Patent ID: 6816773
Filing Date: 2004-11-09
Classification: F02B,F02D,F02M,Y02T

Abstract:
An apparatus for controlling the ratio of the amount of fuel and the amount of air in a natural gas fueled internal-combustion engine intended to work in a specified engine-specific load-rotation speed diagram, said apparatus comprising:a throttle (8) for controlling the amount of air supplied to combustion chambers in the internal-combustion engine; injection devices for controlling the amount of natural gas supplied to the combustion chambers; control devices (21) for controlling the throttle and the injection devices, whereby the control device (21) is arranged to control the ratio of the amount of fuel and the amount of air dependent on the current operating point in the internal-combustion engine load-rotation speed diagram wherein the load-rotation speed diagram is divided into a first area where the internal-combustion engine operates in lean mode and a second area where the internal-combustion engine operates in stochiometric or rich mode and by that the area for stochiometric operation is arranged to be used for operating points in the load-rotation speed area with low power.