Why 2-stroke diesel engine is used in ships?

When a ship is being constructed in a shipyard, the most important machinery that is to be selected is the main propulsion machinery. A two-stroke engine can burn low-grade fuel oil and hence reduce the running cost of the ship.

What is 2-stroke engine in ship?

The 2 stroke engines are used for vessel propulsion and are bigger in size as compared to the 4 stroke engines. In this engine, the complete sequence is complete in two cycles i.e.

What is 2-stroke marine diesel engine?

A two-stroke diesel engine is an internal combustion engine that uses compression ignition, with a two-stroke combustion cycle. It was invented by Hugo Güldner in 1899. In compression ignition, air is first compressed and heated; fuel is then injected into the cylinder, causing it to self-ignite.

What is crosshead in marine diesel engine?

A crosshead is a mechanism used as part of the slider-crank linkages of long reciprocating engines and reciprocating compressors to eliminate sideways pressure on the piston.

Where is 2-stroke engine used?

Two-stroke engines are still found in a variety of small propulsion applications, such as outboard motors, small on- and off-road motorcycles, mopeds, scooters, tuk-tuks, snowmobiles, go-karts, ultralight and model airplanes.

Why is 2 stroke diesel engine rarely used?

2 stroke engines are rarely used because in this engine the problem of scavenging occurs. Scavenging is termed as incomplete combustion of fuel and air mixture i.e. some of the fuel doesn’t gets burnt out, it goes into the exhaust without getting in combustion.

Are diesel engines 2 stroke?

Diesel combustion. The diesel engine is an intermittent-combustion piston-cylinder device. It operates on either a two-stroke or four-stroke cycle (see figure); however, unlike the spark-ignition gasoline engine, the diesel engine induces only air into the combustion chamber on its intake stroke.

How does a 2 stroke marine engine work?

A 2-stroke engine goes through two steps to effect combustion, and each involves the piston moving the length of the cylinder, or making a “stroke.” 1. As the piston begins to move up, it compresses the air/fuel mixture in the cylinder and closes off both the intake and exhaust valves.

What is the difference between crosshead and trunk type engine?

CROSSHEAD ENGINES HAVE A DIAPHRAGM THAT SEPARATES THE CYLINDER SPACE FROM THE CRANKCASE WHILE TRUNK TYPE DONOT HAVE. CROSSHEAD ENGINE HAVE DIFFERENT CYLINDER LUBRICATION SYSTEM WITH DIFFERENT LUB OIL THAN CRANKCASE OIL WHILE TRUNK TYPE HAVE SAME LUB OIL AS THAT OF CRANKCASE.

What is 2 stroke IC engine?

A two-stroke (or two-stroke cycle) engine is a type of internal combustion engine that completes a power cycle with two strokes (up and down movements) of the piston during one power cycle, this power cycle being completed in one revolution of the crankshaft.

Is a diesel engine 2 or 4 stroke?

Can a 2 stroke engine run on diesel?

A 2-stroke built to run on gasoline will not run on diesel. But there is a large number of 2-stroke engines built to run on diesel, which manage just fine.

What is the purpose of a cross head in a diesel engine?

A cross head eliminates the side load on a piston and in the case of a steam engine allows the back of the piston to be used for another power stroke (double acting ) In large 2 stroke diesels the area below the piston can be sealed from the crankcase and used for an air supply to the ports without oil problems.

Why are two stroke engines used on ships instead of four strokes?

But since only a two-stroke drive can burn low-grade heavy fuel oil but a four-stroke marine engine can not; we see less 4 strokes in ships than in automobiles. Large & Powerful: Using a two-stroke design allows for large cylinders and thus more power is produced per stroke.

Why is it called 2 stroke diesel engine?

That is, in one cycle there are only two piston steps namely the piston step up and the piston step down. From these two steps, the name 2 stroke diesel was taken. What are the advantages? The two stroke diesel engine only has advantages in the power sector that is larger than the four stroke type.

Why is crankcase oil used in 2 stroke engines?

This can supply the required oxygen for a crankcase explosion should a hot spot develop. The crankcase oil must have additives which can cope with contamination from products of combustion, and the acids formed during combustion due to the sulphur in the fuel. The majority of 2 stroke engines encountered at sea are of ” cross head ” type.