Panipat C& I Deepak - Copy

8/11/2019 Panipat C& I Deepak - Copy

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ACKNOWLEDGEMENT

Inspiration and guidance are invaluable in all aspect of life,

especially when it is academic. I acknowledge my gratitude to all those

who has given me timely help me in completing my training report.

I also want to express deep sense and gratitude to

Er. AJAY A!"A, #E$ %E&' ( )*+ Er. -.. A-/A"0A!, AEE

%()*+

for his personal efforts in taking me to sites, explaining the

working of power plant 1urbine, 2enerator its aux. his valuable

guidance during my training at 3anipat 1hermal 3ower tation.

PREFACE

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Industrial training for a student is an evolution of his skill and

knowledge, which he had ac5uiesced over his learning period. As in our

course namely6

ENGINEERING

IN

ELECTRICAL

I also have a industrial training after the completion of forth

semester of above mentioned course it7s main aim is to improve or inflect

practical skill of the student and to develop the 5uality of cooperation

with her colleagues.

I noticed various branches of engineering mainly &echanical,

Electrical, chemical, computer, electronics working in collaboration to

produce electricity. In my case, I have undergone one month practical

training at 3anipat 1hermal 3ower tation %A 8nit of /aryana 3ower

generation corporation !td., /329!+ during the period from :; th Jun

4uly 4


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=.+ A81?&A1I9 9?$1"?!

*.+ E$@I"?&E$1A! I8E

ORGANISATION" AN INTRO!UCTION

1hermal 3ower tations re5uire a number of e5uipments performing a

number of complex processes with the ultimate aim to convert chemical

energy of coal or oil to electrical energy. 1his involves the generation of

steam in the boiler by burning coal andor oil. 1he steam in turn drives

the turbine. 1he generator coupled with the turbine produces electricity

which is stepped up with the help of transformers and is fed into grid

station through transmission lines.

INTRODUCTION P.T.P.S.

/aryana 3ower sector comprises four wholly tateBowned 9orporations

viC. /329!, /@3$!, 8/-@$! and '/-@$! which after unbundling

of the /E- in :DD are responsible for power generation, transmission,

distribution and trading in the tate. 1he tate power sector was

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restructured on August :=, :DD. 1he /aryana tate Electricity -oard

%/E-+ was recogniCed initially into two tateBowned 9orporations

namely /aryana @idyut 3rasaran $igam !td. %/@3$+ and /aryana

3ower 2eneration 9orporation !td. %/329!+. /329! was made

responsible for operation and maintenance of tate7s own power

generating stations. /@3$! was entrusted the power transmission and

distribution functions. 1he demand of /aryana is increasing

exponentially F more than := G per year on account of industrialiCation

and more consumption on agriculture sector and also because of being

part of $ational 9apital "egion. 1he power availability from above

mentioned pro>ects is not sufficient to meet the demand of the tate

particularly during peak 3addy and "abi crop season

3anipat 1hermal 3ower tation is a unit of /aryana 3ower

2eneration 9orporation !td. %/329!+. 1he main ob>ect of the /329! is

to 2enerate 3ower in the tate of /aryana from the existing generating

stations in most efficient manner on commercial lines and follows 343

theory of producing electricity. 1hat is

-Power to Peope/

And to set up new power pro>ects in the tate ector. 1his power station

at 3anipat is in seven stages.

Sr.

No.Na0e o1 Power Station

Capa2ity (M3) 4

Unit No.

!ate o1

Co00i55ionin

T6er0a Power Station7 Panipat

tageBI ::


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tageB@ 4*< &0 8nitBH 4.


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1he water in the 0A1E" 1"EA1&E$1 3!A$1 is I!1E"E' and

'E&I$E"A!IE'. 1he filtered water is sent to 3!A$1 and

9?!?$Y through plant and colony potable pumps. 1he

'E&I$E"A!IE' 0A1E" %'.& water+ is stored in bulk storage tanks

for use in boiler and turbine. 1he cooling water for condensation of steam

is circulated with the help of 9?$'E$A1E 0A1E" %9.0+ 38&3

through 9??!I$2 1?0E". 1he hot water from the outlet of the

condenser is sprayed in the cooling towers to reduce its temperature.

ome part of it is used in cooling various auxiliaries in plant through

-EA"I$2 9??!I$2 0A1E" 38&3.

4. 8E! ?I!

In this power house, three types of fuel oil are used, for preheating and at

low load of the boiler due to less problems faced in ignition of oil rather

than coal. 1hese three types are6

:. /I2/ 3EE' 'IEE! ?I!.

4. /EA@Y 8"$A$9E ?I!.

(. !?0 8!3/E" /EA@Y 1?9.

1he high speed diesel oil reaches 3ower tation by !?""Y 1A$E".

1he oil is decanted through pumps and is stored in -8! 1?"A2E1A$. 1he /..? !../. comes to site through rail tankers. As this

oil is viscous, it is heated with steam and decanted with pumps. 1he oil is

stored in bulk storage tanks with steam heating coils. /..? !../. is

burnt in the furnace of -oiler after atomiCing with steam.

(. 9?A!6


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1he coal reaches the 3ower tation in "AI!0AY 0A2?$. 1he daily

consumption of coal in 1A2EBIII is about (


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maintained at :


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(. AI" !8E 2A 9Y9!E

or the proper combustion to take place in the boiler right amount of

?xygen or air is needed in the boiler. 1he air is provided to the furnace in

two waysB 3"I&A"Y AI" E9?$'A"Y AI". 3rimary air is

provided by 3.A. fans and enters the boiler along with powdered coal

from the mills. 0hile the secondary air is pumped through ?"9E'

'"A1 A$ better known as .' ans which are also two in numbers

A-. 1he outlet of .' fans combine and are again divided into two

0hich goes to team coiled Air pre heaters %.9.A.3./+ A- where its

temperature is raised by utiliCing the heat of waste steam. 1hen it goes to

Air 3re heaterBA- where secondary air is heated further utiliCing the

heat of flue gases. 1he temperature of air is raised to improve the

efficiency of the unit for proper combustion in the furnace. 1hen this

air is fed to the furnace. rom the combustion chamber the flue gases

travel to the upper portion of the boiler and give a portion of heat to the

3!A1I8& 83E" /EA1E". urther up it comes in contact with the

"E/EA1E" and heats the steam which is inside the tubes of reheated.

1hen it travels horiContally and comes in contact with I$A! 83E"

/EA1E". After imparting the heat to the steam in super heater flue gases

go downward to the E9?$?&IKE" to heat the cold water pumped by

the -?I!E" EE' 38&3 %-..3.+. 1hese all are enclosed in thefurnace. After leaving the furnace the flue gases go to the Air /eaters

where more heat of the flue gases is extracted to heat primary and

secondary air. 1hen it goes to the E!E91"?1A1I9 3"E9I3I1A1?"

%E..3.+ tage A- where the suspended ash from the flue gases is

removed by passing the flue gas between charged plates. 1hen, it comes

the I$'89E' '"A1 A$ %I.'. an+ which sucks air from E..3. and

releases it to the atmosphere through chimney. 1he pressure inside the

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=. 1EA& 0A1E" 9Y9!E

1he most complex of all the cycles is the steam water cycle. team is

the working substance in the turbines in all the thermal and nuclear power

plants. As there is very high temperature and pressure inside the boiler,

initially water has to be pumped to a very high pressure. 0ater has also to

be heated to a suitably high temperature before putting it inside the

boiler so that cold water does not cause any problem. Initially cold water

is slightly heated in low pressure heaters. 1hen it is pumped to a very

high pressure of about 4


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1he turbine speed is controlled by /Y'"? 'Y$A&I9 2?@E"$I$2

Y1E&.

ig6 B A view of 1urbine

1he three turbines are on the same shaft which is coupled with

2E$E"A1?". 1he generator is e5uipped with '.9 E#9I1A1I?$

Y1E&. 1he steam from the final super heater comes by &AI$

1EA& !I$E to the /.3 turbine. After doing work in the /.3 1urbine its

1emperature is reduced. It is sent back to the boiler by 9?!' "E/EA1

!I$E to the "E/EA1E". /ere its temperature is increased and is sent to

the I.3 turbine through /?1 "E/EA1 !I$E. After doing work in the I.3

turbine steam directly enters !.3 turbine. 1he pressure of !.3 turbine is

maintained very low in order to reduce the condensation point of steam.1he outlet of !.3 turbine is connected with condenser. In the condenser,

arrangement is made to cool the steam to water. 1his is done by using

cold water which is made to flow in tubes. 1his secondary water which is

not very pure gains heat from steam becomes hot. 1his secondary

water is sent to the cooling towers to cool it down so that it may be

reused for cooling. 1he water thus formed in the condenser is sucked by

:*


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9?$'E$A1E 0A1E" 38&3 %9.0. 38&3+ and is sent to

deaerator.

ig6 B A view of 'eaerator

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A suitable water level is maintained in the hot well of condenser. 0ater or

steam leakages from the system are compensated by the make up water,

line from storage tanks which are connected to the condenser. 1he

pressure in side condenser is automatically maintained less then

atmospheric pressure and large volume of steam condense here to form

small volume of water. In the 'eairator the water is sprayed to small

droplets the air dissolved in it is removed so that it may not cause

trouble at high temperatures in the -oiler. &oreover, the water level

which is maintained constant in the 'eaerator also acts as a constant

water head for the -?I!E" EE' 38&3. 0ater from 'eaerator goes

to the -oiler feed pumps after the heated by !.3. /eaters. 1hus the water

cycle in the boiler is completed and water is ready for another new cycle.

1his is a continuous and repetitive process. 1he ma>or steam parameters

for boilers under =M::


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deviations.

ii+ Automatic 9ontrol6 1o correct the deviation and bring back

the system to normal.

iii+ Annunciation 6 1o warn about the excessive

deviations, if any.

iv+ 3rotection 6 1o isolate the e5uipments process from

dangerous operating conditions caused due to

such excessive deviations.

2. POWER STATION INSTRUMENTATION:

4.: 1he proportionate cost of instrumentation during seventies was

about 4.( to 4.*G of the total cost of boiler, turbine and their

Auxiliaries. 0hen the unit siCe were ;


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iii+ Expected change in the duty cycles of the boiler and turbine

facilitating two shift operation, 5uick run up etc.

iv+ Improved awareness among the personnel about the utility of

the instruments.

4.4 T$PE OF INSTRUMENTS"

1he emphasis is only on the process instrumentation measuring the

physical 5uantities such as temperature, pressure, level flow etc. 1he

other type of instruments are the electrical instruments, measuring

electrical 5uantities such as current, voltage etc. 1he different type of

instruments normally in use are given below6

4.4.: I$'I9A1?"

Indicators are of two categories local indicators are self contained, self

operative and are mounted at site. 1he remote indicators are used for

telemeter purposes and mounted in the centralised control room or control

panel. 1he indicators both local and remote are some times provided with

signaling contacts where ever re5uired. 1he remote indicators depend

upon electricity, electronics, pneumatic or hydraulic system for their

operation and accordingly they are named. 1he indicators can beclassified as analogue or digital on the basis of final display of the

reading. Indicators are available for single point measurement or can be

connected to a number of points through a selectors switch or automatic

scanner system. 1his multipoint system considerably reduces the number

of instruments without affecting the measurements much.

*.*.* RECOR!ERS

:D


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load are specified. 1he instruments and system design engineers decide

the location for the measurement of various parameters such as level,

pressure, flow differential pressure, temperature and other parameters

based on the system design and layout conditions.

;. 9?$9E31 ? I$1"8&E$1 I$ 1/E"&A! 3?0E" 1A1I?$

1he concepts of instrumentation are that6

:. Instruments should be independent for their working.

4. 1he total instrumentation should be interBdependent to each other

in assessing the process condition.

(. Instrumentations should be sufficient to provide ade5uate

information7s to the operators for 6

a+ 9old start of the unit

b+ 0armhot start of the unit

c+ hut down both planned and emergency shut down.

H. 3?0E" 1A1I?$ I$1"8&E$1A1I?$

1he process conditions and the e5uipment conditions are to be assessed

by the operators from the information7s received from the various

instruments. 1he instruments and range vary widely as per the process

media. 1he following section deals with these instruments. 1he inter

dependence and inter relations of these instrument play very significant

roll in the stability and the efficiency of the heat balance.

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change such as current. @oltage, resistance capacitance, reluctance

inductance etc. which is utiliCed as a measure of pressure in the

secondary instruments. 1he secondary instruments are either indicators or

recorders which may incorporate signally contacts.

D. !E@E! &EA8"E&E$1

!evel measurement is generally carried out as differential pressure

measurement. In power stations, level measurement in open tanks such as

'.&. storage tank and fuel oil and lub oil tanks and is closed tanks such

as deaerator, condenser hot well, boiler drum and !.3. /.3. heaters are

to make. 2auge glasses and floats are used for local indication of levels

and the transmitters used for measuring the differential pressures are used

along with the secondary instruments for remote level measurements. 1he

measurement of boiler drum level poses many problems because of

varying pressure and temperatures and many computations and

corrections are to be made in order to get correct levels. A recent

development in this area is the Q/Y'"A 1E3R. 1hough it is very costly

but it improves the accuracy and reliability of this measurement. ?ther

problem area is the solid level measurement where the coal bunker levels

and dust collector hopper level are re5uired. In both these cases

continuous level measurement is not possible. /owever fairly reliable andaccurate provisions are available to indicate the extreme levels on either

directions %low or high+. 1he nucleonic level gauges or the capacitance

and resistance type sensors serve in this area very well.

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made very accurately, the gas flow measurement cannot be done

accurately whereas steam flow measurement re5uires density correction

under varying pressures. 1he air and flue gas flow measurement suffer

accuracy and reliability due to variation in pressure, temperature, duct

leakage, dust accumulation etc. 1he solid flow measurement is very

difficult and only a rough idea is arrived at about the 3.. flow through

differential means. In power stations flow measurements are based on

differential 3rinciples. 'ifferential 3ressure are created by placing

suitable throttling devices in the flow path of the fluids in the pipesducts.

1he throttling devices are suitably selected depending upon the media,

flow 5uantity etc. from among orifice, venturi, flow noCCle ball tube etc.

1he differential pressure developed across such sensing devices in

proportional to the s5uare of the flow 5uantity. 1he differential pressure is

measured by the devices discussed in with additional s5uare root

extraction facilities.

. ANAL$TICAL INSTRTUMENTS

Apart from the above there are few 5uantity measurements necessary in

thermal power generating plants of high capacities. 1hese include feed

water 5uality measuring instruments such as conductivity 3/ dissolved

oxygen, and sodium instruments, steam 5uality measuring instruments

such as conductivity, silica and /3 analyCers. 1he combustion 5uality isassessed by the measurement of the percentage of oxygen, carbon

monoxide or carbon dioxide in the flue gases. 1he purity of hydrogen

inside in the generator housing is measured by utiliCing the thermal

conducting capacity of the hydrogen gas. 1he water and steam purity is

measured as the electrolytic conductivity by electronic bridge method in

which one arm from the electrodes of conductivity cell dipped into the

medium. 1he volume percentage of oxygen in combustion gases are

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made utilising the paramagnetic properties of oxygen. 1he carbon mono

oxide percentage is measured by the QA-?"31I?$ ?

E!E91"?&A2$E1I9 "A'IA1I?$R 3rinciple. -oth these gas

analysers re5uire elaborate sampling and sample conditioning system

resulting in poor reliability and availability of these measurements.

"ecent developments in these fields have brought out on line Qin situR

instruments for these two parameters where the problem of sampling is

dispensed with. 1he QA$A!Y1I9A! I$1"8&E$1R as the above

instruments are called had been the neglected lot so far in the power

stations. -ut now the authorities seem to think their importance for the

process.

TESTING AN! CALIRATION OF PRESSURE GUAGES"

:+ 9omparison method

4+ 'ead weight method

:. 9?&3A"II?$ &E1/?'

In this method inside the tubes there is oil. 1here are two outlets on the

tube, on one outlet, master gauge %accurate+ is applied and on the otherend the gauge to be checked or calibrated is applied. @alve $o.: and 4 are

opened. ?il from chamber connected to valve :%9hamber : say+ goes to

chamber connected to valve 4 %say chamber 4+. $ow tighten the valve :

so that on tightening valve the oil should not reenter chamber : rather

goes to the two gauges. $ow valve 4 is steadily tightened so that the

pressure shown by both the gauges should be exactly e5ual. In this way

the gauge can be checked or calibrated.

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4. 'EA' 0EI2/1 &E1/?'

1his method is more accurate than the former one. 1he basic principle of

its working is almost same as that of former one. /ere instead of

employing a master gauge, we use weights placed on a pan. 1he master

gauge may be wrong but weights are always correct so this is more

accurate method.

AUTOMATIC CONTROL

Introd82tion To Contro Enineerin And Ter0inooy

POWER PLANT CONTROLPOWER PLANT CONTROL

UNIT CONTROL

TURINE GENERATOR OILER

4D


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*.4.: Introduction

An automatic control scheme compares a control condition value with a

desired value and automatically corrects any deviation. 1here are three

basic types of controls and they are as follows6

:. 3"?3?"1I?$A!

4. I$1E2E"A!

(. 'E"I@A1I@E

@arious combinations of these basic types may be employed to suit the

plant characteristics.

*.4.4 3"?3?"1I?$A! 9?$1"?!

1his type of control is used where the deviation is not very large or the

deviation is not sudden. 1he control gives a change in regulator position

which is directly proportional to a change in conditions. 1he regulator

position is directly related to the deviation and for every controlled

MEASUREMENT

CLOSE#LOOP

CONTROL

OPEN#LOOP

CONTROL

PROTECTION

MONITORING

INSTRUMENTATION

AN!

CONTROL

INSTRUMENTATION

AN!

CONTROL

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condition value there is a regulator position which is dependent upon the

control sensitivity. 1he regulator takes up a position tending to reduce the

deviation, the amount of excursion from its initial setting being dependent

upon the sensitivity setting. If the deviation is increasing rapidly the

regulator will apply the correction rapidly. 1he regulator position

resulting from a deviation of the variable from a desired value depends

upon the position it occupies when there is no deviation. 1his latter

setting is about *


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desired value indicator will no longer be displaying the true desired value.

As a high proportional sensitivity %narrow proportional band+ enables the

regulator to move a large amount for a very small deviation, it is possible

to reduce the offset to negligible amount if a sufficiently small

proportional band is permissible. $ormally, the proportional band must

be made wide to avoid hunting or instability, so as alternative method of

deviating offset must sometimes be used %proportional plus integral

control+.

Another effect of increasing the proportional band is to increase the

period of cycling, so that the initial deviation becomes larger. 1he offset

also becomes larger and it is, therefore, important that the proportional

band of a controller be set to the very minimum that is consistent with

stable recovery.

*.4.( I$1E2E"A! 9?$1"?!

0ith Integral 9ontrol the controller is only at rest when the controlled

condition is at the desired value. 1he regulator moves, when there is a

deviation, in a direction which applies correction and continues to move

until either the extreme regulator position is reached or the variable

returns to the desired value. 1he speed of movement of the regulator is

directly proportional to the amount of deviation, and can be ad>usted to

give any re5uired speed per unit deviation. 1his ad>ustment is known asIntegral Action 1ime ad>ustment. 1he speed of regulator movement is

related to the amount of deviation and not, as in proportional control, to

the rate of deviation. or certain integral action time sensitivity the speed

of travel of the regulator for a one unit deviation is half the speed of

travel for a two unit deviator.

1he term SintegralS is derived from the mathematical consideration of this

type of control. Integral calculus considers the sum of an infinite number

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of small increments the actual regulator position at any instant is

dependent on the amount of deviation and the time for which the

deviation has been maintained. Integral control can be used in a system

but deadBtime results in a sustained hunting unless the sensitivity is

drastically reduced. 1he systemRs main attribute is that the regulator

position is not rigidly tied to the set point. 1herefore, if used with

proportional control, integral control provides automatic elimination of

offset.

*.4.= 'E"I@A1I@E 9?$1"?!

8sing this control the regulator is not influenced by the desired value but

moves in accordance with the direction and with rate of change of the

deviation. If the change in the variable is a sudden step movement, its rate

of change is infinitely fast and the regulator travels %moves+ gradually at a

constant rate, the regulator will move by an amount proportional to that

rate and then stop until the rate of change of deviation alters. 'erivative

control is not used alone but normally in con>unction with proportional or

proportional plus integral control.

9.*.9 COMINATION OF PROPORTIONAL7 INTEGERAL

AN! !ERI:ATI:E CONTROL

1he combination of proportional and integral control provides automaticelimination of the offset. 0hen a deviation occurs, the regulator moves

under proportional control by an amount proportional to the deviation.

1he regulator then continues to move under integral control at a constant

rate towards its extreme position. 1he combined integral and proportional

wave lags behind the proportional wave by a value of less than Dusted to

give either a fast or a slow return to the desired value after a change in

load has resulted in an offset. 1he period of oscillation will become

progressively longer as the integral sensitivity is increased the integral

action time is decreased. 1he integral derivative action gives the regulator

a slight offset movement because the rate of change is low. As the change

progresses at a constant rate the derivative action remains constant. 1he

remaining regulator movement will now be controlled by the combined

proportional and integral action. 1he proportional action is linear and is a

mirror image of the deviation response the integral action continually

increases the speed of the regulator towards its extreme travel as the

amount of deviation increases. 1he resultant regulator travel is

represented graphically by a curve.

*.( "EL8I"E&E$1 ? 9?$1"?! Y1E&

A control system, to be effective, must satisfy the following re5uirements.

It must be possible o measures the condition to be controlled, preferably

by the standard application of a proven instrument. 1he regulator must be

capable of handling the plant under all load conditions and at all probable

desired value settings, preferably with a little range to spare if the system

is continually out ranging the regulator, satisfactory control will be

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impossible. 1he measuring point must be as close as possible to the

regulator in order to minimiCe lags.

*.= E$I1I@I1Y A'J81&E$1

1hese two conditions are incompatible since an increase in

sensitivity improves one at the expense of the other. ensitivity

is normally ad>usted to give as fat a return to stable control as

possible without causing overshoot and a tendency to QhuntR

about the set point. In the combination of proportional and

derivative control, the derivative function is derived from the

proportional function and not directly from the deviation. 1he

effect is the same since the speed of the proportional action is in

turn related to the rate of change of deviation. 1he derivative

function is not only dependent on its own sensitivity ad>ustment

but also on the proportional sensitivity. 1he derivative wave

leads the proportional wave by D< degree and for a combination

of proportional plus derivative control the load is less than D

Documents

Panipat C& I Deepak - Copy