Patent ID: 7581394
Filing Date: 2009-09-01
Classification: F01D,F02B,F05D,Y02T

Abstract:
1. A method for operating an internal combustion engine, the method comprising the steps of: providing a first turbocharger and a second turbocharger arranged in parallel with respect to the engine, wherein the second turbocharger comprises a turbine comprising a turbine wheel disposed within a turbine housing, the turbine housing receiving exhaust gas from an engine, the turbine having an annular nozzle defined between an inboard wall and an outboard wall for guiding the exhaust gas to the turbine wheel, wherein the annular nozzle comprises a variable nozzle device comprising: completely closing the variable nozzle device of the second turbocharger when the engine is operating below a certain rotational speed, such that only the first turbocharger works to supercharge the engine; and opening the variable nozzle device of the second turbocharger when the engine is operating above said certain rotational speed.