Two-stage supercharging system having an exhaust gas purification device for an internal combustion engine and method for controlling the same

摘要

The system (20) has a high pressure supercharging stage formed by a high pressure turbo-compressor (22). The turbo-compressor has an expansion turbine (26) connected to a compressor (30). An exhaust gas purification unit i.e. precatalyst (92), is placed between an exhaust gas outlet (40) and the expansion turbine. An exhaust gas derivation branch (70) derives the exhaust gas starting from the outlet and reaching an expansion turbine (28) of a low pressure turbo-compressor (24) of a low pressure supercharging stage. An independent claim is also included for a method for controlling a double-stage supercharging system.