To realize the target of reliability and durability, the reduction of thermal stress is attempted through selection of materials, optimization of part shape and improvement of the cooling method. In addition, the design maximum firing pressure is set at 20 MPa, a value higher to actual firing pressure, to allow sufficient margin in mechanical stress and to aim at prolongation required maintenance periods and improvement of part durability.
Furthermore, thorough countermeasures are incorporated to prevent fire hazards.
2.2 Easy Maintenance and Low Maintenance Cost
By adopting the marine type three-parts connecting rod, piston disassembly height is reduced. Furthermore, because the bolts of main parts, cylinder head bolts and main bearing bolts and side bolts and etc, are tightened by the hydraulic tools, the correct tightening forth and the high reliability is guaranteed and at the same time the labor saving and the ageing workforce are also got over.
For simplification and labor saving in maintenance and inspection work, the inspection side are concentrated on one side, and at the same time, the number of components are reduced by at least 30% compared with conventional engines.
2.3 Environmental Protection
Low specific fuel consumption and low NOx value is achieved by optimizing the injection system and intake and exhaust systems. The New DK series engines have achieved to meet the primary IMO's NOx regulation without much affection to the specific fuel consumption.
The vibration is reduced to approx. 1/2 to 1/4 of that of conventional engines, and the noise level is reduced by 3 to 4 db(A) through design of optimum combustion pattern and rigidity of engines such as double construction frame.
