Five dual-fuel MAN 51/60DF engines to form diesel-electric propulsion plant
MAN Diesel & Turbo is playing a part in powering a 300 m LNG carrier. Five dual-fuel MAN 51/60DF engines, each delivering 8000 kW at 514 r/min, serve as the diesel-electric propulsion plant for the new LNG vessel Castillo de Santisteban, which was delivered by Korean shipbuilder STX Offshore & Shipbuilding to shipping company Empresa Naviera Elcano.
The vessel has been assigned by her charterer, Spanish energy company Repsol – Gas Natural LNG (Stream), to the Peruvian Camisea/Pampa Melchorita gas project, a gas liquefaction plant in South America. The carrier has a carrying capacity of 173 600 m3 LNG. “When it comes to ship propulsion technology, the future is gas,” said Klaus Deleroi, senior vice president, MAN Diesel & Turbo SE. “Not only for LNG carriers, but also for cargo vessels, ferries and even cruise liners. Knowing this, it is important for MAN Diesel & Turbo to have a strong reference already at sea with our new 51/60 dual-fuel engine, and that is exactly what we have with the Castillo de Santisteban.”
The entry of the LNG vessel into active service represents a milestone for MAN Diesel & Turbo in that the order for the ship’s dual-fuel engines was the first received for this engine type, said the company. The engine is designed for LNG carrier and gas-fueled ship propulsion systems and focuses on the safety requirements stipulated by classification societies for gas operation.
MAN Diesel & Turbo’s 51/60DF dual-fuel engine offers a 1000 kW per cylinder output at 514 r/min for 60 Hz generator sets in both its gaseous and liquid-fuel operating modes. For marine applications, it is offered in inline versions with six, seven, eight and nine cylinders and vee-configuration versions with 12, 14, 16 and 18 cylinders in a power range from 6000 to 18 000 kW, according to MAN Diesel & Turbo. The engine model uses the common rail micro-pilot fuel-injection system for liquid fuel, which is necessary when running on gas to ignite the air-gas mixture. The system ensures independent control of injection timing, injection pressure and injection volume.
When running on liquid fuel, the 51/60DF works with a conventional fuel-injection system, injecting the fuel oil through a separate main fuel injector in a camshaft-actuated pump-line-nozzle system. The fuel injection control is integrated within the engine’s Safety and Control System (SaCoSone). The SaCoSone allows the engine to operate safely in both modes while keeping fuel consumption and emissions optimized. In gas mode, the system controls various parameters for each cylinder independently, including air-fuel ratio, load, valve timing, pilotfuel injection and charge-air temperature.
This creates optimal combustion while permitting operation within a wide range of the air-fuel ratio, avoiding incomplete-ignition failures, misfiring or knocking, the company said. The 8L51/60DF engines are designed to run on gaseous fuels, such as vaporized LNG or liquid fuels of a wide quality range (HFO/MDO/MGO), and have low emission levels. At 1.5 g/ kWh (IMO cycle E2) in gaseous-fuel operating mode, the 51/60DF complies with future IMO Tier 3 limits for NOx without the need for exhaust-gas treatment or any other countermeasures, the company said.