Patent ID: 7469687

Claim:
A method for operating an internal combustion engine having an intake duct connected to an inlet of a cylinder and a tank purging valve configured to control an initiation of a tank purging flow into the intake duct at an inlet point upstream of the respective inlet of the respective cylinder, comprising: determining subvolumes of a fluid flowing into the intake duct in each instance during a predetermined time period; determining tank purging values of a characteristic quantity for each of the predetermined time periods; determining a total subvolume by adding a current subvolume to successive subvolumes until the total subvolume is greater than or equal to an effective intake duct volume downstream of the tank purging valve; determining a cylinder tank purging fuel mass which flows into a cylinder during a working cycle of a respective cylinder of relevance, wherein the cylinder tank purging fuel mass is determined as a function of the tank purging value that is at an interval from the currently determined tank purging value that is equal to the number of added together subvolumes of the totaled subvolume; and storing the determined cylinder tank purging fuel mass in a memory storage device.