LNG som drivstoff for skip - Gasskonferansen torsdag - LNG som drivstoff for skip...Norsk...
Transcript of LNG som drivstoff for skip - Gasskonferansen torsdag - LNG som drivstoff for skip...Norsk...
Norsk Marinteknisk Forskningsinstitutt
Per Magne Einang
Forskningssjef
MARINTEK
www.marintek.com
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LNG som drivstoff for skip Fremtidig utvikling
Den Norske Gasskonferansen Stavanger Mars 2014
50 LNG fuelled ships in operation (2013):
- Ferries (22)
- Offshore support vessels (13)
- Coast guard vessels/Patrol vessel (4)
- Product tanker (1), LNG tanker (3)
- Fish fodder (2)
- ROPAX (3)
- High speed ROPAX, (1) Barge (1)
>40 LNG propelled ships under construction
More than 90 LNG fuelled ships by 2016
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LNG fuelled ships -challenges
•Gas quality
•Methane slip
• LNG storage and handling
• Cost level (mainly capital cost LNG equipment)
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MARINTEK
Independent research and development institute
Trondheim Norway
Utilization of Boil off from LNG carriers
Havfru former Venator Experience for different propulsion machinery Gas turbines and low pressure Dual Fuel
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Lab test set up HPDF – 1 cylinder lab engine (1982)
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Demonstration project for High Pressure Dual fuel 1981-83
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Machinery Laboratory Gas engine development since 1980
Wärtsilä Vasa 32
Rolls-Royce K-type
Rolls-Royce B-type
Dual Fuel (high pressure) gas engines
Dual Fuel (low pressure) gas engines
Lean Burn gas engines
- Constant speed (generator load)
- Variable speed (propeller load)
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LNG supply and quality
Requirements for gas quality for piston engines
Two main factors: • Heating value
• Methane number
Methane number (MN) is equivalent to octane rating of gasoline
CH4: MN 100
H2: MN 0
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Worldwide LNG composition
Note the variation of Methane Number (MN) 87.4 – 69.5
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Typical LNG composition in volime %
LNG export terminals C1 C2 C3 C4 C5+ N2 LHV[MJ/kg] MNArun (Indonesia) 89,33 7,14 2,22 1,17 0,01 0,08 49,4 70,7
Arzew (Algeria) 87,4 8,6 2,4 0,05 0,02 0,35 49,1 72,3
Badak (Indonesia) 91,09 5,51 2,48 0,88 0 0,03 49,5 72,9
Bintulu (Malaysia) 91,23 4,3 2,95 1,4 0 0,12 49,4 70,4
Bonny (Nigeria) 90,4 5,2 2,8 1,5 0,02 0,07 49,4 69,5
Das Island (Emirates) 84,83 13,39 1,34 0,28 0 0,17 49,3 71,2
Lumut (Brunei) 89,4 6,3 2,8 1,3 0,05 0,05 49,4 69,5
Point Fortin (Trinidad) 96,2 3,26 0,42 0,07 0,01 0,01 49,9 87,4
Ras Laffan (Qatar) 90,1 6,47 2,27 0,6 0,03 0,25 49,3 73,8
Skida (Algeria) 91,5 5,64 1,5 0,5 0,01 0,85 49 77,3
Snøhvit (Norway) 91,9 5,3 1,9 0,2 0 0,6 49,2 78,3
Withnell (Australia) 89,02 7,33 2,56 1,03 0 0,06 49,4 70,6
Three different gas engine concepts for ships
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Rolls-Royce proprietary information
Gas engine technologies
Otto process:
− Spark ignited Lean Burn Gas engine
− Low pressure Dual Fuel (LPDF)
Diesel process:
− High Pressure Dual Fuel (HPDF)
Spark ignited Lean Burn gas engine concept
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Air and Gas
Intake Compression of
Gas/Air Mixture Spark Ignition
Air and Gas
Intake
Compression of
Gas/Air Mixture
Ignition by Pilot Fuel
injection
Low Pressure Dual Fuel
gas engine concept
Methane slip - development trends (2011)
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Load E2 cycle ISO/IMO corrected spec. methane emission
Lean burn SI engine [g CH4/kWh] 3.9-5.2
Low pressure DF engine [g CH4/kWh] ~7-10
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• Rolls-Royce C26
Spark Ignited Lean Burn gas engine characteristics
Single fuel, low pressure gas supply (4-5 bar)
High energy efficiency, at high load higher than the
diesel counterpart
Low emissions, meets IMO tire III
Challenge on methane slip, minimized by design
and combustion process control
GHG reduction potential in the range of 20-30%
ref. to HFO (incl. methane)
Load pickup similar to the diesel engine
Sensitive to gas quality (MN) technology is
available to handle MN variation
Potential for further reduction of fuel consumption
(2-stage turbocharging, Variable Valve Timing,
combustion process control )
Not suitable for conversion of existing engines
Spark Ignited Lean Burn vs Diesel oil Tier II Propeller load
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0,3
0,35
0,4
0,45
0,5
0,55
0 20 40 60 80 100 120
Engi
ne
eff
icie
ncy
Engine load [%]
Engine efficiency, variable speed
Lean Burn Gas Tier III
Diesel oil Tier II
Diesel process:
High Pressure Dual Fuel (HPDF)
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High pressure Dual Fuel (high pressure injection of gas)
Pure air intake Compression of air Injection of pilot fuel
Ignition, injection of gas
Need high pressure in the range of 300 -350 bar
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Dual-Fuel (high pressure) engine characteristics
•High pressure gas injection (300 -350 bar) 4-stoke and 2- stroke Maintain diesel engine performance. Potential for improvement in fuel consumption
•No methane slip, GHG reduction in the range of 30% with reference to HFO
•NOx reduction in the range of 40% (4-stroke).Need NOx reduction techniques to meet IMO tier III like EGR or SCR
•Not sensitive to gas quality (MN)
•Pumping LNG to 350 bar and heating is mature technology and with low energy requirement (about 0,5%)
• Load pickup as for the diesel engine
• Flexibility in fuel mix
•Suitable for conversion of existing engines (simple rebuilding)
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MAN D&T two - storke
TOTE Maritime Container Feeder Dual Fuel High Pressure Gas Injection
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Source: Internet Illustration
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Concluding remarks • LNG is considered to be the main alternative fuel to fuel oils. LNG is available all over
the World. LNG fuelled ships will meet all the known emission requirements and have a considerable potential to a net reduction of GHG.
• Gas engine technology is available for all types of piston engines. Potential for lower fuel consumption compared to fuel oil operation
• LNG storage and onboard handling need more development to be robust in sea state conditions
• LNG fuelled ships will have a higher building cost. Can be justified by lower operating costs (fuel and emissions). Cost level is challenging for converting for fuel oil to LNG