Basic Introduction or Principle: We all are aware with the term "Generator". A device which converts mechanical energy into electrical energy is known as generator. This generator makes rotate with the help of some kind of external energy. When this energy extract from the energy of steam, the plant is known as steam power plant. A simple steam plant works on Rankine cycle. In the first step, water is feed into a boiler at a very high pressure by BFP (boiler feed pump). This high pressurized water is heated into a boiler which converts it into high pressurized super heated steam. This high energized steam passes through steam turbine (a mechanical device which converts flow energy of fluid into mechanical energy) and rotate it. Owing to extract full energy of steam, three stage turbines is used which is known as LPT (Low pressure turbine), IPT (intermediate pressure turbine) and HPT (High pressure turbine). The turbine shaft is connected to the...
1. Top dead center (T.D.C.)
In a reciprocating engine the piston moves to and fro motion in the cylinder. When the piston moves upper direction in the cylinder, a point at which the piston comes to rest or change its direction known as top dead center. It is situated at top end of cylinder.
2. Bottom dead center (B.D.C.)
When the piston moves in downward direction, a point at which the piston come to rest or change its direction known as bottom dead center. It is situated in bottom side of cylinder.
3. Stroke (L)
The maximum distance travel by the piston in single direction is known as stroke. It is the distance between top dead center and bottom dead center.
4. Bore (b)
The inner diameter of cylinder known as bore of cylinder.
5. Maximum or total volume of cylinder (Vtotal)
It is the volume of cylinder when the piston is at bottom dead center. Generally, it is measure in centimeter cube (c.c.).
6. Minimum or clearance volume of cylinder (Vclearance)
It is the volume of cylinder when the piston is at top dead center.
7. Swept or displace volume (Vswept)
It is the volume which swept by the piston. The difference between total volume and clearance volume is known as swept volume.
Swept volume = Total volume - Clearance volume
8. Compression ratio
The ratio of maximum volume to minimum volume of cylinder is known as the compression ratio. It is 8 to 12 for spark ignition engine and 12 to 24 for compression ignition engine.
Compression ratio = Total volume / Clearance volume
9. Ignition delay
It is the time interval between the ignition start (spark plug start in S.I. engine and inject fuel in C.I. engine) and the actual combustion starts.
10. Stroke bore ratio
Stroke bore ratio is the ratio of bore (diameter of cylinder) to length of stroke. It is generally equal to one for small engine and less than one for large engine.
Stroke bore ratio = inner diameter of cylinder / length of stroke
11. Mean effective pressure
The average pressure acting upon the piston is known as mean effective pressure. It is given by the ratio of the work done by the engine to the total volume of engine.
Mean effective pressure = Work done by engine / Total volume of cylinder
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