Shipowners continue to favour low-pressure, two-stroke LNG dual-fuel engines in the newest generation of LNG carriers, driven by the technology’s superior fuel consumption and lower capex
In one of the latest orders, four 174,000-m3 LNG carrier newbuilds for Japan’s NYK Line will be fitted with low-pressure, LNG dual-fuel MAN B&W ME-GA engines from MAN Energy Solutions (MAN ES).
Controlling one of the largest LNG carrier fleets in the world, the Japanese shipowner has previously added newbuilds with slow-speed, LNG dual-fuel, Otto-cycle, WinGD X-DF engines from Swiss engine designer Winterthur Gas & Diesel (WinGD).
This latest order, for a total of eight MAN 5G70ME-GA Mk 10.5 engines, all with MAN ES proprietary exhaust gas recirculation bypass (EGRBP) emissions-reduction technology, represents a first for NYK Line.
Understandably pleased by the order, head of two-stroke business, MAN ES Bjarne Foldager partly credits the success of the ME-GA to its packaging with the EGRBP. “Demand for the engine has been continuously strong since its introduction, especially due to its accompaniment by our self-developed EGR system that comes proven by more than a decade of in-service, operational experience and optimisation” says Mr Foldager.
MAN B&W ME-GA engines equipped with EGRB technology exhibit a lower methane slip compared with first generation Otto-cycle engines, while offering improved fuel efficiency in both gas and fuel-oil operation. EGR actively reduces emissions and improves efficiency in both IMO Tier II and Tier III. Initially focused on achieving NOx Tier III compliance, the system has since matured into a robust, engine-tuning tool, says MAN ES.
The EGRB system comes as standard with the engine, along with a new control element in its engine-control system called ME-GA-opti. ME-GA-opti is an advanced and intelligent network of control algorithms that have been developed by the engine designer to optimise the combustion process on an individual-cylinder basis.
The Copenhagen-based engine designer began developing the ME-GA engine in 2018, following increased shipowner demand for a lower capex alternative and the growing success of the WinGD low-pressure, dual-fuel X-DF engine in the LNG carrier segment.
Resounding success
In less than three years since its introduction, the MAN B&W ME-GA has been a resounding success among LNG shipowners. Since May 2021, MAN ES head of promotion and customer support, Thomas S Hansen, said the Danish engine designer has accumulated 278 ME-GA engine orders. “Of these, seven vessels have already entered service with 14 ME-GA engines on board”.
A South Korean-built LNG carrier owned by Norwegian shipowner Knutsen OAS Shipping was the first to be equipped with an MAN B&W ME-GA engine.
The MAN B&W ME-GA engine delivers a low capex solution aimed at LNG carriers that can use ‘boil-off’ gas as a source of fuel.
The first two-stroke, Otto-cycle engine from MAN ES, the ME-GA complements the engine designer’s well proven, high-pressure, dual-fuel ME-GI Diesel-cycle engine range.
Forecasts are that two generations of WinGD X-DF propulsion systems will dominate LNG newbuild deliveries in 2024, with MAN B&W ME-GA engines gaining market share starting 2025 and onwards, according to the latest data available from the International Gas Union.
“The ME-GI, ME- GA, and X-DF systems represent a major shift in favour of efficiency, economies of scale, and environmental performance from the popular propulsion systems of the previous generation – steam turbine, dual-fuel diesel-electric and tri-fuel diesel electric,” notes the IGU.
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