A fuel oxygen conversion unit includes a contactor defining a liquid fuel inlet, a stripping gas inlet and a fuel/gas mixture outlet. The fuel oxygen conversion unit also includes a fuel/gas separator defining a fuel/gas mixture inlet in flow communication with the fuel/gas mixture outlet of the contactor, an axial direction, and a radial direction. The fuel/gas separator includes a separator assembly including a core including a gas-permeable section extending along the axial direction and defining a maximum diameter, the maximum diameter of the gas-permeable section being substantially constant along the axial direction; and a stationary casing, the fuel/gas separator defining a fuel/gas chamber in fluid communication with the fuel/gas mixture inlet at a location inward of the stationary casing and outward of the gas-permeable section of the separator assembly along the radial direction.

An internal combustion engine inducts no air from outside atmosphere and it discharges no gas into outside environment. The engine receives hydrocarbon fuel and oxygen, and its combustion gas consists mostly of carbon dioxide and water vapor. Carbon dioxide is captured, stored and subsequently sequestered by using it with water to create a hydrocarbon fuel that can be supplied back to the engine. In that way, the engine fuel is repeatedly regenerated and reused, and the engine operates in a carbon neutral mode of operation. Some of the combustion gas is used as a diluent gas in the engine. High specific heat and high density of that gas permit operation in high-efficiency overexpanded cycle without an increase in the engine size. Various methods of the engine control and operation are described, including methods to reduce pumping loss. Various modes of in-cylinder diluent gas formation are considered.

This invention provides means and a method to eliminate emissions from an internal combustion engine during cold-starts and warm-starts. An oxidizer intake valve external to the engine head and an exhaust valve following the after-treatment system and condensing heat exchanger are closed, thus sealing all gasses inside the engine and the exhaust after-treatment system before starting the engine. Oxygen and hydrogen are used as the oxidizer and fuel to start this engine and operate this engine until the exhaust after-treatment systems have reached their required operating temperatures. This emissions-free startup system works equally well on two, four, six, or eight stroke engines, one or multiple cylinder engines, and spark or compression ignition engines. This invention also provides a means and method to clean the interior of an engine and the after-treatment systems of soot, particulate, and the catalytic surfaces without disassembling the engine or the after-treatment systems.

Methods and systems are provided for increasing engine power via partial engine enrichment and exhaust gas recirculation. In one example, a method may include enriching a first set of engine cylinders and enleaning a second, remaining set of the engine cylinders, exhaust gas from the first set and the second set producing a stoichiometric mixture at a downstream emission control device, and providing exhaust gas recirculation (EGR) to an intake passage of the engine from the first set of cylinders and not from the second set. In this way, cooling effects from the partial enrichment and the EGR enable engine air flow, and thus engine power, to be increased while an efficiency of the emission control device is maintained, thereby decreasing vehicle emissions.

Methods and systems are provided for increasing engine power via partial engine enrichment and exhaust gas recirculation. In one example, a method may include enriching a first set of engine cylinders and enleaning a second, remaining set of the engine cylinders, exhaust gas from the first set and the second set producing a stoichiometric mixture at a downstream emission control device, and providing exhaust gas recirculation (EGR) to an intake passage of the engine from the first set of cylinders and not from the second set. In this way, cooling effects from the partial enrichment and the EGR enable engine air flow, and thus engine power, to be increased while an efficiency of the emission control device is maintained, thereby decreasing vehicle emissions.

Methods and systems are provided for detecting cylinder-to-cylinder air-fuel ratio (AFR) imbalance in engine cylinders. In one example, a method may include detecting an AFR imbalance of an engine cylinder based on an individual crankshaft acceleration of the cylinder relative to a mean crankshaft acceleration produced by all cylinders of the engine, and correcting a fuel amount of the cylinder via a fuel multiplier value, the fuel multiplier value selected from a plurality of fuel multiplier values based on an imbalance source. In this way, the AFR imbalance may be accurately detected and correcting using existing engine system sensors.

Methods and systems are provided for detecting cylinder-to-cylinder air-fuel ratio (AFR) imbalance in engine cylinders. In one example, a method may include detecting an AFR imbalance of an engine cylinder based on an individual crankshaft acceleration of the cylinder relative to a mean crankshaft acceleration produced by all cylinders of the engine, and correcting a fuel amount of the cylinder via a fuel multiplier value, the fuel multiplier value selected from a plurality of fuel multiplier values based on an imbalance source. In this way, the AFR imbalance may be accurately detected and correcting using existing engine system sensors.

This invention provides a method to clean the inside surfaces of an engine and its exhaust after-treatment system each time the engine is shut down. This cleaning is accomplished without disassembly of the engine and without involvement of the engine's operator. This cleaning includes the combustion chamber, valves, intake and exhaust ports, particulate filters, catalytic after-treatment processes, and exhaust piping. This is accomplished by leaving the shut down engine and its exhaust after-treatment systems in an oxygen rich atmosphere where oxidation of the hydrocarbons on the inside surfaces continues.

This invention provides a method to clean the inside surfaces of an exhaust after-treatment system each time the engine is shut down. This cleaning is accomplished without disassembly of the engine and without involvement of the engine's operator. This cleaning includes the exhaust ports, particulate filters, catalytic after-treatment processes, and exhaust conduits. This is accomplished by leaving the exhaust after-treatment systems in an oxygen rich atmosphere, with the engine shut down, where oxidation of the hydrocarbons on the inside surfaces continues.

Methods and systems are provided for using compression heating to heat a cylinder piston before cylinder combustion is resumed. Cylinder heating is achieved using combinations of slow unfueled engine rotation where the engine cylinders are heated via compression stroke heating, and slow compressor rotation where the cylinders are heated via compression heating. One or more intake or exhaust heaters may be concurrently operated to expedite cylinder heating.