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Retrofitting a dual-fuel engine is one of the most effective ways to drive greater efficiency and profitability from your fleet. A dual-fuel conversion gives you the fuel flexibility to take advantage of optimal fuel prices; it can make sure your vessel complies with IMO emissions targets and can extend the operational lifetime of your vessel, which means a greater return for your investments.
MAN PrimeServ dual-fuel retrofit solutions
Our dual-fuel retrofit solutions range from a straightforward conversion of the main engine to turnkey solutions that include gas systems. To ensure the process is executed seamlessly from start to finish, MAN PrimeServ covers everything from research and site survey to engineering and project management, and finally to hardware commissioning.
Our dual-fuel retrofit solutions are not limited to the main engine and customized projects can be provided as a turnkey solution, or to include gas systems in partnership with MAN Cryo.
Diesel to dual-fuel gas conversion
One of the biggest retrofit options
is to convert an existing diesel engine to a dual-fuel gas
engine. This enables you to switch between diesel and gas as necessary, to both
reduce operational costs and take advantage of optimal
fuel prices as they arise.
In addition, using alternative fuels, such as LNG, ethane, LPG, or methanol, mean you can greatly reduce SOx, NOx, CO2, and particulate matter, enabling you to comply with global environmental regulations, secure worldwide port access, and meet your own sustainability targets.
A retrofitted vessel generates 35 times less CO2 emissions compared to a new build vessel.
The project scope of a dual-fuel conversion
The scope includes changes to the main engine, installation of a Fuel Gas Supply System (FGSS), and the installation of bunker tank(s) or integration into an existing gas cargo system. In addition, MAN Energy solutions can also provide turnkey solutions that include the FGSS.
The following explanation is based on an LNG conversion.
The engine conversion mainly consists of rebuilding existing engine parts to enable the installation of a gas safety system and a fuel injection system.
This includes exchanging the existing cylinder cover and fuel oil pipes, and adding gas injection valves, gas control blocks, and gas chain pipes. Additional parts may also need changing, which is determined by a detailed study of your engine.
FGSS for LNG
As with any dual-fuel engine, to deliver efficient gas injection the conversion requires a complete Fuel Gas Supply System (FGSS). The main function of this, together with a Gas Valve Train (GVT), is to pressurize and vaporize LNG from liquid to gas by increasing the pressure to 300 bar and 45°C, so that it can be injected into the engine.In recent years, MAN Energy Solutions has developed a Pump and Vaporizer Unit (PVU) that is interlinked with our main engine control system and forms a main part of the FGSS.
Bunker tanks or an integration
If the vessel does not already operate with gas as a cargo, bunker tanks for your chosen fuel will be required. This is an important decision and can be one of the project’s largest financial considerations.Choosing the right bunker tank(s) depends on several factors, such as tank type, size, location, and price. If the vessel you are converting is a gas carrier, you can benefit from an integration to the existing cargo system.
Once converted, your vessel will operate on the same principles as before, with the same operational profile and load responses as with an ME-C engine. The main benefits of converting to a dual-fuel engine are significantly reduced emissions, enhanced operational flexibility, increased sustainability, and greater long-term value.
Which vessel types can be converted?
Any ME-C engine with a bore size of at least 50 can be converted for dual-fuel operation.
It is also important that a parent engine exists, which is a reference engine that has the same specifications as the engine you wish to convert to. The technical specification of the engine is needed to prepare emission calculations and ensure class approvals.
If a parent engine does not already exist, it will have to be built before a conversion can begin. Alternatively, the existing engine output can be aligned to an already existing reference engine.
Ready to start?
Are you looking to increase the efficiency, longevity, and profitability of your vessel with a dual-fuel retrofit conversion? Simply send us an e-mail and we’ll be in touch to start exploring your options.