INTRODUCTION TO THERMAL POWER PLANT: 

थर्मल पावर प्लांट (तापीय विद्युत संयंत्र ) उन  संयंत्रो को कहा जाता है जिसमें कोयले को ईंधन के रूप में प्रयोग किया जाता है। कोयले को वाष्पित्र की भट्टी (फर्नेस) में जलाकर इसके द्वारा उत्सर्जित ऊष्मा से पानी को गर्म कर भाप बनायीं जाती है एवं इस भाप द्वारा टरबाइन घूमाया जाता है। इस विधि में पानी को लगातार  एक क्लोज्ड साइकिल में घुमाया जाता है।  यह प्लांट मॉडिफाइड रैंकिन साइकिल पर आधारित होता है। 

Simple power plant steam water cycle 

Rankine Reheat and Regenerative Cycle [2]

On large turbines, it becomes economical to increase the cycle efficiency by using reheat, by returning partially expanded steam, to a reheater, the average temperature at which heat is added, is increased and, by expanding this reheated steam to the remaining stages of the turbine, the exhaust wetness is considerably less than it would otherwise be conversely.

Regenerative heating of the boiler feed water is widely used in modern Power plants; the effect being to increase the average temperature at which heat is added to the cycle, thus improving the cycle efficiency. steam extracted at various stages of turbine and added to feed water according to their pressure stage. [1]


Various circuits used in thermal power plant

Fuel (Coal) Circuit :

Coal Handling Plant -> Conveyor -> Coal Bunker - > Coal feeder -> Pulverizer (Coal Mill) -> Coal pipe -> Furnace (Boiler)

Water Circuit :

Water Treatment Plant - > Condensate storage tank -> Condensser -> Gland cooler -> L.P.Heater  -> Dearretor -> Boiler feed pump (BFP) -> H.P. Heater -> Economiser (Boiler)

Steam Circuit :

Boiler -> H.P.Turbine -> Re-heater (Boiler) -> I.P.Turbine -> L.P.Turbine -> Condenser 

Air circuit:

Primary air (PA) fan ->Air pre heater -> Coal mill -> Boiler

Force drought (FD) fan -> Air Pre Heater -> Wind Box -> Boiler

Flue Gas Circuit :

Furnace -> Platen SH -> Reheate -> Final SH -> LTSH -> Economizer -> APH -> ESP -> ID Fan -> Chimney

For more details about thermal power plant boiler click on link below
 http://blog.mechanicsoflife.in/2016/03/thermal-power-plant23.html

References :
[1] Power plant familiarization (Vol.-1), N.P.T.I. Document
[2] Thermodynamics by P.K.Nag