GE’s Marine Solutions, in collaboration with China’s Dalian Shipbuilding Industry (DSIC), has developed a preliminary design that can convert a steam turbine powered liquefied natural gas (LNG) carrier (LNGC) to a gas turbine-based propulsion system.
The design was created as part of a feasibility study that expects to help the development of fuel-efficient LNGCs.
GE US Marine Operations vice-president Brien Bolsinger said: “This feasibility study provides ship owners a competitive retrofit solution for ten to 15-year-old steam-powered LNG carriers.”
The final design to be developed under the study will include GE’s Combined Gas turbine, Electric and Steam (COGES) system, which is capable of providing a simpler conversion that requires less dry dock time.
DSIC deputy technical director Yingbin Ma said: “A gas turbine’s smaller footprint allows for the minimum necessary conversion work required by the shipyard.
“By converting to a COGES power system, the fuel efficiency of the ship will be improved by 30%. This allows ship owners to increase the charter rate and win back opportunities in a market dominated by dual-fuel diesel engines.
“This study achievement is based on a 138,000m³ LNGC powered by a steam turbine, but it can be applied on other similar size ships.”
According to GE, three sizes of its LM2500 family of gas turbines can be used to adapt the COGES power system to a specific ship size and to optimise performance.
A gas turbine features a dry low emissions (DLE) combustor or a single annular combustor (SAC) and can help operators reduce nitrogen oxide (NOx) emissions to meet the International Maritime Organisation (IMO) Tier III and the US Environmental Protection Agency Tier IV requirements.