ENGINEERING, PROCUREMENT AND CONSTRUCTION PROJECT OF THERMAL POWER PLANT
To develop, implement innovative construction and on site implementation methods to meet the best industrial standards and to continuously improve on cycle time reduction and modernization of construction methods applicable for the power, process and infrastructure industries.
MAIN PLANT AREAS
a) Bunker bay
b) Turbine generator bay
These are in ‘process storage silos used for storing crushed coal from the coal handling system. Generally, these are made up of welded steel plates.’ Normally, there are six such bunkers supplying coal of the corresponding mills. These are located on top of the mills so as to aid in gravity feeding of coal. Coal feeders
Each mill is provided with a drag link chain/rotary/gravimetric feeder to transport raw coal from the bunker to the inlet chute, leading to mill at a desired rate. Mills
There are six mill (25% capacity each), for every 200 MW unit, located adjacent to the furnace at “0” M lever. These mills pulverize coal to the desired fineness to be fed to the furnace for combustion.
Air pre-heater transfer heat from flue gases to cold primary and/or secondary air by means of rotating heating surface elements. Beneath these regenerative type air pre-heaters, there exists a steam coil air pre-heater. These are located in the secondary pass of the furnace at a height of around ‘16’ M level. Each 200 MW unit is provided with two such air pre-heaters.
P. A. fan
The primary air fans (2 per unit- 50% capacity each) are designed for handling atmospheric air upto a temperature of 50 deg C. these fans are located at *0’ M level near the boiler. F. D. fan
The forced draft fans (2 per unit – 50% capacity each) are designed for handling secondary air for the boiler. These fans are located at ‘0’ M level near the PA fan ID fans
There are two induced Draft fans per boiler located between the Electrostatic precipitator and the chimney. These fans are used for sucking flue gas from furnace. Economizer:
The purpose of economizer is to preheat the boiler feed water before it is introduced into the steam drum by recovering heat from the flue gases leaving the boiler. The economizer is located in the boiler rear gas pass below the rear horizontal superheater. The economizer is continuous unpinned loop type and water flows in upward direction and gas in the downward direction. Super heater
There are three stages of superheater beside the side walls and extended sidewalls. The first stage consists of horizontal superheater of convection mixed flow type with upper and lower banks located above economizer assembly in thermal pass. The upper bank terminates into hanger tubes, which are connected to outlet header of the first stage superheater. The second stage superheater consists of pendant platen which is of radiant parallel flow type. The third stage superheater pendant space is of convection parallel flow type. Boiler drum
The function of steam drum is to separate the water from the steam generated in the furnace walls and to reduce the dissolved solid contents of the steam to below the prescribed limit of 1 ppm. The drum is located on the upper front of boiler. Reheater
The function of reheater is to reheat the steam coming out from high pressure turbine to a temperature of 540 deg C. The reheater is composed of two sections: The front pendant section and rear pendant section. The rear pendant section is located above the furnace arc and the rear water wall and front pendant section is located between the rear water hanger tubes and the superheater platen section. Condensate System
The steam after condensing in the condenser known as condensate is extracted out of the condenser hot well by condensate pump and taken to the deaerator through ejectors, gland steam cooler and series of LP heaters. These pumps have four...
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