MAN B&W Diesel A/S launched the ME-GI engine, a range designed for the LNG carrier market. The ME-GI design combines with the developments in the latest electronically controlled ME engines. "The LNG carrier market, like all sectors of the transportation industry, needs to control and, where possible, reduce operational expenses, while securing sound profit. We see many new opportunities in this area for cost-down solutions permitted by the increased flexibility and greater control with the ME-GI engine," Vice President of Two-Stroke Sales, Ole Grøne, said. "Among the many proposals and ideas for LNG carrier propulsion the ME-GI, also installed with reliquefaction technology, where preferred, provides the best solution for the future needs of the LNG transportation market
Traditionally, LNG carriers have been driven by steam turbines that are fed from boilers fired by the boil off gas, supported by heavy fuel oil. Responding to a market demand for more efficient engines, while retaining the option to burn the boil off gas, MAN B&W is reintroducing its high pressure gas injection low speed diesels - now in electronically controlled execution. Designated ME-GI, this gas burning option is being offered in parallel to the heavy fuel-burning solution with gas reliquefaction.
The combination of the ME-GI engine, installed with a reliquefaction plant, allows the owners and operators the choice to either use the boil off gas in the engine or to reliquefy the gas and use HFO instead.
Out of all the options for the prime mover, the low speed two stroke diesel engine, according to MAN B&W, gives the best thermal efficiency for any conventional propulsion system. This is especially the case for LNG carriers, where the power requirement is around 30 to 40 MW.
Thermal efficiencies of around 50 percent for diesel engines exceed the 30 percent offered by steam turbines and any other combination alternatives. The ME-GI dual fuel enhanced engine control and monitoring systems enable the latest ME technical developments to be applied to the LNG carriers. The precise timing and combustion rate shaping gained through the use of the electronic control of injection and exhaust valves produce greater control at any load.
The ME-GI dual fuel engine builds on the experience gained from the MC-GI dual fuel engine. A 12K80MC-GI-S engine has been in operation in the Chiba power plant (Japan) since the Summer of 1994.
The reliquefaction technology that is proposed as an additional feature to allow the sale of more gas is state-of-the-art technology. It is well known in the process industry and is derived from the numerous reliquefaction units installed on LPG ships. The ME engine range has proved to be very successful since its introduction. The first ME engine was put into service on the 37,500 dwt chemical tanker M/T Bow Cecil (Odfjell, Norway).