Abstract: The present invention relates to a two-stage supercharging system for an internal-combustion engine (10) comprising at least one cylinder (12) with an intake distributor (16) and an exhaust manifold (18), as well as a recirculation line (78) for recycling the exhaust gas to the intake of said engine, said system comprising a high-pressure supercharging stage (22) with a turbocharger including an expansion turbine (26) connected to a compressor (30) and a low-pressure supercharging stage (24) with a turbocharger including an expansion turbine (28) connected to a compressor (32), and exhaust gas purification means arranged between exhaust outlet (40) and turbine (26) of the high-pressure turbocharger. According to the invention, the system comprises an exhaust gas bypass branch (70) going from outlet (40) of the engine exhaust and ending at turbine (28) of low-pressure turbocharger (24).

Abstract: The present invention relates to a two-stage supercharging system for an internal-combustion engine (10) comprising at least one cylinder (12) with an intake distributor (16) and an exhaust manifold (18), as well as a recirculation line (78) for recycling the exhaust gas to the intake of said engine, said system comprising a high-pressure supercharging stage (22) with a turbocharger including an expansion turbine (26) connected to a compressor (30) and a low-pressure supercharging stage (24) with a turbocharger including an expansion turbine (28) connected to a compressor (32), and exhaust gas purification means arranged between exhaust outlet (40) and turbine (26) of the high-pressure turbocharger. According to the invention, the system comprises an exhaust gas bypass branch (70) going from outlet (40) of the engine exhaust and ending at turbine (28) of low-pressure turbocharger (24).