Patent ID: 7752844

Claim:
An engine braking method for an internal combustion engine ( 1 ) having two exhaust gas turbochargers ( 2 , 6 ), each of the two exhaust gas turbochargers ( 2 , 6 ) having an exhaust gas turbine ( 3 , 7 ) arranged in series in the an exhaust tract of the engine ( 1 ) and each of the two exhaust gas turbines ( 3 , 7 ) including a fixed geometry turbine inlet passage, a bypass line ( 10 , 14 ) extending around each exhaust gas turbine ( 3 , 7 ) with a control valve ( 11 , 15 ) in each bypass line ( 10 , 14 ) for selectively permitting the exhaust gas flow to bypass at least one of the turbines, and each of the two exhaust gas turbochargers ( 2 , 6 ) including a first compressor ( 4 ) and a second compressor ( 8 ) arranged in series in an intake tract of the engine ( 1 ) and the first compressor ( 4 ) arranged in the intake tract nearer the engine ( 1 ) including a bypass line ( 12 ) with a valve ( 13 ) for selectively permitting the compressed intake air to bypass the first compressor ( 4 ) arranged nearer the engine, said method comprising the steps of: controlling the air mass flow bypassing the first compressor ( 4 ) arranged nearer the engine and the exhaust gas mass flow through at least one of the bypass lines ( 10 , 14 ) around the two exhaust gas turbines ( 3 , 7 ) depending on the desired engine braking power, and, for increasing the engine braking power, opening the valve ( 15 ) of the bypass of the turbine ( 7 ) remote from the engine ( 1 ) to permit exhaust gas to flow through the bypass line ( 14 ) past the turbine ( 7 ) remote from the engine ( 1 ).