Abstract: A method of turbo-charger surge detection may include the steps of measuring a rate of air flow through a turbo-charger compressor, measuring a temperature of the air flow, calculating a standard mass flow rate of the air flow at the rate and the temperature, measuring a pressure ratio across the turbo-charger compressor, calculating a surge mass flow rate at a surge line of the compressor at the pressure ratio, comparing the standard mass flow rate to the surge mass flow rate, and reducing an EGR flow or reducing the pressure ratio by opening a vane of the compressor if the standard mass flow rate is lower than the surge mass flow rate.

Abstract: In a method of maintaining temperature of engine exhaust gas from cylinders of a multi-cylinder engine (23) with a desired range, exhaust gas from a first group of cylinders (25) including at least one cylinder is routed to at least one of an EGR system (53) and an exhaust system (41). Exhaust gas from a second group of cylinders (27) including at least one of the cylinders is routed to the exhaust system (41). Routing of the exhaust gas from the first group of cylinders between the EGR system and the exhaust system is controlled to maintain a temperature of engine exhaust gas within a desired range. An engine (23), a control system (69), and a controller (71), as well as an exhaust gas mixture, are also disclosed.

Abstract: A method of turbo-charger surge detection may include the steps of measuring a rate of air flow through a turbo-charger compressor, measuring a temperature of the air flow, calculating a standard mass flow rate of the air flow at the rate and the temperature, measuring a pressure ratio across the turbo-charger compressor, calculating a surge mass flow rate at a surge line of the compressor at the pressure ratio, comparing the standard mass flow rate to the surge mass flow rate, and reducing an EGR flow or reducing the pressure ratio by opening a vane of the compressor if the standard mass flow rate is lower than the surge mass flow rate.

Abstract: In a method of maintaining temperature of engine exhaust gas from cylinders of a multi-cylinder engine (23) with a desired range, exhaust gas from a first group of cylinders (25) including at least one cylinder is routed to at least one of an EGR system (53) and an exhaust system (41). Exhaust gas from a second group of cylinders (27) including at least one of the cylinders is routed to the exhaust system (41). Routing of the exhaust gas from the first group of cylinders between the EGR system and the exhaust system is controlled to maintain a temperature of engine exhaust gas within a desired range. An engine (23), a control system (69), and a controller (71), as well as an exhaust gas mixture, are also disclosed.

Abstract: An EGR recovery system and method includes calculating a transient volume of EGR sufficient to maintain NOx emitted by an engine below a predetermined level during a period of transient operation of said engine, supplying an actual volume of EGR during said period of transient operation, measuring said actual level of EGR during said period of transient operation, calculating an EGR deficit between said transient volume of EGR and said actual of volume of EGR during said period of transient operation, integrating said EGR deficit over said period of transient operation to calculate a deficit volume of EGR, calculating a following steady-state volume of EGR sufficient to maintain NOx emitted by said engine of said engine below said predetermined level during a following period of substantially steady-state operation of said engine, and supplying said following steady-state volume of EGR plus said deficit volume of EGR during said following period of substantially steady-state operation of said engine.