wartsila 2-stroke gas engine
DESCRIPTION
EngineTRANSCRIPT
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WRTSIL 2-STROKE GAS
1 Wrtsil Wrtsil 2-stroke / Gas Engine / September 2012
Ship PowerMarch 2013
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Natural Gas as marine fuel
Wrtsil 2-stroke / Gas Engine / September 20122 Wrtsil
1965-72: low pressure loop scavenged engine 6RD76 tested in Winterthur7RNMD90 installed in 29400m3 LNG-carrier MV Venator in 1972
60s-70s Today
CO2
NOx
SOx
Particulates
Dual-Fuel enginein gas mode
Dieselengine
0
10
20
30
40
50
60
70
80
90
100
Emissionvalues [%]
-25%
-85%
-100%
-99%
4 stroke DF results
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Basic concept (2 stroke low pressure)
Wrtsil 2-stroke / Gas Engine / September 20123 Wrtsil
Principles: Engine operating accordingly
to Otto process
Injection of gas at mid-stroke. Low pressure gas injection(
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Other concept (2 stroke high pressure)
Wrtsil 2-stroke / Gas Engine / September 20124 Wrtsil
Principles: Engine operating accordingly
to Diesel process
Injection of gas close to TDC. Air is completely compressed and, therefore, high pressure gas injection (300 bar) is required.
No significant NOX reduction
Requires SCR or EGR (not proven) in order to meet IMO Tier III levelsScavenging/
compressionPilot & HP gas
injection Expansion
Direct injection, diffusion combustion
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Otto & Diesel cycle: effects on NOX
Wrtsil 2-stroke / Gas Engine / September 20125 Wrtsil
Big temperature difference
NOx formation!
Diesel, max flame temp.Otto, max flame temp.Otto, max flame temp.
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Technical features Gas admission
Wrtsil 2-stroke / Gas Engine / September 20126 Wrtsil
Gas admission system
2 x GAV (gas admission valve) per cylinder
GAV actuated by hydraulically fast-switching solenoid valves
Hydraulic power supply from exhaust valve servo oil system
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Technical features Pilot fuel system
Wrtsil 2-stroke / Gas Engine / September 20127 Wrtsil
Pilot fuel system
Pilot fuel utilized for ignition (as in four-strokes DF engines)
Micro pilot valves utilization. Pilot fuel consumption < 1% of BSFC
Pre-chamber technology for best ignition and combustion stability
Fuel supply based on common-rail technology (as in four-strokes DF engines)
Pilot fuel injectors
Pre-chamber
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Technical features Pilot fuel system
Wrtsil 2-stroke / Gas Engine / September 20128 Wrtsil
Pilot fuel system
Single fuel oil pump serving all cylinders (common-rail technology)
Filters and pressure regulation included
Pilot fuel pump can be electrically or mechanically driven
UNIC
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Technical features Gas feed system
Wrtsil 2-stroke / Gas Engine / September 20129 Wrtsil
Gas Valve Unit (GVU)
Wrtsil standardized and proven design applied
Pressure regulation, gas filtering and safety valves included
Emergency venting procedure and leakage test features introduced
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Technical features Automation
Wrtsil 2-stroke / Gas Engine / September 201210 Wrtsil
Engine automation and control system
UNIC based control system
Individual control of combustion related parameters
Safety functions related to gas operation included
Pilot fuel injectorPilot fuel injector
Gas admission valvesGas admission valves
Test cylinder running on gas
Control system
2x Gas admission valves2x Gas admission valvesPilot fuel injectorsPilot fuel injectors
Engine speed/CA-signalEngine speed/CA-signalEngine stop signalEngine stop signal
Gas durationGas duration
Gas pressureGas pressure
(Pilot fuel pressure)(Pilot fuel pressure)
Exhaust valve driveExhaust valve drive
Exhaust valveExhaust valve
Pilot fuel injector
Gas admission valves
Test cylinder running on gas
Control system
2x Gas admission valvesPilot fuel injectors
Engine speed/CA-signalEngine stop signal
Gas duration
Gas pressure
(Pilot fuel pressure)
Exhaust valve drive
Exhaust valve
- Performance targets (
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Project overall time schedule
Wrtsil 2-stroke / Gas Engine / September 201212 Wrtsil
Project activities 2010 2011 2012 2013 2014Pre-study Concept evaluations Product requirement spec.
Technology development Simulations & design for 1 cyl Engine tests 1 cyl
Industrialisation 6 cylinder engine design Full scale engine tests
Introduction Concept release Pilot installation data release:
information release installation manual (MIM)
Full scale engine testing: customer demo (lab engine) validation at licensee
First sailing validation
Design, development, preparationEngine testing
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2-stroke gas engine development
13 Wrtsil Wrtsil 2-stroke / Gas Engine / September 2012
2-stroke gas engine development based on vastexperience from 4-stroke dual fuel engines/installations
4-stroke dual fuel references: Power plants, Merchant, Offshore, Cruise & Ferry, Special ~190 installations > 5,000,000 running hours
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Minimum gas quality requirements
14 Wrtsil
Property Unit ValueLower heating value (LHV), min 1) MJ/m3N 2) 28
Methane number (MN), min 3) 90 (IMO Tier 1)
80 (IMO Tier 2)Methane (CH4), min % volume 70
Hydrogen sulphide (H2S), max % volume 0.05
Hydrogen (H2), max 4) % volume 3
Ammonia, max mg/m3N 25
Chlorine + Fluorines, max mg/m3N 50
Particles or solids at engine inlet, max mg/m3N 50
Particles or solids at engine inlet, max size um 5
Gas inlet temperature C 060
Water and hydrocarbon condensates at engine inlet not allowed 5)
1) The required gas feed pressure is depending on the LHV (see section Gas feed pressure in chapter Fuel system).2) Values given in m are at 0C and 101.3 kPa. 3) The methane number (MN) is a calculated value that gives a scale for evaluation of the resistance to knock of gaseous fuels. Above table is valid for a
low Methane Number optimized engine. Minimum value is depending on engine configuration, which will affect the performance data.
However, if the total content of hydrocarbons C4 and heavier is more than 1% volume Wrtsil has to be contacted for further evaluation. 4) Hydrogen content higher than 3% volume has to be considered project specifically.
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BSFC characteristics for W5X72
15 Wrtsil
0
1
2
3
4
5
6
134
135
136
137
138
139
140
141
142
143
144
30 40 50 60 70 80 90 100 110
Pilo
t fue
l MDO
[g/k
Wh]
LNG
BSFC
[g/k
Wh]
Engine load [%]LNG consumption [g/kWh] Pilot fuel MDO [g/kWh]
High efficiency turbocharger ABB A100 or MET MB / ISO, LCV of 42700 kJ/kgTol. +5% between 85 to 100% load, +6% between 65 to 84% load, +7% between 50 to 64% load
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Fuel Gas Handling System
Qh
Qv
LNG FUEL GAS MODULE
Low pressure compressor set
Heater
Evaporator
LNG tank
Low pressurefeed pump
16 Wrtsil
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WRTSIL 2-STROKE GASRT-flex engine conversion to gas (DF)
17 Wrtsil Wrtsil 2-stroke / Gas Engine /
RT-flex (Dual Fuel)RT-flex
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RT-flex engine conversion to gas
Wrtsil 2-stroke / Gas Engine / 18 Wrtsil
Cylinder
CCM-20 (Additional)
Exhaust valve
2/3 Pilot fuel injectors & Pre-chambersReplacement of cylinder cover
2 x Gas Admission Valves (GAV)Extra machining of cylinder liner 2 x Gas Rail
MDO supply unitSupport platform for MDO SUMDO pipes to injectors
PRELIMINARYPRELIMINARY
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RT-flex engine conversion to gas
Wrtsil 2-stroke / Gas Engine / 19 Wrtsil
Action Component and description Quantity
Existing components to be replaced Cylinder cover 1 per cylinder
Existing RT-flex parts to be modified Machining cylinder liner for gas admission valves(might also need replacement) 1 per cylinder
New fuel system related partsMDO pump unit for fuel pilot injectors 1 per engine
MDO pipes to fuel pilot injectors 1 system per engine
Ignition systemPilot fuel injectors 2/3 per cylinder
Pre-chambers 2/3 per cylinder
Turbocharging & Scavenge air system partsWaste gate on the turbocharger 1 per engine
By-pass valve on the turbocharger (possibly) 1 per engine
Gas admission system components
Gas admission valves 2 per cylinder
Servo oil piping to gas admission valves 2 per cylinder
Gas rails (piping) 2 per engine
New automation system related parts (Installed automation system dependant)
CCM-20 1 per cylinder
Booster 8 per cylinder
Cylinder pressure sensor 1 per cylinder
Knocking sensor 1 per cylinder
Other Assembly, relocation of pipes, sensors, small components. -
PRELIMINARYPRELIMINARY