Abstract
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 and inlet/exhaust valve actuation on the diesel engine is expected as an effective method to reduce harmful exhaust emissions and fuel consumption because of achievement of optimum engine operation in response to changing conditions including engine loads and fuel properties. Now, we have mounted this system on the medium speed 4-cycle 3-cylinder diesel engine. It enables to control each fuel injection timing and each valve opening/closing timing independently. And even if low engine rotation, high fuel injection pressure and high speed of the valve actuation can be obtained. As the experimental result, it was found that using the electronically controlled marine diesel engine it was possible to improve thermal efficiency and to reduce harmful exhaust emissions synthetically at low load.
