7/31/2019 ntpc 1 (1)

1/81

1

INDEX

1.Acknowledgements2.About the company2.1. NTPC group2.2. Evolution of NTPC2.3. Electricity from Coal

3.Definition of Automation4.Benefits of Automation5.Control Mechanisms6.Control & Instrumentation6.1. Manometry Lab6.2.

Protection & Interlock Lab

7/31/2019 ntpc 1 (1)

2/81

2

6.3. Automation Lab6.4.

Pyrometry Lab

6.5.Furnace Safety & Supervisory

Lab

6.6.Electronics Lab

7.Ecological MonitoringProgramme

8.Ash Utilization9.Environment Management &

safety System

7/31/2019 ntpc 1 (1)

3/81

3

List of Figures

Fig. 1 Installed Capacity &

its Growth

Fig. 2 Fortin Barometer

Fig. 3 Typical

Arrangement of Bourdon Gauge

Fig. 4 Dewrance Critical

Pressure Gauge

7/31/2019 ntpc 1 (1)

4/81

4

Fig. 5 Air Purge Level

MeasurementFig. 6 Rod Type

Thermostat

Fig. 7 Helical Bi-Metal

Strip

Fig. 8 Liquid Expansion

Thermometer with C Bourden

Fig. 9 Bulb Forms

Fig.10 Thermocouple

7/31/2019 ntpc 1 (1)

5/81

5

ABOUT THE COMPANY

7/31/2019 ntpc 1 (1)

6/81

6

Corporate Vision:

A world class integrated power

major, powering Indias growth,

with increasing global presence

Core Values:

B-Business Ethics

C-Customer Focus

O-Organizational & Professional

pride

M-Mutual Respect and Trust

I- Innovation & Speed

T-Total quality for Excellence

NTPC Limited is the largest thermal

power generating company of India.

A public sector company, it was

7/31/2019 ntpc 1 (1)

7/81

7

incorporated in the year 1975 to

accelerate power development in the

country as a wholly owned company

of the Government of India. At

present, Government of India holds

89.5% of the total equity shares of

the company and the balance 10.5%

is held by FIIs, Domestic Banks,

Public and others. Within a span of

31 years, NTPC has emerged as a

truly national power company, with

power generating facilities in all the

major regions of the country.

7/31/2019 ntpc 1 (1)

8/81

8

Figure 1

EVOLUTION OF NTPC

NTPC was set up in 1975

with 100% ownership bythe Government of India.

In the last 30 years,

NTPC has grown into the

1975

7/31/2019 ntpc 1 (1)

9/81

9

largest power utility in

India.

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.

NTPC became a listed

company with majority

1997

2004

7/31/2019 ntpc 1 (1)

10/81

10

Government ownership

of 89.5%.

NTPC becomes third

largest by Market

Capitalisation of listed

companies

The company

rechristened as NTPC

Limited in line with its

changing business

portfolio and transform

itself from a thermal

power utility to an

integrated power utility.

2005

7/31/2019 ntpc 1 (1)

11/81

11

NTPC is the largest power utility inIndia, accounting for about 20% of

Indias installed capacity.

NTPC Limited

Subsidiaries

NTPC Vidyut Vyapar

Nigam Limited

100%

NTPC Electric Supply

Co. Limited

100%

Pipavav Power

Development Co. Ltd

100%

NTPC Hydro

Limited

100%

7/31/2019 ntpc 1 (1)

12/81

12

Joint Ventures

Utility Powertech

Limited

50%

NTPC Alstom Power

Services Pvt. Limited

50%

Bhilai Electric Supply

Co. Pvt. Limited

50%

NTPC-SAIL Power

Company Pvt. Limited

50%

Ratnagiri Gas &

Power Private Ltd

28.33%

PTC India Limited

8%

NTPC Tamilnadu

Energy Co. Limited

50%

7/31/2019 ntpc 1 (1)

13/81

13

GENERATION OF ELECTRICITY

FROM COAL

7/31/2019 ntpc 1 (1)

14/81

14

Coal from the coal wagons is

unloaded with the help of wagon

tipplers in the C.H.P. this coal is

taken to the raw coal bunkers with

the help of conveyor belts. Coal is

then transported to bowl mills bycoal feeders where it is pulverized

and ground in the powered form.

This crushed coal is taken away to

the furnace through coal pipes withthe help of hot and cold mixture P.A

fan. This fan takes atmospheric air,

a part of which is sent to pre

heaters while a part goes to the mill

for temperature control.

Atmospheric air from F.D fan in the

air heaters and sent to the furnace

7/31/2019 ntpc 1 (1)

15/81

15

as combustion air. Water from

boiler feed pump passes through

economizer and reaches the boiler

drum . Water from the drum passes

through the down comers and goes

to the bottom ring header. Waterfrom the bottom ring header is

divided to all the four sides of the

furnace. Due to heat density

difference the water rises up in thewater wall tubes. This steam and

water mixture is again taken to the

boiler drum where the steam is sent

to super heaters for super heating.

The super heaters are located inside

the furnace and the steam is super

heated (540 degree Celsius) and

7/31/2019 ntpc 1 (1)

16/81

16

finally it goes to the turbine. Fuel

gases from the furnace are

extracted from the induced draft

fan, which maintains balance draft

in the furnace with F.D fan. These

fuel gases heat energy to thevarious super heaters and finally

through air pre heaters and goes to

electrostatic precipitators where

the ash particles are extracted. Thisash is mixed with the water to from

slurry is pumped to ash period. The

steam from boiler is conveyed to

turbine through the steam pipes

and through stop valve and control

valve that automatically regulate

the supply of steam to the turbine.

7/31/2019 ntpc 1 (1)

17/81

17

Stop valves and controls valves are

located in steam chest and governor

driven from main turbine shaft

operates the control valves the

amount used. Steam from

controlled valves enter highpressure cylinder of turbines, where

it passes through the ring of blades

fixed to the cylinder wall. These act

as nozzles and direct the steam intoa second ring of moving blades

mounted on the disc secured in the

turbine shaft. The second ring turns

the shaft as a result of force of

steam. The stationary and moving

blades together.

7/31/2019 ntpc 1 (1)

18/81

18

AUTOMATION : THE DEFINITION

The word automation is widely used

today in relation to various types of

applications, such as office

automation, plant or process

automation.

This subsection presents the

application of a control system for

7/31/2019 ntpc 1 (1)

19/81

19

the automation of a process / plant,

such as a power station. In this lastapplication, the automation actively

controls the plant during the three

main phases of operation: plant

start-up, power generation in stable

or put During plant start-up and

shut-down, sequence controllers as

well as long range modulating

controllers in or out of operation

every piece of the plant, at the

correct time and in coordinated

modes, taking into account safety as

well as overstressing limits.

7/31/2019 ntpc 1 (1)

20/81

20

During stable generation of power,

the modulating portion of theautomation system keeps the actual

generated power value within the

limits of the desired load demand.

During major load changes, the

automation system automatically

redefines new set points andswitches ON or OFF process pieces,

to automatically bring the individual

processes in an optimallycoordinated way to the new desired

load demand. This load transfer is

executed according to pre-

7/31/2019 ntpc 1 (1)

21/81

21

programmed adaptively controlled

load gradients and in a safe way.

AUTOMATION: THE BENEFITS

7/31/2019 ntpc 1 (1)

22/81

22

The main benefits of plant

automation are to increase overall

plant availability and efficiency. The

increase of these two factors is

achieved through a series of features

summarized as follows:

1. Optimisation of house loadconsumption during plant start-

up, shut-down and operation,

via:

Faster plant start-up throughelimination of control errors

creating delays.

Faster sequence of controlactions compared to manual

7/31/2019 ntpc 1 (1)

23/81

23

ones. Figures 1 shows the

sequence of a rapid restart

using automation for a typical

coal-fired station. Even a well-

trained operator crew would

probably not be able to bring

the plant to full load in the

same time without considerable

risks.

Co-ordination of house load tothe generated power output.

2. Ensure and maintain plantoperation, even in case of

disturbances in the control

system, via:

7/31/2019 ntpc 1 (1)

24/81

24

Coordinated ON / OFF andmodulating control switchover

capability from a sub process to

a redundant one.

Prevent sub-process andprocess tripping chain reaction

following a process component

trip.

3. Reduce plant / processshutdown time for repair and

maintenance as well as repair

costs, via:

Protection of individual processcomponents against overstress

7/31/2019 ntpc 1 (1)

25/81

25

(in a stable or unstable plant

operation).

Bringing processes in a safestage of operation, where

process components are

protected against overstress

CONTROL AND MONITORING

MECHANISMS

There are basically two types of

Problems faced in a Power Plant

7/31/2019 ntpc 1 (1)

26/81

26

Metallurgical

Mechanical

Mechanical Problemcan 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

Turbile is 1060 oC so temperature

should be below the limit.

7/31/2019 ntpc 1 (1)

27/81

27

Monitoring of all the parameters is

necessary for the safety of both:

EmployeesMachines

So the Parameters to be monitored

are :

SpeedTemperatureCurrentVoltagePressure

7/31/2019 ntpc 1 (1)

28/81

28

Eccentricity

Flow of GasesVaccum PressureValvesLevelVibration

CONTROL AND INSTRUMENTATION

This division basically calibrates

various instruments and takes care

of any faults occur in any of the

auxiliaries in the plant. It has

following labs:

7/31/2019 ntpc 1 (1)

29/81

29

1. MANOMETRY LAB2. PROTECTION AND INTERLOCK

LAB

3. AUTOMATION LAB4. WATER TREATEMENT LAB5. FURNACE SAFETY

SUPERVISORY SYSTEM(FSSS)6. ELECTRONICS TEST LAB

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.

7/31/2019 ntpc 1 (1)

30/81

30

MANOMETRY LAB

7/31/2019 ntpc 1 (1)

31/81

31

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 andamplified. 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 ismounted below main process piping

and for gas measurement

transmitter is placed above pipe.

MANOMETER: Its a tube which is

bent, in U shape. It is filled with a

liquid. This device corresponds to a

7/31/2019 ntpc 1 (1)

32/81

32

difference in pressure across the

two limbs.

BOURDEN PRESSURE GAUGE :Its

an oval section tube. Its one end is

fixed. It is provided with a pointer to

indicate the pressure on acalibrated scale. It is of 2 types: (a)

Spiral type: for Low pressure

measurement.

(b) Helical Type: for High pressure

measurement.

Pressure Measurement

The U-Tube or Manometer: Liquid

contained in a tube bend in the form

of a U will respond to a difference in

pressure across the two limbs. A

7/31/2019 ntpc 1 (1)

33/81

33

glass tube of uniform cross-

sectional-area is bent to form a U

and partly filed with a liquid of

known density 'd' p.s.l.

Measurement of Atmospheric

Pressure: Atmospheric pressure willsupport calcium of Mercury

approximately 30 inches in a U-tube

provided a good vacuum is

maintained in one limb. Ifa U-tube isreplaced with a straight limb about

35 inches long, one end closed, then

being filed with clean, dry mercury

and then inverted in a container ofmercury open to the atmosphere, the

mercury would fall in the tube

forming a good vacuum above it.

7/31/2019 ntpc 1 (1)

34/81

34

7/31/2019 ntpc 1 (1)

35/81

35

Fig.2Fortin.Barometer

Single Tube Manometer This is

used for measuring low pressure and

for testing and recalibration low-

pressure instruments of al types. If

the ratio of the area of one tube is

considerably greater than other, then

practically al the movement takes

place in the smal manometer tube

and for al practical purposes only the

one limb need be read.

Kenotometer The low pressures

produced in steam condensers are

7/31/2019 ntpc 1 (1)

36/81

36

usually measured in inches of

mercury, marking downwards from

atmospheric pressure. A high

working vacuum of 29.5 inches of

mercury is the same as an absolute

pressure of 0.5 inch of mercury, or

approximately 0.25 p.s.i (absolute).

One device for measuring the

absolute pressure in a condenser is

the Kenotometer.

Bourdon Pressure Gauge: This is

the most commonly used of al

pressure measuring devices. (Range

10- 80,000 p.s.i). Here, a tube ofoval section is bent into a circular

arc. One end is sealed and the other

end fixed to a solid block into which

the applied pressure is fed. The tube

7/31/2019 ntpc 1 (1)

37/81

37

will "uncurl" as the pressure

(operating Force) increases, or will

'Curl up' as the vacuum increases; so

giving a movement of the free end

which is proportional to the change

in pressure. The Controlling Force

will depend upon the thickness of

the tube and the material from which

it is made.

7/31/2019 ntpc 1 (1)

38/81

38

Fig.3 Typical

Arrangement of Bourden Gauge

SpecialTypes Of Pressure Gauges

Spiral Tube: This type is used for

low-pressure indication and

recording when a C-shaped Bourdentube is not suitable and where power

is required. By making the oval tube

in the form of a spiral an enlarged

movement of the free end isachieved and thus the tube becomes

more sensitive over pressure ranges

below 10 p.s.i.

Helical Tube: For higher pressures

the tube is wound in the form of a

helix and is often used in pressure

recorders. Range 0-80,000 p.s.i.

7/31/2019 ntpc 1 (1)

39/81

39

Critical Type: This is used in boiler

houses to enable distant reading of

the steam pressure to be made to the

nearest 1 p.s.i over a range of say

15 p.s.i. The movement of a pressure

sensitive element is transmitted to a

pointer and scale via linkages, which

only allow the pointer to operate

over a selected range of pressure to

either side of the normal steam

pressure.

7/31/2019 ntpc 1 (1)

40/81

40

Fig.4 Dewrance Critical PressureGauge

Measurement of Level

7/31/2019 ntpc 1 (1)

41/81

41

Direct Methods

'Sight Glass' is used for localindication on closed or open vessels.

A sight glass is a tube of toughened

glass connected at both ends through

packed unions and vessel. The liquidlevel will be the same as that in the

vessel. Valves are provided for

isolation and blow down.

"Float with Gauge Post" is normallyused tor local indication on closed or

open vessels.

"Float Operated Dial" are used for

small tanks and congested areas. The

float arm is connected to a quadrant

and pinion which rotates the pointer

over a scale.

7/31/2019 ntpc 1 (1)

42/81

42

Pressure operated types Since the

pressure acting on any area at the

bottom of a tank depends only upon

the depth and density of the

contained liquid, a measure of this

pressure is proportional to the liquid

level.

Bourden Pressure Gauge A

Bourdon pressure gauge calibrated

in any fact head is often connectedto a tank at or near the datum level.

"Mercury Manometer" is used for

remote indication of liquid level.

The working principle is the same asthat of a manometer one limp of a

U-tube is connected to the tank, the

other being open to atmosphere. The

manometer liquid must not mix with

7/31/2019 ntpc 1 (1)

43/81

43

the liquid in the vessel, and where

the manometer is at a different level

to the vessel, the static head must be

allowed in the design of the

manometer.

'Diaphragm Type' is used forremote level indication in open tanks

or docks etc. A pressure change

created by the movement of a

diaphragm is proportional to achange in liquid level above the

diaphragm. This consists of a

cylindrical box with a rubber or

plastic diaphragm across its openend as the level increases .the liquid

pressure on the diaphragm increases

and the air inside is compressed.

This pressure is transmitted via a

7/31/2019 ntpc 1 (1)

44/81

44

capillary tube to an indicator or

recorder incorporating a pressure

measuring element.

Sealed Capsule Type The

application and principle is the same

as for the diaphragm box. In thistype, a capsule filed with an inert

gas under a slight pressure is

exposed to the pressure due to the

head of liquid and is connected by acapillary to an indicator. In some

cases the capsule is fitted external to

the tank and is so arranged that it

can be removed whilst the tank isstill full, a spring loaded valve

automatically shutting of the tapping

point.

7/31/2019 ntpc 1 (1)

45/81

45

Air Purge System This system

provides the simplest means of

obtaining an indication of level, or

volume, at a reasonable distance and

above or below, the liquid being

measured. The pressure exerted

inside an open ended tube below the

surface of a liquid is proportional to

the depth of the liquid.

Fig.5 Air Purge Level

Measurement

7/31/2019 ntpc 1 (1)

46/81

46

PROTECTION AND INTERLOCK LAB

INTERLOCKING : It is basically

interconnecting two or more

equipments so that if one

equipments 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 providedfor all the equipments. Tripping can

be considered as the series of

instructions connected through OR

GATE. When a fault occurs and any

7/31/2019 ntpc 1 (1)

47/81

47

one of the tripping is satisfied a

signal is sent to the relay, which

trips the circuit. The main

equipments of this lab are relay and

circuit breakers. Some of the

instrument uses for protection are:1. 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

7/31/2019 ntpc 1 (1)

48/81

48

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 fullcapacity normal current ratings are

assured for the long time. b) The

conductivity of the silver is

unimpaired by the surges of thecurrent 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.

7/31/2019 ntpc 1 (1)

49/81

49

3. 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 carryingcontacts, one movable and other

fixed. When a fault occurs the

contacts separate and are is stuck

between them. There are threetypes of - MANUAL TRIP - THERMAL

TRIP - SHORT CIRCUIT TRIP

7/31/2019 ntpc 1 (1)

50/81

50

AUTOMATION LAB

This lab deals in automating theexisting equipment and feeding

routes. Earlier, the old technology

dealt with only (DAS) Data

Acquisition System and came to beknown 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.

7/31/2019 ntpc 1 (1)

51/81

51

However, the relays are also

provided but they are used only for

protection and interlocks. Once the

measured is common i.e. pressure

the control circuits can easily be

designed with single chips havingmultiple applications. Another point

is the universality of the supply, the

laws of electronic state that it can

be any where between 12V and 35Vin the plant. All the control

instruments are excited by 24V

supply (4-20mA) because voltage

can be mathematically handled with

ease therefore all control systems

use voltage system for

computation. The latest technology

7/31/2019 ntpc 1 (1)

52/81

52

is the use of ETHERNET for control

signals.

7/31/2019 ntpc 1 (1)

53/81

53

PYROMETERY LAB

The most important parameter in

thermal power plant is temperature

and its measurement plays a vital

role in safe operation of the plant.

Rise of temperature in a substance is

due to the resultant increase in

molecular activity of the substance

on application of heat; which

increases the internal energy of the

material

Temperature Measurement

. The change may be observed with

substance itself or in a subsidiary

7/31/2019 ntpc 1 (1)

54/81

54

system in thermodynamic

equilibrium.

Fig.6 Rod Type Thermostat

Solid Rod Thermometers: A

temperature sensing - Controlling

device may be designed

incorporating in its construction the

principle that some metals expand

7/31/2019 ntpc 1 (1)

55/81

55

more than others for the same

temperature range.

Bi-Metalic Strip : These are

composed of two metals, as the

name implies, whose coeficients of

linear expansion are dissimilar.These two metal plates are welded

together as a sandwich. When

heated, both metals expand, but the

metal with greatest coeficient oflinear expansion wil expand more

causing the sandwich to curl up or

down depending on the position of

this metal.

7/31/2019 ntpc 1 (1)

56/81

56

Fig.7 Helical Bi-

Metallic Strip

Liquid in Glass Thermometers :

The coeficient of cubical expansionof mercury is about eight time

greater that of glass. Therefore, a

glass container holding mercury,

when heated, wil expand far lessthan the mercury it contains. At a

high temperature the mercury will

occupy a greater fraction of the

7/31/2019 ntpc 1 (1)

57/81

57

volume of the container than it will

at a low temperature.

Under normal atmospheric

conditions mercury normally boils at

a temperature of (347C). To extend

the range of a mercury in glassthermometer beyond this point the

top end of a thermometer bore opens

into a bulb which is many times

larger in capacity than the bore. Thisbulb plus the bore above the

mercury, is then filed with nitrogen

or carbon dioxide gas at a

sufficiently high pressure to preventboiling at the highest temperature to

which the thermometer may be used.

7/31/2019 ntpc 1 (1)

58/81

58

Mercury in Steel: The range of

liquid in glass thermometers

although quite large, does not lend

itself to al industrial practices. This

fact is obvious by the delicate nature

of glass also the position of the

measuring element is not always the

best position to read the result.

Types of Hg in Steel Thermometers

are:

Bourdon Tube : Most commonand simplest type

Spiral type : More sensitive andused where compactness is

necessary

7/31/2019 ntpc 1 (1)

59/81

59

Helical Type : Most sensitive andcompact.Pointer may be mounteddirect on end of helix which

rotates, thus eliminating backlash

and lost motion.

Fig.8 Liquid Expansion

Thermometer with C Bourden

7/31/2019 ntpc 1 (1)

60/81

60

(1) LIQUID IN GLASS

THERMOMETER : Mercury in the

glass thermometer boils at 340

degree Celsius which limits the

range of temperature that can be

measured. It is L shapedthermometer which is designed to

reach all inaccessible places.

Fig.9 Bulb Forms

A. PLAIN BULB B. UNION BULB; C.

POCKET BULB D. WALL MOUNTING

7/31/2019 ntpc 1 (1)

61/81

61

E. SHORT COtL. F. LONG COIL; G.

FINNED STRAIGHT H.WATCH

CAPSULE

2) ULTRA VIOLET SENSOR : This

device is used in furnace and it

measures the intensity of ultraviolet rays there and according to

the wave generated which directly

indicates the temperature in the

furnace.

(3) THERMOCOUPLES : This device

is based on SEEBACK and PELTIER

effect. It comprises of two junctionsat different temperature. Then the

emf is induced in the circuit due to

the flow of electrons. This is an

important part in the plant.

7/31/2019 ntpc 1 (1)

62/81

62

Fig.10

Thermocouple

(4) 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

7/31/2019 ntpc 1 (1)

63/81

63

(for low range devices) and in small

furnace (for high range devices).

Gas Thermometers : In Efect of

Heat, the volume of a gas. at

constant pressure, wil change withrelation to temperature change, and

that at constant volume the pressure

changes in relation to temperature.

Therefore, if a bulb, capillary andbourdon tube enclose a certain

volume of gas and the both of that

assembly is subjected to heat, or

change of the same, the changes ofpressure, effected by the heat, within

the system, can be directly related to

temperature. The later will, of

7/31/2019 ntpc 1 (1)

64/81

64

course be shown though the

movement of the free end of the

bourdon tube.

FURNACE SAFETY AND

SUPERVISORY SYSTEM LAB

This lab has the responsibility ofstarting fire in the furnace to enable

the burning of coal. For first stage

coal burners are in the front and

7/31/2019 ntpc 1 (1)

65/81

65

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 degreeCelsius and its height is 18 to 40 m.

It is made up of mild steel. An ultra

violet sensor is employed in furnace

to measure the intensity of ultraviolet 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

7/31/2019 ntpc 1 (1)

66/81

66

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 employedthat is feeder mills are not fed

directly from coal but are fed from

three feeders but are fed from

pulverized coalbunkers. The furnacecan operate on the minimum feed

from three feeders but under not

circumstances should any one be

left out under operation, to prevent

creation of pressure different with

in the furnace, which threatens to

blast it.

7/31/2019 ntpc 1 (1)

67/81

67ELECTRONICS LAB

7/31/2019 ntpc 1 (1)

68/81

68

This lab undertakes the calibrationand testing of various cards. It

houses various types of analytical

instruments like oscilloscopes,

integrated circuits, cards autoanalyzers 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.

ANNUNCIATION CARDS : They are

used to keep any parameter like

7/31/2019 ntpc 1 (1)

69/81

69

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.

7/31/2019 ntpc 1 (1)

70/81

70

ECOLOGICAL MONITORING

PROGRAMME

NTPC has undertaken a

comprehensive Ecological

Monitoring Programme through

Satellite Imagery Studies covering

an area of about 25 Kms radius

around some of its major plants. The

7/31/2019 ntpc 1 (1)

71/81

71

studies have been conducted through

National Remote Sensing Agency(NRSA), Hyderabad at its power

stations at Ramagundam, Farakka,

Korba, Vindhyachal, Rihand and

Singrauli. These studies have

revealed significant environmental

gains in the vicinity areas of the

project as a result of pursuing sound

environment management practices.

Some of these important gains

which have been noticed are

increase in dense forest area,

increase in agriculture area, increase

7/31/2019 ntpc 1 (1)

72/81

72

in average rainfall, decrease in waste

land etc. In general, the studies, assuch, have revealed that there is no

significant adverse impact on the

ecology due to the project activities

in any of these stations. Such studies

conducted from time to time around

a power project have established

comprehensive environment status

at various post operational stages of

the project.

7/31/2019 ntpc 1 (1)

73/81

73

USE OF WASTE PRODUCTS &

SERVICES -ASH UTILIZATION

Ash is the main solid waste which is

put into use for various products and

7/31/2019 ntpc 1 (1)

74/81

74

services. NTPC has adopted user

friendly policy guidelines on ashutilisation.

In order to motivate entrepreneurs to

come forward with ash utilisation

schemes, NTPC offers several

facilities and incentives. These

include free issue of all types of ash

viz. Dry Fly Ash / Pond Ash /

Bottom Ash and infrastructure

facilities, wherever feasible.

Necessary help and assistance is also

offered to facilitate procurement of

land, supply of electricity etc from

7/31/2019 ntpc 1 (1)

75/81

75

Government Authorities. Necessary

techno-managerial assistance isgiven wherever considered

necessary. Besides, NTPC uses only

ash based bricks and Fly Ash

portland pozzolana cement (FAPPC)

in most of its construction activities.

Demonstration projects are taken up

in areas of Agriculture, Building

materials, Mine filling etc. The

utilisation of ash and ash based

products is progressively increasing

as a result of the concrete efforts of

these groups.

7/31/2019 ntpc 1 (1)

76/81

76

7/31/2019 ntpc 1 (1)

77/81

77

Environment Management,

Occupational Health and

SafetySystems:

NTPC has actively gone for adoptionof best international practices on

environment, occupational health

and safety areas. The organization

has pursued the Environmental

Management System (EMS) ISO

7/31/2019 ntpc 1 (1)

78/81

78

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.

While deciding the appropriate

technology for its projects, NTPC

integrates many environmental

7/31/2019 ntpc 1 (1)

79/81

79

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 mentioned below have been

installed to control air and water

pollution.

Electrostatic Precipitators

Flue Gas Stacks

Neutralisation Pits

Low-NOX Burners

7/31/2019 ntpc 1 (1)

80/81

80

Coal Settling Pits / Oil

Settling Pits

DE & DS System

Cooling Towers

Ash Dykes & Ash Disposal

systems

Ash Water Recycling

System

Dry Ash Extraction System

(DAES)

Liquid Waste Treatment

Plants & Management System

Sewage Treatment Plants &

7/31/2019 ntpc 1 (1)

81/81

Facilities

Environmental Institutional

Set-up

Environment Reviews

Up gradation & retrofitting

of Pollution Control Systems