Granted Patent B2

US 12,338,763 · App. 18/604,954 · Granted Jun 24, 2025

Inventors: Fabien G. Redon (San Diego, CA); Ming Huo (Novi, MI)

Assignee: Achates Power, Inc.

F02B43/10F02B75/28F02D19/021F02D41/0027F02D41/0047

Abstract

Claims (27)

1. A two-stroke cycle opposed-piston engine, comprising:

at least one ported cylinder with a bore;

a pair of pistons disposed for mutually opposing movements in the bore, such that a maximum volume is defined in the bore when the pistons are furthest apart during a compression stroke of the engine and a minimum volume is defined in the bore when the pistons are closest together during an expansion stroke of the engine;

an air intake channel configured to convey a flow of charge air to an intake port of the cylinder;

an exhaust channel configured to receive a flow of exhaust gas through an exhaust port of the cylinder;

a hydrogen fuel provisioning device configured to provide hydrogen fuel;

at least one fuel injection device coupled to the hydrogen fuel provisioning device and configured to inject the provided hydrogen fuel into the cylinder bore; and,

a control unit coupled to the at least one fuel injection device and programmed to:

operate the at least one fuel injection device to cause a pilot injection of hydrogen fuel during an occurrence of a maximum volume defined in the bore between the first and second pistons; and,

operate the at least one fuel injection device to cause a main injection of hydrogen fuel during an occurrence of a minimum volume defined in the bore between the first and second pistons;

whereby, the hydrogen fuel auto-ignites in response to compression of the charge air in the cylinder.

2. The opposed-piston engine of claim 1 , wherein the control unit is further configured to:

cause the pilot injection of hydrogen fuel after the maximum volume is defined; and,

cause injection of the main charge of hydrogen fuel following the pilot injection of the hydrogen fuel.

3. The opposed-piston engine of claim 1 , wherein the control unit is configured to cause the at least one fuel injection device to inject the hydrogen fuel based on closure of the intake port by a first piston of said pair of pistons.

4. The opposed-piston engine of claim 1 , further including means for diluting the mixture of charge air and injected hydrogen.

5. The opposed-piston engine of claim 4 , wherein the means for diluting the mixture comprises an EGR channel.

6. The opposed-piston engine of claim 1 , in which the control unit is further programmed to control a trapped temperature of the cylinder by retention of exhaust gas in the cylinder when both ports are closed.

7. A method for operating an opposed-piston engine, comprising the steps of:

providing a flow of charge air into a combustion chamber defined in a cylinder bore between the end surfaces of two pistons of the engine;

directly injecting hydrogen fuel into the combustion chamber;

forming a mixture of injected hydrogen fuel and charge air in the combustion chamber; and,

auto-igniting the mixture of injected hydrogen fuel and charge air by compressing the mixture.

8. The method of claim 7 , the step of directly injecting comprising injecting a pilot injection of hydrogen fuel followed by a main injection of hydrogen fuel;

wherein the pilot injection auto-ignites in response to compression of the mixture of hydrogen fuel and charge air.

9. The method of claim 7 , further comprising recirculating exhaust gas to be mixed with said charge air.

10. The method of claim 7 , further comprising retaining exhaust gas to be mixed with the charge air in the combustion chamber.

Assignments (3)

Continuity (3)

References Cited (43)