2. 1 • Overview ofThe Conventional Power Plants in Marine System.
2 • The Electric Propulsion System .
3
• Types of Electric Propulsion System .
4
• Electric propulsion system components .
5 • The Advantages and the Disadvantages of the Electric Propulsion
6 • Case Study.
7 • FutureTrends of Power Electronics and Drives .
8 • Conclusion
4. Selection
of
marine
power
plant
system
1. Reliability.
2. Machinery space and arrangement
3. Machinery weight and volume requirements
4. Type of fuel and fuel consumption
5. Machinery costs .
6. Interrelations with auxiliaries
7. Maintainability
8. Vibration and noise .
9. Reversing capability .
10. Operating personal .
5. Classification of Conventional Marine Power Plants
Diesel Engine Power Plant
Steam turbine power plant
Gas turbine power plant
Nuclear power plant
Combined power plants
6. Diesel Engine Power Plant
The Main demerits of marine diesel engines in
conventional system
1. The DE is slightly greater weight compare to the gas turbine
for the same power .
2. The high speed DE provides high fraction losses in operation
particularly at partial loads .
3. The DE has a high fuel consumption at partial load .
4. The high and medium speed engine must coupled to a GEAR
BOX .
7. Fuel consumption of the DE :
The efficiency drops fast as the load becomes lower than 50% of MCR.
At this working condition, the combustion is inefficient, with high NOx and SOx
content , and with a high degree of soothing which increases the need for
maintenance .
9. Steam turbine power plant
The Disadvantages Of Steam Power Plant :
1. Fuel consumption is considerably higher than the diesel engine .
2. Low Efficiency engine compared to Diesel Engine .
4. Capital cost of the Steam power plant is high .
3. Turbines must run at high speed for best efficiency so a high ratio
reduction gear is essential to obtain an economical propeller speed .
12. Gas turbine power plant
The Disadvantages of GasTurbine system .
1- The GasTurbine has high fuel consumption .
2- It needs a big reduction gear and reversing mechanism .
3- It requires large area and space for the inlet air system .
13.
14. Nuclear power plants
The Disadvantages Of The Nuclear
Power Plant are :
1. Reactor plants are heavy and require
very dense shielding to contain
radiation .
2. The high capital costs of installation
, operation and maintenance .
18. History Of Electric Propulsion
… more than 170 years
1839: a small Russian ferry was built which was propelled by an electric
motor fed by a storage battery.
In 1903 / 1904 , diesel engines were reliable enough to be used as ship
propulsion but they were still non-reversible. At that time,
electric power transmission therefore was the only method to overcome
this basic technical problem.
After the rather experimental applications of battery driven electric
propulsion at the end of the 19th century took place in Russia and
Germany…
19. • As a result of the strong competence of reducing transatlantic crossing times for
passenger liners.
• the high propulsion power demand could only be achieved by turbo-electric machinery.
First generation of electric propulsion 1920’S
Steam turbine generators
provided electric power that
was used to drive the 29MW
synchronous electrical
motors on each of the four
screw shafts.
20. Second generation of electric propulsion 1980’S
• In the middle of the 20th century ,diesel engines appeared with :
1- High efficiency.
2- Economical value.
Therefore, steam turbine technology and electric propulsion disappeared from merchant
marine vessels.
21. • The development of variable speed electric drives :
• First by the AC/DC rectifier in the 1970’s .
• Second by the AC/DC converters in the early 1980’s.
• These solutions were firstly used in special vessels like survey ships and icebreakers,
but also in cruise vessels.
• “S/S Queen Elizabeth II” was converted to electric propulsion in the mid 1980’s.
22. Breakthrough for Electric Propulsion 1990’S
• Podded propulsion was introduced in early 1990’s where the electric motor is installed
directly on the FPP shaft in a submerged, rotatable pod.
• Enhance the performance of icebreakers, it benefits on hydrodynamic efficiency and
maneuverability.
• After the fist application in a cruise liner, “M/S Elation”, podded propulsion became a
standard on new cruise liners.
23. The market for electrical propulsion will grow significantly
0 %
5 %
10 %
15 %
20 %
25 %
0
1000
2000
3000
4000
5000
2003
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
ELECTRICALANDHYBRIDPROPULSIONSHAREOFTOTAL
ORDEREDVESSELS
ORDEREDVESSELS#
Ordered vessels over 2000GT by vessel number, (ABB Estimate)
Share of vessels with electrical propulsion, % (ABB Estimate)
Electrical propulsion share of vessels by number, % (ABB estimate based
on Diesel&Gas Turbine Worldwide 2010)
Electric propulsion has become the
technology of choice for several vessel
segments due to the fuel efficiency and
low emissions.
Electric propulsion will become as the
solution for new merchant vessel
segments, e.g.: container, dry cargo
vessels.
Electrical propulsion vessels are
projected to represent 20% of vessel
numbers in 2020.
25. Types of electric propulsion system
1- DIESEL ELECTRIC MACHINERY SYSTEM .
2- CODED “COMBINED DIESEL-ELECTRIC AND DIESEL-MECHANICAL
MACHINERY ” .
3- DUAL FUEL ELECTRIC PROPULSION .
4- CODLAG ” COMBINED DIESEL-ELECTRIC AND GAS MACHINARY ” .
5- COGES “ COMBINED-CYCLE GAS AND STEAMTURBINE ELECTRIC
MACHINERY ” .
26. 1- Diesel-electric propulsion system
By using diesel electric propulsion, we will able to operate diesel engines at :
1- Raise the overall efficiency.
2- Reducing emissions.
3- Making the ship greener.
A medium speed diesel engine has a low fuel consumption at the optimum operation
point.
27.
28. 3- Dual fuel electric propulsion
Most of regulations focus on NOX and SOX emissions that for the most part, have
a local impact on the environment.
The only ways for ships to reduce their
CO2 emissions are either to reduce fuel
consumption is natural gas.
Switching from HFO to natural gas will
significantly reduce all important
exhaust gas emissions from a ship,
including a 30% reduction in CO2
emissions .
29. 4- CODLAG:
This means that there is at least one diesel engine and one gas turbine driving
generators to create electric power for both the propulsion and the hotel side.
The CODLAG concept was to be able to operate without any smoke
formation in special areas such as Alaska.
30. Gas turbines are directly connected to the alternators. Heat-recovery boilers are fitted in the
gas turbine exhaust lines and the resulting superheated steam (at approximately 30bar) is
led to a steam turbo alternator. This solution changes completely the
properties of a simple-cycle turbine; whereas gas turbine efficiency decrease at
low load, the steam turbine recovers the lost power.
5- COGES:
Heat for ship’s services is taken
directly from the steam turbine
exhaust (back-pressure turbine),
and thus there is normally no need
to fire-up auxiliary boilers.
31. General comparison :
Total fuel cost COGES HIGHERTHAN CODLAG & DIESEL-ELECTRIC
Weight of the machinery CODLAG LOWERTHAN DIESEL-ELECTRIC
The space needed COGES SMALLERTHAN DIESEL-ELECTRIC
All these systems have the advantages of electric propulsion but with different values
The CODED machinery is better than diesel-electric machinery combines the benefits
Reduce : The first cost
The fuel consumption.
Compare between dual fuel electric machinery and other systems
Offers significantly lower emission levels
34. Electric propulsion system components:
ELECTRIC
POWER
GENERATION
Prime mover.
Generators.
Energy storage
system.
ELECTRIC
POWER
DISTRIBUTION
Energy Transmission
“SWITCHBOARDS”
Transformers, filters
and power
converters.
ELECTRIC
POWER
CONSUMPTION
Electric propulsion
motors.
Propulsion units.
35.
36. ELECTRIC POWER GENERATION:
1-The prime mover :
The function of the prime mover is to deliver mechanical energy
which will be converted into electrical energy.
• May be one of the following:
Diesel engine
Gas turbine
Steam turbine
Combined cycles
37. 2- Generators :
A device that converts mechanical energy obtained from prime
mover into electrical energy.
Wound rotor synchronous generator.
Permanent magnet synchronous generator.
3- Energy storage system:
Batteries
Super capacitors
38. 2-Transformers, filters and power converters:
Transformers and
filters.
AC/DC converters.
Variable frequency
converters.
1- EnergyTransmission “SWITCHBOARD”
AC transmission. DC transmission.
ELECTRIC POWER DISTRIBUTION:
39. ELECTRIC POWER CONSUMPTION:
The electrical motor is the most commonly used device for conversion from
electrical to mechanical power and is used for electric propulsion.
1- Electric
propulsion
motors
Induction motors.
Synchronous motors.
Permanent magnet
motors.
High temp.
superconductor
motors.
41. • Podded Propulsion benefits :
1- Increases the hydrodynamic efficiency of the propeller.
2- Reduces the risk for cavitation.
3- Reduced noise and vibrations.
Podded propulsion units
have been in operation
in a decade
in cruise vessels,
icebreakers, service
vessels and tankers.
42. CHAPTER (5) :
The Advantages and the
Disadvantages of the Electric
Propulsion
43. THE ADVANTAGES OF THE ELECTRIC PROPULSION SYSTEM :
Flexibility of layout
It is estimated that a reduction of about 30% volume is possible
compared to the conventional mechanical drive system
44. Load diversity
There are advantages in having a single central power generation
facility which can service the propulsion and all other ship loads as
required .
Fuel savings
For ships spending more time at low speed, fewer engines can run at full
power, resulting in greater energy efficiency and hence less fuel
consumption.
The navy ship with IEP may save an estimated 15–25% in fuel compared
to a similar ship with mechanical drive. The lifetime cost saving from
reduced fuel consumption may exceed the higher initial procurement
cost of electrical propulsion .
45. The Norwegian Epic cruise ship
It has a beneficial impact on
the environment from
reducing fuel consumption
by 14,000 tons per year .
46. Greater maneuverability
The use of podded propulsion can permit a tighter turning radius and give an
ability to change the direction or orientation of the ship even at very low
speeds Moreover, the speed and direction of the prime mover need not be
changed to affect the speed, direction, and rotation of the propeller For
icebreakers, ferries, tugboats, oceanographic
vessels , and cable-laying ships that require
frequent speed changes and direction
reversals, electric propulsion offers a great
advantage over mechanical propulsion .
47. Low noise
An electric motor is able to provide a drive with very low
vibration characteristics and this is of importance in warships,
oceanographic survey vessels and cruise ships where, for
different reasons, a low noise signature is required .
Higher automation
The electric propulsion system can be designed to be highly
automated and self-monitoring , hence requiring less
maintenance and fewer crew members to operate than with a
mechanical drive system.
52. Disadvantages of
System
Lower overall energy efficiency for ships running at full-rated
speed all the time due to losses
Higher initial capital cost
Different and improved training for ship’s crew as the system is
completely different from mechanical system and involves major
automation.
53.
54. Losses Component Fuel ( 100 % )
53 % Prime mover 47 %
4 % Generation 45.12 %
1 % Distribution 44.67 %
1 % Transformers 44.22 %
4 % Propulsion convertor 42.45 %
4 % Propulsion Motor 40.75 %
lower
overall
energy
efficiency
for ships
running at
full-rated
speed all
the time
due to
losses
55. Losses Component Fuel ( 100 % )
43.6 %
Variable speed Prime mover
Estimated 20 % improvement in
efficiency
56.9 %
4 % HTS generation 54.14 %
0.77 % DC Distribution
estimated 23 % reduction in losses
53.72 %
3.16 %
Use silicon- carbide Propulsion
convertor estimated 21 %
reduction in losses
52.02 %
4 % HTS Propulsion Motor 49.94 %
The
solutions
:
58. Mitsubishi Heavy Industries, Ltd. (MHI)
has designed and constructed an electric propulsion carrier for MISC Berhad
that makes use of dual-fuel diesel engines.
This paper describes our dual-fuel diesel–electric propulsion LNG carrier, which
is the first ship of its kind constructed in Japan.
59.
60. The measured fuel oil consumption rate
(FOCR) of this carrier during its sea trial
and FOCR of an identical horsepower
steam-turbine propulsion plant are shown
in Figure . The propeller shaft horsepower
FOCR indicated approximately 20%
energy savings compared to the steam-
turbine propulsion plant .
63. Main Specification of the boat :
- 18 [kWh] lithiumion battery of which
weight is about 400 [kg]
- 80 % of full charge of the battery can be
recharged by the quick charger within
-30 [min]
-The operational time with the full
charged battery is about 45 [min].
- the motor power is about 25 [kW] .
-The maximum speed of “RAICHO-I” is
about 10 [knots] with half load and 8.5
[knots] with full load. Full load means 2
crews and 10 passengers on board.
65. Length 80 m
Wide 20 m
Electric motor 2 each with 450 KW output
Material Aluminum .
Batteries 10 ton
Passengers about 360
vehicles about 120
ferry travels 6 Km across the fjord 34 times a day, with
each trip taking around 20 minutes.
66. The Norled ferry will consume around two million kWh per year,
whereas a traditional diesel ferry consumes at least one million liters
of diesel a year and emits 570 tons of CO2 and 15 metric tons of NOx
Reduces cost of fuel by 60 percent
Ferry only uses 150 kilowatt hours (kWh) per route
67. Batteries lithium-ion batteries which are charged from
hydro power.
The 260-kWh-units supply electricity to the ferry
while it waits.
More efficient and less expensive in the next few years,
which tip the scales further away from diesel as the
most popular fuel source.
Developed by Siemens and Norwegian shipyard
Fjellstrand, the vessel can recharge its batteries in
just ten minutes.
68. ADVANTAGES OF All-ELECTRIC SYSTEM :
1- Zero emission of NOx, SOx and CO2 when running .
2- Low noise and vibration .
3- No smell of exhaust gas .
4- 50 – 70 % of CO2 can be reduced by electric boats
compared with conventional boats.
69. Conclusion:
Using Electric Propulsion System means :
1- Increase space for payload.
2- Less maintenance of generator sets.
3- Improve dynamic response and maneuverability.
4- Up to 25 % fuel saving.
5- Low emissions.