“In , DNV GL developed the LNG-fuelled VLCC concept Triality,” noted Deng Ling, DNV GL project manager and ship type expert for LNG. Today, DNV unveiled a concept tanker design called Triality, an LNG powered VLCC featuring a hull shape that completely removes the need. A noteworthy project undertaken by Det Norske Veritas, called TRIALITY, incorporates several new and interesting concepts in ship design and.
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In the next decade the shipping industry rtiality face significant technical, operational triallity associated economic challenges as a result of upcoming environmental regulations for air emissions and ballast water treatment.
Development of new ship concepts may be an attractive way to respond to these challenges. A noteworthy project undertaken by Det Norske Veritas, called TRIALITY, incorporates several new and interesting concepts in ship design and operations, with the aim of meeting possible future stricter environmental regulations.
A baseline VLCC typically carries 80, totonnes of ballast water on the return leg. To illustrate the amount,tonnes of ballast water equates to about twice the volume of the Eiffel Tower, assuming it is watertight. This gives rise to additional fuel consumption for propulsion power and pumping of ballast water. A significant cost-saving is achieved by eliminating the installation and operation of a ballast water treatment system, in particular for the large plant required by an ordinary VLCC.
Ballast tanks need to satisfy high coating standards PSPC during newbuilding. The cost of maintaining the coating and possibly renewing some steel in the water ballast tanks due to corrosion over the lifetime of a vessel can also be significant. The coating standard for the void space inside the TRIALITY double hull can be somewhat reduced compared to segregated sea water ballast tanks, and there will be significant savings associated with surface preparations, coating thickness and maintenance cost.
A ballast-free hull design is therefore very attractive. This is to ensure sufficient draft for propeller immersion and limiting slamming in unloaded condition. The ballast-free design has no possibility to use ballast water to adjust the trim, but TRIALITY incorporates around 3, tons of freshwater on board, which in a closed system can be shifted between the fore peak and aft peak tanks as needed.
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LNG tankers using boil off gas for propulsion have operated for some 30 years. These are relatively new vessels and have all been built during the last 10 years.
All of them are small and operate in the coastal waters of Norway. Another 20 vessels are on order. Rules for such propulsion have existed for the past 10 years. There is a perception that LNG fuel for ships is an alternative for short-sea shipping only. MAN ME-GI engines have operated successfully on land for power plants and successful pilot installations on board ships demonstrate their applicability for large vessels. Two engines represent increased redundancy compared to a standard VLCC.
Wartsila is also working on a version of a two-stroke engine trialoty similar output. MDO back-up capacity for 10 days of oil fuel operation is included triqlity the design. The fuel capacity of 13, m3 – or about 6, tons – is sufficient for an operational range of 25, nautical miles, which corresponds to a round the world trip.
CO2 emissions are reduced by some 22 per cent, SOx and particular matter emissions are reduced by some 94 per cent, and NOx emissions are reduced by some 84 per cent with the EGR system.
This is partly carried out through heat exchangers. A glycol circuit has been incorporated rriality will circulate cooling capacity on board almost at no additional cost.
TRIALITY – Definition and synonyms of triality in the English dictionary
This glycol circuit does not introduce adverse safety issues and allows cooling for different purposes. Similarly, the low temperature glycol is used to recover VOC during voyage. Studies show that as much as to tons of VOC can be vented into the atmosphere on each round trip. The VOC can be either re-circulated into the cargo, or, as suggested in the TRIALITY concept, collected in separate tanks and supplied as fuel to auxiliary boilers producing steam for the cargo pumps or cargo heating.
In addition to the applications of the cooling capabilities of LNG as outlined above, additional cooling opportunities may include air conditioning, freezers and coolers.
Concepts on such applications are currently being developed for fishing vessels.
UK: DNV’s Triality Tanker Concept Wins Lloyd’s List Innovation Award | World Maritime News
If VOC is used for the main engines, the fuel efficiency increases to 25 per cent. Additional capital expenditures in the order of USD 30 million is needed for the vnv steel for the hull, the LNG tanks and systems, additional cost for engines and boiler, and cost of the VOC systems and tanks, as well as the cooling systems.
Capital savings of some USD 10 million are achieved from reduced coating cost in the void spaces, and from saving cost for a SOx scrubber system and water ballast treatment system, which the baseline VLCC must have installed to satisfy environmental regulations.
On the operational expense side, the comparison has only been made for the fuel cost, as this is the most significant. But will LNG be available as fuel? Today LNG as fuel for ships is only available in a few places. An extensive infrastructure to provide LNG for ships has, however, been developed in Norway over just a few years.
A case in point is Singapore Power, which is building an LNG hub with the possibilities of marine dmv and distribution potentials. Ras Tanura is located close to Qatar with the biggest LNG production and export terminal in the world.
Loading is also possible in the LOOP, US Gulf, with North America vnv an abundance of shale gas and some import terminals already planning to convert for export. The avoidance of all ballast water issues with this design is an additional operational benefit of high value and convenience to a vessel operator.
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