1 Ch l Ch i iti l i t t Li it d f ti
1. Choose a less powerful engine
Cheaper initial investment Limits speed for entire ship life
2. Derate a new Significant SFOC reduction Typically limits speed for engine
g yp y p
entire ship life 3. Part load optimised Lower SFOC at part load;
Ship is able to sail at
Not available on some engines
Ship is able to sail at
increased speed if required
engines
4. Apply a ”Low Load” Can be applied in service; Not available on some
mode possible for continuous
operation <20% SMCR
engines
Engine Application Engine Application
Power
MP
2 Heavy propeller curve - Engine margin
Sea margin
MP: Specified propulsion MCR point SP: Service propulsion point
PD: Propeller design point
PD`: Alternative propeller design point
PD
Engine speed
2 6
LR: Light running factor
HR: Heavy running HR
1 Choosing a Less Powerful engine 1. Choosing a Less Powerful engine
= SMCR point
Power
= SMCR point A = 100% Speed
Smaller engine, reduced installation space
Reduced initial investment L2
Reduced initial investment
Permanent solution, limited to
Methods of Engine Application for a reduced Service Speed for a reduced Service Speed
Method Advantage Disadvantage
1 Ch l Ch i iti l i t t Li it d f ti
1. Choose a less powerful engine
Cheaper initial investment Limits speed for entire ship life
2. Derate a new Significant SFOC* Typically limits speed for engine
g
reduction
yp y p
entire ship life 3. Part load optimised Lower SFOC at part load;
Ship is able to sail at
Not available on some engines
Ship is able to sail at
increased speed if required
engines
4. Apply a ”Low Load” Can be applied in service; Not available on some
mode possible for continuous
operation <20% SMCR with precautions
engines
* Specific Fuel Oil Consumption in
g/kWh p
g/kWh
2 Derate a New Engine 2. Derate a New Engine
T i ll i l kW
Typically involves
increasing the number of cylinders or choosing a
75,000
70,000
74,760 kW
12K98ME7
Engine layout diagrams
ated
higher mark number, and then reducing the shaft power output by various
70,000
= de-rating with same FPP to reduce engine speed to 91.3rpm
55,000 90 r/min 97 r/min
reduce engine speed to 91.3rpm
= de-rating with different FPP to maintain engine speed
Complete engine system designed around de-rated engine
SFOC Reduction by Derating a K98ME7 Engine SFOC Reduction by Derating a K98ME7 Engine
SFOC curves g/kWh
SFOC curves for 10, 11, and 12 cylinder versions of the K98
175
170 Nominal
SMCR = 62,300 kW x 97 r/min Matching point = 100% SMCR LCV = 42,700 kJ/kg
engine shown for SMCR
Total saving of 5.8g/kWh equates to an annual fuel cost
165
Derated Derated 10K98ME7
equates to an annual fuel cost saving of $1M/yr
160
Methods of Engine Application for a reduced Service Speed for a reduced Service Speed
Method Advantage Disadvantage
1 Ch l Ch i iti l i t t Li it d f ti
1. Choose a less powerful engine
Cheaper initial investment Limits speed for entire ship life
2. Derate a new Significant SFOC reduction Typically limits speed for engine
g yp y p
entire ship life 3. Part load optimised Lower SFOC at part load;
Ship is able to sail at
Not available on some engines
Ship is able to sail at
increased speed if required
engines
4. Apply a ”Low Load” Can be applied in service; Not available on some
mode possible for continuous
operation <20% SMCR
engines
3 Part Load Optimisation 3. Part Load Optimisation
Optimising/Matching point to
b l t d id i th
be selected considering the average ship service speed
Involves TC matching,
compression volume (shims), exhaust gas valve timing, and g g,
De-rating / part load optimisingDe rating / part load optimising•
Turbo charger cut out•
Turbo charger cut outReduced SFOC for Part Load Optimisation of ME/ME-C Engines when Operating in Economy Mode
174
MC/MC-C 100% SMCR optimised
Economy mode:
S = Continuous Service Rating:
168
FOC
ME/ME-C 100% SMCR optimised MC/MC C 100% SMCR optimised
ME/ME-C Part load optimised
3-4g/kWh
3-4g/kWh
Service Rating:
SME is 70% of
Optimising Point for
SF
Engine shaft power
Optimising Point for MC engines
Increase in SFOC reduction when operating below ~70% engine power
Methods of Engine Application for a reduced Service Speed for a reduced Service Speed
Method Advantage Disadvantage
1 Ch l Ch i iti l i t t Li it d f ti
1. Choose a less powerful engine
Cheaper initial investment Limits speed for entire ship life
2. Derate a new Significant SFOC reduction Typically limits speed for engine
g yp y p
entire ship life 3. Part load optimised Lower SFOC at part load;
Ship is able to sail at
Not available on some engines
Ship is able to sail at
increased speed if required
engines
4. Future possibility to Could be applied in Would not available on apply a ”Low Load”
mode
service; possible for continuous operation
<20% SMCR with
some engines
4 Application of Low Load Mode 4. Application of Low Load Mode
= SMCR pointp
Would only be available on electronically controlled
L4
electronically controlled engines (ME/ME-C)
Could be applied in servicepp
Changes injection timings and exhaust gas valve
actuation for specific Low Load area
Reduced SFOC for Low Load Mode of ME/ME-C Engines
of ME/ME-C Engines
Further increase in SFOC reduction when operating in low load areasp g
Typically 1-2g/kWh reduction for low load area
Increased SFOC when operating at high loads; 1-2g/kWh increase at
174
Increased SFOC when operating at high loads; 1 2g/kWh increase at 100% SMCR
C
ME/ME-C Economy mode ME/ME-C Low load mode
1-2g/kWh
Part Load Optimisation & Low Load Mode Part Load Optimisation & Low Load Mode
Combined effect of a part load optimised engine and p p g utilisation of a low load mode
Gives a total SFOC reduction in low load areas of 4-6g/kWh
Reduced Fuel Consumption at Low Load Operation for Large Container Vessels Operation for Large Container Vessels
12K98MC C6 d 12K98ME C6 SMCR 68 520 kW t 104 / i 12K98MC-C6 and 12K98ME-C6, SMCR = 68,520 kW at 104 r/min
Considerations regarding boiler typesConsiderations regarding boiler types Smoke tube boilersSmoke tube boilers
Limited soot deposits in the tubes - High velosity of exhaust gas - High velosity of exhaust gas
- Smooth gas passage
Limited demand for cleaning
Water tube boiler with fins
- Limited demand for cleaning
More prone to soot deposits on fins and tubes
L l it f th h t
- Low velosity of the exhaust gas
- Risk for boiler fires and melting down
Technical Problems Technical Problems
Operating at low speed can create problems, such as:
p ,
Deposting of of soot particles in exhaust gas boiler resulting in burning/melting
tubes tubes
Build up of soot in Turbocharger, requiring more frequent cleaning, or reduced efficiency
reduced efficiency
Cutting in/out of auxiliary blowers
Exhaust valve spindels
-Increased burn rate during ”Low Load”
Increased burn rate during Low Load
In few cases has been observed increased
Technical Solutions Technical Solutions
For MC engines:
Solenoid valve Group 1
Solenoid valve Group 2
Without cylinder cut-out
For MC engines:
Increase engine load to above 75%
for 1hour, every 12hours
Air supply 7 bar
Introduction of slides valves
Cylinder cut-out system for
i b l 40% d With cylinder cut-out
manoeuvring below 40% speed
Exhaust gas boiler bypass for loads
<40%
<40%
For ME engines:
Increase engine load to above 75%
Increase engine load to above 75%
for 2hours, every week
Exhaust gas boiler bypass for loads g yp
Technical Solutions Technical Solutions
Fuel Valves
Cylinder Oil Regulation at Low Load Cylinder Oil Regulation at Low Load
For engines with Alpha lubricator (lubrication as a lubricator (lubrication as a function of engine load),
significant savings can also be
d li d l b il
made on cylinder lube oil consumption
80% MCR results in reduction80% MCR results in reduction of 50% ~$165,000/yr
Service experience with low load operation Service experience with low load operation