Fuel valve for injecting gaseous fuel into a combustion chamber of a self-igniting internal combustion engine and method

A fuel valve for injecting gaseous fuel into the combustion chamber of a large two-stroke low-speed turbocharged self-igniting internal combustion engine, said fuel valve comprising:

• an elongated fuel valve housing with a rear end and a front end, a nozzle with a plurality of nozzle holes opening to a sac volume inside the nozzle, said nozzle being disposed at the front end of said elongated fuel valve housing, said nozzle comprising a base and an elongated nozzle body, said nozzle being connected with the base to said front end of said elongated fuel valve housing, said nozzle having a closed tip with said plurality of nozzle holes arranged close to said closed tip, a gaseous fuel inlet port in said elongated fuel valve housing for connection to a source of high pressure gaseous fuel, an axially displaceable valve needle slidably received in a longitudinal bore in said elongated fuel valve housing, said axially displaceable valve needle having a closed position and an open position, said axially displaceable valve needle rests on a valve seat in said closed position and said axially displaceable valve needle has lift from said valve seat in said open position, said valve seat being placed between a fuel chamber and an outlet port, said fuel chamber is fluidly connected to said gaseous fuel inlet port, said outlet port is fluidly connected to said sac volume in said nozzle, an actuator system for controllably moving said axially displaceable valve needle between said closed position and said open position, an ignition liquid inlet port for connection to a source of high pressure ignition liquid, wherein said source of high pressure ignition liquid has a pressure that is higher than the pressure of the source of high pressure gaseous fuel, and an ignition liquid supply conduit connecting said ignition liquid inlet port to said fuel chamber, said ignition liquid supply conduit including a fixed flow restriction, said fixed flow restriction being configured to throttle the flow of ignition liquid from said ignition liquid inlet port to said fuel chamber in order to allow a small amount of ignition liquid as a constant flow of ignition fluid through said fixed flow restriction to accumulate in the fuel chamber above the valve seat when the axially displaceable valve needle rests on the valve seat.