Classification of INTERNAL COMBUSTION ENGINES | MEO CLASS 4

Classification of INTERNAL COMBUSTION ENGINES.
Classification can be done under various categories:
1) 2-stroke or 4-stroke: Usually, 2-stroke is preferred for marine engine propulsion while 4-stroke is preferred for auxiliary diesel generation.
2) Fuel used: Petroleum fuel ( gasoline, naphtha, kerosene, gas oil, diesel oil), heavy fuel ( motor oil, burner fuel), residual fuels, gaseous fuels (natural or producer gas) and mixed fuel (liquid fuel for starting combustion and gaseous fuel for running ).
3) Single or Double Acting: A single acting engine is one where the upper part of the cylinder is used for combustion. A double acting engine is one which uses both the upper and lower part of the cylinder alternatively. e.g. Opposed piston engines.
4) Naturally Aspirated or Supercharged: In naturally aspirated engines, the piston itself sucks in air (e.g. 4-stroke engines) or is fed by a scavenge pump (2-stroke engines). In supercharged engines, air under pressure is supplied to the cylinder which is pressurized externally by mechanical means or an exhaust blower.
5) Compression Ignition (marine diesel engines) or Spark Ignition (carburetor and gas engines): In compression ignition, the fuel ignites with the air due to high temperature caused by compression of air. In spark ignition, an external electric spark is used for ignition.
6) Trunk type engines (4-stroke engines) or Crosshead engines
(2-stroke engines): In trunk type engines, the piston has an extended skirt which acts as a guide. In crosshead engines, there is a crosshead which has shoes sliding over the crosshead guides.
7) Single or Multi cylinder: Modern marine engines use 4 to 12 cylinders.
8) V, W or X pattern of arrangement of the cylinders.
9) Main Propulsion use (Ship’s propeller drive) or Auxiliary engine use (power generation & auxiliaries).
10) Low, Medium, and High Speed Low speed
(100 to 350 rpm)
Medium speed
(350 to 750 rpm)
High speed
(750 to 2500 грт).
11) Mean Piston Speed
Low speed
(4.5 m/s to 7 m/s)
Medium speed
(7 m/s to 10 m/s)
High speed
(10 m/s to 15 m/s).
12) Uni directional (same direction) or Reversible Engines using a reversing mechanism.
13) Ahead direction in clockwise or anti-clockwise direction.