Methods and systems for a blow-off line

An internal combustion engine, comprising:

• three cylinders in an in-line arrangement;
• wherein each of the three cylinders further comprises:
• at least one inlet opening to admit charge air from an intake system;
• and
• at least two outlet openings to discharge exhaust gas to an exhaust-gas discharge system;
• wherein each of the at least two outlet openings is adjoined by separate exhaust lines;
• at least one exhaust-gas turbocharger comprising a turbine arranged in the exhaust-gas discharge system and a compressor arranged in the intake system;
• separate exhaust lines being formed into first and second groups;
• wherein the first and second groups comprise at least one exhaust line from each cylinder;
• wherein the exhaust lines of each of the first and second groups merge, and form two separate exhaust manifolds being a first overall exhaust line and a second overall exhaust line separate from one another;
• wherein the first overall exhaust line of the first group opens into the turbine upstream of an exhaust-gas aftertreatment system;
• and
• wherein the second overall exhaust line of the second group opens into the intake system upstream of the compressor;
• and
• a blow-off line branching off the second overall exhaust line forming a first junction;
• wherein the blow-off line further comprises a shut-off element downstream of an accumulator to capture hydrocarbons;
• and
• wherein the blow-off line merges with the first overall exhaust line at a second junction downstream of the shut-off element to form a third overall exhaust line.

A system, comprising:

• a turbocharged engine comprising a plurality of cylinders, wherein each cylinder of the plurality of cylinders comprises a first exhaust valve of a plurality of first exhaust valves and a second exhaust valve of a plurality of second exhaust valves;
• a first overall exhaust line fluidly coupled to the plurality of first exhaust valves and a second overall exhaust line fluidly coupled to the plurality of second exhaust valves;
• a blow-off line branching off of the second overall exhaust line at a first junction upstream of a LP-EGR valve arranged in the second overall exhaust line, and where the blow-off line comprises a hydrocarbon trap close-coupled to the engine upstream of a second junction where the blow-off line merges with the first overall exhaust line to form a third overall exhaust line, and where the second junction is downstream of a turbine arranged in the first overall exhaust line;
• and
• a controller with computer-readable instructions stored on non-transitory memory thereof that when executed enable the controller to:
• in response to a cold-start being complete as determined via the controller, retarding an opening of the plurality of second exhaust valves to flow a first mixture of gas to the hydrocarbon trap and portions of the second overall exhaust line downstream of the first junction toward the LP-EGR valve, and where the plurality of first exhaust valves oscillate between open and closed positions;
• and
• in response to the cold-start as determined via the controller, advancing an opening of the plurality of second exhaust valves to flow a second mixture of gas to only the hydrocarbon trap, and where the plurality of first exhaust valves are maintained closed for a duration of the cold-start.