The Wartsila-Sulzer RTA96-C turbocharged two-stroke diesel engine is the most powerful and most efficient prime-mover in the world today. The Aioi Works of Japan 's Diesel United, Ltd built the first engines and is where some of these pictures were taken.. 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. The cylinder bore is just under 38 and the stroke is just over 98. Each cylinder displaces 111,143 cubic inches (1820 liters) and produces 7780 horsepower. Total displacement comes out to 1,556,002 cubic inches (25,480 liters) for the fourteen cylinder version.
Total engine weight:2300 tons (The crankshaft alone weighs 300 tons.)Length: 89 feet Height: 44 feet Maximum power: 108,920 hp at 102 rpm Maximum torque: 5,608,312 lb/ft at 102rpm
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. For comparison, most automotive and small aircraft engines have BSFC figures in the 0.40-0.60 lbs/hp/hr range and 25-30% thermal efficiency range. Even at its most efficient power setting, the big 14 consumes 1,660 gallons of heavy fuel oil per hour. A cross section of the RTA96C:
The internals of this engine are a bit different than most automotive engines.The top of the connecting rod is not attached directly to the piston. The top of the connecting rod attaches to a crosshead which rides in guide channels. A long piston rod then connects the crosshead to the piston.I assume this is done so the the sideways forces produced by the connecting rod are absorbed by the crosshead and not by the piston. Those sideways forces are what makes the cylinders in an auto engine get oval-shaped over time. Installing the thin-shell bearings. Crank rod journals are 38 in diameter and 16 wide:
The crank sitting in the block (also known as a "gondola-style" bedplate). This is a 10 cylinder version. Note the steps by each crank throw that lead down into the crankcase:
A piston & piston rod assembly. The piston is at the top. The large square plate at the bottom is where the whole assembly attaches to the crosshead:
The "spikes" on the piston rods are hollow tubes that go into the holes you can see on the bottom of the pistons and inject oil into the inside of the piston which keeps the top of the piston from overheating. Some high-performance auto engines have a similar feature where an oil squirter nozzle squirts oil onto the bottom of the piston.
The cylinder deck (10 cylinder version). Cylinder liners are die-cast ductile cast iron. Look at the size of those head studs!:
The first completed 12 cylinder engine:
Thursday, May 03, 2012
27 responses to "Worlds biggest single diesel engine"
"Diesel" Refers to the engine, not the fuel. What we call Diesel fuel is only what's commonly rated for consumer cars with diesel engines, but diesel engines have been built to run on everything from propane to coal dust, making them far more flexible than spark-fired internal combustion engines.
It is a Diesel engine because it runs on the Diesel cycle, i.e.. compression/ignition. These large ship engines are started on #2 marine Diesel but run on heavy fuel oil (HFO) or bunker C. Bunker C is just about the last product extracted from crude oil before it gets to be tar. The bunker oil has to be heated with steam before it is liquid enough to be pumped through fuel separators (centrifuges) and used by the engine.
Anytime the engine is started, before the ship leaves or enters port or when the engine is to be shut down the fuel is switched from bunkers to Diesel. If the engine is shut down while on bunker and allowed to cool for any extended length of time the bunker oil will harden and require major time and man power to clean out the entire fuel system.
I worked for years on VLCC/ULCCs in the Persian Gulf and know a bit about their engines.
Diesel comes from the the original creator of the first compression-ignition engine. Rudolph Diesel. So any compression-ignition engine no matter what fuel is being used will always be referred to as a Diesel engine because he patented the design in the late 1800s.
Diesel engines will run on oil. This is a diesel engine that is designed to run on much less refined oil than your average car. On the other end of the spectrum, jet fuel is super-refined oil that a diesel engine can also run on.