1Rendez-vous du Monde Maritime – 11 mars 2015
Rendez-vous du Monde Maritime
2Rendez-vous du Monde Maritime – 11 mars 2015
Avantages/InconvénientsGaz Naturel
3Rendez-vous du Monde Maritime – 11 mars 2015
Propulsions DisponiblesUtilisant le Gaz Naturel Comme Carburant
4Rendez-vous du Monde Maritime – 11 mars 2015
Steam turbine vs T/DFDE Engines
Benefits•Higher efficiency compared to steam propulsion (but lower compared to slow speed diesel options) •Higher availability of experienced crew comparing to steam turbine•High propulsion redundancy (with back up engine)•Reduced emissions
Disadvantages:• Higher capital cost TFDE• Higher maintenance as a result of more
moving parts, higher speed and more cylinders
• About 10 or 12% efficiency loss in the electric power generation process
• Sensitive to gas quality: knocking with automatic load reduction
• Crew member are not trained to operate electrical equipment and a large part of failure need experimented makers
• Maintenance: scheduled overhaul more stringent (Dry Dock issues) & expensive
5Rendez-vous du Monde Maritime – 11 mars 2015
Propulsions DisponiblesUtilisant le Gaz Naturel Comme Carburant
6Rendez-vous du Monde Maritime – 11 mars 2015
7Rendez-vous du Monde Maritime – 11 mars 2015
•* •*•*•*•* •*•*•*
•*•*•*•*•*•*•*•*•*•*•*•*•*
•* •*
Intake ofair and gas
Compression ofair and gas
Ignition bypilot diesel fuel
Otto principle
Low-pressure gas admission 4 to 6 barg
Pilot diesel injection
Power 2,5 MW to 17,5 MW
Gas mode: •Ex. •In. •Ex. •In.•Ex. •In.
Intake ofair
Compression ofair
Injection ofdiesel fuel
Diesel principle
Diesel injection
Diesel mode:Ex. In. Ex. In.Ex. In.
Dual-fuel engine operating principle
© Wärtsilä
8Rendez-vous du Monde Maritime – 11 mars 2015
The Diesel dual fuel engines are four stroke engines with either gas (BOG) or diesel as main fuel. The operating principle in gas mode is the lean-burn concept (Otto cycle). A lean-mixture of gas and air is provided to the combustion chamber of each cylinder by individually controlled gas admission valve. The mixture is ignited by a small amount of pilot Diesel fuel.
Dual-fuel engine operating principle
9Rendez-vous du Monde Maritime – 11 mars 2015
Low Speed Diesel Engines
• The dual-fuel (low-speed) diesel mechanical propulsion is a dual or triple-fuel type like the DFDE capable of burning both the BOG and liquid oil simultaneously.
10Rendez-vous du Monde Maritime – 11 mars 2015
Diesel / Otto cycle
Low Speed Diesel Engines
11Rendez-vous du Monde Maritime – 11 mars 2015
Benefits• Consumption: about 20% less than for TFDE• Robustness (not sensitive to knocking )• Efficiency• Lower maintenance compare to 4 strokes (maintenance done on board by crew )• conditioning based maintenance: Improve flexibility regarding Dry dock issues• High fuel flexibility
Disadvantages• Safety: Gas Fuel Pressure supply around 300 Bars for MEGI• Compare to DFDE, MEGI & XDF cannot be operated in Gas Mode at low load• No redundancy in gas chain equipment (In case of failure or maintenance, BOG
handling issues)• MEGI & XDF are not proven technology in marine industry• MEGI & XDF engines are not complying with Marpol requirements
• Defeat devices will be required
Low Speed Diesel Engines
12Rendez-vous du Monde Maritime – 11 mars 2015
Gas Turbine
Avantages :
• Poids inférieur (15 t. pour le module LM2500 )• Montée en puissance très rapide• Facilité d'entretien ( échanges standard d'éléments )• Pollution limitée
Inconvénients :
• Consommation spécifique plus élevée que les moteurs diesel (235 g/kWh à 25 °C )
• Sensible à la température ambiante ( LM 2500 : 23000 kW à 25 °C et 21000 kW à 35 °C )
• Volumes importants des conduites d'arrivée d'air et d'échappement des gaz
• chute importante du rendement à charge partielle en particulier pour les machines à simple arbre
• Redondance?
13Rendez-vous du Monde Maritime – 11 mars 2015
GAZOCEAN, one of the oldest companies specialised in maritimetransportation of liquefied gases and, is a pioneer in the development of LNGcarriers technologies as cargo containment or propulsion systems.
Founded in 1957 by R. Boudet, in 2013, GDF SUEZ LNG (80%) and NYKLine (20%) are the shareholders.
GAZOCEAN is providing Crew ,Technical and Commercial Managementservices for LNG and LPG carriers, Consulting services and Training for theGas Industry.
GAZOCEAN is certified ISO 9001-2008, ISO 14001, ISM, ISPS and integraterequirements of NYK NAV 9000 and OCIMF TMSA in his Quality System.
14Rendez-vous du Monde Maritime – 11 mars 2015
Pioneer in MaritimeTransportation
of Liquefied Gases