Method for starting a power system

A method for starting a power system, the power system comprising an internal combustion engine and a turbo which in turn comprises an inlet air compressor and an exhaust gas turbine, the exhaust gas turbine comprising a turbine wheel, the power system comprising an exhaust gas conduit assembly comprising at least one exhaust gas conduit wherein the exhaust gas turbine is adapted to receive exhaust gases from the internal combustion engine via the exhaust gas conduit assembly, the power system comprising an inlet air conduit assembly comprising at least one inlet air conduit wherein the internal combustion engine is adapted to receive inlet air from the inlet air compressor via the inlet air conduit assembly,

• the power system further comprising a throttle arrangement arranged between the internal combustion engine and the turbine wheel, as seen in a direction of flow from the internal combustion engine to the turbine wheel, the throttle arrangement being adapted to assume a plurality of different conditions for throttling exhaust gas from the internal combustion engine to the turbine wheel, the plurality of different conditions comprising an open condition with a smallest throttling of the exhaust gas amongst the plurality of different conditions as well as an at least partially closed condition associated with a throttling being larger than the smallest throttling,
• the power system further comprising a first exhaust gas recirculation path connecting a portion of the exhaust gas conduit assembly located upstream the throttle arrangement, as seen in a direction of flow from the internal combustion engine to the turbine wheel, to a portion of the inlet air conduit assembly located downstream the inlet air compressor, as seen in a direction of flow from the inlet air compressor to the internal combustion engine,
• the power system further comprising a first exhaust gas recirculation path valve adapted to control at least a flow through the first exhaust gas recirculation path;
• the method comprising:
• detecting temperature information (TI) indicative of an ambient air temperature of the power system, and
• in response to determining that the TI indicates the ambient air temperature of the power system being equal to or below a threshold temperature, initiating a cold starting procedure comprising:
• controlling the throttle arrangement such that an exhaust gas counterpressure upstream the throttle arrangement is within a target exhaust gas counterpressure range, and
• controlling the first exhaust gas recirculation path valve such that an amount of nitrogen oxides in exhaust gases emitted from the internal combustion engine is within a target nitrogen oxides amount range,
• wherein the cold starting procedure commences by controlling the power system so as to assume a cold starting initial condition comprising that:
• the throttle arrangement assumes the open condition, and
• the first exhaust gas recirculation path valve is fully closed.

A method for starting a power system, the power system comprising an internal combustion engine and a turbo which in turn comprises an inlet air compressor and an exhaust gas turbine, the exhaust gas turbine comprising a turbine wheel, the power system comprising an exhaust gas conduit assembly comprising at least one exhaust gas conduit wherein the exhaust gas turbine is adapted to receive exhaust gases from the internal combustion engine via the exhaust gas conduit assembly, the power system comprising an inlet air conduit assembly comprising at least one inlet air conduit wherein the internal combustion engine is adapted to receive inlet air from the inlet air compressor via the inlet air conduit assembly,

• the power system further comprising a throttle arrangement arranged between the internal combustion engine and the turbine wheel, as seen in a direction of flow from the internal combustion engine to the turbine wheel, the throttle arrangement being adapted to assume a plurality of different conditions for throttling exhaust gas from the internal combustion engine to the turbine wheel, the plurality of different conditions comprising an open condition with a smallest throttling of the exhaust gas amongst the plurality of different conditions as well as an at least partially closed condition associated with a throttling being larger than the smallest throttling,
• the power system further comprising a first exhaust gas recirculation path connecting a portion of the exhaust gas conduit assembly located upstream the throttle arrangement, as seen in a direction of flow from the internal combustion engine to the turbine wheel, to a portion of the inlet air conduit assembly located downstream the inlet air compressor, as seen in a direction of flow from the inlet air compressor to the internal combustion engine,
• the power system further comprising a first exhaust gas recirculation path valve adapted to control at least a flow through the first exhaust gas recirculation path;
• the method comprising:
• detecting temperature information (TI) indicative of an ambient air temperature of the power system, and
• in response to determining that the TI indicates the ambient air temperature of the power system being equal to or below a threshold temperature, initiating a cold starting procedure comprising:
• controlling the throttle arrangement such that an exhaust gas counterpressure upstream the throttle arrangement is within a target exhaust gas counterpressure range, and
• controlling the first exhaust gas recirculation path valve such that an amount of nitrogen oxides in exhaust gases emitted from the internal combustion engine is within a target nitrogen oxides amount range,
• wherein the target exhaust gas counterpressure range is determined based on one or more of the following parameters:
• an engine speed of the internal combustion engine, a load of the internal combustion engine, the TI, an exhaust temperature of exhaust gases emitted from the internal combustion engine;
• a coolant temperature of a coolant adapted to cool the internal combustion engine, and an aftertreatment temperature of a portion of an exhaust gas aftertreatment system adapted to receive exhaust gases from the exhaust gas turbine.

A method for starting a power system, the power system comprising an internal combustion engine and a turbo which in turn comprises an inlet air compressor and an exhaust gas turbine, the exhaust gas turbine comprising a turbine wheel, the power system comprising an exhaust gas conduit assembly comprising at least one exhaust gas conduit wherein the exhaust gas turbine is adapted to receive exhaust gases from the internal combustion engine via the exhaust gas conduit assembly, the power system comprising an inlet air conduit assembly comprising at least one inlet air conduit wherein the internal combustion engine is adapted to receive inlet air from the inlet air compressor via the inlet air conduit assembly,

• the power system further comprising a throttle arrangement arranged between the internal combustion engine and the turbine wheel, as seen in a direction of flow from the internal combustion engine to the turbine wheel, the throttle arrangement being adapted to assume a plurality of different conditions for throttling exhaust gas from the internal combustion engine to the turbine wheel, the plurality of different conditions comprising an open condition with a smallest throttling of the exhaust gas amongst the plurality of different conditions as well as an at least partially closed condition associated with a throttling being larger than the smallest throttling,
• the power system further comprising a first exhaust gas recirculation path connecting a portion of the exhaust gas conduit assembly located upstream the throttle arrangement, as seen in a direction of flow from the internal combustion engine to the turbine wheel, to a portion of the inlet air conduit assembly located downstream the inlet air compressor, as seen in a direction of flow from the inlet air compressor to the internal combustion engine, the power system further comprising a first exhaust gas recirculation path valve adapted to control at least a flow through the first exhaust gas recirculation path;
• the method comprising:
• detecting temperature information (TI) indicative of an ambient air temperature of the power system, and
• in response to determining that the TI indicates the ambient air temperature of the power system being equal to or below a threshold temperature, initiating a cold starting procedure comprising:
• controlling the throttle arrangement such that an exhaust gas counterpressure upstream the throttle arrangement is within a target exhaust gas counterpressure range, and
• controlling the first exhaust gas recirculation path valve such that an amount of nitrogen oxides in exhaust gases emitted from the internal combustion engine is within a target nitrogen oxides amount range,
• wherein the target nitrogen oxides amount range is determined based on one or more of the following parameters:
• an engine speed of the internal combustion engine, a load of the internal combustion engine, the TI, an exhaust temperature of exhaust gases emitted from the internal combustion engine;
• a coolant temperature of a coolant adapted to cool the internal combustion engine, and an aftertreatment temperature of a portion of an exhaust gas aftertreatment system adapted to receive exhaust gases from the exhaust gas turbine.