressure set point and extracting a velocity term.

8. The method of claim 1 , further comprising the step of calibrating the plurality of gas admission valves during a time in which the rate of pressure change is zero.

9. The method of claim 8 , wherein the step of calibrating the plurality of gas admission valves further comprises calibrating based on the first mass flow determined by the electronic pressure regulator.

10. The method of claim 1 , further comprising the step of changing the first effective area of the electronic pressure regulator so as to create a pressure change and wherein the adjusting step comprises adjusting the second effective area of the plurality of gas admission valves in response to the calculated rate of pressure change.

11. The method of claim 10 , further comprising the step of coordinating the step of changing the first effective area of the electronic pressure regulator and the step of adjusting the second effective area of the plurality of gas admission valves so as to maintain a desired second mass flow through the plurality of gas admission valves.

12. The method of claim 11 , further comprising the step of providing first finite bandwidth limitations for the first effective area of the electronic pressure regulator and second finite bandwidth limitations for the second effective area of the plurality of gas admission valves;
wherein the step of changing the first effective area of the electronic pressure regulator does not exceed the first finite bandwidth limitations;
wherein the step of adjusting the second effective area of the plurality of gas admission valves does not exceed the second finite bandwidth limitations; and
wherein the rate of pressure change is saturated during the steps of adjusting the first effective area and the second effective area.

13. The method of claim 1 , wherein the adjusting step further comprises adjusting at least one of the first effective area of the electronic pressure regulator or the second effective area of the plurality of gas admission valves so that the rate of pressure change transitions to zero.

14. The method of claim 13 , wherein, after the rate of pressure change has transitioned to zero, the first mass flow and the second mass flow both equal a third mass flow that is different from either of the first mass flow and the second mass flow.

15. A gaseous fuel regulation system, comprising:
a fuel rail;
an electronic pressure regulator (EPR) upstream of and in fluid communication with the fuel rail, the EPR configured to meter a first mass flow of a gaseous fuel flowing through the EPR;
a plurality of gas admission valves, each gas admission valve being downstream of and in fluid communication with the fuel rail; and
a controller, the controller being configured to receive a mass flow delivery command and to set a first effective area of the EPR and a second effective area of the plurality of gas admission valves based at least in part on the mass flow delivery command and on the first mass flow.

16. The gaseous fuel regulation system of claim 15 , wherein a pressure of the fuel rail is communicated to the controller, wherein the controller is configured to calculate a rate of change of the pressure, and wherein the controller is configured to set the first and second effective areas based also on the rate of change of the pressure.

17. The gaseous fuel regulation system of claim 16 , further comprising a first order filter configured to filter a pressure set point and extract a velocity term in order to calculate the rate of change of the pressure.

18. The gaseous fuel regulation system of claim 16 , wherein the controller is configured to calculate the rate of change of the pressure by extracting a velocity term from a dynamic model or a dynamic system.

19. The gaseous fuel regulation system of claim 16 , wherein, when the rate of change of the pressure is positive, the controller is configured to decrease the first effective area.

20. The gaseous fuel regulation system of claim 19 , wherein, when the rate of change of the pressure is negative, the controller is configured to increase the first effective area.

21. The gaseous fuel regulation system of claim 20 , wherein, for a given mass flow command, the controller is configured to increase or decrease the first effective area without adjusting the second effective area.

22. The gaseous fuel regulation system of claim 15 , wherein the controller is configured to set the first effective area and the second effective area asynchronously.

23. A gaseous fuel regulation system, comprising:
a fuel rail;
an electronic pressure regulator (EPR) upstream of and in fluid communication with the fuel rail, the EPR configured to meter a first mass flow of a gaseous fuel flowing through the EPR;
a plurality of gas admission valves, each gas admission valve being downstream of and in fluid communication with the fuel rail; and
a controller, the controller being configured to receive a mass flow delivery command and to set a first effective area of the EPR and a second effective area of the plurality of gas admission valves based at least in part on the mass flow delivery command and on the first mass flow;
wherein the plurality of gas admission valves each have upper and lower operability pressure limits and wherein the controller is configured to maintain a pressure in the fuel rail within the upper and lower operability limits of the gas admission valves.

24. A dual fuel system, comprising:
a first fuel rail carrying a liquid fuel;
a second fuel rail carrying a gaseous fuel; and
a plurality of engine cyli

Assignees

• Farrow Timothy J
• Buehner Michael Ryan
• Hampson Gregory James
• Karspeck John
• Woodward Inc

Inventors

• Farrow Timothy J
• Buehner Michael Ryan
• Hampson Gregory James
• Karspeck John

Classifications

• F02M21/0239

  Pressure or flow regulators therefor · CPC title

• F02D19/023 Primary

  to adjust the fuel mass or volume flow · CPC title

• F02D41/3854

  with elements in the low pressure part, e.g. low pressure pump · CPC title

• F02M21/0245

  High pressure fuel supply systems; Rails; Pumps; Arrangement of valves · CPC title

• F02D41/402

  Multiple injections · CPC title