Almighty 2-stroke

J.J. · #1 (**permalink**) 11-20-2004

Seeing this is Everything2stroke.com I thought I'd share with you guys what I do at work.
I am a mechanical engineer, working for a shipping company, building container ships in S.Korea. Here are some pics of the dyno run we did on a main propulsion engine a while back... (Pics are at the engine manufacturer, not inside the ship)

MAN B&W 12K98MC-C, 12 cylinder, quad turbo, 2-stroke diesel.
Bore 980mm x stroke 2400mm

This engine is a single acting, directly reversable, compression ignition (diesel), crosshead type, 2-stroke engine. At the moment this is one of the most powerful internal combustion engines in production. Period!

This pic shows the engine spinning a Zollner 150 ton waterbrake dyno that's connected directly to the flywheel.

At this dyno run we got 102432BHP (ISO) at 104RPM at steady state conditions.
Torque on the waterbrake dyno was 6701KNM.
MEP (Mean effective pressure) was 19.4Bar
Pmax (Maximum combustion pressure) was 141Bar

This engine is directly coupled to the ship's propellor shaft with no clutch or gearbox.
To manoeuvre the ship ahead and astern the engine has to be stopped and started in the opposite direction.
Starting is by compressed air at 30Bar, using a distributer at each end of a chain driven camshaft that directs the air to the top of the correct piston.

The propellor shaft weighs 166000kg and the OD is 975mm.
The propellor is a 6 fixed bladed propellor with an OD of 9 meter weighing in at 85600KG

As mentioned this is a crosshead type engine, the purpose of which is to seal the crankcase from the under piston space and scavenge air receiver.

Anyways, the turbo's force the inlet air thru a water/air intercooler, then thru flap valves (reeds on your 'Shee) in to a common scavenge air trunking.(Meaning all 4 turbo's push air into here)
From there its forced into the respective cylinders as soon as the piston uncovers the inlet ports on the down stroke.
After combustion,(remember, compression ignition) the exhaust goes out a hydraulically actuated exhaust valve that is mounted in the centre of the cylinder head. This is a Uni-flow design that gives much better scavenging than conventional loop scavenge exhaust port type 2-strokes.
At low RPM's, the turbo chargers are assisted by electric motor driven blowers.

After exiting the cylinder the gas is exhausted into a common exhaust trunk, (this keeps the turbo's at a constant speed and helps prevent pulsing and surging of the turbine rotor), then passes thru an exhaust gas steam boiler to generate steam and then out the funnel.

The fuel is residual fuel oil, and thick like tar at room temperature, so we heat it to about 120DegC (using steam) to thin it to a viscosity of 15 Centistokes, to give good injection and atomising.

The crankshaft is manufactured in parts that are shrunk fit together.
The camshaft is chain driven and actuates the exhaust valves, individual fuel injection pumps and the air start distributer.

After the shop test and dyno run the engine is stripped, cases are split, con-rods are disconnected from the crank and all the parts transported to the shipyard (in this case Samsung Heavy Industries) and then re-assembled inside the ship's engine room.

Thanks for taking the time to look!

Banshee · #2 (**permalink**) 11-20-2004

WOW, Do you think you could hook me up with a good price. I think I need that in my banshee...j/k

Good info though

racezilla500 · #3 (**permalink**) 11-20-2004

Man, that is awesome! Sounds like you know your sh!t too!

J.J. · #4 (**permalink**) 11-20-2004

Quote:

Originally Posted by Banshee

WOW, Do you think you could hook me up with a good price. I think I need that in my banshee...j/k

Good info though

Jason, get your people to hook up with my people to proceed with negotiations, hopefully we can reach a mutually rewarding conclusion to said negotiations... a word of warning though, Toomey is not an the list of OEM component sub-vendors, so I doubt that a satisfactory agreement will be reached...

Banshee · #5 (**permalink**) 11-20-2004

Yeah probably for the better because i think my frame wouldn't be able to hold the motor. That motor must be what 20-30lbs more than my banshee motor...j/k

Really cool to see the most powerfull motor being a 2-stroke.