philosophy of rt-flex technology and differences to...
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RT-flex Design Aspects
© Wärtsilä Land & Sea Academy Page 1 Chapter 10 16-Sep-11
Philosophy and Design Aspects of RT-flex Technology and Differences to Conventional
RTA Engines
RT-flex Training
Chapter 10
RT-flex Design Aspects
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History
History of
RTARTA introduced in 19822’854 RTA engines sold with 52M kW(Aug. 10)
RT-flexFirst RT-flex workshop in 1996Start of first RT-flex engine in 2001 (6RT-flex58T-B / GYPSUM CENTENNIAL)913 RT-flex engines sold with total 25M kW (Jun. 11)
RT-flex Design Aspects
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RTX Generations
1st generationRTX-1
2nd generationRTX-2
3rd generationRTX-3
4th generationRTX-4
2007
RT-flex Design Aspects
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Cylinder Pressures
Maximum cylinder pressure
Mean effective pressure
RT-flex Design Aspects
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Power Range
RT-flex Design Aspects
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Differences RTA to RT-flex engines
RT-flex Design Aspects
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Differences to RTA engines
RT-flex Design Aspects
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Comparison Table
RTA RT-flex
Developing fuel oil pressure One fuel pump per cylinder Fuel pumps on supply unit„Storing“ of fuel oil pressure - Fuel railTiming of injection Fuel cam on camshaft WECS-9520 / ICUDeveloping pressure for exhaust valve activation
One activating pump per cylinder
Servo pumps on supply unit
„Storing“ of servo oil pressure - Servo railTiming of exhaust valve activation
Valve cam on camshaft WECS-9520 / VCU
Governor actuator (RTA)
Fuel pump actuator (RT-flex)
Regulating fuel injection quantity / control by governor regulator
Keeping fuel rail pressure and control by WECS-9520
Electronic governor Releasing fuel injection pump position to the actuator
Releasing fuel command to WECS-9520
Fuel injection quantity control by
Governor and fuel injection pump
WECS-9520 / ICU acc. to governor’s fuel command
RT-flex Design Aspects
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Comparison Table
RTA RT-flex
Timing of starting air Starting air distributor WECS-9520Reversing Reversing of cam WECS-9520Alarm and monitoring system External (internal: OSC-3) ExternalEmergency control By mechanic shaft and cams
acting on pneumatic valves of the engine control
Backup panels deliver manoeuvring signals and fuel commands to WECS inputs, independent from the RC inputs channels
Load signal RC receives load signal from angle transmitter on intermediate shaft
WECS supplies a fuel command feedback as load signal to the RC system
VIT, VEC Functions provided in RC system
Functions (plus VEO) included in WECS
Wiring from engine to external Individual cables Bus-system
RT-flex Design Aspects
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Why Common-Rail
Higher efficiency than conventional engines (lower fuel consumption)
Reduced part load fuel consumption and smoke
Possibilities to reduce emissions
Lower minimum engine speed
Better manoeuvrability
RT-flex Design Aspects
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Advantages of RT-flex
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0.25
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0 10 20 30 40 50 60 70 80 90 100Engine Load [% ]
Filte
r Sm
oke
Num
ber [
FS
N ] HFO
380 cSt 3% sulphur 0.1% ash
Conventional low speed engine
OFF Aux. BlowerON
6RT-flex 58T-B with common rail
Smoke visibility limit
Wärtsilä 6 RT-flex58T-B MV Gypsum CentennialSmoke measurement on combinator curve during sea trials
RT-flex Design Aspects
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Advantages of RT-flex
RT-flex Design Aspects
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Engine Numbering and Designations
DRIVING END
Thrust Bearing Pads Main Bearing Numbering
FREE END
Cylinder Numbering
Turbocharger 1 Turbocharger 2
1 2 3 4 5 6 7
RT-flex Design Aspects
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Engine Numbering and Designations
FUEL SIDE EXHAUST SIDE
Clockwise RotationCounter-clockwise Rotation