Electronic control operation of fuel injection, inlet and exhaust valve on marine diesel engine

摘要

Recently, from the viewpoint of prevention of serious air pollution and global warming, reduction of harmful exhaust emissions and further improvement of thermal efficiency are requested. The electronically controlled hydraulic system for fuel injection had been mounted on the medium speed 4-stroke diesel engine and reduced specific fuel consumption and harmful exhaust emissions simultaneously. This time, the engine has been also added the electronically controlled hydraulic system for inlet/exhaust valve actuation and we report the test results of the engine with the electronically controlled fuel injection and inlet/exhaust valve actuation. Because the fuel injection pump and the inlet/exhaust valve were driven by hydraulic pressure on this electronic control system, time lag between control signal and motion of them existed, and unevenness caused by the electromagnetic valve motion and others existed inevitably. That was serious problem to operate the engine. To cope with that, average values of each motion-timing datum were displayed and stable operation of the engine was realized. As the experimental result, it was found that further improvement of engine performance could be expected by optimum combination of fuel injection timing and inlet/exhaust valve opening/closing timing.