3731 results about "Exhaust gas recirculation" patented technology

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.

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.

A portion of the exhaust generated by a turbomachine is recirculated through an inlet portion by an exhaust gas recirculation system. The system reduces the level of harmful constituents within the exhaust before the exhaust is recirculated.

EGR systems for an internal combustion engine configured to operate using multiple-staged turbochargers, or a pair of single stage turbochargers, to provide exhaust gas recirculation to meet emissions requirements while not affecting engine performance. One or two EGR loops operating at low, intermediate, or high pressures may be employed. EGR exhaust gases may be taken directly from the exhaust manifold, or after the exhaust stream has passed through a turbocharger turbine. EGR exhaust gases may be injected at an intermediate pressure between stages of a multiple stage turbocharger, or alternatively between a low pressure turbocharger compressor and high pressure turbocharger compressor, before being boosted to a pressure high enough to ensure the desired mass flow to the engine and delivered to the intake manifold. Intake air may be pressurized prior to mixing with the EGR exhaust gases.

At least one main air compressor makes a compressed ambient gas flow. The compressed ambient gas flow is delivered to a turbine combustor at a pressure that is greater than or substantially equal to an output pressure delivered to the turbine combustor from a turbine compressor as at least a first portion of a recirculated gas flow. A fuel stream is delivered to the turbine combustor, and a combustible mixture is formed and burned, forming the recirculated gas flow. A turbine power is produced that is substantially equal to at least a power required to rotate the turbine compressor. At least a portion of the recirculated gas flow is recirculated through a recirculation loop. An excess portion of the recirculated gas flow is vented or a portion of the recirculated gas flow bypasses the turbine combustor or both.