Abstract: A diesel engine system includes a diesel engine, a NOx control device downstream of the engine, an exhaust line between the engine and the NOx control device, a bypass line connected to the exhaust line at a first end upstream of the NOx control device, and a bypass valve connecting the exhaust line and the bypass line, the bypass valve permitting flow through the exhaust line to the NOx control device when in an open position and preventing flow through the exhaust line to the NOx control device and permitting flow through the exhaust line to the bypass line when in a closed position. A controller can arranged to control opening and dosing of the bypass valve, such as when an operating condition of the engine reaches a predetermined operating condition.

Abstract: A turbocharger unit for an internal combustion engine having at least one exhaust line for the evacuation of exhaust gases from the combustion chamber of the engine and at least one inlet line for the supply of air to the combustion chamber is provided. The turbocharger unit includes a turbine which interacts with a compressor in order to extract energy from the exhaust-gas flow of the engine and pressurize the inlet air of the engine. The compressor is of the radial type and is provided with an impeller having backswept blades in which the blade angle between an imaginary extension of the center line of the blade between root section and tip section in the direction of the outlet tangent and a line connecting the center axis of the impeller to the outer tip of the blade is at least about 40 degrees. The ratio between the inlet diameter of the impeller and its outlet diameter lies within the range 0.50-0.62.