Power Plant Gyan

Coal pulverizer system is classified in two types  Direct fired system. Stored fired system. DIRECT FIRE SYSTEM:-  In it coal leaving from each mill goes directly to the combustion process. Air dry the fuel and evaporated the moisture also increase the fuel temperature. This hot fuel air mixture goes for combustion in to the furnace. STORAGE FIRE SYSTEM:- In this system coal is separated from air or gas.  In this system moisture is separated and not participate in combustion process. Stored ground coal is injected in to the furnace with new air. Requirement of direct firing system:- Raw coal feeder- this regulate the coal quantity in to the mill. Heat source:- this dry the coal and preheat the air and fuel. Primary air fan:- this supply the air to the mill. Piping:- direct the coal and primary air to and from the mill. Burner:- this mix the coal and primary air from the pulverizer to the burners.

Boilers are specified by four parameter as listed:- Steam flow rate or evaporation Steam outlet pressure Steam outlet temperature Feed water inlet temperature Steam Flow or Evaporation or Boiler Output:- This is the amount of steam generated from the FW supplied at a certain temperature. It is the capacity or the rating of the boiler expressed in ton per hours. Boiler ratings are better designated by the heat duty than evaporation. Super heater outlet pressure:- It is the pressure at which steam is available for further consumption. Usually it is approximate 5% higher than process or turbine inlet pressure to account for the piping loss. In fixed-pressure boilers, this pressure is held constant as the turbine inlet valves vary the steam pressure to the inlet nozzles. SH Outlet Temperature:- Super heater outlet temperature is the temperature at which the steam leaves the super heaters. It is the highest temperature gain by the steam in a boiler. RH steam is s

Circulation is the flow of water, steam or both through the tube circuits of a boiler (from boiler drum,boiler down comer, riser water walls ). Adequate circulation is necessary for all the circuits to remove the heat  from the boiler furnace and cool the heating surfaces by carry the heat. Due to carry the heat from the the metal surfaces the temperature of metals remain cools within a specific limit. Sufficient circulation in provided in steam water circuit to avoid any salts deposits on the inner metallic  surface of boiler. In a circuit if the fluid enters at the inlet and leaves the outlet to the next circuit it is a once through system.   If part of the fluid from the outlet of the circuit is returned to the inlet of the same circuit it is a re circulation system.    In a boiler the following circuits always adopt once through system. Economiser Super heaters Re heaters In these circuits the inlet pressure of the fluid effects the circulation.  The water walls or evaporator circu

Introduction :- The Furnace Safeguard Supervisory System (FSSS) is designed for  To assure the execution of a safe, orderly operating sequence in the start up & shut down of fuel firing equipment. To prevent errors of omission and commission in following such a safe operating procedure. The system provides protection, should there be a malfunction of fuel firing equipment and associated air systems. The safety features of the system are designed for protection in most common emergency situations. Basic Functions of FSSS:- Prevent any fuel firing unless a satisfactory furnace purge sequence has first been completed.  Prevent start-up of individual fuel firing equipment unless certain permissive interlocks have first been satisfied.  Monitor and control the proper component sequence (manual or automatic) during start-up and shutdown of fuel firing equipment. Make continued operation of fuel firing equipment subject to certain safety interlocks remaining satisfied.  Provide components

The notification from MoEF & CC dated 7th December-2015 amends existing norms related to emission of SPM and introduces new norms for emission of SO2, NOx and Mercury from Thermal Power Plants (TPPs). I t also specifies modified limits for specific water consumption by TPPs. To convert existing once through based condenser cooling system to recirculation type. Different limits are specified based on capacity of power plant and year of installation.   NEW REGULATIONS ON EMISSION A summary of new regulations on air emission is given in below: Date of Installation PM SO2 Nox Mercury (Hg) Before 31-12 -2003 100 mg/Nm3 600 mg/Nm3 for <500MW 600 mg/Nm3 0.03 mg/Nm3 for >=500MW 200 mg/Nm3 for >=500MW After 01-01-2003 & Upto 31-12-2016 50 mg/Nm3 600 mg/Nm3 for <500 MW 300 mg/Nm3 0.03 mg/Nm3 for >=5

Generator cooling system INTRODUCTION In a big turbo-generators where a huge mass of metal is used. As  as current flows through conductors  large heat is generated in the winding of stator and rotor of generator. When turbo generator is started then heat generation in metallic parts are starting if this heat is not removed from the generator then this is chance to failed the generator winding.    As i n generator large amount of heat is generated and is not possible to dissipate this heat from natural system. So forced cooling system is adopted. in force cooling system air or hydrogen gases are used.      In smaller turbo-generators, the cooling is by air circulation.  In bigger turbo generator hydrogen cooling system came in the field.      So e fficient cooling & ventilation system is required for generator to keep temperature of winding bellow certain limits. For the cooling of generator following system is adopted Air cooling system - In this air is forced into the generator

CIRCULATING WATER SYSTEM ·       The circulating water system supply cold water to the condenser. ·       The cold water absorbs the latent heat of condensation from exhaust steam in the form of sensible heat . ·       Steam exhaust from low pressure steam turbine condenses in a condenser & condensed water reused in the cycle again. ·       In a surface condenser, the steam flows over a tube bundle & condensed and cooling water flowing inside the tubes. ·       Heat is transferred from steam to water with the help of tubes. Tubes are works as a barrier between cooling water and stem to be condensed. ·       Further the temperature of cooling water increases and become warm. ·       It is a continuous process in which heat is continues removed from the condenser. ·       This warm water reject their heat to the atmosphere through cooling towers or spray ponds or warm water dumped in to the natural water reservoir ·       In all thermal power plants surface co