karthikdattag

Hi Guys,

The forum title says “Thumpers, Two Strokes and Exotics” and the topic which I will be discussing here will pretty much justify this title in a big way.

Yes, its about the biggest & most powerful 2-Stroke Engine ever to be produced by Wartsila and its application is for the powerplant in the ship named Emma Maersk. This is truly a remarkable achievement as far as Engineering is concerned.

Before I start off with the specification and other technical aspects of this Engine, I would like to share some practical application of IC Engines used in Ships. With a PG in Power Electronics Engineering I do know quite a few things about how ships & locomotives work, hence same thing I will be penning down here.


Use of IC Engine in Ships:

An I.C Engine (2 or 4 Stroke) typically runs with Diesel fuel (as is the case with typical DG sets for Islanded Power plant application) is mechanically coupled to an A.C Generator (3-Phase Alternator) which is typically of similar rating as compared to I.C engine (Kilo Watt Power). This A.C generator normally generates the required power at 11,000 Volts & this is fed to a step down transformer and at the secondary we get voltage of any choice. This voltage is then fed to a small sub-station which is basically a distributing network to other electrical loads. One such load is a variable frequency drive (a.k.a frequency converter or VFD) which basically takes in fixed-voltage and fixed-frequency and converts to variable-voltage and variable-frequency output (VVVF). This VVVF output is fed to an A.C Motor & thus speed control of which is easily achieved. This Motor is coupled to the Azipod propulsion system which is basically the drive train in the ship. Pretty much similar concept is used in Locomotives as well (Diesel-Electric traction) wherein the traction motors are fed through similar I.C engine + A.C Generator combination, which are coupled to the wheels of the engine via gearbox.

Hence these I.C engines power the Drive train (Azipod in case of ships & wheels in case of locos) indirectly. The A.C generator is also used to power other accessories on ship such as the HVAC unit, hotel load, other auxiliary equipments.


Some Facts about this 2-Stroke Engine:

The Wärtsilä RT-flex96C is a two-stroke turbocharged low-speed diesel engine manufactured by the Finnish manufacturer Wärtsilä. It is currently considered the largest reciprocating engine in the world, designed for large container ships, running on heavy fuel oil. It stands at five stories (13.5 metres (44 ft)) high, is 27.3 m (90 ft) long, and weighs over 2300 tonnes in its largest 14-cylinder version — producing 109,000 brake horsepower (81.3 MW).

It was put into service in September 2006 aboard the Emma Mærsk. The design is based on the older RTA-96C engine, but revolutionary common rail technology has done away with the traditional camshaft, chain gear, fuel pumps and hydraulic actuators. The result is better performance at low revolutions per minute (rpm), lower fuel consumption, and lower harmful emissions. As of 2008, the power output of the 14 cylinder version has been increased to 84.42 MW (114,800 bhp).

It is available in 6 through 14 cylinder versions, all are inline engines. These engines were designed primarily for very large container ships. Ship owners like a single engine/single propeller design and the new generation of larger container ships needed a bigger engine to propel them.

Fuel consumption at maximum power is 0.278 lbs per hp per hour (Brake Specific Fuel Consumption). Fuel consumption at maximum economy is 0.260 lbs/hp/hour. At maximum economy the engine exceeds 50% thermal efficiency. That is, more than 50% of the energy in the fuel in converted to motion. Even at its most efficient power setting, the big 14 consumes 1,660 gallons of heavy fuel oil per hour.

Technical Specification of Wärtsilä RT-flex96C:

engine configuration
turbocharged two-stroke diesel straight engine, 6 to 14 cylinders

cylinder bore
960 millimetres (37.79 inches)

piston stroke
2500 millimetres (98.42 inches)

engine displacement
1820 litres per cylinder (111,063 cubic inches)

engine speed
92–102 revolutions per minute

torque
7,603,850 newton metres (5,608,310 ft·lbf) @ 102 revolutions per minute

mean effective pressure
1.96 MPa @ full load, 1.37 MPa @ maximum efficiency (85% load)

mean piston speed
8.5 metre per second

specific fuel consumption
171 g/(kW·h) (126 g/(bhp·h), approx. 3.80 litres per second) @ full load; 163 g/(kW·h) (120 g/(bhp·h)) @ maximum efficiency

power
up to 6030 kW per cylinder, 36,180 to 84,420 kW (49,200 to 114,800 bhp) altogether

power density
29.6 to 34.8 kW per tonne, 2301 tonnes for the 14 cylinder version

amount of fuel injected in a single cycle of single piston
~160 grammes @ full load

Hope you all had a good experience reading about this engineering marvel.

With Regards,
- Karthik..

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Aryan

Topic Approved.

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joeprodigy

Wow...That's one huge 2 stroke engine !!

Great info. Thanks Karthikdattag.

nipunblaze135LS

When you post there kind of things please mention SOURCE.

i have seen it in Discovry,
and the engine is realy mamoth size.
Just imagine a 5story engine churning out tons of bhp's, what a sight it will be!

Bladerunner

Wonder how much 2T oil it needs!

sixspeedtwin

2-stroke deisels do not need 2-t Oil. It has a slightly modded splash and pressure feed type lubrication seen on most 4 strokes.

sixspeedtwin

Now THAT's the engine I want for my project cafe racer!!!!

vikas_r15

I have worked on this engine !!!!

karthikdattag

Hi, can you please share your personal experience with this machine.

__________________
************************************************** ************************************************** *********

‘It throws itself around in a brash and unseemly manner, shouting for attention. To ride this bike is an event with a race-tuned soundtrack.’

- Yamaha RD

************************************************** ************************************************** *********

Kindly visit URL :

http://www.xbhp.com/talkies/448234-post.html

for spares of RX135/RX-Z/RXG/RD