Fig. 2 Transition of Power Rate of 4 Stroke Medium Speed Diesel Engines
Fig. 3 Comparison of Engine Size between ADD30V and Conventional Engine
a) Outstanding increase in engine power
Fig. 2 shows the transition of power rate (B.M.E.P. x mean piston speed) for medium speed diesel engines. The ADD30V engine achieves extremely high power, 40-50% higher than the conventional engines of the same cylinder bore, with B.M.E.P. up to 2.7MPa and mean piston speed up to 12m/s. The max. cylinder pressure is raised up to 19.7MPa.
b) light and compact
In comparison with the Mitsui V42M engines of the equivalent cylinder power, as shown in Fig.3, the ADD30V engine is 45% lighter in weight and 60% smaller in space.
i.e. the weight/power ratio of 7.0kgf/kW and the power/volume ratio of 140kW/m3 for 12 cylinders' engine. This feature yields the big space saving. It is expected to greatly increase the performance of high-speed vessels, coupled with high power, in particular.
c) Low fuel consumption
The ADD30V engine achieves low fuel oil consumption of 184g/kWh under the extremely high power owing to the newly developed systems shown in Fig. 4, such as;
- single valve gas exchanging system
- fuel injection system with high injection pressure
- side injection
The engine is designed to burn heavy fuel oil up to 380cSt/50℃. In addition, NOx of ＜950ppm (13% O2) is obtained by adapting the water-emulsified fuel or the combination between high compression ratio and timing retard, minimizing losses in fuel economy.
d) High reliability
Many kinds of breakthroughs shown in Fig. 4 ensure the high degree of reliability under the extremely high power in combination with the modern production technologies, such as;
- welded integral engine frame of steel modules
- piston of diffusion-bonded integral without screw connections
