| 摘要 |
An object is to, during operation in the single combustion mode where only an oil fuel is injected, prevent blockage of nozzle holes of gas fuel injectors so as to smoothly shift from the single combustion mode to a dual combustion mode. When shifting to the single combustion mode, an electromagnetic opening-and-closing valve V 1 is closed so as to block a gas fuel. Then, an electromagnetic opening-and-closing valve V 3 is opened so as to discharge the gas fuel remaining in a gas fuel supply path 50 to the outside of the system. Then, an electromagnetic opening-and-closing valve V 2 is opened so as to introduce a replacement gas from a replacement gas reservoir tank 44 to the gas fuel supply path 50, thereby replacing the contents inside the gas fuel supply path 50 with the replacement gas. After completing the replacement, the electromagnetic opening-and-closing valves V 2 and V 3 are closed. Next, the electromagnetic opening-and-closing valve V 2 is opened and the replacement gas is injected from the gas fuel injectors 26 to a combustion chamber "c". |
