A method for controlling hydrogen combustion in a hydrogen internal combustion engine system includes a combustion chamber linked to an intake port via an intake valve, the hydrogen internal combustion engine system comprising a piston slidably moving between a top dead center position and a bottom dead center position, characterized by the steps of: injecting water in liquid phase in the intake port when the piston is between 0 and 40 crank angle degrees before opening of the intake valve, injecting hydrogen after opening of the intake valve and when the piston is between 0 and 60 crank angle degrees after the top dead center position, stopping hydrogen injection when the piston is between 0 and 100 crank angle degrees before the bottom dead center position.

A method for controlling hydrogen combustion in a hydrogen internal combustion engine system includes a combustion chamber linked to an intake port via an intake valve, the hydrogen internal combustion engine system comprising a piston slidably moving between a top dead center position and a bottom dead center position, characterized by the steps of: injecting water in liquid phase in the intake port when the piston is between 0 and 40 crank angle degrees before opening of the intake valve, injecting hydrogen after opening of the intake valve and when the piston is between 0 and 60 crank angle degrees after the top dead center position, stopping hydrogen injection when the piston is between 0 and 100 crank angle degrees before the bottom dead center position.

Some embodiments described herein relate to a method of operating a compression ignition engine. The method of operating the compression ignition engine includes opening an intake valve to draw a volume of air into a combustion chamber, closing an intake valve, and moving a piston from a bottom-dead-center (BDC) position to a top-dead-center (TDC) position in the combustion chamber at a compression ratio of at least about 15:1. The method further includes injecting a volume of fuel into the combustion chamber at an engine crank angle between about 330 degrees and about 365 degrees during a first time period. The fuel has a cetane number less than about 40. The method further includes combusting substantially all of the volume of fuel. In some embodiments, a delay between injecting the volume of fuel into the combustion chamber and initiation of combustion is less than about 2 ms.

Some embodiments described herein relate to a method of operating a compression ignition engine. The method of operating the compression ignition engine includes opening an intake valve to draw a volume of air into a combustion chamber, closing an intake valve, and moving a piston from a bottom-dead-center (BDC) position to a top-dead-center (TDC) position in the combustion chamber at a compression ratio of at least about 15:1. The method further includes injecting a volume of fuel into the combustion chamber at an engine crank angle between about 330 degrees and about 365 degrees during a first time period. The fuel has a cetane number less than about 40. The method further includes combusting substantially all of the volume of fuel. In some embodiments, a delay between injecting the volume of fuel into the combustion chamber and initiation of combustion is less than about 2 ms.

Typically, an engine-compressor for compressing natural gas for use as a fuel has a single cooling circuit to cool both its combustion unit and compression unit. A single cooling circuit design is not ideal because the optimal temperature for the combustion unit is higher than the compression unit of the engine-compressor. The present invention provides a dual zone cooling system to cool the combustion unit separately from the compression unit.

Typically, an engine-compressor for compressing natural gas for use as a fuel has a single cooling circuit to cool both its combustion unit and compression unit. A single cooling circuit design is not ideal because the optimal temperature for the combustion unit is higher than the compression unit of the engine-compressor. The present invention provides a dual zone cooling system to cool the combustion unit separately from the compression unit.

The engines include compression cylinders, combustion cylinders, an air rail, and a heat exchanger. The methods of operating a compression ignition engine include taking air into a compression cylinder of the engine, compressing the air in the compression cylinder to raise the pressure and temperature of the air, passing the compressed air through a heat exchanger, and from the heat exchanger into a combustion cylinder, further compressing the compressed air during a compression stroke of the combustion cylinder, igniting fuel in the combustion cylinder at or near the end of the compression stroke by compression ignition, followed by a power stroke, and opening an exhaust valve at the end of the power stroke and passing at least some of the exhaust in the combustion cylinder through the heat exchanger to heat air that has been compressed in the compression cylinder and is then passing through the heat exchanger.

The engines include compression cylinders, combustion cylinders, an air rail, and a heat exchanger. The methods of operating a compression ignition engine include taking air into a compression cylinder of the engine, compressing the air in the compression cylinder to raise the pressure and temperature of the air, passing the compressed air through a heat exchanger, and from the heat exchanger into a combustion cylinder, further compressing the compressed air during a compression stroke of the combustion cylinder, igniting fuel in the combustion cylinder at or near the end of the compression stroke by compression ignition, followed by a power stroke, and opening an exhaust valve at the end of the power stroke and passing at least some of the exhaust in the combustion cylinder through the heat exchanger to heat air that has been compressed in the compression cylinder and is then passing through the heat exchanger.

A method for supplying hydrogen-operated internal combustion engines with oxygen, wherein an inert gas is cycled. An economical local supply of pure oxygen for a closed-cycle hydrogen engine with argon cycling is realized by separating the oxygen from the atmosphere without relying on the useful work of the engine. OSM ceramics and exhaust gas heat and low oxygen partial pressure of the exhaust gas are used to generate oxygen. Two reactors filled with OSM ceramics are used, these reactors being alternately purged with exhaust gas and regenerated with air. Losses of inert gases and the entry of atmospheric nitrogen are avoided by intermediate purging with steam. The steam is generated by the heat of the exhaust gas or exhaust air. A mixture of water vapor, inert gas and oxygen is formed during purging. Subsequently, the oxygen content in the gas phase is markedly increased since water vapor is condensed out.

A method for supplying hydrogen-operated internal combustion engines with oxygen, wherein an inert gas is cycled. An economical local supply of pure oxygen for a closed-cycle hydrogen engine with argon cycling is realized by separating the oxygen from the atmosphere without relying on the useful work of the engine. OSM ceramics and exhaust gas heat and low oxygen partial pressure of the exhaust gas are used to generate oxygen. Two reactors filled with OSM ceramics are used, these reactors being alternately purged with exhaust gas and regenerated with air. Losses of inert gases and the entry of atmospheric nitrogen are avoided by intermediate purging with steam. The steam is generated by the heat of the exhaust gas or exhaust air. A mixture of water vapor, inert gas and oxygen is formed during purging. Subsequently, the oxygen content in the gas phase is markedly increased since water vapor is condensed out.