Engine operating strategy using pulsed injection of gaseous hydrogen fuel

Patent metadata

Field	Value
Publication number	US-12553396-B2
Application number	US-202418784290-A
Country	US
Kind code	B2
Filing date	Jul 25, 2024
Priority date	Jul 25, 2024
Publication date	Feb 17, 2026
Grant date	Feb 17, 2026

Abstract

Operating an engine includes energizing an electrical actuator for a valve in a fuel injector according to a waveform alternating a plurality of on-times with a plurality of dwell times, and outputting a pulsed injection of a gaseous hydrogen fuel from the fuel injector entraining air between pulses of the gaseous hydrogen fuel. Entrainment breaks are produced between the plurality of pulses in a spray cone of the pulsed injection. The gaseous hydrogen fuel and air experience enhanced in-cylinder mixing based upon the air entrainment. Related apparatus is also disclosed.

First claim

What is claimed is:

1 . A method of operating an engine comprising:
moving a piston between a bottom-dead-center position and a top-dead-center position in a cylinder in an engine having an engine housing; energizing an electrical actuator for a valve in a fuel injector according to a waveform alternating a plurality of on-times with a plurality of dwell times; outputting a pulsed injection of a gaseous hydrogen fuel from the fuel injector and, inside the engine housing, entraining air into the pulsed injection between a plurality of pulses of the gaseous hydrogen fuel, based on the energizing the electrical actuator; and combusting the gaseous hydrogen fuel and air in the cylinder.

2 . The method of claim 1 wherein the waveform includes a square waveform and the plurality of on-times are longer in duration than the plurality of dwell times.

3 . The method of claim 2 wherein the plurality of pulses of the pulsed injection includes a number of pulses greater than two.

4 . The method of claim 3 wherein the number of pulses is from 3 to 8.

5 . The method of claim 1 wherein the outputting a pulsed injection includes outputting the pulsed injection into a feed of pressurized intake air conveyed into the cylinder.

6 . The method of claim 1 wherein the outputting a pulsed injection includes outputting the pulsed injection directly into the cylinder.

7 . The method of claim 6 wherein the outputting a pulsed injection includes outputting the pulsed injection prior to a crank angle timing corresponding to the top-dead-center position of the piston.

8 . The method of claim 7 wherein the crank angle timing is from 40° prior to an intake valve closing timing to 40° after an intake valve closing timing.

9 . The method of claim 8 wherein the pulsed injection is split around the intake valve closing timing.

10 . The method of claim 1 wherein the gaseous hydrogen fuel includes gaseous molecular hydrogen, and further comprising feeding the gaseous hydrogen fuel to the fuel injector at an injection pressure.

11 . A gaseous fuel engine system comprising:
an internal combustion engine having a cylinder formed therein, and a piston movable in the cylinder between a bottom-dead-center position and a top-dead-center position and including a center cone; a fuel system including a gaseous hydrogen fuel supply, a fuel injector fluid connected to the gaseous hydrogen fuel supply and having a valve electrical actuator, and the fuel injector extending into the cylinder and including a fuel outlet arranged to produce a spray cone of injected gaseous hydrogen fuel advanced from the fuel outlet and targeting the center cone for impingement; the fuel system further including a fueling control unit structured to:
output electrical control commands to the valve electrical actuator;
energize the valve electrical actuator based on the electrical control commands according to a pulsed waveform; and
cause the fuel injector to output a pulsed injection of the gaseous hydrogen fuel forming the spray cone for combustion in the cylinder based on the energizing of the valve electrical actuator.

12 . The engine system of claim 11 wherein the pulsed waveform includes a square waveform alternating a plurality of on-times with a plurality of dwell times.

13 . The engine system of claim 12 wherein the plurality of on-times are longer in duration than the plurality of dwell times.

14 . The engine system of claim 13 wherein the pulsed injection includes a plurality of pulses corresponding in number to the plurality of on-times, and the number is from 3 to 8.

15 . The engine system of claim 12 wherein the fuel injector includes a total number of fuel outlet holes of 3 or less.

16 . The engine system of claim 14 wherein the internal combustion engine further includes an intake port extending to the cylinder, an intake runner extending to the intake port, and a fuel injector fluid connected to the gaseous hydrogen fuel supply and extending into one of the intake port or the intake runner.

17 . The engine system of claim 14 wherein the fuel injector extends into the cylinder.

18 . A method of operating an engine comprising:
feeding a gaseous hydrogen fuel to a fuel injector coupled to an engine; actuating the fuel injector to output a pulsed injection of the gaseous hydrogen fuel into intake air in the engine; producing a plurality of entrainment breaks between a plurality of pulses of the gaseous hydrogen fuel in a spray cone of the pulsed injection; entraining air into the spray cone in the plurality of entrainment breaks; and combusting the gaseous hydrogen fuel and air in a cylinder in the engine.

19 . The method of claim 18 wherein the feeding the gaseous hydrogen fuel to the fuel injector includes feeding the gaseous hydrogen fuel at an injection pressure.

20 . The method of claim 19 wherein the plurality of pulses includes from 3 to 8 pulses split around an intake valve closing timing.

Assignees

• Caterpillar Inc

Inventors

• Mcdavid Robert Michael
• Koci Chad Palmer
• Anders Jonathan W

Classifications

• F02D41/20

  Output circuits, e.g. for controlling currents in command coils · CPC title

• F02D41/401

  Controlling injection timing (F02D41/402 takes precedence) · CPC title

• F02D2041/389

  for injecting directly into the cylinder · CPC title

• Y02T10/30

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

• F02D19/024 Primary

  by controlling fuel injectors · CPC title