8533results about "Exhaust gas recirculation" patented technology

During operation with part load, a gasoline internal combustion engine is operated with a lean air / fuel mixture by auto-ignition. During operation with full load, spark-ignition is used to operate the engine. The internal combustion engine is operated in three auto-ignition combustion modes depending upon magnitude of a predetermined operating parameter. The operating parameter is indicative of the engine load or the engine speed. The three auto-ignition combustion modes are a gasoline reform auto-ignition combustion mode, an auto-ignition stratified charge combustion mode, and an auto-ignition homogeneous charge combustion mode. In the gasoline reform auto-ignition combustion mode that may be selected during operation with low part load, a first fuel injection during an exhaust gas retaining phase produces sufficient amount of active fuel radicals for promotion of auto-ignition of air / fuel mixture produced by a second fuel injection during the subsequent compression phase. In the auto-ignition stratified charge combustion mode that may be selected during operation with intermediate part load, a fuel injection during compression phase supports auto-ignition. In the auto-ignition homogeneous charge combustion mode that may be selected during operation with high part load, a fuel injection during intake phase supports auto-ignition.

Part load operating point for a controlled auto-ignition four-stroke internal combustion engine is reduced without compromising combustion stability through load dependent valve controls and fueling strategies. Optimal fuel economy is achieved by employing negative valve overlap to trap and re-compress combusted gases below a predetermined engine load and employing exhaust gas re-breathing above the predetermined engine load. Split-injection fuel controls are implemented during low and intermediate part load operation whereas a single-injection fuel control is implemented during high part load operation. Split-injections are characterized by lean fuel / air ratios and single-injections are characterized by either lean or stoichiometric fuel / air ratios. Controlled autoignition is thereby enabled through an extended range of engine loads while maintaining acceptable combustion stability and emissions at optimal fuel economy.

An exhaust gas recirculation (EGR) system of an internal combustion engine has an EGR cooler in an EGR passage connecting an exhaust manifold with an intake manifold. The EGR cooler cools EGR gas recirculated through the EGR passage. Cooling performance detecting means included in an electronic control unit (ECU) determines that cooling performance of the EGR cooler is degraded when intake pressure measured by an intake pressure sensor is lower than a normal intake pressure by at least a predetermined value. When the degradation of the cooling performance is detected, cooling performance regeneration controlling means included in the ECU increases the temperature inside the EGR cooler by heating the exhaust gas to eliminate soot or unburned hydrocarbon by oxidization. Thus, the cooling performance of the EGR cooler is regenerated.

Improved exhaust gas recirculation system and methods that use one or more of the engine's cylinders as dedicated EGR cylinders. All of the exhaust from the dedicated EGR cylinders is recirculated back to the engine intake. Thus, the EGR rate is constant, but the EGR mass flow may be controlled by adjusting the air-fuel ratio of the dedicated EGR cylinders or by using various variable valve timing techniques.

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.

The present invention relates to a system and method for cooling a combustion gas charge prior. The combustion gas charge may include compressed intake air, exhaust gas, or a mixture thereof. An evaporator is provided that may then receive a relatively high temperature combustion gas charge and discharge at a relatively lower temperature. The evaporator may be configured to operate with refrigeration cycle components and / or to receive a fluid below atmospheric pressure as the phase-change cooling medium.

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.

Systems and methods for turbocharging an internal combustion engine include operating two turbochargers in a series configuration for a first operating region and a parallel configuration for a second operating region. Systems and methods for controlling exhaust gas recirculation (EGR) in a turbocharged internal combustion engine provide low pressure EGR upstream of a compressor inlet for a first operating region and high pressure EGR downstream of a compressor outlet for a second operating range to further improve turbocharger operating margin and overall efficiency.

In an internal combustion engine provided with two exhaust gas turbochargers which each comprise a turbine in an exhaust line and one compressor in an intake section of the engine, two exhaust lines are provided which are each assigned to at least one of the exhaust gas turbines, an exhaust gas recirculation device being arranged between an exhaust line upstream of an exhaust gas turbine and the intake section downstream of a compressor and the two exhaust lines including bypass lines with a control valve for selectively permitting the exhaust gas to bypass the turbine closer to the engine.