CESC Limited : Generation : Process Of Generation

CESC : PROCESS OF GENERATION

CHRONOLOGY OF CESC GENERATION ...

	1897-1907- Four small Powerhouses were set up and three-wire 450/225 DC distribution system laid. Area of operation 14.44 Sq. Km.
	1926-1938--Southern Generating Station commissioned in 1926.
	1938-1950--Mulajore Generating Station commissioned in 1940. Southern Generating station capacity augmented to 110 MW.
	1950-1956--New Cossipore Generating Station commissioned. Mulajore Generating Staion capacity augmented to 150 MW.
	1963-- New Cossipore Generating Station capacity augmented to 160 MW.
	1983-1985--Titagarh Generating Station was commissioned.
	1987-1991--Existing plant of Southern Generating Station closed down and new 2 X 67.5 MW replacement units commissioned.
	1997-1999--Budge Budge Generating Station commissioned.

TURBINE FLOOR OF BBGS DURING ERECTION

Electricity is generated here in Thermal Power Plants. Thermal energy is derived from Boilers by burning Coal and the steam produced in Boilers is led to rotate Steam Turbines, which in turn act as the prime movers of Alternators for generating Electrical Power.
In a Boiler or Steam Generator, water is heated until it turns to Steam at temperature above 350 degree Centigrade, depending on the pressure of the Boiler. Then it is further superheated to temperature above 500 degree Centigrade. When water is boiled into steam, its volume increases about 1600 times, producing heat energy – the force used to turn the turbine rotor that generates electricity.

In all Steam Generating Stations, the water used to create steam must be highly purified. This is important because the steam is forced against the row of blades that rotate the shaft. The steam constantly hits these metal parts, so even the tiniest impurities will erode the metal blades.

The water is softened, filtered and demineralised until it is as pure as distilled water. Each Generating Station has a chemical Lab. Where water purifying process is regularly monitored.

As the Steam releases heat energy to turn the turbine, its temperature drops. To reuse water used in Generating Power, the Steam is condensed back into water. To condense the steam, it is discharged into a vacuum and passed over cooling water in tubes.

In Mulajore and New Cossipore Generating Stations, Stoker fired Boilers are in operation where Coal is fed to Boiler in small sized lumps. This sort of firing requires Coal of higher GCV which costs more. With the advent of new technology as first introduced in Titagarh Generating Station, Coal in Pulverised form was used for firing in Boilers. The success of pulverised-coal burning stems from the greater surface exposed by breaking a given mass of coal in smaller pieces. Greater surface per unit mass of coal allows faster combustion reactions because more carbon becomes exposed to heat and oxygen. Poor quality of Coal can be used in this form of firing which is less costly. This system of firing is also used in Budge Budge and Southern Generating Station.
Steam Turbines of varying capacities are used in all five Stations. In Steam Turbines of PF stations, advanced technology with automated controls are used for better efficiency.
Alternators of all five Staions run on same principle except for certain differences in output voltage, system of cooling and constructional features.

CESC GENERATING STATIONS : CHANGE IN TEMPERATURE AND PRESSURE OVER THE YEARS

PrTempChange.gif (9397 bytes)

*CESC Limited : Generation Division*	*Generating Power Since 1899 ...*