thermal power plant

1. Training Project Presentation On
Electrical Maintenance Department, Panipat Thermal Power Plant

2. Three Major Inputs of PTPS
Water :
Water has been taken from nearby Yamuna Canal. This water is lifted by raw
water pumps and is sent to clarifier to remove turbidity of water. The clear
water is sent to water treatment plant, cooling water system and service water
system. The water is de-mineralized (DM) by water treatment plant.
Fuel Oil :
The fuel oil used is of two types:
a)Low Sulphur high stock oil (LSHS)
b)High speed diesel oil (HSD)
The high speed diesel oil reaches the power station through the lorry tankers.
The oil is stored in large tanks for the future use in the boiler.
COAL :
The coal reaches the plant in the railways wagons. The unloading of coal is
done mechanically by tilting the wagons by tippler. The coal is sent to the coal
storage yard through the conveyor belts. The crushed coal from store is sent to
the mill bunkers through conveyor belts.

3. Types of Fan
Induced Draft Fan:
• Induced draft fan is normally located at the outlet between dust collector and
chimney.
• The fan takes hot flue gases from the boiler through dust collector and delivers it
to the chimney into the open atmosphere. ID fan creates negative pressure or
suction to discharge the gases out after combustion from the furnace.
• Since ID fans can handle hot flue gases, they have more corrosion and erosion
problems even when used with Electrostatic precipitators.
Forced Draft Fan:
• FD fan or forced draft fan, draws air from the atmosphere and forces it into the
furnace through a preheater. These fans are located at the inlet of the boiler to
push high pressure fresh air into combustion chamber, where it mixes with the
fuel to produce positive pressure. The most common centrifugal fans used as FD
fans are backward curved and air foil centrifugal fans.
• In power plants, where coal is used as fuel for combustion, FD fans are used as
secondary air fans to regulate proper combustion and maximize efficiency of the
fuel.

4. • Primary Air Fan
 The main function of the Primary air fan or PA fan is to carry fuel to the furnace for combustion.
 In power plants PA fans supply air for conveying of the pulverized coal from coal mills to the
furnace area. These fans produce a pressure upstream the pulverizer, to push the coal and air
mixture through pulverizer into the furnace.
 The most common centrifugal fan used as PA fan is backward curved centrifugal fan.

5. Boiler
Steam boiler or simply a boiler is basically a closed vessel into which water is
heated until the water is converted into steam at required pressure. The utility
boilers are large capacity steam generators used purely for the electrical power
generation. In boiler heat energy is released from the combustion of fossils fuel and
heat is transferred to different fluids in the system and a part of it is lost or left out
as unutilized.
Main Process
• Send DM water to the boiler through boiler drum to boiler tubes.
• Sending fuel (furnace oil and coal) to the boiler through dampers (3000 MT/day).
• Sending required amount of primary (300T/hr) and secondary air (600T/hr) to the
boiler.
• Supplies superheated steam (5400C) of adequate temperature and pressure to
turbines.
• Extracting flue gases from the boiler and discharging them to atmosphere.
• Removing bottom ash formed as a result of combustion process.
• Removing fly ash from electrostatic precipitator hoppers.

7. Turbine
Turbine is an engine that converts energy of fluid into mechanical
energy. The steam turbine is steam driven rotary engine. Steam Turbine
Converts the Heat Energy (Kinetic Energy) into Mechanical Energy.
Working Principle of Steam Turbine
• A steam turbine works on the principle of conversion of High pressure &
temperature steam into high Kinetic energy, thereby giving torque to a moving
rotor.
• For above energy conversion there is requirement of converging Diverging
Sections.
• Such above requirement is built up in the space between two consecutive
blades of fixed and moving blades rows.

9. Generator
In electricity generation, a generator is a device that converts
mechanical energy to electrical energy for use in an external circuit.
The source of mechanical energy may vary widely from a hand crank to
an internal combustion engine and turbine used in power plants.
Generators provide nearly all of the power for electric power grids.
Principle of Generation
• The basic requirements for generation of AC power are as follows.
• Conductor
• Magnetic Field
• Relative Speed
• Faraday's laws of electromagnetic induction:
First Law: - Whenever there is change in magnetic flux associated with
a coil, an emf is induced in it.
Second law: - The magnitude of induced emf is directly proportional to
the rate of change of flux through the coil.

11. Cooling Tower
A cooling tower is a heat rejection device, which
extracts waste heat to the atmosphere though the
cooling of a water stream to a lower temperature.
The type of heat rejection in a cooling tower is termed
"evaporative" in that it allows a small portion of the
water being cooled to evaporate into a moving air
stream to provide significant cooling to the rest of that
water stream. The heat from the water stream
transferred to the air stream raises the air's temperature
and its relative humidity to 100%, and this air is
discharged to the atmosphere.

12. Circuit Breakers
• It is a mechanical device used to open and close contact under
normal and abnormal conditions.
• Relay is used as a sensor with circuit breaker for automatic operation.
• Circuit breaker carry normal current without over-heating or damage.
Function of circuit breakers are :
• To carry full load current continuously.
• To open and close the circuit under no load.
• To break the circuit under short-circuit condition.
Various Circuit Breakers used in thermal power plant are :
• Oil Circuit Breaker
• Air Circuit Breaker
• Vacuum Circuit Breaker
• SF6 Circuit Breaker

14. Relays
• Relay is electro-mechanical device which sense the excessive flow of
current and send signal to the circuit breaker.
• Relays has three essential elements :
• Sensing Element : It sense and measure the change
• Comparing Element : It compare the measured quantity to threshold value
• Controlling Element: It send signal to circuit breaker.

15. MEASUREMENT OF SHAFT VOLTAGE
The shaft voltage is measured
between the shaft grounding on the
turbine end and a measuring brush
on the exciter end. This shaft
voltage is present during generator
operation and depends on the
generator power output.
Continuous monitoring of shaft
voltage and shaft grounding
current. Regular testing for proper
functioning of the shaft grounding
brushes.