Abstract: The present disclosure relates to a combustion engine system and a method of operation thereof. The combustion engine system includes a pollutant conversion system and an exhaust gas turbocharger that includes a variable turbine geometry and a waste gate valve. The variable turbine geometry includes adjustable guide elements surrounding the turbine wheel in a circumferential direction and are arranged to define an overall cross-section in their respective position for the exhaust gas. In a control mode where the pollutant conversion system comprises a temperature above a threshold temperature, the guide elements are adjusted such that the overall cross-section is between a control minimum value and a control maximum value. In a heat-up mode at temperatures of the pollutant conversion system below the threshold temperature, the guide elements are moved to a heat-up position where the overall cross-section is smaller than the control minimum value.

Abstract: The present disclosure relates to a combustion engine system and a method of operation thereof. The combustion engine system includes a pollutant conversion system and an exhaust gas turbocharger that includes a variable turbine geometry and a waste gate valve. The variable turbine geometry includes adjustable guide elements surrounding the turbine wheel in a circumferential direction and are arranged to define an overall cross-section in their respective position for the exhaust gas. In a control mode where the pollutant conversion system comprises a temperature above a threshold temperature, the guide elements are adjusted such that the overall cross-section is between a control minimum value and a control maximum value. In a heat-up mode at temperatures of the pollutant conversion system below the threshold temperature, the guide elements are moved to a heat-up position where the overall cross-section is smaller than the control minimum value.