Exhaust system for an internal combustion engine

An exhaust system for an internal combustion engine, said exhaust system comprising an exhaust conduit adapted to fluidly connect said internal combustion engine to a turbine of a turbo, said exhaust system further comprising a valve comprising a valve flap located in said exhaust conduit in a position between said internal combustion engine and said turbine, as seen in a direction of flow from said internal combustion engine to said turbine, when said exhaust conduit fluidly connects said internal combustion engine to said turbine, said valve flap being pivotally connected to at least a portion of said exhaust conduit, said exhaust system further comprising an actuator adapted to impart a load on at least a portion of said valve to thereby control a pivotal position of said valve flap in said exhaust conduit to thereby control a gas flow via said exhaust conduit, said exhaust system further comprising an actuator load sensor adapted to detect load information indicative of a magnitude of the load that the actuator currently imparts on at least said portion of said valve, wherein said exhaust system further comprises a control system adapted to receive load information from said actuator load sensor and to issue control information to said actuator in response to said load information, wherein said control system is adapted to determine a counterpressure value, indicative of a current exhaust gas counterpressure in said exhaust conduit, upstream of said valve flap, as seen in a direction of flow from said internal combustion engine to said turbine, on the basis of said load information.

A method for controlling an internal combustion engine system comprising an internal combustion engine, a turbo, which in turn comprises a turbine, and an exhaust system, said exhaust system comprising an exhaust conduit adapted to fluidly connect said internal combustion engine to the turbine of the turbo, said exhaust system further comprising a valve comprising a valve flap located in said exhaust conduit in a position between said internal combustion engine and said turbine, as seen in a direction of flow from said internal combustion engine to said turbine, said valve flap being pivotally connected to at least a portion of said exhaust conduit, said exhaust system further comprising an actuator adapted to impart a load on at least a portion of said valve to thereby control a pivotal position of said valve flap in said exhaust conduit to thereby control a gas flow via said exhaust conduit, said exhaust system further comprising an actuator load sensor adapted to detect load information indicative of a magnitude of the load that the actuator currently imparts on at least said portion of said valve, said method comprising:

• detecting said load information, and
• controlling said actuator in response to said load information,
• said method further comprising determining a counterpressure value, indicative of a current exhaust gas counterpressure in said exhaust conduit, upstream of said valve flap, as seen in a direction of flow from said internal combustion engine to said turbine, on the basis of said load information, wherein said turbo comprises a compressor and wherein the method further comprises determining information indicative of a rotational speed of a compressor of said turbo as well as information about a current charge air pressure downstream said compressor, said method further comprising determining an actual air mass flow downstream said compressor on the basis of said counterpressure value, said information about said current charge air pressure downstream said compressor and said information indicative of said rotational speed of said compressor, said internal combustion engine system comprises an inlet conduit adapted to fluidly connect said compressor to said internal combustion engine, said internal combustion engine system further comprising an intake throttle valve adapted to control an air mass flow via said inlet conduit, said method comprising controlling said intake throttle valve in response to a target air mass flow and said actual air mass flow.