Btps Final

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PRESENTATION REPORT ON

Industrial Training at

NTPC Badarpur Thermal Power Station

( ISO 9001/ ISO 14001 Power Station )

Submitted By:

AKASH MISHRA (ME/11/705)

Department of Mechanical EngineeringSHRI BALWANT INSTITUTE OF TECHNOLOGY

Approved by AICTE, Min of HRD, Govt of India & DTE, Govt of Haryana

Affiliated to DCR University of Science and Technology,

Murthal,Sonepat-131001, Haryana


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Abstract

Training at BTPS : I was appointed to do a 4 week training at the Badarpur Thermal PowerStation under the National Thermal Power Corporation from 3 rd June 2013 to 29th June2013 . I was assigned to visit various divisions of the plant, which were :

BMD:

1. Boiler Maintenance Department-I (BMD-I)2. Boiler Maintenance Department-II (BMD-II)3. Boiler Maintenance Department-III (BMD-III) .

PAM:

1. Control Structure Pump House.2. Water treatment Plant.3. Cooling Towers.4. Ash Slurry Pump House.5. Air Compressor House.

TMD:

1. Turbine Maintenance Department.

This report has been made by my experience at BTPS. The material in this report hasbeen gathered from my textbook, senior student reports and trainers manuals and powerjournals provided by training department. The specification and principles are aslearned by me from the employees of each division of BTPS.

ii


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TABLE OF CONTENTS

1. INTRODUCTION:i. About Ntpc .

ii. Badarpur Thermal Power Station .

iii. Powerplant .

2. DESCRIPTION:i. Rankine Cycle

ii. A COAL powered station .iii .Coal to power .

iv. BMD .v. PAM.

vi. TMD.3. INFERENCES

4. REFERENCES


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INTRODUCTION :-

About NTPC : NTPC Limited (formerly National Thermal Power

Corporation) is the plant largest Indian state-owned electric utilities company

based in New Delhi, India. It is listed in Forbes Global 2000 for 2012 ranked at 337thin the world. With an electric power generating capacity of 41,184 MW, NTPC has

embarked on plans to become a 128,000 MW company by 2032. It was founded on 7November 1975. On 21 May 2010, NTPC was conferred Maharatna status by the

Union Government of India. The total installed capacity of the company is 36,514 MW(including JVs) with 16 coal-based and seven gas-based stations, located across the

country. In addition under JVs (joint ventures), six stations are coal-based, and anotherstation uses naphtha/LNG as fuel. By 2017, the power generation portfolio is expected

to have a diversified fuel mix with coal-based capacity of around 27,535 MW, 3,955MW through gas, 1,328 MW through hydro generation, about 1,400 MW from nuclear

sources and around 1,000 MW from Renewable Energy Sources (RES). NTPC has

adopted a multi-pronged growth strategy which includes capacity addition throughgreen field projects, expansion of existing stations, joint ventures, subsidiaries and

takeover of stations.

NTPC has been operating its plants at high efficiency levels. Although the companyhas 19% of the total national capacity it contributes 29% of total power generation due

to its focus on high efficiency. NTPCs share at 31 Mar 2001 of the total installed

capacity of the country was 24.51% and it generated 29.68% of the power of thecountry in 200809. Every fourth home in India is lit by NTPC. As at 31 Mar 2011

NTPC's share of the country's total installed capacity is 17.18% and it generated 27.4%of the power generation of the country in 201011. NTPC is lighting every third bulb

in India. 170.88BU of electricity was produced by its stations in the financial year20052006. The Net Profit after Tax on 31 March 2006 was 58.202 billion. Net profit

after tax for the quarter ended 30 June 2006 was 15.528 billion, which is 18.65%

more than that for the same quarter in the previous financial year. Pursuant to a specialresolution passed by the Shareholders at the Companys Annual General Meeting on23 September 2005 and the approval of the Central Government under section 21 of

the Companies Act, 1956, the name of the Company "National Thermal PowerCorporation Limited" has been changed to "NTPC Limited" with effect from 28

October 2005. The primary reason for this is the company's foray into hydro andnuclear based power generation along with backward integration by coal mining.

Badarpur Thermal Power Station is located at Badarpurarea in NCT Delhi. The

power is one of the coal based power plants ofNTPC. TheNational Power Training

Institute (NPTI) forNorth IndiaRegion underMinistry of Power, Government of India

was established at Badarpur in 1974, within the Badarpur Thermal power plant (BTPS)
https://en.wikipedia.org/wiki/Indiahttps://en.wikipedia.org/wiki/Electric_utilitieshttps://en.wikipedia.org/wiki/Forbes_Global_2000https://en.wikipedia.org/wiki/Maharatnahttps://en.wikipedia.org/wiki/Coalhttps://en.wikipedia.org/wiki/Natural_gashttps://en.wikipedia.org/wiki/Naphthahttps://en.wikipedia.org/wiki/Liquified_natural_gashttps://en.wikipedia.org/wiki/Hydroelectric_powerhttps://en.wikipedia.org/wiki/Nuclear_powerhttps://en.wikipedia.org/wiki/Renewable_energyhttps://en.wikipedia.org/wiki/Renewable_energyhttp://en.wikipedia.org/wiki/Badarpur,_Delhihttp://en.wikipedia.org/wiki/National_Capital_Territory_of_Delhihttp://en.wikipedia.org/wiki/Coalhttp://en.wikipedia.org/wiki/National_Thermal_Power_Corporationhttp://en.wikipedia.org/wiki/National_Power_Training_Institutehttp://en.wikipedia.org/wiki/National_Power_Training_Institutehttp://en.wikipedia.org/wiki/North_Indiahttp://en.wikipedia.org/wiki/North_Indiahttp://en.wikipedia.org/wiki/Ministry_of_Power_(India)http://en.wikipedia.org/wiki/Government_of_Indiahttps://en.wikipedia.org/wiki/Indiahttps://en.wikipedia.org/wiki/Electric_utilitieshttps://en.wikipedia.org/wiki/Forbes_Global_2000https://en.wikipedia.org/wiki/Maharatnahttps://en.wikipedia.org/wiki/Coalhttps://en.wikipedia.org/wiki/Natural_gashttps://en.wikipedia.org/wiki/Naphthahttps://en.wikipedia.org/wiki/Liquified_natural_gashttps://en.wikipedia.org/wiki/Hydroelectric_powerhttps://en.wikipedia.org/wiki/Nuclear_powerhttps://en.wikipedia.org/wiki/Renewable_energyhttp://en.wikipedia.org/wiki/Badarpur,_Delhihttp://en.wikipedia.org/wiki/National_Capital_Territory_of_Delhihttp://en.wikipedia.org/wiki/Coalhttp://en.wikipedia.org/wiki/National_Thermal_Power_Corporationhttp://en.wikipedia.org/wiki/National_Power_Training_Institutehttp://en.wikipedia.org/wiki/National_Power_Training_Institutehttp://en.wikipedia.org/wiki/North_Indiahttp://en.wikipedia.org/wiki/Ministry_of_Power_(India)http://en.wikipedia.org/wiki/Government_of_India


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complex.

Power Plant : - The Badarpur Thermal Power Station has an installed capacity of 705MW. It is situated in south east corner of Delhi on Mathura Road near Faridabad. It

was the first central sector power plant conceived in India, in 1965. It was originallyconceived to provide power to neighbouring states of Haryana, Punjab, Jammu and

Kashmir, U.P., Rajasthan, and Delhi. But since year 1987 Delhi has become its solebeneficiary. It was owned and conceived by Central Electric Authority. Its construction

was started in year 1968, and the First unit was commissioned in 26 July 1973. The

coal for the plant is derived from the Jharia Coal Fields. This was constructed underownership ofCentral Electric Authority, later it was transferred to NTPC. It receives

its water from the Agra Canal .

Efficiency :- The energy efficiency of a conventional thermal power station,considered usable energy produced as a percent of the heating value of the fuel

consumed, is typically 33% to 48%. As with all heat engines, their efficiency islimited, and governed by the laws of thermodynamics. By comparison, most

hydropower stations in the United States are about 90 percent efficient in convertingthe energy of falling water into electricity. The energy of a thermal not utilized in

power production must leave the plant in the form of heat to the environment. This

waste heat can go through a condenser and be disposed of with cooling wateror incooling towers. If the waste heat is instead utilized for district heating, it is calledco-generation. An important class of thermal power station are associated with

desalination facilities; these are typically found in desert countries with large suppliesof natural gas and in these plants, freshwater production and electricity are equally

important co-products .

Electricity Costs : The direct cost of electric energy produced by a thermal power

station is the result of cost of fuel, capital cost for the plant, operator labour,maintenance, and such factors as ash handling and disposal. Indirect, social or

environmental costs such as the economic value of environmental impacts, or

environmental and health effects of the complete fuel cycle and plantdecommissioning, are not usually assigned to generation costs for thermal stations inutility practice, but may form part of an environmental impact assessment.

THERMAL POWER STATION :-

Basic operation or cycle of operation of a thermal power station : -

In fossil-fueled power plants, steam generatorrefers to a furnace that burns the fossilfuel to boil water to generate steam. In the nuclear plant field, steam generatorrefers to

a specific type of large heat exchangerused in a pressurized water reactor (PWR) tothermally connect the primary (reactor plant) and secondary (steam plant) systems,

which generates steam. In a nuclear reactor called a boiling water reactor (BWR),
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water is boiled to generate steam directly in the reactor itself and there are no units

called steam generators. In some industrial settings, there can also be steam-producing

heat exchangers called heat recovery steam generators (HRSG) which utilize heat fromsome industrial process. The steam generating boiler has to produce steam at the high

purity, pressure and temperature required for the steam turbine that drives the electricalgenerator.

Geothermal plants need no boiler since they use naturally occurring steam sources.Heat exchangers may be used where the geothermal steam is very corrosive or contains

excessive suspended solids.

Rankine Cycle:-

Rankine cycle is the idealized cycle for steam power plants. This cycle is shown on p-v,

T-v, h-s, diagram in the above figures. It consists of following processes:of TechnologyProcess 1-4: Water from the condenser at low pressure is pumped into the boiler athigh pressure. This process is reversible adiabatic.Process 4-5: Water is converted into steam at constant pressure by the addition of heatin the boiler.Process 6-3: Bleed water taken for regeneration .

Process 5-7: Reversible adiabatic expansion of steam in the steam turbine.
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Process 7-1: Constant pressure heat rejection in the condenser to convert condensate

into water.

The steam leaving the boiler may be dry and saturated, wet or superheated.

A Coal powered station :-

Typical diagram of a coal-fired thermal power station1.Cooling tower 10. SteamControl valve 19.Superheater

2. Cooling water pump 11. High pressuresteam turbine 20. Forced draught (draft) fan

3.transmission line(3-phase) 12. Deaerator 21. Reheater

4. Step-up transformer(3-phase) 13. Feedwater heater 22.Combustionair intake

5.Electrical generator(3-phase) 14. Coalconveyor 23.Economiser

6. Low pressuresteam turbine 15. Coal hopper 24.Air preheater

7.Condensate pump 16. Coal pulverizer 25.Precipitator

8.Surface condenser 17. Boiler steam drum 26. Induced draught (draft) fan
http://en.wikipedia.org/wiki/Cooling_towerhttp://en.wikipedia.org/wiki/Cooling_towerhttp://en.wikipedia.org/wiki/Control_valvehttp://en.wikipedia.org/wiki/Control_valvehttp://en.wikipedia.org/wiki/Superheaterhttp://en.wikipedia.org/wiki/Superheaterhttp://en.wikipedia.org/wiki/Steam_turbinehttp://en.wikipedia.org/wiki/Steam_turbinehttp://en.wikipedia.org/wiki/Centrifugal_fanhttp://en.wikipedia.org/wiki/Electrical_power_transmissionhttp://en.wikipedia.org/wiki/Electrical_power_transmissionhttp://en.wikipedia.org/wiki/Electrical_power_transmissionhttp://en.wikipedia.org/wiki/Three-phasehttp://en.wikipedia.org/wiki/Deaeratorhttp://en.wikipedia.org/wiki/Transformerhttp://en.wikipedia.org/wiki/Three-phasehttp://en.wikipedia.org/wiki/Three-phasehttp://en.wikipedia.org/wiki/Feedwater_heaterhttp://en.wikipedia.org/wiki/Combustionhttp://en.wikipedia.org/wiki/Combustionhttp://en.wikipedia.org/wiki/Combustionhttp://en.wikipedia.org/wiki/Electrical_generatorhttp://en.wikipedia.org/wiki/Electrical_generatorhttp://en.wikipedia.org/wiki/Three-phasehttp://en.wikipedia.org/wiki/Coalhttp://en.wikipedia.org/wiki/Conveyorhttp://en.wikipedia.org/wiki/Conveyorhttp://en.wikipedia.org/wiki/Economiserhttp://en.wikipedia.org/wiki/Economiserhttp://en.wikipedia.org/wiki/Steam_turbinehttp://en.wikipedia.org/wiki/Steam_turbinehttp://en.wikipedia.org/wiki/Coalhttp://en.wikipedia.org/wiki/Air_preheaterhttp://en.wikipedia.org/wiki/Air_preheaterhttp://en.wikipedia.org/wiki/Condensate_pumphttp://en.wikipedia.org/wiki/Condensate_pumphttp://en.wikipedia.org/wiki/Pulverizerhttp://en.wikipedia.org/wiki/Electrostatic_precipitatorhttp://en.wikipedia.org/wiki/Electrostatic_precipitatorhttp://en.wikipedia.org/wiki/Surface_condenserhttp://en.wikipedia.org/wiki/Surface_condenserhttp://en.wikipedia.org/wiki/Steam_drumhttp://en.wikipedia.org/wiki/Centrifugal_fanhttp://en.wikipedia.org/wiki/Cooling_towerhttp://en.wikipedia.org/wiki/Control_valvehttp://en.wikipedia.org/wiki/Superheaterhttp://en.wikipedia.org/wiki/Steam_turbinehttp://en.wikipedia.org/wiki/Centrifugal_fanhttp://en.wikipedia.org/wiki/Electrical_power_transmissionhttp://en.wikipedia.org/wiki/Three-phasehttp://en.wikipedia.org/wiki/Deaeratorhttp://en.wikipedia.org/wiki/Transformerhttp://en.wikipedia.org/wiki/Three-phasehttp://en.wikipedia.org/wiki/Feedwater_heaterhttp://en.wikipedia.org/wiki/Combustionhttp://en.wikipedia.org/wiki/Electrical_generatorhttp://en.wikipedia.org/wiki/Three-phasehttp://en.wikipedia.org/wiki/Coalhttp://en.wikipedia.org/wiki/Conveyorhttp://en.wikipedia.org/wiki/Economiserhttp://en.wikipedia.org/wiki/Steam_turbinehttp://en.wikipedia.org/wiki/Coalhttp://en.wikipedia.org/wiki/Air_preheaterhttp://en.wikipedia.org/wiki/Condensate_pumphttp://en.wikipedia.org/wiki/Pulverizerhttp://en.wikipedia.org/wiki/Electrostatic_precipitatorhttp://en.wikipedia.org/wiki/Surface_condenserhttp://en.wikipedia.org/wiki/Steam_drumhttp://en.wikipedia.org/wiki/Centrifugal_fan


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9. Intermediate pressuresteam

turbine18. Bottom ash hopper 27.Flue gas stack
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DESCRIPTION :-

COAL TO STEAM

Coal from the coal wagons is unloaded in the coal handling plant. This coal is transported upto the raw coal bunkers with the help of belt conveyors. .

Coal - How much Coal required for a 100 MW plant per year =

Power Plant Wattage x Coal unit/ Hr x Hr/ Yr = :

100 x (Per unit Heat Required/ Coal Heat Value) x (24 x 365) = 100 x (10.765/ 20) x 8760 kg/ Yr =

471.51 x 1000 kg/ Yr = 471.51 mT/ Yr

Coal is transported from the mine to loading place .Wagon Tripler Transported through conveyors

into bunkers . From bunkers the coal is sent into mills i.e bowl mills where the coal gets pulverized or

powdered .The powdered coal is then put into furnace and burnt .The heat generated is used to heat

water, steam, air etc .

BOILER COAL BUNKER :

Boiler Coal Coal bunker supplies coal to pulverizing fuel mills. Each bunker can hold 1,000 tonnes of

coal, and there may be six to eight bunkers per unit .Power station coal is not as lumpy as coal used in

the home. Typically around half of it is less than 12.5 millimeters across and 95% is less than 50

millimeters . That is the powdered coal passes through a sieve with so many holes in square inch area.

It is better than the face powder in terms of size

COAL FEEDERS :

The variable speed coal feeder feeds coal from the bunkers to the mill . It uses a conveyor to movecoal through a fixed gap at a precisely controlled speed. Varying the speed controls the amount of

coal supplied to the boilers. These are precision bits of equipment that have to move exact amounts of

coal .They can move 40 tonnes of coal in an hour .

THE MILL :

The mill consists of a round metallic table on which coal particles fall. This table is rotated with the

help of a motor. There are three large steel rollers, which are spaced 120 apart. When there is no

coal, these rollers do not rotate but when the coal is fed to the table it packs up between the roller and

the table and this forces the roller to rotate. Coal is crushed by the crushing action between the rollers

and the rotating table .This crashed coal is taken away to the furnace through coa pipes with the help of hot and cold air

mixture from the prmary air fans .

PRIMARY AIR FAN:

The P.A. fan takes atmospheric air, a part of which is sent to the air preheaters for heating while a

part goes directly to the mill for temperature control. Fan makes 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 .

Wh i d ith t f i th d d l b h lik th lid P i


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catches fire .This is followed by heavy furnace oil (HFO), once a stable flame is established the

coal/air mix is blown through the burner where it lights spontaneously The oil are then shut off.

Burner position, coal flow and air flow are controlled to achieve desired output of temperature,

pressure and flow.

BOILER :

To produce steam each boiler converts energy, in the form of coal, into steam The boiler is lined with

steel tubing in which pure boiler feed water is turned to steam by the heat created from the burning of

coal .Each boiler is as high as 60 mts and weighs about 40,00,000 kg (4000 T)Inside the boiler there is

enough steel tubing to stretch the 500 kilometres and they are joined together by about 20,000 joints

Pressure inside the tubes could be about hundred times that of cars wheel pressure .

Water from the boiler feed pump passes through economiser and reaches the boiler drum.

ECONOMISER :-

Flue gases leaving the superheater and reheater still contain useful energy . Water from the high

pressure feed heaters is heated in the economizer from 250C to 290C before it continues to the

steam drum Having given up its last heat in the boiler, the flue gases move on to the air heater31.

Drum After leaving the economizer, the feed water reaches the drum, which is a cylindrical vessel at

the top of the boiler From here the water flows by natural circulation through downpipes into the

boiler Saturated steam collects here ready to go to the superheater does the important function of

-separating steam from a mixture of steam and water .

CONTROL VALVES :-

Control valves are valves used within industrial plants and elsewhere to control operating conditions

such as temperature,pressure,flow,and liquid Level by fully partially opening or closing in response to

signals received from controllers that compares a set point to a process variable whose value is

provided by sensors that monitor changes in such conditions. The opening or closing of control valves

is done by means of electrical, hydraulic or pneumatic systems

DAERATOR :-

Dearator is a device for air removal and used to remove dissolved gases (an alternate would be the

use of water treatment chemicals) from boiler feed water to make it non-corrosive. A deaeratortypically includes a vertical domed deaeration section as the deaeration boiler feed water tank.

A Steam generating boiler requires that the circulating steam, condensate, and feed water should be

devoid of dissolved gases, particularly corrosive ones and dissolved or suspended solids. The gases

will give rise to corrosion of the metal. The solids will deposit on the heating surfaces giving rise to

localized heating and tube ruptures due to overheating. Under some conditions it may give to stress

corrosion cracking. Deaerator level and pressure must be controlled by adjusting control valves- the

level by regulating condensate flow and the pressure by regulating steam flow. If operated properly,

most deaerator vendors will guarantee that oxygen in the deaerated water will not exceed 7 ppb by

weight (0.005 cm3/L) .


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A Feed water heater is a power plant component used to pre-heat water delivered to a steam generating

boiler. Preheating the feed water reduces the irreversible involved in steam generation and therefore

improves the thermodynamic efficiency of the system. This reduces plant operating costs and also helps to

avoid thermal shock to the boiler metal when the feed water is introduces back into the steam cycle. In a

steam power (usually modeled as a modified Ranking cycle), feed water heaters allow the feed water to be

brought up to the saturation temperature very gradually. This minimizes the inevitable irreversibilitys

associated with heat transfer to the working fluid (water). A belt conveyor consists of two pulleys, with a

continuous loop of material- the conveyor Belt that rotates about them. The pulleys are powered, moving

the belt and the material on the belt forward. Conveyor belts are extensively used to transport industrial

and agricultural material, such as grain, coal, ores etc.

PULVERISER:

A pulveriser is a device for grinding coal for combustion in a furnace in a fossil fuel power plant.

BOILER STEAM DRUM:

Drums are a regular feature of water tube boilers. It is reservoir of water/steam at the top end of the water

tubes in the water-tube boiler. They store the steam generated in the water tubes and act as a phase

separator for the steam/water mixture. The difference in densities between hot and cold water helps in the

accumulation of the hotter-water/and saturated steam into steam drum. Made from high-grade steel

(probably stainless) and its working involves temperatures 390 C and pressure well above 350psi

(2.4MPa). The separated steam is drawn out from the top section of the drum. Saturated steam is drawn

off the top of the drum. The steam will re-enter the furnace in through a super heater, while the saturated

water at the bottom of steam drum flows down to the mud-drum /feed water drum by down comer tubes

accessories include a safety valve, water level indicator and fuse plug. A steam drum is used in the

company of a mud-drum/feed water drum which is located at a lower level. So that it acts as a sump forthe sludge or sediments which have a tendency to the bottom.

SUPER HEATER:

A Super heater is a device in a steam engine that heats the steam generated by the boiler again increasing

its thermal energy and decreasing the likelihood that it will condense inside the engine.

Super heaters increase the efficiency of the steam engine, and were widely adopted. Steam which has

been superheated is logically known as superheated steam; non-superheated steam is called saturatedsteam or wet steam; Super heaters were applied to steam locomotives in quantity from the early 20th

century, to most steam vehicles, and so stationary steam engines including power stations.

AIR PREHEATERS:

Air preheater is a general term to describe any device designed to heat air before another process (for

example, combustion in a boiler). The purpose of the air preheater is to recover the heat from the boiler

flue gas which increases the thermal efficiency of the boiler by reducing the useful heat lost in the fuel

gas. As a consequence, the flue gases are also sent to the flue gas stack (or chimney) at a lower

temperature allowing simplified design of the ducting and the flue gas stack. It also allows control over the

temperature of gases leaving the stack.

ESPS:


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dust and smoke from the air steam. ESP s continue to be excellent devices for control of many industrial

particulate emissions, including smoke from electricity-generating utilities (coal and oil fired), salt cake

collection from black liquor boilers in pump mills, and catalyst collection from fluidized bed catalytic

crackers from several hundred thousand ACFM in the largest coal-fired boiler application. The original

parallel plate-Weighted wire design (described above) has evolved as more efficient ( and robust)

discharge electrode designs were developed, today focusing on rigid discharge electrodes to which many

sharpened spikes are attached , maximizing corona production. Transformer rectifier systems apply

voltages of 50-100 Kilovolts at relatively high current densities. Modern controls minimize sparking and

prevent arcing, avoiding damage to the components. Automatic rapping systems and hopper evacuation

systems remove the collected particulate matter while on line allowing ESP s to stay in operation for

years at a time.

FUEL GAS STACK:

A Fuel gas stack is a type of chimney, a vertical pipe, channel or similar structure through which

combustion product gases called fuel gases are exhausted to the outside air. Fuel gases are produced whencoal, oil, natural gas, wood or any other large combustion device. Fuel gas is usually composed of carbon

dioxide (CO2) and water vapor as well as nitrogen and excess oxygen remaining from the intake

combustion air. It also contains a small percentage of pollutants such as particulates matter, carbon mono

oxide, nitrogen oxides and sulfur oxides.

BOILER MAINTENANCE DEPARTMENT:

The Boiler Maintenance Department (I,II,III) are departments who are seployed for the proper

working and maintenance of the boilers . At BTPS there are 5 boilers, 3 of 95 MW and 2 of 210 MW

each. Each boiler is considered as one unit.Structure of units 1,2,3 is same and so is of unit 4,5 .

Units 1/2/3 (95 MW each):

1. I.D Fans 2 in no.

2. F.D Fans 2 in no.

3. P.A.Fans 2 in no.

4. Mill Fans 3 in no.


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6. RC feeders 3 in no.

7. Slag Crushers 5 in no.

8. DM Make up Pump 2 in no.

9. PC Feeders 4 in no.

10. Worm Conveyor 1 in no.

11. Turnikets 4 in no.

Units 4/5 (210 MW each):

1. I.D Fans 2 in no.

2. F.D Fans 2 in no.

3. P.A Fans 2 in no.

4. Bowl Mills 6 in no.

5. R.C Feeders 6 in no.

6. Clinker Grinder 2 in no.

7. Scrapper 2 in no.

8. Seal Air Fans 2 in no

Milling System :

RC BUNKER: -


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RC FEEDER: - It transports pre crust coal from raw coal bunker to mill. The quantity of raw coal

fed in mill can be controlled by speed control of aviator drive controlling damper and aviator

change.

BALL MILL: - The ball mill crushes the raw coal to a certain height and then allows it to fall

down. Due to impact of ball on coal and attraction as per the particles move over each other as

well as over the Armor lines, the coal gets crushed. Large particles are broken by impact and full

grinding is done by attraction. The Drying and grinding option takes place simultaneously inside

the mill.

CLASSIFIER:- It is an equipment which serves separation of fine pulverized coal particles

medium from coarse medium. The pulverized coal along with the carrying medium strikes the

impact plate through the lower part. Large particles are then transferred to the ball mill.

CYCLONE SEPARATOR : -It separates the pulverized coal from carrying medium. The mixture of pulverized coal vapour

caters the cyclone separators. .

TURNIKET: -

It serves to transport pulverized coal from cyclone separators to pulverized coal bunker or to

worm conveyors. There are 4 turnikets per boiler.

WORM CONVEYER: -

It is equipment used to distribute the pulverized coal from bunker of one system to bunker of

other system. It can be operated in both directions. 8. Mills Fans: - It is of 3 types Six in all and

are running condition all the time.

(a) ID Fans: - Located between electrostatic precipitator and chimney. Type-radical Speed-1490

rpm

20Rating-300 KW Voltage-6.6 KV Lubrication-by oil ..

(b) D Fans: - Designed to handle secondary air for boiler. 2 in number and provide ignition of coal.

Type-axial Speed-990 rpm Rating-440 KW Voltage-6.6 KV

(c) Primary Air Fans: - Designed for handling the atmospheric air up to 50 degrees Celsius, 2 in

numbers,and they transfer the powered coal to burners to firing. Type-Double suction radial Rating-

300 KW Voltage-6.6 KV Lubrication-by oil Type of operation-continuous

BALL MILL: - One of the most advanced designs of coal pulverizes presently manufactured. Motor

specification squirrel cage induction motor Rating-340 KW Voltage-6600KV Curreen-41.7A Speed-

980 rpm Frequency-50 Hz No-load current-15-16 A .


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PLANT AUXILIARY MAINTENANCE (PAM) :-

This unit of the plant mainly dealt with the auxiliary or helping parts in the plant eg: water treatment,

ash treatment, pump division etc.This two week of training in this division were divided as follows:

1. Control Structure Pump House (CSPH)

2. Water Treatment Plant (WTP)

3. Ash Pump House (APH)

4. Compressed Air Systems

The details of the above sub units are as follows:

CONTROL STRUCTURE PUMP HOISE (CSPH) :

This unit consists of all types of pumps used in plants for purposes like water supply, ash slurry flow

etc.

The various types of pumps

Sr.No Types No.

1 CRW Pump 3

2 Fire Fighting

Pump

2

3 Diesel Fire

Pump

1

4 Low Pressure

Pump

3

5 High Pressure

Pump

6

6 TWS Pump 3

CRW pump is raw water pump used in CSPH, through which raw water is sent into water treatment

plant to get demineralised water . Fire Fighting Pump are used to pacify fire, which occurs most of the

time in Coal Handling Plant. These pumps direct the screened or strained water into the areas wherefire has started. Diesel Fire Pump is an alternative to Fire fighting pump. It acts as spare. Low

Pressure Pump is used to direct treated water into turbines and cooling lines of units 1, 2, 3, 4, 5. In


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TWS pump is used to screen the catchable impurities, plastics, dirt through screens placed in the inlet

of the agra canal channel.

WATER TREATMENT PLANT:

The raw water from CSPH is sent to WTP where it is processed and converted into DM water. This

unit has 8 pumps in all, of which 3 pumps are of 210 MW and are used in running plant, whereas

other 5 are 100 MW pumps used in cooling water circulation. Here, initially raw water is mixed with

alum and chlorine, and then passed through chambers of carbon filter to convert it to clarified water.

This water is passed through resin filter and then mixed with 30 % HCL solution, to form ions. Then

it is passed through cation chamber to separate cations, and similarly anions are removed through

anion chamber. Thus we get carbonated water, this water is passed through the process of

decarbonation, and thus we get DM or Demineralised water.

Layout :


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Ash Pump House :

In the bottom ash system the ash slag discharged from furnace bottom is collected in two water

impounded scraper troughs installed below bottom ash hoppers. The ash is continuously transported

by means of scrapper chain conveyor, on to the respective cinker grinders which reduces the lump

size to required fineness.

The crushed ash from clinker grinders falls into the ash sluice trench provided below bottom ashhopper from where ash slurry is further transported to ash slurry sump aided by the ash sluice channel.


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2 Quencher Cooled Ash Hopper

The various ash disposal systems are:

Fly Ash System :

The fly ash collected in these hoppers drop continuously to flushing apparatus where fly ash gets

mixed with flushing water and the resulting slurry drops into the ash sluice channel. Low pressure

water is applied through the nozzle directing tangentially yto the section of pipe to create turbulence

and proper mixing of ash with water. For the maintenance of flushing apparatus plate valve is

provided between apparatus and connecting chute.

Ash Water System:

High pressure water required for B.A. hopper quenching nozzles, B.A. hoppers window spraying,

clinker grinder sealing scrapper bars, cleaning nozzles, B.A. hopper seal through flushing,Economizer hoppers flushing nozzles and sluicing trench jetting nozzles is tapped from the high

pressure water ring main provided in the plant area.

Low pressure water required for bottom ash hopper seal through make up, scrapper conveyor makeup,

flushing apparatus jetting nozzles for all.. F.A.hoppers excepting economiser hoppers, is tapped from

low pressure water ring mains provided in the plant area.

Ash Slurry System :

Bottom ash and fly ash slurry of the system is sluiced upto ash slurry pump along the channel with the aid

of high pressure water jets located at suitable intervals along the channel.Slurry pump suction line consisting of reducing elbow with drain valve reducer and butterfly valve and

portion of slurry pump delivery line consisting of butterfly valve, pipe and fittings has also been provided.

Compressed Air Systems :

Instrument air is required for operating various dampers , burner tilting devices, diaphragm valves

etc., in the 210 MW units. Station air meets the general requirement of the power statin such as light

oil atomising air, for cleaning filters and for various maintenance works. The control air compressors

have been housed separately with separate receivers and supply headers and their tappings.

Control Air System :

These have been installed for supplying moisture free dry air required for instrument used. The output

from the compressor is fed to air receivers via non return valves. From the receiver air is passed

through the dryers to the main instrument air line which runs alongwith the boiler house and turbine

house of 210 MW unit.

There is one interconnection between service air and instrument air headers just at the inlet of dryingunits. This connection has been provided as an emergency provision to meet the requirement of


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supplied to the instrument air header which is then passed through air drier units. Instrument air

compressor are of double acting horizontal cross head type of two opposed cylinder. The compressors

are driven by electric motor through V belts. Gear wheel type lubricating oil pump is provided to feed

the main bearing. Connecting rod bearing and cross heads of one side ie. to the opposite side of crank

shaft rotation piston. The compressor is equipped with water cooled inter cooler or header, pressure

regulator to load and unload the compressor and safety valves for first and second stages. The suction

air filter is at the middle of the cylinder so that air can enter at both ends of the piston. After

compression the air passes through the delivery valves to the intercooler where the air is cooled and

enters the HP cylinder. The entrapped air in HP side is compressed in a similar manner as in LP

cylinder to the required pressure and enters the header connected to the HP cylinders through the

delivery valves and then finally to the air receiver.

Air Drying Unit :

Air contains moisture which tends to condense, and cause trouble in operation of various devices bycompressed air. Therefore drying of air is accepted widely in case of instrument air. Air drying unit

consists of dual absorption towers with embedded heaters for reactivation. The absorption towers are

adequetly filled with specially selected silica gel and activated alumina .While one tower is drying the

air , the other tower is under reactivation. Thus the unit maintains continuous supply of dry air for

plant requirement. Thus the system is completely automatic.

TURBINE MAINTENANCE DIVISION (TMD)

A turbine, being a form of engine, requires in order to function a suitable working fluid, a source of

high grade energy and a sink for low grade energy. When the fluid flows through the turbine, part ofthe energy content is continuously extracted and converted into useful mechanical work.

The data about the turbine of 210 MW is shown below :

MAIN TURBINE DATA Rated

output of Turbine

210 MW

Rated speed of turbine 3000 rpm

Rated pressure of steam before

emergency

130 kg/cm^2

Stop valve rated live steamtemperature 535 degree Celsius

Rated steam temperature after

reheat at inlet to receptor valve

535 degree Celsius

Steam flow at valve wide open

condition

670 tons/hour

Rated quantity of circulating water

through condenser

27000 cm/hour

1. For cooling water temperature

(degree Celsius)

24,27,30,33

1.Reheated steam pressure at inlet of

interceptor valve in kg/cm^2 ABS

23,99,24,21,24,49,24.82

2.Steam flow required for 210 MW in 68,645,652,662


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Turbine Components :

The Main Turbine

The 210 MW turbine installed in our power stations is predominantly of condensing-tandom -

compound, three cylinder, horizontal, disc and diaphragm, reheat type with nozzle governing and

regenerative system of feed water heating and is coupled directly with A.C. generator

The various main components of the steam turbine are as follows :

Turbine casings

I. High Pressure Casing

II. Intermediate Pressure Casing

III. Low Pressure Casing

Rotors

I. High Pressure Rotor

II. Intermediate Pressure Rotor

III. Low Pressure Rotor

Blades

Blades fitted in stationary part are called guide blades or nozzles and those fitted in the rotor are

called moving or working blades. The following are three main types of blades.

Arrangement Of Turbine Auxiliaries

The turbine cycle can be viewed in the form of different systems as given in following paragraphs

Vacuum System

I. Condenser- 2 per 210 MW unit at the exhaust of LP turbine .


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II. Ejectors- One starting and two main ejectors connected to the condenser located near the turbine

III. C.W. pumps Normally two per unit of 50 % capacity

Condensate System

I. Condensate Pumps- 3 per unit of 50% capacity each located near the condenser hot well.

II. LP heaters- Normally 4 in number with no.1 located at ther upper part of the condenser and nos

2,3,4 around 4m level

III. Deaerator- One per unit located around 18 M level in CD bay

Feed Water System

I. Boiler Feed Pump- 3 per unit of 50% capacity each located in the 0 meter level in TG bay

II. High Pressure Heaters- Normally 3 in number and are situated in the TG bay

Drip Pumps

Generally two in number of 100% capacity each situated beneath the LP heaters

Turbine Lub Oil system

This consists of Main Oil Pump(MOP), Starting Oil Pump(SOP), AC standby oil pumps and

emergency DC oil pump and Jacking Oil Pump (JOP) (one each per unit)

Auxiliary Steam System

The main 16 ata header runs parallel to BC bay at the level of around 18M.

The arrangement of turbine auxiliaries is shown in the following figure:


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INFERENCE :

In my four week training, I was assigned the work of three units, which were BMD, PAMand TMD. These 3 units are explained above in chapter 3, of this report. Boiler and turbine

are the most important part of the power plant, without which the power plant cannot run.This plant produces 705 MW of electricity, with the help of its 5 units. 3 units of 95 MW

each and 2 units of 210 MW each. The 95 MW units were the first ones to be establishedfollowed by the 210 MW units in the later years. As for the unit PAM, it is equally

important. It takes care of all the auxiliary processes going on in the plant. It provides waterto all the parts of the plant with the help of pumps present in CSPH. Also it produces DM

water from raw water by passing it through water treatment plant. The ash or the wasteproduced on burning is taken care of, by Ash handling plant. The compressed air required

in any part of the plant is provided by the unit comprising of the compressor, also known ascompressor house. The fuel used was coal which was pulverized with the help of bowl and

ball mills. These pulverized coal was the fuel burnt in the furnace to produce heat, whichthen heated the water to superheated steam.

.


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REFERENCES

1. Training Staff at

BTPS badarpur

2. Manuals provided

by NTPC .

3. Senior students

and Teachers .

Btps Final

Documents

Transcript of Btps Final