| 摘要 |
PROBLEM TO BE SOLVED: To improve heat efficiency without injecting a gas fuel at a pressure higher than a present pressure, and suppressing production of NOx, so that environmental conservation and cost reduction can be achieved.SOLUTION: A fuel injection system of a gas injection engine, includes: a main gas fuel injection valve 5 for injecting a gas fuel into a cylinder 1 at a high pressure; a pilot fuel injection valve 6 for pilot-injecting a diesel fuel into the cylinder; a main gas fuel supply device 8 for supplying the high pressure gas fuel to the main gas fuel injection valve; an auxiliary gas fuel injection valve 7 for further injecting the gas fuel into the cylinder; and an auxiliary gas fuel supply device 10 for supplying the gas fuel into the auxiliary gas fuel injection valve. The auxiliary gas fuel injection valve performs pre-injection into the cylinder while a part of the gas fuel necessary for combustion is supplied from the auxiliary gas fuel supply device, before the diesel fuel is pilot-injected from the pilot fuel injection valve, and the main gas fuel injection valve injects the remaining part of the gas fuel into the cylinder at a high pressure after the pilot injection. |
