Engine braking in hydrogen internal combustion engines
AssigneeEaton Intelligent Power Limited
InventorsJames E. McCarthy, Jr., Mihai Dorobantu, Kevin Snyder
Life of this patent
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Abstract
A method of operating a system including a hydrogen internal combustion engine and a supercharger between a normal operating mode and an engine braking mode. In the normal operating mode, the supercharger operates at a first rotational speed to deliver air to an intake manifold of the engine. In the engine braking mode, the supercharger operates at a second rotational speed to deliver air to the intake manifold and a restriction is provided to increase a pressure ratio across the supercharger.
Claims26
A method of enhancing decompression engine braking to offset reduced power braking potential in a low compression internal combustion engine, the method comprising:
- initiating an engine braking operation in the internal combustion engine, wherein the internal combustion engine consumes a hydrogen fuel and has a compression ratio in a normal operating mode of no more than 14:1;
- boosting intake manifold pressure with an air compressor to create a boosted airflow stream;
- introducing the boosted airflow stream air into a cylinder of the internal combustion engine;
- compressing the air in the cylinder with a piston;
- and
- releasing the compressed air from the cylinder in a controlled compression release event.
The method of 8, wherein the at least two speeds comprise a first speed for driving operations and a second, faster, speed for braking operations.
A system for decompression braking in a low compression internal combustion engine, the system comprising:
- a hydrogen internal combustion engine (H2 ICE) having at least one cylinder, the at least one cylinder including a piston and an intake valve;
- an air compressor in communication with the intake valve;
- and
- a controller having a propulsion mode and a braking mode, wherein the air compressor is operated by the controller during the braking mode to supply air to the cylinder during an intake stroke by the piston.
A method of operating a system including a hydrogen internal combustion engine and a supercharger between a normal operating mode and an engine braking mode, the method comprising:
- a) operating the system in the normal operating mode wherein the supercharger operates at a first rotational speed to deliver air to an intake manifold of the engine;
- and
- b) operating the system in the engine braking mode, the engine braking mode including:
- i) operating the supercharger to deliver an airflow stream to the intake manifold;
- ii) increasing a pressure ratio across the supercharger to increase parasitic losses by one or both of operating the supercharger at a second rotational speed higher than the first rotational speed and operating a restriction valve arrangement;
- iii) introducing the airflow stream air into a cylinder of the internal combustion engine;
- iv) compressing the air in the cylinder with a piston;
- and
- v) releasing the compressed air from the cylinder in a controlled compression release event.
Dependencies are inferred from the claim text.