-:A SUMMER TRAINIG EXPERIENCE: IN

-:NATIONAL THERMAL POWER PLANT{DADRI}:-

PRESENTED BY:-

EMAM RAZA

ROLL.NO-1002940032

M.E STUDENT OF KIET(GZB)

UNDER THE GUIDANCE OF:-

MR. R.K SHINHADGM, EE Department of power plant (DADRI)

-:About NTPC:-

• NTPC, the largest power Company in India, was setup in 1975 to accelerate power development in the country.

• Dr.Arup Roy choudhary is chairman & MD since 1/09/2010.• NTPC has installed capacity of 41,684 MW.• NTPC ranked 300th in the ‘2013, Forbes Global 2000’ ranking of the World’s

biggest companies. • NTPC plans to become a 128,000 MW company by 2032.

• It has 16 coal based power stations (23,395 MW)• 7 gas based power stations (3,955 MW)• 4 power stations in Joint Ventures (1,794 MW).• NTPC has been awarded NO-1,best workplace in india among large

organization and the best psu for the year 2010.

-:NTPC, DADRI:-

TOTAL CAPACITY OF DADRI POWER PLANT :-

(A) THERMAL I:- 04X210 MW = 840 MW II:- 02X490 MW = 980 MW TOTAL = 1820 MW

B) GAS = 817 MW

(C) SOLAR = 05MW

GRAND TOTAL = 2642 MW

April 12, 2023

PMI Revision 00 5

Diagram of a typical coal-fired thermal power station

-:Generation of Electricity:-

• Prime mover coupled to Alternator

• Prime mover is driven by energy obtained from various sources such as

• burning of fuel• pressure of water• Force of wind etc.

Fig. Fundamental of generation of Electricity

-:Thermal Power Plant:-• A generating station which converts heat energy of coal combustion

into electrical energy is known as a steam power station.

• Steam is produced in the boiler by utilizing the heat of coal combustion. The steam is then expanded in the steam turbine and is condensed in a condenser to be fed into the boiler again. The steam turbine drives the alternator which converts mechanical energy of the turbine into electrical energy.

-:Basic Power Plant Cycle:-

-:WORKING OF STEAM POWER PLANT:-

• Coal is burnt in a boiler ,which converts water into steam.

• The steam is expanded in a turbine used to drive alternator.

• The steam expanded is condensed in a condenser to be feed into the boiler again.

• The entire arrangement of steam power plant can be divided into.

a. fuel and ash plant.b. air and fuel gas plant.c. feed water and steam plant.d. cooling water plant.

-:Main and Auxiliary Equipments:-1. Coal handling plant2. Stoker3. Pulverizer4.Boiler5.Superheater6.Eonomiser & Air preheater7.Reheater8.Deaerator9.Condenser10.Primary air fan11.Turbine(prime mover)12.Draft fan & chimney13.Electo-static precipitator14.Cooling tower15.Ash handling plant16.Electrical equipmenta. Generatorb. Transformersc. Switch yard

-:Coal handling plant:-

•The function of coal handling plant is automatic feeding of coal to the boiler furnace. • A thermal power plant burns enormous amounts of coal. •A 200MW plant may require around 2000 tons of coal daily

Coal conveyor : This is a belt type of arrangement. With this coal is transported from coal storage place in power plant to the place near by boiler. 

Stoker : The coal which is brought near by boiler has to put in boiler furnace for combustion. This stoker is a mechanical device for feeding coal to a furnace.

Pulverizer : The coal is put in the boiler after pulverization. For this pulverizer is used. A pulverizer is a device for grinding coal for combustion in a furnace in a power plant. A pulverizer is a device for grinding coal for combustion in a furnace in a power plant.

Pulverizing mills are further classified as:

1.Contact mill2.Ball mill3.Impact mill

-:Boiler:-A boiler is closed vessel in which water is converted into steam by utilising the heat of coal combustion. Steam boilers are broadly classified into following two types:base on the relative position of water and gases.(a) Water tube boilers (b) Fire tube boilers

In a water tube boiler, water flows through the tubes and the hot gases of combustion flow over these tubes. Water-tube boilers are used for high-pressure boilers Examples: cochron, Lancashire, locomotive boiler.

In a fire tube boiler, the hot products of combustion pass through the tubes surrounded by water.

• The heated water then rises into the steam drum. Here, saturated steam is drawn off the top of the drum. The steam will reenter the furnace in through a superheater in order to become superheated. Superheated steam is used in driving turbines. Since water droplets can severely damage turbine blades, steam is superheated to 730°F (390°C) or higher in order to ensure that there is no water entrained in the steam.

-:Super heater:-• A device which removes last traces of moisture.• It helps in reduction in requirement of steam quantity.• steam being dry reduces the mechanical resistance of

turbine.• No corrosion at the turbine blades.

-:Economizer and Air Pre-heater:-

• An economizer is a heat transfer device used for heating the feed water with the help of hot flue gases before leaving the chimney.

• It helps in improving the efficiency of the power plant.

• Air preheater is a device which utilizes the waste heat of the flue gases leaving the economizer to heat the air to be supplied to the boiler.

-:Reheater :- Some of the heat of superheated steam is used to rotate the turbine where it loses some of its energy. The steam after reheating is used to rotate the second steam turbine where the heat is converted to mechanical energy. This mechanical energy is used to run the alternator, which is coupled to turbine , there by generating electrical energy.

-:DEAERATOR:- •A steam generating boiler requires that the boiler feed water should be devoid of air and other dissolved gases, particularly corrosive ones.• In order to avoid corrosion of the metal, power station uses a Deaerator, for the removal of air and other dissolved gases from the boiler feed water.•A deaerator has a vertical, domed deaeration section mounted on top of a horizontal cylindrical vessel which serves as a deaerated boiler feed water storage tank.

-:Condenser:-Which condenses the steam at the exhaust of turbine.

•It creates a very low pressure at the exhaust of turbine, this helps in converting heat energy of steam into mechanical energy in the prime mover.

•The condensed steam can be used as feed water to the boiler. •Classification of condenser1.Jet condensers or contact condensers,2. Surface condensers

Primary Air Fan:-

• Air to blow the coal from the mill to the boiler, called the primary air, is supplied by a large fan driven by a variable speed motor

• When mixed with a stream of air the powdered coal behaves more like a gas than a solid

• Primary air does two jobs – heating the coal powder and secondly lifting it into the furnace through pipelines

-:Prime Mover (i.e. Turbine):-A steam turbine is a mechanical device that extracts thermal energy from pressurized steam, and converts it into mechanical energy.

The steam turbine is a form of heat engine that derives much of its improvement in thermodynamic efficiency from the use of multiple stages in the expansion of the steam, which results in a closer approach to the ideal reversible expansion process.

About 86% of all electric generation in the world is by use of steam turbines.

BOILER GENERATOR

STEAM TURBINE

-:Cooling Towers:-

• Remove heat from the water discharged from the condenser so that the water can be discharged to the river or re circulated and reused.

• Air can be circulated in the cooling towers through natural draft and mechanical draft.

• Type of cooling tower1. Wet cooling tower2. Dry cooling tower

Induced Draught (ID) Fan

• Two induced draught fans draw gases out of the boiler

• The gas has already passed through the air heaters and precipitators before it has reached these fans

• The heat from the flue gases or smoke is used in the air heaters to heat up the primary and secondary air

Chimney

• The chimney is 275 meters' high and 50,000 tonnes of reinforced concrete were used to make it

• It consists of flues each of which serve typically two or three boilers (two units)

 It is a device which removes dust or other finely divided particles from flue gases by charging the particles inductively with an electric field, then attracting them to highly charged collector plates. Also known as precipitator. The process depends on two steps. In the first step the suspension passes through an electric discharge (corona discharge) area where ionization of the gas occurs. The ions produced collide with the suspended particles and confer on them an electric charge. The charged particles drift toward an electrode of opposite sign and are deposited on the electrode where their electric charge is neutralized. The phenomenon would be more correctly designated as electrode position from the gas phase

-:Electro-Static Precipitator:-

Top View of ESP Schematic Diagram Side view of ESP Schematic Diagram

-:COAL TRANSPORTATION SYATEM:- Source of coal = Piparwar Mines North Karanpur (Jharkhand) Location = Near Ranchi Means of transportation-Railway

Rout of ply=kalari-gawaroad,seonnogar- mughalsarai,Allahabad,Kanpur,Aligarh,dadri-plant unloading area.

Distance = 1124 Km from kholori to dadri with electrified trak from seonnogar.

Type of coal = F-grade (Washed),E grade(Raw)

C.V(calorific value)=3600-3800 kcal/kg.

Coal requirement = 13,000 MT/Day(04 rakes)

Type of wagon= 1.BOBR(bogy open rapid discharge) = 2.Box-N(min 2 door on each said)

ASH HANDLING PLANT• The percentage of ash in coal is 5% in good quality coal & about 40% in poor

quality coal.• Power plants generally use poor quality of coal , thus amount of ash produced

by it is quite large.• A modern 1000MW plant produces about 4800 tons of ash daily.• The stations use some conveyor arrangement to carry ash to dump sites.

-:Electrical Equipments:-AlternatorAn alternator is coupled to a steam turbine and converts mechanical energy of the turbine into electrical energy.It may be hydrogen or air cooled.The necessary excitation is provided by means of main and pilot exciters directly coupled to the alternator shaft.Transformers(a) main step-transformers, which steps-up generated voltage transmission of power(b) station transformers, general purpose(c) auxiliary transformers, which supply to individual unit-auxiliaries.Control Room and Switchyard : The control room monitors the overall operation of the plant. It is provided with controls for real and reactive power flow. It is provided with safety relays and switchgears.

-:Coal Ash can be used in:-

• Construction of embankments and fills• Construction of road in sub-base• Manufacture of cement• Manufacture of bricks/blocks• Filling as flowable fill material• Agriculture as soil amendment/source of

essential plant nutrients

-:TRIPICAL DIAGRAM OP THERMAL POWER PLANT:-

Efficiency of Thermal Power Station or Plant

The overall efficiency of a thermal power station or plant varies from 20% to 26% and it depends upon plant capacity.