DNV GL © 2017 04 April 2017 SAFER, SMARTER, GREENERDNV GL © 2017
Ungraded
04 April 2017
George Dimopoulos, PhD.
MARITIME
LPGreen: concept design VLGC of tomorrow
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Joint development project
Project partners:
3rd session of the Gas Tanker Committee, Athens
DNV GL © 2017 04 April 2017
Introduction
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• Gas carriers: forefront of innovation, technology,
safety and quality in the merchant shipping fleet.
• Complexity of technologies and operations: high in
LPG carriers & increasing
• Highly volatile market conditions and regulatory
pressure: necessary to evolve ship designs.
• New trade routes and future requirements: Flexible
and robust ship design and operations.
• Integration of systems and operations & holistic
approach to design is the key.
• LPGreen’s objective:
develop a more cost efficient, environmentally
friendly, and safer LPG carrier using latest developed
technology, within the bounds of existing
shipbuilding methods.
DNV GL © 2017 04 April 2017
Exploring possibilities for further improving their latest VLGCdesign ensuring overall concept feasibility and performance
Developing further their cargo handling solutions, increasingsystems performance and capabilities to server better owners
Looking new ways to improve safety, operability, efficiency andasset competitiveness, introducing holistic approachescombined with advanced computer tools CFD and COSSMOS
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LPGreen Project – Partners’ rationale
Being at the forefront of technology by maximizing fleet efficiency and asset competitiveness, ensuring safety and operational flexibility to meet future trading requirementsShip owner
Cargo systems
Ship Yard
System integrator
DNV GL © 2017 04 April 2017
LPGreen approach
3 main pillars:
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LPGreen
Design for trade
Efficiency &
Economic viability
Cargo and fuels flexibility
Market and trade considerations
Intended operating profile
Multiple cargoes flexibility
LPG / cargo as potential fuel
Efficiency and energy recovery variants
Business case for ship owner
Techno-economic feasibility
DNV GL © 2017 04 April 2017
Competitive reference - baseline
CMM’s Hellas Gladiator Vessel
HHI built, In operation mid 2016
Optimised hull form
Energy recovery options
CMM’s VLGC experience encapsulated
Competitive Baseline for quantifying LPGreen improvements
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DNV GL © 2017 04 April 2017
Design for trade
Intended operating profile
Use of AIS data + CMM
Used for all LPGreen analyses
– CFD Hull & hydrodynamics
– COSSMOS & integrated machinery
– Cargo handling incl. non-sailing modes
Actual operating conditions
Extreme / design conditions only
used for verification of designs
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Trading patterns analysis
Operating profile & modes
DNV GL © 2017 04 April 2017
LPGreen Philosophy
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Improve cargo handling
systems and operations
Further optimise hull form and
hydrodynamic performance
Improve overall energy efficiency
Introduce LPG as fuel
LPGreen
DNV GL © 2017 04 April 2017
Hull form & Hydrodynamics – Calm water
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Overview
• Hull optimisation
– operational profile (laden & ballast)
– Short bulb (baseline)
No bulb (concept)
– Lengthen vessel (~3m) to compensate for
new IGC code and IMO Tier III
• Propulsion
− Larger diameter / lower rpm propeller
− Rudder Bulb
− Hi-FIN & Hi-PSD
• Performance evaluation
− CFD simulations (HHI & DNV GL)
− Model and Full scale (Fully viscous RANSE)
2% to 4.5% Propulsion demand reduction
DNV GL © 2017 04 April 2017
Hull form & Hydrodynamics – Adder resistance in waves
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Overview
• Added resistance evaluation
– operational profile (laden & ballast)
– trading pattern
– all headings
• Computational tools
− 3D potential flow solvers (DNVGL & HHI)
− Non-linear effects captured
− Hydro-elastic response phenomena
− Wave field formulation added resistance
WASIM
2.0% to 3.4% Added resistance reduction(average on typical US-China route)
DNV GL © 2017 04 April 2017
Cargo tank design
Modified design with 99% filling limit
– ~ 1% increase cargo capacity
– additional steel & CAPEX (~ 250 tn)
Tank reinforcement for higher MARV
limit (0.5 / 0.4 barg)
– More efficient loading
– additional steel & CAPEX (~ 95 tn)
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Conventional
Prismatic Type A
Modified
No trapped vapour pockets
98% FL 99% FL
DNV GL © 2017 04 April 2017
Cargo handling systems - framework
Multiple configurations: model-
based assessment in COSSMOS
Multiple cargoes and conditions:
loading & sailing
Realistic environmental
conditions
Extreme & design cases used to
verify feasibility and acceptance
Adequate redundancy
Major operating modes:
– Sailing: pressure maintenance
– Cooling down
– Loading
– Laden & Ballast
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Cargo
tanks
Reliquefaction
plant
Loading
line
Goal for improvements: Energy efficiency
Operational (time) efficiency Cargo flexibility Operability Adequate redundancy
DNV GL © 2017 04 April 2017
Cargo handling systems - results
Higher capacity compressors
with variable frequency drives
2 x reliquefaction plants +
butane condenser
Potential reduction in cargo
handling room space and
requirements
Development of unmanned
cargo machinery room concept
Improvements vary with cargo
type and operations
(Interface with LPG fuelled concept)
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Cargo
tanks
Reliquefaction
plant
Loading
line
Up to
30%
Up to
7%
Up to
5%
Faster
Loading
Less energy
@ loading
Less energy
@ sailing
DNV GL © 2017 04 April 2017
Machinery configurations & energy recovery
Integrated system model using
COSSMOS
Main engine
– IMO Tier III compliant (HP SCR)
– Conventional & LPG-fuelled (LGIP)
Auxiliary engines
– IMO Tier III compliant (SCR)
Energy recovery variants
– Auxiliary engines economisers
– Shaft generator
– Power management
Operating profile with all sailing
and non-sailing modes
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Shaft generator
Aux. Engines
Economisers
Aux. Boiler
ME Economiser
Main
Engine
Aux.
Gen-sets
Operating
Profile
DNV GL © 2017 04 April 2017
LPG as a fuel
LPG-fuelled engine technology available
LPG fuel handling concept developed
Deck fuel (and buffer) tank required
Additional CAPEX estimated
Technical Feasibility
Commercial and chartering framework
needs to be developed
Initiate / provoke discussion
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+/–
CAP 2020 compliance
Favourable price differential with conventional fuel(s)
Lower consumed quantity due to the higher LHV
CAPEX & complexity
Commercial frame not in place
Deck
Tank
DNV GL © 2017 04 April 2017
Model-based integrated machinery system assessment
Integration between sub-systems captured
Intercalations and trade-offs
Hull / Machinery / Cargo systems performance
Operating profile & modes
Overall efficiency & performance assessment
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Cargo
taks
DNV GL © 2017 04 April 2017
LPGreen: Final concept appraisal
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Cargo handling:
− Design for faster loading
− Reduced energy demand
− Reduced reliquefacton plant size
− Un-manned cargo room concept
− Adequate redundancy
Hull and propeller
− Optimised for both calm
water and waves
− Multiple speeds and loading
conditions
− Energy saving devices
Tank design
− 99% filling limit: 1% additional cargo
− Higher tank design pressure
Machinery configurations:
− Improved overall efficiency
− Conventional and LPG as a fuel
− Energy recovery technologies
− IMO Tier III compliant
LPG as fuel
− Technical feasibility
− SOx CAP compliant
− Reduction of fuel expenses
LPGreen
1%Increased
cargo capacity
6-9%Overall Efficiency
Improvement
30%Reduction of
Fuel Expenses
30%Reduction of
Loading time
Up to Up to
DNV GL © 2017 04 April 2017
Conclusions
Innovation to develop more competitive ship designs
Collaboration paradigm: industry leaders across geographies
Advanced methods and tools that manage complexity in practice
LPGreen: new VLGC concept design
– Trade and operational practice @ the core
– Improved energy efficiency & cargo capacity
– Can be built today
Robust decision making supported
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LPGreen
DNV GL © 2017 04 April 2017
SAFER, SMARTER, GREENER
www.dnvgl.com
LPGreen: concept design VLGC of tomorrow,
… that can be ordered and build today!
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LPGreen
George Dimopoulos Ph.D.
Principal Specialist,
Maritime R&D and Advisory
E-mail [email protected]
Mobile +30 6956 200947 | Phone +30 2104100200
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