Method for operating an internal combustion engine with a reduction or deactivation of a piston cooling function of a modeled piston temperature and corresponding internal combustion engine

摘要

Method for operating an internal combustion engine (1) with direct fuel injection, wherein in at least one operating state of the internal combustion engine (1) a piston temperature of a piston (5) of the internal combustion engine (1) is modeled from a heat input variable and a heat dissipation quantity, characterized in that falls below a first Piston temperature limit is performed by the piston temperature Kolbenaufheizbetrieb in which a piston cooling is reduced or deactivated, the heat input quantity and the heat removal quantity are each determined from a heat transfer coefficient, from a temperature difference or a temperature gradient and from a heat transfer surface, and wherein the heat transfer surface of the heat input from the Cylinder bore of a cylinder (2) receiving the piston (5) and the heat transfer surface of at least one of the cylin contained in the heat removal quantity the bore as well as a piston stroke of the piston (5) is determined.