slow steaming solutions
DESCRIPTION
solutionsTRANSCRIPT
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Slow Steaming Solutions for fuel consumption reduction
2013-05-17
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QMD
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Background
1. Background
Duo to ever rising fuel oil prices, owners and
operators of larger-bore two-stroke low-speed
engines have been looking for different ways to
save on fuel expenses without having to
compromise on engine reliability and emissions.
Since the worldwide financial crisis developed in
the second half of 2008, low-load operation or slow
steaming has been the standard of the day for
many owners operating two-stroke engines. In the
early days of slow steaming, mainly container
vessel operators requested to operate at low load.
Today, also operators of tankers, bulkers, etc. are
beginning to operate continuously at low loads.
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QMD
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Background
Slow steaming operation
Low-speed two-stroke crosshead diesel engines are normally operated in a load
range above 40% CMCR.
Todays increasing fuel costs require rather slow vessel service speeds resulting
in an continuous engine operation between 20% and 40% engine load.
When running the engine continuously at loads lower than Normal Load , it is
called Slow Steaming.
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QMD
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Background
Low load operation disadvantage without any modification :
1. Low turbocharger efficiency.
2. Higher exhaust gas temperatures.
3. Continuous operation in the Very Low Load range may result in increased
cold corrosion due to low combustion chamber temperatures, increased deposit
formation, and general engine fouling.
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QMD
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Slow Steaming _Running with T/C cut off
Service Letter ( SL) RT-139, Running of main
engines with turbocharger cut-off
To protect engine against excessive high load,
temperature and stress while T/C cut off
operation
Introduction of power limit guidance for
unlimited continuous operation with T/C cut- off
operation
Special attention to monitor performance
parameters if engine operate above guided limit
Emergency operation due to unexpected T/C
failure are not intended
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Service Letter RT-139
WRTSIL 2-STROKE SERVICE EXPERIENCE Big Bore May 2013
All TC in operation (25%,45% & 50% load), 8 RT-flex96C
1 TC in Operation (25%,45% & 50% load), 8 RT-flex96C
Excessive high
P max with T/C
cut off operation
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QMD
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Slow Steaming _Running with T/C cut off
Installations with Wrtsil slow steaming upgrade kit
Wrtsil SSUK service product has Automatic limitation function for power limit
- 90% of max allowed T/C speed
- 90% Scav. pressure from FAT
proper setting of alarm to be monitored
Installations with turbocharger cut- off not supplied by Wrtsil
- Reset manual fuel limiter setting on Speed control system
- Reset Speed set point
- Monitoring of Shaft power meter
- On-line power monitoring system ( i.e ICC/ ICM )
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QMD
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Installations with Wrtsil slow steaming upgrade kit
Engine operation in the load range between 20% and 100% CMCR without any
additional restrictions.
Electronically-controlled turbocharger cut-off without compromising on engine
reliability.
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QMD
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Installations with Wrtsil slow steaming upgrade kit
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QMD
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Installations with Wrtsil slow steaming upgrade kit
The Upgrade Kit Slow Steaming enables:
Operating the engine at lower load without operation of the auxiliary blower
Reduction the risk of turbocharger and economiser fouling
Significant reduction of specific fuel consumption
Additional fuel cost savings, on top of the savings due to low-load operation
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QMD
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Installations with turbocharger cut- off not supplied by Wrtsil
With fitting blind flanges between the turbocharger and
exhaust manifold. Continuous operation between
20%~ 50% (2 T/Cs), and 20% ~ 66% (3 T/Cs).
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QMD
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Installations with turbocharger cut- off not supplied by Wrtsil
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QMD
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Installations with turbocharger cut- off not supplied by Wrtsil
Flap valve is closed because seal air is supplied from engine side through seal air pipe.
In the result, sealing air is supplied to the seal air passage in bearing pedestal without
leakage to scroll.
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QMD
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Installations with turbocharger cut- off not supplied by Wrtsil
Flap valve is opened because seal air is supplied from scroll. In the result, sealing air is
supplied to the seal air passage from scroll and seal air pipe.
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CONFIRMATION TRIAL
Engine Type : QMD-Wartsila 6RT-flex82C
Data : Sept. 22, 2012
Place : QMD assembly shop
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CONFIRMATION TRIAL
Engine performance and emission
confirmation
Engine Type : QMD-Wartsila 6RT-flex82C
T/C Type : MET 66MA x 2 sets
Pmax at 100% CMCR : 159 bar
Pscav at 100% CMCR : 2.95 bar
T/C speed nmax : 14,300 r/min Remove expansion joint between
the turbocharger and exhaust
manifold and fit blind flanges.
Remove expansion joint between
the turbocharger air outlet and
diffusor, and fit blind flanges.
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PERFORMANCE
Engine Type : QMD-Wartsila 6RT-flex82C
Data : Sept. , 2012
Place : QMD
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FUEL CONSUMPTION
Engine Type : QMD-Wartsila 6RT-flex82C
Data : Sept. , 2012
Place : QMD
Annual fuel saving at 45% load operation
168
170
172
174
176
178
180
182
184
186
10% 15% 20% 25% 30% 35% 40% 45% 50%
FOCNormal
Fuel Consumption comparison
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EMISSION
NOx measurement result
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APPLICATION EXAMPLE
Vessel Information
Vessel Type : 3,100 TEU Container Carrier
Vessel Name : Niledutch Beijing
Engine Type : QMD-Wartsila 6RT-flex82C
Classification : GL
QMD modified the main engine of vessel
Nileductch Beijing with blink flanges from
normal condition to slow steaming condition
according to the requirement of the ship
owner.
After No. 2 turbocharger cut off, main engine
show good performance during main engine
normal operation and fuel consumption meet
expected value.
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APPLICATION EXAMPLE
Vessel Information
Vessel Type : 3,100 TEU Container Carrier
Vessel Name : Niledutch Beijing
Engine Type : QMD-Wartsila 6RT-flex82C
Classification : GL
Date : 2013, 04
Normal voyage fuel consumption operation with slow steaming
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THANK YOU FOR YOUR ATTENTION.
Qingdao Qiyao Wartsila MHI Linshan Marine Diesel Co., Ltd.
Add:501 Li Jiang East Road, Economic and Technological Development
Zone, Qingdao, China
Tel : 086-0532-86708080
Fax : 086-0532-86708080-788