NTPC BADARPUR Summer Tranning report

NATIONAL THERMAL POWER COOPERATION

BADARPUR THERMAL POWER STATION

NEW DELHI

Submitted by:

Ravi Jain

B.Tech 2nd Year

20085063

Electronics and communication Engineering

MNNIT ALLAHABAD

Duration- 24/05/2010 to 19/06/2010

ACKNOWLEDGEMENT I am highly grateful to Proff. SATISH CHANDRA, Training and Placement Department, MNNIT ALLAHABAD, for providing this opportunity to carry out 4 weeks industrial training at NATIONAL THERMAL POWER CORPORATION , BADARPUR, NEW DELHI. I would like to express a deep sense of gratitude and thanks to Mr AJEET KUMAR OJHA-DGM(HR) without the wise counsel and able guidance, it would have been impossible to complete the report in this manner. The help rendered by Mrs RACHANA SINGH BHAL, Sr. Manager, National Thermal Power Corporation for experimentation is greatly acknowledged. I would also like to express gratitude to the HOD and other faculty members of department of Electronics and communication engineering, MNNIT for their intellectual support throughout the course of this work. Finally, I would like to thanks Er. SONIA SINGH and all other technical staff of B.T.P.S. for giving helping me throughout the training period.

Ravi Jain

ECE-MNNIT ALLAHABD

[email protected]

CONTENT

1. INTRODUCTION TO THE COMPANY

2. OPERATION OF POWER PLANT

3. VARIOUS CYCLE AT POWER STATION

4. CONTROL & INSTRUMENTATION

5. IT DEPARTMENT

6. REFERENCE

About The Company

Vision

Strategies

Environmental Policy

Evolution

About The Company NTPC, the largest power Company in India, was setup in 1975 to accelerate power development in the country. It is among the world’s largest and most efficient power generation companies. In Forbes list of World’s 2000 Largest Companies for the year 2007, NTPC occupies 411th place.

A View Of Badarpur Thermal Power Station, New-Delhi

NTPC has installed capacity of 29,394 MW. It has 15 coal based power stations (23,395 MW), 7 gas based power stations (3,955 MW) and 4 power stations in Joint Ventures (1,794 MW). The company has power generating facilities in all major regions of the country. It plans to be a 75,000 MW company by 2017.

Types Of Power Station Number Capacity(MW)

Coal Based Power Station 15 23,395

Gas Based Power Station 7 3,955

Joint Venture 4 1,794

Total Capacity – 29,394 MW

NTPC has gone beyond the thermal power generation. It has diversified into hydro power, coal mining, power equipment manufacturing, oil & gas exploration, power trading & distribution. NTPC is now in the entire power value chain and is poised to become an Integrated Power Major. NTPC's share on 31 Mar 2008 in the total installed capacity of the country was 19.1% and it contributed 28.50% of the total power generation of the country during 2007-08. NTPC has set new benchmarks for the power industry both in the area of power plant construction and operations. With its experience and expertise in the power sector, NTPC is extending consultancy services to various organizations in the power business. It provides consultancy in the area of power plant constructions and power generation to companies in India and abroad. In November 2004, NTPC came out with its Initial Public Offering (IPO) consisting of 5.25% as fresh issue and 5.25% as offer for sale by Government of India. NTPC thus became a listed company with Government holding 89.5% of the equity share capital and rest held by Institutional Investors and Public. The issue was a resounding success. NTPC is among the largest five companies in India in terms of market capitalization.

Growth Of NTPC Generation & PLF %

Recognizing its excellent performance and vast potential, Government of the India has identified NTPC as one of the jewels of Public Sector 'Navratnas'- a potential global giant. Inspired by its glorious past and vibrant present, NTPC is well on its way to realize its vision of being "A world class integrated power major, powering India's growth, with increasing global presence".

VISION

Corporate vision: - “A world class integrated power major, powering India's growth with increasing global presence.”

Mission :-Develop and provide reliable power related products and services at competitive prices,

integrating multiple energy resources with innovative & Eco-friendly technologies and contribution to the

society.

Core Values - BCOMIT • Business ethics

• Customer Focus

• Organizational & Professional Pride

• Mutual Respect & Trust

• Innovation & Speed

• Total Quality for Excellence

A View Of Well Flourished Plant

STRATEGIES

Technological Initiatives

Introduction of steam generators (boilers) of the size of 800 MW.

Integrated Gasification Combined Cycle (IGCC) Technology.

Launch of Energy Technology Center -A new initiative for development of technologies with

focus on fundamental R&D.

The company sets aside up to 0.5% of the profits for R&D.

Roadmap developed for adopting ‘Clean Development.

Mechanism’ to help get / earn ‘Certified Emission Reduction.

Corporate Social Responsibility

As a responsible corporate citizen NTPC has taken up number of CSR initiatives.

NTPC Foundation formed to address Social issues at national level.

NTPC has framed Corporate Social Responsibility Guidelines committing up to 0.5% of net

profit annually for Community Welfare Measures on perennial basis.

The welfare of project affected persons and the local population around NTPC projects are

taken care of through well drawn Rehabilitation and Resettlement policies.

The company has also taken up distributed generation for remote rural areas.

STRATEGIES

Sustainable

Development

Maintain

sector

Leadership

Further Enchance

Fuel Security

Exploit New

Business

Opportunities

Technology

Initiatives

Nuturing

Human

Resource

ENVIROMANTAL POLICY

NTPC is committed to the environment, generating power at minimal environmental cost and

preserving the ecology in the vicinity of the plants. NTPC has undertaken massive a forestation in

the vicinity of its plants. Plantations have increased forest area and reduced barren land. The

massive a forestation by NTPC in and around its Ramagundam Power station (2600 MW) have

contributed reducing the temperature in the areas by about 3°c. NTPC has also taken proactive

steps for ash utilization. In 1991, it set up Ash Utilization Division

A "Centre for Power Efficiency and Environment Protection- CENPEE" has been established in

NTPC with the assistance of United States Agency for International Development- USAID. CENPEEP

is efficiency oriented, eco-friendly and eco-nurturing initiative - a symbol of NTPC's concern

towards environmental protection and continued commitment to sustainable power development

in India.

As a responsible corporate citizen, NTPC is making constant efforts to improve the socio-economic

status of the people affected by its projects. Through its Rehabilitation and Resettlement

programmes, the company endeavors to improve the overall socio economic status Project

Affected Persons.

NTPC was among the first Public Sector Enterprises to enter into a Memorandum of Understanding-

MOU with the Government in 1987-88. NTPC has been placed under the 'Excellent category' (the

best category) every year since the MOU system became operative.

Harmony between man and environment is the essence of healthy life and growth. Therefore,

maintenance of ecological balance and a pristine environment has been of utmost importance to

NTPC. It has been taking various measures discussed below for mitigation of environment pollution

due to power generation.

NTPC is the second largest owner of trees in the country after the Forest

department.

Environment Policy & Environment Management System Driven by its commitment for sustainable growth of power, NTPC has evolved a well defined

environment management policy and sound environment practices for minimizing environmental

impact arising out of setting up of power plants and preserving the natural ecology.

NTPC Environment Policy As early as in November 1995, NTPC brought out a comprehensive document entitled "NTPC

Environment Policy and Environment Management System". Amongst the guiding principles

adopted in the document are company's proactive approach to environment, optimum utilization

of equipment, adoption of latest technologies and continual environment improvement. The policy

also envisages efficient utilization of resources, thereby minimizing waste, maximizing ash

utilization and providing green belt all around the plant for maintaining ecological balance.

Environment Management, Occupational Health and Safety Systems: NTPC has actively gone for adoption of best international practices on environment, occupational

health and safety areas. The organization has pursued the Environmental Management System

(EMS) ISO 14001 and the Occupational Health and Safety Assessment System OHSAS 18001 at its

different establishments. As a result of pursuing these practices, all NTPC power stations have been

certified for ISO 14001 & OHSAS 18001 by reputed national and international Certifying Agencies.

Pollution Control systems: While deciding the appropriate technology for its projects, NTPC integrates many environmental

provisions into the plant design. In order to ensure that NTPC comply with all the stipulated

environment norms, various state-of-the-art pollution control systems / devices as discussed below

have been installed to control air and water pollution.

Electrostatic Precipitators: The ash left behind after combustion of coal is arrested in high efficiency Electrostatic Precipitators

(ESP’s) and particulate emission is controlled well within the stipulated norms. The ash collected in

the ESP’s is disposed to Ash Ponds in slurry form.

Flue Gas Stacks: Tall Flue Gas Stacks have been provided for wide dispersion of the gaseous emissions (SOX, NOX

etc) into the atmosphere.

Low-NOX Burners: In gas based NTPC power stations, NOx emissions are controlled by provision of Low-NOx Burners

(dry or wet type) and in coal fired stations, by adopting best combustion practices.

Neutralisation Pits: Neutralisation pits have been provided in the Water Treatment Plant (WTP) for pH correction of the

effluents before discharge into Effluent Treatment Plant (ETP) for further treatment and use.

Coal Settling Pits / Oil Settling Pits: In these Pits, coal dust and oil are removed from the effluents emanating from the Coal Handling

Plant (CHP), coal yard and Fuel Oil Handling areas before discharge into ETP.

DE & DS Systems: Dust Extraction (DE) and Dust Suppression (DS) systems have been installed in all coal fired power

stations in NTPC to contain and extract the fugitive dust released in the Coal Handling Plant (CHP).

Cooling Towers: Cooling Towers have been provided for cooling the hot Condenser cooling water in closed cycle

Condenser Cooling Water (CCW) Systems. This helps in reduction in thermal pollution and

conservation of fresh water.

Ash Dykes & Ash Disposal systems: Ash ponds have been provided at all coal based stations except Dadri where Dry Ash Disposal

System has been provided. Ash Ponds have been divided into lagoons and provided with garlanding

arrangements for changeover of the ash slurry feed points for even filling of the pond and for

effective settlement of the ash particles.

Ash in slurry form is discharged into the lagoons where ash particles get settled from the slurry and

clear effluent water is discharged from the ash pond. The discharged effluents conform to

standards specified by CPCB and the same is regularly monitored.

At its Dadri Power Station, NTPC has set up a unique system for dry ash collection and disposal

facility with Ash Mound formation. This has been envisaged for the first time in Asia which has

resulted in progressive development of green belt besides far less requirement of land and less

water requirement as compared to the wet ash disposal system.

Ash Water Recycling System: Further, in a number of NTPC stations, as a proactive measure, Ash Water Recycling System (AWRS)

has been provided. In the AWRS, the effluent from ash pond is circulated back to the station for

further ash sluicing to the ash pond. This helps in savings of fresh water requirements for

transportation of ash from the plant.

The ash water recycling system has already been installed and is in operation at Ramagundam,

Simhadri, Rihand, Talcher Kaniha, Talcher Thermal, Kahalgaon, Korba and Vindhyachal. The scheme

has helped stations to save huge quantity of fresh water required as make-up water for disposal of

ash.

Dry Ash Extraction System (DAES): Dry ash has much higher utilization potential in ash-based products (such as bricks, aerated

autoclaved concrete blocks, concrete, Portland pozzolana cement, etc.). DAES has been installed at

Unchahar, Dadri, Simhadri, Ramagundam, Singrauli, Kahalgaon, Farakka, Talcher Thermal, Korba,

Vindhyachal, Talcher Kaniha and BTPS.

Liquid Waste Treatment Plants & Management System: The objective of industrial liquid effluent treatment plant (ETP) is to discharge lesser and cleaner

effluent from the power plants to meet environmental regulations. After primary treatment at the

source of their generation, the effluents are sent to the ETP for further treatment. The composite

liquid effluent treatment plant has been designed to treat all liquid effluents which originate within

the power station e.g. Water Treatment Plant (WTP), Condensate Polishing Unit (CPU) effluent,

Coal Handling Plant (CHP) effluent, floor washings, service water drains etc. The scheme involves

collection of various effluents and their appropriate treatment centrally and re-circulation of the

treated effluent for various plant uses.

NTPC has implemented such systems in a number of its power stations such as Ramagundam,

Simhadri, Kayamkulam, Singrauli, Rihand, Vindhyachal, Korba, Jhanor Gandhar, Faridabad, Farakka,

Kahalgaon and Talcher Kaniha. These plants have helped to control quality and quantity of the

effluents discharged from the stations.

Sewage Treatment Plants & Facilities: Sewage Treatment Plants (STPs) sewage treatment facilities have been provided at all NTPC

stations to take care of Sewage Effluent from Plant and township areas. In a number of NTPC

projects modern type STPs with Clarifloculators, Mechanical Agitators, sludge drying beds, Gas

Collection Chambers etc have been provided to improve the effluent quality. The effluent quality is

monitored regularly and treated effluent conforming to the prescribed limit is discharged from the

station. At several stations, treated effluents of STPs are being used for horticulture purpose.

Environmental Institutional Set-up: Realizing the importance of protection of the environment with speedy development of the power

sector, the company has constituted different groups at project, regional and Corporate Centre

level to carry out specific environment related functions. The Environment Management Group,

Ash Utilisation Group and Centre for Power Efficiency & Environment Protection (CENPEEP)

function from the Corporate Centre and initiate measures to mitigate the impact of power project

implementation on the environment and preserve ecology in the vicinity of the projects.

Environment Management and Ash Utilisation Groups established at each station, look after

various environmental issues of the individual station.

Environment Reviews: To maintain constant vigil on environmental compliance, Environmental Reviews are carried out at

all operating stations and remedial measures have been taken wherever necessary. As a feedback

and follow-up of these Environmental Reviews, a number of retrofit and up-gradation measures

have been undertaken at different stations.

Such periodic Environmental Reviews and extensive monitoring of the facilities carried out at all

stations have helped in compliance with the environmental norms and timely renewal of the Air

and Water Consents.

Waste Management Various types of wastes such as Municipal or domestic wastes, hazardous wastes, Bio-Medical

wastes get generated in power plant areas, plant hospital and the townships of projects. The

wastes generated are a number of solid and hazardous wastes like used oils & waste oils, grease,

lead acid batteries, other lead bearing wastes (such as garkets etc.), oil & clarifier sludge, used

resin, used photo-chemicals, asbestos packing, e-waste, metal scrap, C&I wastes, electricial scrap,

empty cylinders (refillable), paper, rubber products, canteen (bio-degradable) wastes, buidling

material wastes, silica gel, glass wool, fused lamps & tubes, fire resistant fluids etc. These wastes

fall either under hazardous wastes category or non-hazardous wastes category as per classification

given in Government of India’s notification on Hazardous Wastes (Management and Handling)

Rules 1989 (as amended on 06.01.2000 & 20.05.2003). Handling and management of these wastes

in NTPC stations have been discussed below.

EVOLUTION

• NTPC was set up in 1975 with 100% ownership by the Government of India. In the last 30 years, NTPC has grown into the largest power utility in India.

1975

• In 1997, Government of India granted NTPC status of “Navratna" being one of the nine jewels of India, enhancing the powers to the Board of Directors.1997

• NTPC became a listed company with majority Government ownership of 89.5%.

• NTPC becomes 3rd largest by Market Capitalization of listed companies

2004

• The company rechristened as NTPC Limited in line with its changing business portfolio and transforms itself from a thermal power utility to an integrated power utility.

2005

• National Thermal Power Corporation is the largest power generation company in India. Forbes Global 2000 for 2008 ranked it 411th in the world.2008

OPERATION OF POWER PLANT

INTRODUCTION

BASIC PRINCIPLE

ELECTRICITY FROM COAL

OPERATION OF BOILER

OPERATION OF TURBINE

INTRODUCTION BADARPUR THERMAL POWER STATION was established on 1973 and it was the part of Central

Government. On 01/04/1978 is was given as No Loss No Profit Plant of NTPC.

Since then operating performance of NTPC has been considerably above the national average. The

availability factor for coal stations has increased from 85.03 % in 1997-98 to 90.09 % in 2006-07,

which compares favourably with international standards. The PLF has increased from 75.2% in

1997-98 to 89.4% during the year 2006-07 which is the highest since the inception of NTPC.

Capacity of BADARPUR THERMAL POWER STATION

Sr. No. Capacity(MW) Number Total Capacity(MW)

1. 210 2 420

2. 95 3 285

Overall Capacity- 705 MW

BASIC PRINCIPLE As per FARADAY’s Law- “Whenever the amount of magnetic flux linked with a circuit changes, an EMF is

produced in the circuit. Generator works on the principle of producing electricity. To change the flux in the

generator turbine is moved in a great speed with steam.”

To produce steam, water is heated in the boilers by burning the coal. In a Badarpur Thermal Power

Station, steam is produced and used to spin a turbine that operates a generator. Water is heated,

turns into steam and spins a steam turbine which drives an electrical generator. After it passes

through the turbine, the steam is condensed in a condenser; this is known as a Rankine cycle.

Shown here is a diagram of a conventional thermal power plant, which uses coal, oil, or natural gas

as fuel to boil water to produce the steam. The electricity generated at the plant is sent to

consumers through high-voltage power lines The Badarpur Thermal Power Plant has Steam

Turbine-Driven Generators which has a collective capacity of 705MW. The fuel being used is Coal

which is supplied from the Jharia Coal Field in Jharkhand. Water supply is given from the Agra

Canal.

Electricity from Coal There are basically three main units of a thermal power plant: 1. Steam Generator or Boiler 2. Steam Turbine 3. Electric Generator

Basic Electricity Generation Chart

Coupling

Functioning of Thermal Power Plant

Typical Diagram of Coal Based Power Plant

Its various parts are listed below:-

1. Cooling tower

2. Cooling water pump

3. Transmission line (3-phase)

4. Unit transformer (3-phase)

5. Electric generator (3-phase)

6. Low pressure turbine

7. Condensate extraction pump

8. Condenser

9. Intermediate pressure turbine

10. Steam governor valve

11. High pressure turbine

12. DE aerator

13. Feed heater

14. Coal conveyor

15. Coal hopper

16. Pulverised fuel mill

17. Boiler drum

18. Ash hopper

19. Super heater

20. Forced draught fan

21. Re heater

22. Air intake

23. Economiser

24. Air preheater

25. Precipitator

26. Induced draught fan

27. Fuel Gas Stack

1. Cooling towers

Cooling Towers are evaporative coolers used for cooling water or other working medium to near the

ambivalent web-bulb air temperature. Cooling tower use evaporation of water to reject heat from

processes such as cooling the circulating water used in oil refineries, Chemical plants, power plants

and building cooling, for example. The tower vary in size from small roof-top units to very large

hyperboloid structures that can be up to 200 meters tall and 100 meters in diameter, or rectangular

structure that can be over 40 meters tall and 80 meters long. Smaller towers are normally factory

built, while larger ones are constructed on site.

The primary use of large , industrial cooling tower system is to remove the heat absorbed in the

circulating cooling water systems used in power plants , petroleum refineries, petrochemical and

chemical plants, natural gas processing plants and other industrial facilities . The absorbed heat is

rejected to the atmosphere by the evaporation of some of the cooling water in mechanical forced-

draft or induced draft towers or in natural draft hyperbolic shaped cooling towers as seen at most

nuclear power plants.

2. Cooling Water Pump It pumps the water from the cooling tower which goes to the condenser.

3.Three phase transmission line

Three phase electric power is a common method of electric power transmission. It is a type of

polyphase system mainly used to power motors and many other devices. A Three phase system uses

less conductor material to transmit electric power than equivalent single phase, two phase, or direct

current system at the same voltage. In a three phase system, three circuits reach their instantaneous

peak values at different times. Taking one conductor as the reference, the other two current are

delayed in time by one-third and two-third of one cycle of the electrical current. This delay between

“phases” has the effect of giving constant power transfer over each cycle of the current and also

makes it possible to produce a rotating magnetic field in an electric motor.

At the power station, an electric generator converts mechanical power into a set of electric currents,

one from each electromagnetic coil or winding of the generator. The current are sinusoidal functions

of time, all at the same frequency but offset in time to give different phases. In a three phase system

the phases are spaced equally, giving a phase separation of one-third one cycle. Generators output at

a voltage that ranges from hundreds of volts to 30,000 volts.

4. Unit transformer (3-phase)

At the power station, transformers: step-up” this voltage to one more suitable for transmission. After

numerous further conversions in the transmission and distribution network the power is finally

transformed to the standard mains voltage (i.e. the “household” voltage).

The power may already have been split into single phase at this point or it may still be three phase.

Where the step-down is 3 phase, the output of this transformer is usually star connected with the

standard mains voltage being the phase-neutral voltage. Another system commonly seen in North

America is to have a delta connected secondary with a center tap on one of the windings supplying

the ground and neutral. This allows for 240 V three phase as well as three different single phase

voltages( 120 V between two of the phases and neutral , 208 V between the third phase ( known as a

wild leg) and neutral and 240 V between any two phase) to be available from the same supply.

5. Electrical generator

An Electrical generator is a device that converts kinetic energy to electrical energy, generally using

electromagnetic induction. The task of converting the electrical energy into mechanical energy is

accomplished by using a motor. The source of mechanical energy may be a reciprocating or turbine

steam engine, , water falling through the turbine are made in a variety of sizes ranging from small 1

hp (0.75 kW) units (rare) used as mechanical drives for pumps, compressors and other shaft driven

equipment , to 2,000,000 hp(1,500,000 kW) turbines used to generate electricity. There are several

classifications for modern steam turbines.

Steam turbines are used in all of our major coal fired power stations to drive the generators or

alternators, which produce electricity. The turbines themselves are driven by steam generated in

„Boilers‟ or „steam generators‟ as they are sometimes called.

Electrical power station use large stem turbines driving electric generators to produce most (about

86%) of the world‟s electricity. These centralized stations are of two types: fossil fuel power plants

and nuclear power plants. The turbines used for electric power generation are most often directly

coupled to their-generators .As the generators must rotate at constant synchronous speeds according

to the frequency of the electric power system, the most common speeds are 3000 r/min for 50 Hz

systems, and 3600 r/min for 60 Hz systems. Most large nuclear sets rotate at half those speeds, and

have a 4-pole generator rather than the more common 2-pole one.

6. Low Pressure Turbine

Energy in the steam after it leaves the boiler is converted into rotational energy as it passes through

the turbine. The turbine normally consists of several stage with each stages consisting of a stationary

blade (or nozzle) and a rotating blade. Stationary blades convert the potential energy of the steam

into kinetic energy into forces, caused by pressure drop, which results in the rotation of the turbine

shaft. The turbine shaft is connected to a generator, which produces the electrical energy.

Low Pressure Turbine (LPT) consist of 4x2 stages. After passing through Intermediate Pressure

Turbine is is passed through LPT which is made up of two parts- LPC REAR & LPC FRONT. As

water gets cooler here it gathers into a HOTWELL placed in lower parts of Turbine.

7. Condensation Extraction Pump

A Boiler feed water pump is a specific type of pump used to pump water into a steam boiler. The

water may be freshly supplied or retuning condensation of the steam produced by the boiler. These

pumps are normally high pressure units that use suction from a condensate return system and can be

of the centrifugal pump type or positive displacement type.

Construction and operation

Feed water pumps range in size up to many horsepower and the electric motor is usually separated

from the pump body by some form of mechanical coupling. Large industrial condensate pumps may

also serve as the feed water pump. In either case, to force the water into the boiler; the pump must

generate sufficient pressure to overcome the steam pressure developed by the boiler. This is usually

accomplished through the use of a centrifugal pump.

Feed water pumps usually run intermittently and are controlled by a float switch or other similar

level-sensing device energizing the pump when it detects a lowered liquid level in the boiler is

substantially increased. Some pumps contain a two-stage switch. As liquid lowers to the trigger point

of the first stage, the pump is activated. I f the liquid continues to drop (perhaps because the pump

has failed, its supply has been cut off or exhausted, or its discharge is blocked); the second stage will

be triggered. This stage may switch off the boiler equipment (preventing the boiler from running dry

and overheating), trigger an alarm, or both.

8. Condenser

The steam coming out from the Low Pressure Turbine (a little above its boiling pump) is brought into thermal contact with cold water (pumped in from the cooling tower) in the condenser, where it condenses rapidly back into water, creating near vacuum-like conditions inside the condenser chest.

9. Intermediate Pressure Turbine Intermediate Pressure Turbine (IPT) consist of 11 stages. When the steam has been passed through

HPT it gets enter into IPT. IPT has two ends named as FRONT & REAR. Steam enters through front

end and leaves from Rear end.

10. Steam Governor Valve

Steam locomotives and the steam engines used on ships and stationary applications such as power

plants also required feed water pumps. In this situation, though, the pump was often powered using a

small steam engine that ran using the steam produced by the boiler. A means had to be provided, of

course, to put the initial charge of water into the boiler(before steam power was available to operate

the steam-powered feed water pump).the pump was often a positive displacement pump that had

steam valves and cylinders at one end and feed water cylinders at the other end; no crankshaft was

required.

In thermal plants, the primary purpose of surface condenser is to condense the exhaust steam from a

steam turbine to obtain maximum efficiency and also to convert the turbine exhaust steam into pure

water so that it may be reused in the steam generator or boiler as boiler feed water. By condensing

the exhaust steam of a turbine at a pressure below atmospheric pressure, the steam pressure drop

between the inlet and exhaust of the turbine is increased, which increases the amount heat available

for conversion to mechanical power. Most of the heat liberated due to condensation of the exhaust

steam is carried away by the cooling medium (water or air) used by the surface condenser.

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

11.High Pressure Turbine

Steam coming from Boiler directly feeds into HPT at a temperature of 540°C and at a pressure of

136 kg/cm2. Here it passes through 12 different stages due to which its temperature goes down to

329°C and pressure as 27 kg/cm2. This line is also called as CRH – COLD REHEAT LINE.

It is now passed to an REHEATER where its temperature rises to 540°C and called as HRH-HOT

REHEATED LINE .

12. Deaerator

A 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 dearator

typically 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)

13. Feed water heater

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.[4] 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 modelled 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

irreversibility‟s 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.

14. Coal conveyor

Coal conveyors are belts which are used to transfer coal from its storage place to Coal Hopper.

15. Coal Hopper Coal Hopper are the places which are used to feed coal to Fuel Mill. It also has the arrangement of entering

of Hoy Air at 200°C inside it which solves our two purposes:-

1. If our Coal has moisture content then it dries it so that a proper combustion takes place.

2. It raises the temperature of coal so that its temperature is more near to its Ignite Temperature so

that combustion is easy.

16. Pulverised Fuel Mill

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

17. Boiler Drum Steam 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.

18. Ash Hopper 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 for the sludge or sediments which have a tendency to the bottom.

19. 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 saturated

steam 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.

20. Force Draught Fan External fans are provided to give sufficient air for combustion. The forced draft fan takes air from

the atmosphere and, first warming it in the air preheater for better combustion, injects it via the air

nozzles on the furnace wall.

21. Reheater

Reheater are heaters which are used to raise the temperature of air which has been fallen down due to

various process.

22. Air Intake

Air is taken from the environment by an air intake tower.

23. Economizers

Economizer, or in the UK economizer, are mechanical devices intended to reduce energy

consumption, or to perform another useful function like preheating a fluid. The term economizer is

used for other purposes as well. Boiler, power plant, and heating, ventilating and air conditioning. In

boilers, economizer are heat exchange devices that heat fluids , usually water, up to but not normally

beyond the boiling point of the fluid. Economizers are so named because they can make use of the

enthalpy and improving the boiler‟s efficiency. They are a device fitted to a boiler which saves

energy by using the exhaust gases from the boiler to preheat the cold water used the fill it (the feed

water). Modern day boilers, such as those in cold fired power stations, are still fitted with

economizer which is decedents of Green‟s original design. In this context they are turbines before it

is pumped to the boilers. A common application of economizer is steam power plants is to capture

the waste hit from boiler stack gases (flue gas) and transfer thus it to the boiler feed water thus

lowering the needed energy input , in turn reducing the firing rates to accomplish the rated boiler

output . Economizer lower stack temperatures which may cause condensation of acidic combustion

gases and serious equipment corrosion damage if care is not taken in their design and material

selection.

24. Air Preheater

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.

25. Precipitator

An Electrostatic precipitator (ESP) or electrostatic air cleaner is a particulate device that removes

particles from a flowing gas (such As air) using the force of an induced electrostatic charge.

Electrostatic precipitators are highly efficient filtration devices, and can easily remove fine

particulate matter such as 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.

26. Induced Draught Fan

The induced draft fan assists the FD fan by drawing out combustible gases from the furnace, maintaining a slightly negative pressure in the furnace to avoid backfiring through any opening. At the furnace outlet, and before the furnace gases are handled by the ID fan, fine dust carried by the outlet gases is removed to avoid atmospheric pollution. This is an environmental limitation prescribed by law, additionally minimizes erosion of the ID fan.

27. 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 when coal, 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. The flue gas stacks are often quite tall, up to 400 meters (1300 feet) or more, so as to disperse the exhaust pollutants over a greater aria and thereby reduce the concentration of the pollutants to the levels required by governmental environmental policies and regulations. When the fuel gases exhausted from stoves, ovens, fireplaces or other small sources within residential abodes, restaurants , hotels or other stacks are referred to as chimneys.

OPERATION OF BOILER

The boiler is a rectangular furnace about 50 ft (15 m) on a side and 130 ft (40 m) tall. Its walls are made of a web of high pressure steel tubes about 2.3 inches (60 mm) in diameter. Pulverized coal is air-blown into the furnace from fuel nozzles at the four corners and it rapidly burns, forming a large fireball at the center. The thermal radiation of the fireball heats the water that circulates through the boiler tubes near the boiler perimeter. The water circulation rate in the boiler is three to four times the throughput and is typically driven by pumps. As the water in the boiler circulates it absorbs heat and changes into steam at 700 °F (370 °C) and 22.1 MPa. It is separated from the water inside a drum at the top of the furnace. The saturated steam is introduced into superheat pendant tubes that hang in the hottest part of the combustion gases as they exit the furnace. Here the steam is superheated to 1,000 °F (540 °C) to prepare it for the turbine. The steam generating boiler has to produce steam at the high purity, pressure and temperature required for the steam turbine that drives the electrical generator. The generator includes the economizer, the steam drum, the chemical dosing equipment, and the furnace with its steam generating tubes and the superheater coils. Necessary safety valves are located at suitable pointsvto avoid excessive boiler pressure. The air and flue gas path equipment include: forced draft (FD) fan, air preheater (APH), boiler furnace, induced draft (ID) fan, fly ash collectors (electrostatic precipitator or baghouse) and the flue gas stack.

Schematic diagram of a coal-fired power plant steam generator

Boiler Furnace and Steam Drum Once water inside the boiler or steam generator, the process of adding the latent heat of vaporization or enthalpy is underway. The boiler transfers energy to the water by the chemical reaction of burning some type of fuel. The water enters the boiler through a section in the convection pass called the economizer. From the economizer it passes to the steam drum. Once the water enters the steam drum it goes down the down comers to the lower inlet water wall headers. From the inlet headers the water rises through the water walls and is eventually turned into steam due to the heat being generated by the burners located on the front and rear water walls (typically). As the water is turned into steam/vapour in the water walls, the steam/vapor once again enters the steam drum.

Fuel Preparation System In coal-fired power stations, the raw feed coal from the coal storage area is first crushed into small pieces and then conveyed to the coal feed hoppers at the boilers. The coal is next pulverized into a very fine powder. The pulverizers may be ball mills, rotating drum grinders, or other types of grinders. Some power stations burn fuel oil rather than coal. The oil must kept warm (above its pour point) in the fuel oil storage tanks to prevent the oil from congealing and becoming un-pumpable. The oil is usually heated to about 100°C before being pumped through the furnace fuel oil spray nozzles.

Fuel Firing System and Ignite System From the pulverized coal bin, coal is blown by hot air through the furnace coal burners at an angle which imparts a swirling motion to the powdered coal to enhance mixing of the coal powder with the incoming preheated combustion air and thus to enhance the combustion. To provide sufficient combustion temperature in the furnace before igniting the powdered coal, the furnace temperature is raised by first burning some light fuel oil or processed natural gas (by using auxiliary burners and igniters provide for that purpose).

Air Path External fans are provided to give sufficient air for combustion. The forced draft fan takes air from the atmosphere and, first warming it in the air preheater for better combustion, injects it via the air nozzles on the furnace wall. The induced draft fan assists the FD fan by drawing out combustible gases from the furnace, maintaining a slightly negative pressure in the furnace to avoid backfiring through any opening. At the furnace outlet, and before the furnace gases are handled by the ID fan, fine dust carried by the outlet gases is removed to avoid atmospheric pollution. This is an environmental limitation prescribed by law, and additionally minimizes erosion of the ID fan.

Fly Ash Collection Fly ash is captured and removed from the flue gas by electrostatic precipitators or fabric bag filters (or sometimes both) located at the outlet of the furnace and before the induced draft fan. The fly ash is periodically removed from the collection hoppers below the precipitators or bag filters. Generally, the fly ash is pneumatically transported to storage silos for subsequent transport by trucks or railroad cars.

Bottom Ash Collection and Disposal At the bottom of every boiler, a hopper has been provided for collection of the bottom ash from

the bottom of the furnace. This hopper is always filled with water to quench the ash and clinkers

falling down from the furnace. Some arrangement is included to crush the clinkers and for

conveying the crushed clinkers and bottom ash to a storage site.

Boiler Make-up Water Treatment Plant and Storage Since there is continuous withdrawal of steam and continuous return of condensate to the boiler, losses due to blow-down and leakages have to be made up for so as to maintain the desired water level in the boiler steam drum. For this, continuous make-up water is added to the boiler water system. The impurities in the raw water input to the plant generally consist of calcium and magnesium salts which impart hardness to the water. Hardness in the make-up water to the boiler will form deposits on the tube water surfaces which will lead to overheating and failure of the tubes. Thus, the salts have to be removed from the water and that is done by a water demineralising treatment plant (DM).

OPERATION OF TURBINE Steam turbines are used in all of our major coal fired power stations to drive the generators or

alternators, which produce electricity. The turbines themselves are driven by steam generated in

'Boilers' or 'Steam Generators' as they are sometimes called. Energy in the steam after it leaves the

boiler is converted into rotational energy as it passes through the turbine. The turbine normally

consists of several stages with each stage consisting of a stationary blade (or nozzle) and a rotating

blade. Stationary blades convert the potential energy of the steam (temperature and pressure) into

kinetic energy (velocity) and direct the flow onto the rotating blades. The rotating blades convert

the kinetic energy into forces, caused by pressure drop, which results in the rotation of the turbine

shaft. The turbine shaft is connected to a generator, which produces the electrical energy. The

rotational speed is 3000 rpm for Indian System (50 Hz) systems and 3600 for American (60 Hz)

systems.

In a typical larger power stations, the steam turbines are split into three separate stages, the first being the High Pressure (HP), the second the Intermediate Pressure (IP) and the third the Low Pressure (LP) stage, where high, intermediate and low describe the pressure of the steam. After the steam has passed through the HP stage, it is returned to the boiler to be re-heated to its original temperature although the pressure remains greatly reduced. The reheated steam then passes through the IP stage and finally to the LP stage of the turbine. High-pressure oil is injected into the bearings to provide lubrication.

VARIOUS CYCLES AT POWER

STATION

COAL CYCLE

CONDENSATE CYCLE

FEED WATER CYCLE

STEAM CYCLE

COAL CYCLE

Coal Stock Yard

RC Bunker

RC Feeder

Mill

Furnace

Condensate Cycle

From LP Turbine

condensor

Condensate

PumpEjector

Gland Steam

LPH1

LPH2 LPH3

Dearrator

FFED WATER CYCLE

Boiler Feed Pump

HPH5

HPH6 HPH7

Feed Water Line

EconomizerBoiler Drum

Down Corner

Water

STEAM CYCLE

From Boiler Drum

LT Super Heater

Final HeaterMain Steam

Line

HP TurbineCold Reheat

Line

ReheaterHot Reheat

Line

Low pressure Line

To Condensor

CONTROL & INSTRUMENTATION

INTRODUCTION

C&I LABS

CONTROL & MONITORING MECHENISM

PRESSURE MONITORING

TEMPERATURE MONITORING

FLOW MEASUREMENT

CONTROL VALVES

INTRODUCTION This division basically calibrates various instruments and takes care of any faults occur in any of the

auxiliaries in the plant.

“Instrumentation can be well defined as a technology of using instruments to measure and

control the physical and chemical properties of a material.”

C&I LABS Control and Instrumentation Department has following labs:

1. Manometry Lab

2. Protection and Interlocks Lab

3. Automation Lab

4. Electronics Lab

5. Water Treatment Plant

6. Furnaces Safety Supervisory System Lab

OPERATION AND MAINTAINANCE Control and Instrumentation Department has following Control Units:

1. Unit Control Board

2. Main Control Board

3. Analog & Digital Signal Control

4. Current Signal Control

This department is the brain of the plant because from the relays to transmitters followed by the

electronic computation chipsets and recorders and lastly the controlling circuitry, all fall under

this.

A View of Control Room at BTPS

1. Manometry Lab

TRANSMITTERS It is used for pressure measurements of gases and liquids, its working principle is that the input

pressure is converted into electrostatic capacitance and from there it is conditioned and amplified. It

gives an output of 4-20 ma DC. It can be mounted on a pipe or a wall. For liquid or steam

measurement transmitters is mounted below main process piping and for gas measurement

transmitter is placed above pipe.

MANOMETER It’s a tube which is bent, in U shape. It is filled with a liquid. This device corresponds to a difference

in pressure across the two limbs.

BOURDEN PRESSURE GAUGE It’s an oval section tube. It’s one end is fixed. It is provided with a pointer to indicate the pressure

on a calibrated scale. It is of 2 types:

(a) Spiral type: for Low pressure measurement.

(b) Helical Type: for High pressure measurement.

While selecting Pressure Gauge these parameters should keep in mind-

1. Accuracy

2. Safety

3. Utility

4. Price

ACCURACY

Higher Accuracy implies Larger Dial Size for accuracy of small and readable pressure scale

increments.

SAFETY

While selecting Pressure Gauge it should consider that Gauge Construction Material should be

chemically compatible with the environment either inside or outside it.

UTILITY

It should keep it mind that range of the Gauge should be according to our need else Overpressure

Failure may occur resulting in damage of Gauge.

PRICE

Lager the Gauge’s Dial size larger would be our price. Better Gauge’s Construction material also

increses the cost. So they must be chosen according to our need.

2. Protection and Interlock Lab

INTERLOCKING It is basically interconnecting two or more equipments so that if one equipment fails other one can

perform the tasks. This type of interdependence is also created so that equipments connected

together are started and shut down in the specific sequence to avoid damage. For protection of

equipments tripping are provided for all the equipments. Tripping can be considered as the series

of instructions connected through OR GATE, which trips the circuit. The main equipments of this lab

are relay and circuit breakers. Some of the instrument uses for protection are:.

RELAY

It is a protective device. It can detect wrong condition in electrical circuits by constantly measuring

the electrical quantities flowing under normal and faulty conditions. Some of the electrical

quantities are voltage, current, phase angle and velocity. 2. FUSES It is a short piece of metal

inserted in the circuit, which melts when heavy current flows through it and thus breaks the circuit.

Usually silver is used as a fuse material because:

a) The coefficient of expansion of silver is very small. As a result no critical fatigue occurs and

thus the continuous full capacity normal current ratings are assured for the long time.

b) The conductivity of the silver is unimpaired by the surges of the current that produces

temperatures just near the melting point.

c) Silver fusible elements can be raised from normal operating temperature to vaporization

quicker than any other material because of its comparatively low specific heat.

Miniature Circuit Breaker-

They are used with combination of the control circuits to.

a) Enable the staring of plant and distributors.

b) Protect the circuit in case of a fault. In consists of current carrying contacts, one movable

and other fixed. When a fault occurs the contacts separate and are is stuck between them.

There are three types of trips

I. MANUAL TRIP

II. THERMAL TRIP

III. SHORT CIRCUIT TRIP.

Protection and Interlock System-

1. HIGH TENSION CONTROL CIRCUIT for high tension system the control system are excited by

separate D.C supply. For starting the circuit conditions should be in series with the starting

coil of the equipment to energize it. Because if even a single condition is not true then

system will not start.

2. LOW TENSION CONTROL CIRCUIT For low tension system the control circuits are directly

excited from the 0.415 KV A.C supply.

The same circuit achieves both excitation and tripping. Hence the tripping coil is provided for

emergency tripping if the interconnection fails.

3. AUTOMATION LAB This lab deals in automating the existing equipment and feeding routes. Earlier, the old technology

dealt with only (DAS) Data Acquisition System and came to be known as primary systems. The

modern technology or the secondary systems are coupled with (MIS) Management Information

System. But this lab universally applies the pressure measuring instruments as the controlling force.

However, the relays are also provided but they are used only for protection and interlocks.

4. PYROMETRY LAB

LIQUID IN GLASS THERMOMETER –

Mercury in the glass thermometer boils at 340° C which limits the range of temperature that can

be measured. It is L shaped thermometer which is designed to reach all inaccessible places.

1. ULTRA VIOLET CENSOR-

This device is used in furnace and it measures the intensity of ultra violet rays there and according

to the wave generated which directly indicates the temperature in the furnace.

2, THERMOCOUPLES –

This device is based on SEEBACK and PELTIER effect. It comprises of two junctions at different

temperature. Then the emf is induced in the circuit due to the flow of electrons. This is an

important part in the plant.

3. RTD (RESISTANCE TEMPERATURE DETECTOR) –

It performs the function of thermocouple basically but the difference is of a resistance. In this due

to the change in the resistance the temperature difference is measured. In this lab, also the

measuring devices can be calibrated in the oil bath or just boiling water (for low range devices) and

in small furnace (for high range devices).

5. FURNACE SAFETY AND SUPERVISORY SYSTEM LAB This lab has the responsibility of starting fire in the furnace to enable the burning of coal. For first

stage coal burners are in the front and rear of the furnace and for the second and third stage corner

firing is employed. Unburnt coal is removed using forced draft or induced draft fan. The

temperature inside the boiler is 1100°C and its heights 18 to 40 m. It is made up of mild steel. An

ultra violet sensor is employed in furnace to measure the intensity of ultra violet rays inside the

furnace and according to it a signal in the same order of same mV is generated which directly

indicates the temperature of the furnace. For firing the furnace a 10 KV spark plug is operated for

ten seconds over a spray of diesel fuel and pre-heater air along each of the feeder-mills. The

furnace has six feeder mills each separated by warm air pipes fed from forced draft fans. In first

stage indirect firing is employed that is feeder mills are not fed directly from coal but are fed from

three feeders but are fed from pulverized coalbunkers. The furnace can operate on the minimum

feed from three feeders but under no circumstances should anyone be left out under operation, to

prevent creation of pressure different with in the furnace, which threatens to blast it.

6. ELECTRONICS LAB This lab undertakes the calibration and testing of various cards. It houses various types of analytical

instruments like oscilloscopes, integrated circuits, cards auto analyzers etc.

Various processes undertaken in this lab are:

1. Transmitter converts mV to mA.

2. Auto analyzer purifies the sample before it is sent to electrodes. It extracts the magnetic portion.

ANNUNCIATIN CARDS

They are used to keep any parameter like temperature etc. within limits. It gets a signal if

parameter goes beyond limit. It has a switching transistor connected to relay that helps in alerting

the UCB.

CONTROL & MONITORING MECHANISMS There are basically two types of Problems faced in a Power Plant

1. Metallurgical

2. Mechanical

Mechanical Problem can be related to Turbines that is the max speed permissible for a turbine is

3000 rpm so speed should be monitored and maintained at that level.

Metallurgical Problem can be view as the max Inlet Temperature for Turbine is 1060° C so

temperature should be below the limit. Monitoring of all the parameters is necessary for the safety

of both:

1. Employees

2. Machines

So the Parameters to be monitored are:

1. Speed

2. Temperature

3. Current

4. Voltage

5. Pressure

6. Eccentricity

7. Flow of Gases

8. Vacuum Pressure

9. Valves

10. Level

11. Vibration

PRESSURE MONITORING Pressure can be monitored by three types of basic mechanisms

1. Switches

2. Gauges

3. Transmitter type

For gauges we use Bourdon tubes. The Bourdon Tube is a non-liquid pressure measurement device.

It is widely used in applications where inexpensive static pressure measurements are needed.

A typical Bourdon tube contains a curved tube that is open to external pressure input on

one end and is coupled mechanically to an indicating needle on the other end, as shown

schematically below.

Typical Bourdon Tube Pressure Gages

For Switches pressure switches are used and they can be used for digital means of monitoring as

switch being ON is referred as high and being OFF is as low.

All the monitored data is converted to either Current or Voltage parameter.

The Plant standard for current and voltage are as under

• Voltage : 0 – 10 Volts range

• Current : 4 – 20 milli-Amperes

We use 4mA as the lower value so as to check for disturbances and wire breaks.

Accuracy of such systems is very high.

ACCURACY : ± 0.1 %

Programmable Logic Circuits (PLCs) are used in the process as they are the heart of

Instrumentation.

TEMPERATURE MONITORING

We can use Thermocouples or RTDs for temperature monitoring. Normally RTDs are used for low

temperatures.

Thermocouple selection depends upon two factors:

1. Temperature Range

2. Accuracy Required

Normally used Thermocouple is K Type Thermocouple:

In this we use Chromel (Nickel-Chromium Alloy) / Alumel (Nickel-Aluminium Alloy) as two metals.

This is the most commonly used general purpose thermocouple. It is inexpensive and, owing to its

popularity, available in a wide variety of probes. They are available in the−200°C to +1200°C range.

Sensitivity is approximately 41 μV/°C.

RTDs are also used but not in protection systems due to vibrational errors.

We pass a constant current through the RTD. So that if R changes then the Voltage also changes

RTDs used in Industries are Pt100 and Pt1000

Pt100 : 0°C – 100 Ω ( 1 Ω = 2.5 0C )

Pt1000 : 0°C - 1000Ω

Pt1000 is used for higher accuracy.

The gauges used for Temperature measurements are mercury filled Temperature gauges.

For Analog medium thermocouples are used and for Digital medium Switches are used which are

basically mercury switches.

FLOW MEASUREMENT

Flow measurement does not signify much and is measured just for metering purposes and for monitoring the processes

ROTAMETERS: A Rotameter is a device that measures the flow rate of liquid or gas in a closed tube. It isoccasionally misspelled as 'Rotometer'. It belongs to a class of meters called variable area meters, which measure flow rate by allowing the cross sectional area the fluid travels through to vary, causing some measurable effect. A rotameter consists of a tapered tube, typically made of glass, with a float inside that is pushed up by flow and pulled down by gravity. At a higher flow rate more area (between the float and the tube) is needed to accommodate the flow, so the float rises. Floats are made in many different shapes, with spheres and spherical ellipses being the most common. The float is shaped so that it rotates axially as the fluid passes. This allows you to tell if the float is stuck since it will only rotate if it is not. For Digital measurements Flap system is used. For Analog measurements we can use the following methods :

1. Flow meters 2. Venturimeters / Orifice meters 3. Turbines 4. Mass flow meters ( oil level ) 5. Ultrasonic Flow meters 6. Magnetic Flow meter ( water level )

Selection of flow meter depends upon the purpose, accuracy and liquid to be measured so different types of meters used .

TURBINE TYPE: They are simplest of all. They work on the principle that on each rotation of the turbine a pulse is generated and that pulse is counted to get the flow rate.

VENTURIMETERS :

Referring to the diagram, using Bernoulli's equation in the special case of incompressible fluids (such as the approximation of a water jet), the theoretical pressure drop at the constriction would be given by (ρ/2)(v2

2 - v12).

And we know that rate of flow is given by: Flow = k √ (D.P) Where DP is Differential Presure or the Pressure Drop.

CONTROL VALVES A valve is a device that regulates the flow of substances (either gases, fluidized solids, slurries, or liquids) by opening, closing, or partially obstructing various passageways. Valves are technically pipe fittings, but usually are discussed separately. Valves are used in a variety of applications including industrial, military, commercial, residential, transportation. Plumbing valves are the most obvious in everyday life, but many more are used. Some valves are driven by pressure only, they are mainly used for safety purposes in steam engines and domestic heating or cooking appliances. Others are used in a controlled way, like in Otto cycle engines driven by a camshaft, where they play a major role in engine cycle control. Many valves are controlled manually with a handle attached to the valve stem. If the handle is turned a quarter of a full turn (90°) between operating positions, the valve is called a quarter-turn valve. Butterfly valves, ball valves, and plug valves are often quarter-turn valves. Valves can also be controlled by devices called actuators attached to the stem. They can be electromechanical actuators such as an electric motor or solenoid, pneumatic actuators which are controlled by air pressure, or hydraulic actuators which are controlled by the pressure of a liquid such as oil or water. So there are basically three types of valves that are used in power industries besides the handle valves. They are :

· PNEUMATIC VALVES – They are air or gas controlled which is compressed to turn or move them

· HYDRAULIC VALVES – They utilize oil in place of Air as oil has better compression

· MOTORISED VALVES – These valves are controlled by electric motors

FURNACE SAFEGUARD SUPERVISORY SYSTEM

FSSS is also called as Burner Management System (BMS). It is a microprocessor based programmable logic controller of proven design incorporating all protection facilities required for such system. Main objective of FSSS is to ensure safety of the boiler. The 95 MW boilers are indirect type boilers. Fire takes place in front and in rear side. That’s why it’s called front and rear type boiler. The 210 MW boilers are direct type boilers (which means that HSD is in direct contact with coal) firing takes place from the corner. Thus it is also known as corner type boiler.

IGNITER SYSTEM Igniter system is an automatic system, it takes the charge from 110kv and this spark is brought in front of the oil guns, which spray aerated HSD on the coal for coal combustion. There is a 5 minute delay cycle before igniting, this is to evacuate or burn the HSD. This method is known as PURGING.

PRESSURE SWITCH Pressure switches are the devices that make or break a circuit. When pressure is applied, the switch under the switch gets pressed which is attached to a relay that makes or break the circuit. Time delay can also be included in sensing the pressure with the help of pressure valves. Examples of pressure valves: 1. Manual valves (tap) 2. Motorized valves (actuator) – works on motor action 3. Pneumatic valve (actuator) _ works due to pressure of compressed air 4. Hydraulic valve

IT DEPARTMENT

IT BTPS VISION

IT ROLE & RESPONSIBLITIES @BTPS

IT APPLICATION @BTPS

BENEFITS OF IT INNOVATION @ BTPS

VARIOUS E-SERVICES @BTPS

SMS ALERT @ BTPS

REWARDS & RECOGNITION

BTPS IT VISION INTEGRATED IT ENABLEMENT OF BUSINESS PROCESSES FOR EFFICIENT PLANT

MANAGEMENT

INFORMATION ANYTIME ANYWHERE

IT ROLE & RESPONSIBILITIES @ BTPS 1. Development, Implementation & Support for Local Applications

2. Procurement & Maintenance of IT Infrastructure ( PCs, Printers, Servers & Network LAN,WAN

etc)

3. Support to users for ERP & modules to supplement ERP.

4. Customization & Implementation support for BTPS Applications to other projects.

IT APPLICATION @ BTPS At BTPS, Information Technology has been used extensively to manage following business

processes-

1. Maintenance Management System

2. Materials Management System

3. Financial Accounting System

4. Contracts Management System

5. Operations & ABT Monitoring System

6. Coal Monitoring & Accounting System

7. Hospital Management System

8. HR, T/S & Training Management System

9. Office Automation & Communication System

10. E-Samadhan complaints monitoring system

Benefits of IT Innovations @ BTPS

1. OPERATIONS

Important & critical parameters of Power Plant operation are monitored online to enable effective

control on operation of various equipments and reduce down time. Online load analysis & Generation

values are monitored to have optimum load balance of various units. Auxiliary power consumption

monitored and controlled. Meritorial operation practicing enabled.

2. MAINTENANCE

Better control over maintenance cost by way of online information available through the system.Based

on failure analysis and equipment history, modified maintenance strategy of Preventive, Predictive and

Risk Based maintenance is implemented. Equipment spares planning are streamlined by way of Annual

requirement, Vendor wise, linked to Equipment, Standardization of defects and repair codes for easy

filling of Work Order Card, for future analysis.

3. MATERIALS

Material Planning and Procurement system streamlined, resulting in reduction in Administrative lead

Time. Further, procurement on Annual Rate Contract basis enabled through the system, Ordering on

actual need basis (just in time). This further reduces lead time and Inventory carrying.

Detection of duplicate and obsolete items, standardization of material description and specification,

Cleaning and Weeding of redundant data, resulting in overall system improvement and functionalities,

Availability of coal stock status online, reduction in demurrages paid to railways.

4. OFFICE AUTOMATION AND COMMUNICATION

With implementation of e-Desk/e-broadcast, e-alerts, auto mail and BTPS website, information is

available instantly to all and all time, resulting in tremendous reduction in paper communication and

cost.

BTPS IT Applications Highlights 1. Single Login screen, Pass Word & Role based secured access .

2. G.U. Interface, Easy information retrieval/search facility.

3. Information captured once at source.

4. Automation of routine activities.

A View of BTPS Login Page

ERP/SAP MODULES IMPLEMENTED

(ERP-ENTERPRISE RESOURCES PLANNING)

Maintenance Management- PM

Finance Management- FI

Materials Management- MM

Human Resource Management- HR

Operations Management- OPN

Employee Self Service- ESS

Maintenance Management system, Anurakshan @ BTPS 1. Permit to Work Issue with detailed feedback.

2. Daily Plant Meeting minutes generated online.

3. Trends of defects priority wise /department wise for a period.

4. Equipment history with detailed feedback available.

5. Analysis of repeated equipment failure for corrective action.

6. Standardization of defects & repair codes.

7. Interface with Materials Management System & CMS for WOC cost

MATERIAL & CONTRACT MANAGEMENT SYSTEM (CMS) 1. Initiation and approval of Contract Proposal.

2. Preparation of Tender Documents and approvals. 3. Preparation and processing of Bills.

FINANANCIAL ACCOUNTING SYSTEM (FAS) 1. Status of Income Tax Details, PF slips, Leave, Accrued Interest, and Earning Card available online.

2. Fund Flow Statements & other Reports for day to day functioning.

3. Bank Reconciliation.

Coal Accounting System (CAS) 1. Online uploading of Wagon wise Weight from Wagon Tipplers.

2. Coal and Rail Freight bill payments accounting & reconciliation.

3. Tariff Summary, coal accounting and MIS reports generated from the system.

HOSPITAL MANAGEMENT SYSTEM (HMS) 1. Online patient registration

2. Doctor’s prescription

3. Medicines issues/availability

4. Investigation reports

5. Annual check-ups, patient history , referrals etc.

A View of Hospital Management System

HR/TRAINING MANAGEMENT SYSTEM 1. Computerized Attendance recording system.

2. Employee database to record/ update information of employees

3. Township/Quarter management system.

4. Performance Management analysis & evaluation system.

A View of Tanning Management System

VARIOUS E-SERVICES @ BTPS

SMS ALERT @ BTPS 1. One more IT initiative for fast & convenient way to information sharing thru SMS

2. Automatic SMS alert is already in use for plant load & unit Trip.

3. Send SMS instantly or scheduled date/time.

4. SMS to groups or individual numbers.

E-SERVICES OFFICE

AUTOMATION & COMMUNICATION

KEY FOCUS AREA

TOWAREDS PAPERLESS OFFICE

E-Desk , E-Broadcast, SMS & E-Mail as Primary

Communication & Document Delivery

System.

Plant Load & Unit Trip SMS Alert

REWARDS & RECOGNITION

Badarpur has achieved unique distinction of being; First site in NTPC, with independent

initiative of Development & Implementation of new Oracle based integrated online

Applications, with in house effort. This has been appreciated by NTPC higher management.

BTPS Received Golden Peacock award for IT Innovation in 2004.

REFERENCE TRAINING REPORTS OF PAST YEARS AT NALANDA LIBRARY

INTERNET

DOCUMENTS OF IT DEPARTMENT