Presentation of vocational training at Hasdeo Thermal Powerplant, Korba West.

1. Thank You HTPS for giving
this wonderful opportunity
to express our view.

2. Chhattisgarh State Power Generation Company Limited

3. • Basically Korba is considered as back bone of power generation individually Korba
generated about 8000 mega watt of energy. Many powerplant are stabilized has one of
Govt. of India enterprise known as national thermal power corporation (NTPC) capacity
2630 mega watt situated in Korba (West) and other of 440 mega watt and 500 mega watt
situated in Korba (East ) & many more. Private sector “sterite” is also running. Another
Hydel Electrical project at Bango of 120 mega watt considering the success of all this project
CSPGCL is planned established two unit of 500 mega watt at Korba (West) as well as Korba
(East) coal needed to all the plant are supplied through south eastern coal field limited
(SECL).
• Since we visited HTPS. We will discus it in detail. HTPS consist of 4X210 MW units & 525
MW unit. First two units are made up of combustion engine boiler and BHEL make turbine
where are as phase two i.e. unit no.3 and 4 made up ABL boiler and BHEL made turbine
boiler or unit no.1 and 2 natural circulation reheat. Only unit no. 4 have cooling tower.
Regenerate type boiler its operation drum pressure is 167 kg/cm2 , 680 T/hr. flow turbine is
of cylinder multistage double flow turbine. Boiler of unit 3 and 4 is superheat regenerated
type natural circulation front fired ABL boiler it’s turbine is some as unit 1 and 2. The main
difference between ABL and BHEL boiler is that BHEL boiler is corner fired while ABL boiler
is front fired boiler.

4. Diagram of a typical coal-fired thermal power station

5. The initial process in coal based thermal power plant is coal
handling. The Function of coal Handling Plant in thermal
power plant is to receive , process, store, feed
the coal bunkers consistently over entire life of the
power plant. Coal is transported in thermal power station
either by railways, roadways or rope ways.
COAL HANDLING PLANT

7. • These are in process storage silos used for
storing crushed coal from the coal handling
system. There are six such bunkers supplying
coal to the corresponding mills. These are
located on the top of the mills so is to aid in
gravity feeding of coal.
• Each mills is provided with a coal feeders to transport raw
coal to the inlet leading to mill at a desired rate.

8. Primary Air Fans are used to lift the pulverized coal from mill to boiler in a power plant.
Further, the air from PA Fan is preheated using air preheaters so that the fluidity of coal
flow can be maintained in coal pipes and also preheat the coal to a certain temperature.
They also provide suction for seal air fans used to seal mill parts.

9. • The crushed coal (coming from primary crusher) is stored in
the cylindrical shape thing known as Bunker which is exactly
on top of the mill to introduce coal into the pulveriser also
known as coal mill.
• The grinding table i.e bowl is rotating as the roller is
maintained at position using spring such as the distance
between bowl and rollers is 1mm. There are three rollers kept
120 degrees apart.
• the coal coming from bunker falls onto the bowl and coal is
crushed in between roller and bowl. The pulverised coal which
is now in particle form is lifted by the air coming from the
bottom of the mill and transfer to the furnace.

10. • FD fan, which is mentioned here for
forced draft fan, is used basically for
providing the required quantity of
hot air to the furnace for smooth and
uniform combustion of fuel. FD fan
will produce the positive pressure
inside the system i.e. furnace

11. • It is used to regulate the flow of steam from the boiler to
the steam pipe or from one steam pipe to the other.
• In a steam-using plant, steam is often generated at high
pressures and reduced locally to provide heat for each
steam user. This is usually done to minimize the diameter
of steam distribution piping and enable more cost-
efficient steam delivery.

12. BOILER
• A boiler is an enclosed vessel that provides a means for combustion and transfers
heat to water until it becomes hot water or steam. The hot water or steam under
pressure is then usable for transferring the heat to a process.
• Pulverized coal-fired boiler are generally used in coal based thermal power plants.
AFBC, CFBC,HRSG and Utility water tube boilers are used in thermal power plants.
The type of boiler depends upon the type of coal you would be using.

13. • A turbine is a mechanical device which converts the kinetic and pressure
energy of steam into useful work. From the superheater steam goes to
the turbine where it expands and loses its kinetic and pressure energy and
rotates the turbine blade which in turn rotates the turbine shaft
connected to its blades. The shaft then rotates the generator which
converts this kinetic energy into electrical energy.
• In addition, as a single welded (or mono-block) rotor is used, the high
pressure (HP), intermediate pressure (IP) and low pressure (LP) sections
can be contained within a single casing. This compact frame turbine (SRT)
can reduce construction costs for the turbine building and foundation. A
smaller number of components also reduce the time required for
inspections and number of spare parts, thus allowing easier maintenance.

14. • The condenser condenses the steam from the exhaust of the turbine into
liquid to allow it to be pumped. If the condenser can be made cooler, the
pressure of the exhaust steam is reduced and efficiency of
the cycle increases. The functions of a condenser are:-
• 1) To provide lowest economic heat rejection temperature for steam.
• 2) To convert exhaust steam to water for reserve thus saving on feed
water requirement.
• 3) To introduce make up water.
• We normally use surface condenser although there is one direct contact
condenser as well. In direct contact type exhaust steam is mixed with
directly with D.M cooling water.

16. Deaerator
• A deaerator is a device that removes oxygen and other
dissolved gases from water, such as feed water for steam-
generating boilers.

17. The water which is coming to the
cooling tower comes from a
‘Condenser’. Now a condenser is a heat
exchanger which cools down steam
coming from a turbine and converts it
into water. This water is different from
the cooling tower water. The water
flowing in and out of a Cooling Tower is
called Cooling water. And the water
which cycles between boiler and turbine
is called DM Water. In HTPS, only 525
MW unit are connected with cooling
tower & rest of units are connected with
natural cooling system.

18. • In Thermal Power Plant’s coal is generally used as fuel and hence the
ash is produced as the byproduct of Combustion. Ash generated in
power plant is about 30-40% of total coal consumption and hence the
system is required to handle Ash for its proper utilization or disposal.
• Ash terminology in power plants?
• Fly Ash ( Around 80% is the value of fly ash generated)
• Bottom ash (Bottom ash is 20% of the ash generated in coal based power stations.
• What is fly ash?
• Ash generated in the ESP which got carried out with the flue gas is generally called Fly ash. It
also consists of Air pre heater ash & Economiser ash (it is about 2 % of the total ash content).
• What is bottom ash?
• Ash generated below furnace of the steam generator is called the bottom ash.