Internal combustion engine having an exhaust gas turbocharger and an exhaust gas recirculation system

An internal combustion engine (1) including first and second groups of cylinders (1a, 1b), an exhaust gas turbocharger (2) and an exhaust gas recirculation system (14), the exhaust gas turbocharger (2) having an exhaust gas turbine (3) with a turbine rotor (8), separate first and second turbine flow passages (11a, 11b) of different flow cross-sections arranged upstream of the turbine rotor (8), each flow passage (11a, 11b) being in communication with a first and, respectively, second exhaust line (4a, 4b) for supplying exhaust gas from the internal combustion engine (1) to the exhaust gas turbine (3), a recirculation line (15) of the exhaust gas recirculation system (14) connecting the first exhaust line (4a) assigned to the smaller first flow passage (11a) to an intake line (6) of the internal combustion engine (1) via an adjustable valve (16) arranged in the recirculation line (15), a bypass line (19), which bypasses the exhaust gas turbine (3) extending from the adjustable valve (16) to a turbine outlet, and a controller (18) for switching the adjustable valve (16), depending on engine operation into the following positions so as to minimize engine emissions:

• the recirculation line (15) and the bypass line (19) shut off for directing all of the exhaust gas of the first group of cylinders (1a) to the first turbine inlet flow passage (11a) during braking operation of the engine,
• the recirculation line (15) opened in a controlled manner and the bypass line (19) shut off for directing the exhaust gas of the first group of cylinders (1a) to the first turbine inlet flow passage (11a) and to the intake line of the engine, during the normal operation of the engine, and
• the recirculation line (15) and the bypass line (19) opened in a controlled manner for recirculating part of the exhaust gas of the first group of cylinders to the engine (1), under high load operation of the engine, so as to provide an exhaust gas pressure in the recirculation line (15) sufficient for recirculating exhaust gas to the engine.