Four Stroke ( 4-stroke) Diesel Engine Working System.
Otto cycle or Four stroke diesel cycle same and there are four stroke is Intake, Compression, Power, Exhaust.AS their implies, four-stroke internal combustion engines have four basic steps thar repeat with every two revolutions of the engines.
1. Intake Stroke .
2. Compression Stroke .
3. Power Stroke.
4. Exhaust Stroke .
1. Intake Stroke:The first stroke of the inernal combussion engine is also know as the suction stroke beacuse the piston moves to the maximum volume position (downward derection in the cylinder). The inlet valve poens as a result of piston movement, and the vaporized fuel mixture enters the combustion chamber. The inlet valve closes at the end of this stroke.
2. Compression Stroke: In this stroke, both valves are closed and the piston its movement to the minimum volume position (upward derection in the cylinder) and comprosses the fuel mixture. During the compression processes, pressure, temperature and the density of the fuel mixture increases.
3. Power stroke: When the piston reaches the minimum volume position, the spark plug ignites the fuel mixture and burns. The fuel produces power that is transmitted to the crank shaft mechanism.
4. Exhaust stroke: In the end of the power stroke, the exhaust valve opens. During this stroke, the piston starts its movement in the minimum volume position. The open exhaust valve allows the exhaust gases to escape the cylinder. At the end of this stroke, the exhaust valve closes, the inlet valve opens, and the sequence repeats in the next cycle. Four-stroke engines require two revolutions.
Many engines overlap these steps in time; jet engines do all steps simultaneously at different parts of the engines. Internal combustionengines require ignition of the mixture either by spark ignition or compression ignition .
Marine Engine and heavy high weight automobile use this system and all diesel engine follow this system.