Common-Rail Low-Speed Diesel Eng Completes Trials

Common rail injector with solenoid valve and hydraulically actuated three-way valve for lowest smoke at low load

Wärtsilä Corporation reports that sea trials have been successfully completed with the world's first large diesel engine having common-rail fuel injection. The engine's exhaust was effectively smokeless throughout the sea trials, even when running on heavy fuel oil. This is because the common-rail fuel injection system maintains the fuel injection pressure at the optimum level right across the engine load range for optimum combustion under all operating conditions. In addition, a selective shut-off of single injectors at very low loads helps to keep smoke emissions below the visible limit.

This Sulzer 6RT-flex58T-B low-speed diesel engine powers the 47,950 tdw self-unloading bulk carrier "Gypsum Centennial", built by Hyundai Mipo Dockyard in Ulsan, Korea. During the trials, the engine maneuvered very easily when varying speed from full ahead to dead slow, and vice versa, and when reversing. It ran very steadily at very low speeds, and demonstrated its ability to run continuously at speeds down to 12 rev/min. The engine has a maximum continuous power output of 11,275 kW (15,350 bhp) at 93 rev/min. The normal service speed will be 15 knots at 85 per cent engine power and a sea margin of 15 per cent.