Change over from Diesel to Gas Fuel on a Large Two-stroke Otto type Dual-fuel Engine

摘要

When changing over from diesel fuel operation to gas fuel operation there will be a situation where the diesel amount in the cylinder is far from sufficient to keep and control the engine load, but the gas amount is not yet sufficient , and the gas/air mixture still is to lean to enable stable combustion with low cycle to cycle variation. Main valves are not controlling gas operation The technical solution is to do the change over one cylinder at the time. On two-stroke Otto type dual-fuel engines this is possible due to the design with a window valve for each GAV Gas Admission Valve, that enables cylinder individual gas shut down.