8534results about "Exhaust gas recirculation" patented technology

The disclosure relates to marine craft which are capable of operating in the hydrofoil mode, many with extensible and retractable hydrofoil posts. Specific embodiments of large commercial hydrofoil craft are described, including those with structure which is the water during hydrofoil travel mode and which can be retracted to partly fit within recesses in the hull during other operating modes. Other craft, including those with hybrid electric drive, are disclosed having un-cooled reciprocating internal combustion engines. A number of arrangements for pistons and cylinders of unconventional configuration are described. These included are toroidal combustion or working chambers, some with fluid flow through the core of the toroid, pistons reciprocating between pairs of working chambers, tensile links between piston and crankshaft, energy absorbing piston-crank links, crankshafts supported on gas bearings. In some embodiments pistons mare rotate while reciprocating. High temperature exhaust emissions systems are described, including those containing filamentary material, as are procedures for reducing emissions during cold start by means of valves at reaction volume exit. Compound engines having the new engines as a reciprocating stage are described.

Improved transient response times are obtained while maintaining low emissions with a low pressure EGR system through methods for quickly obtaining a desired oxygen concentration for charge-air to be used for combustion. Under a first method, fuel quantity in the main combustion event is controlled in the combustion process to produce exhaust around a relatively constant target exhaust oxygen concentration value. By keeping the exhaust oxygen concentration levels at a relatively constant value, lag time in waiting for low pressure EGR valve adjustments during transients may be avoided, and the system's air handling response to meet transients may be paced solely by adjusting the mass of air to be supplied (i.e. boost response). Under a second method, a multiple-stage combustion process is utilized, in which fuel feed is controlled in a small, preliminary HCCI-type combustion event in order to produce a target oxygen concentration of charge-air to be used for the second, main combustion event. Under a third method, exhaust rebreathing is used to produce a target oxygen concentration of charge-air to be used for combustion.