Training Report at Ptps

8/9/2019 Training Report at Ptps

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INDUSTRIAL TRAINING REPORT

ON

C & I MAINTENANCE DIVISION UNIT-8

AT

PANIPAT THERMAL POWER STATION

FROM: 09 JULY 2012 TO 07 AUGUST 2012

Submitted in partial ulillment

O t!e re"uirement a#ard $

THE DEGREE IN

ELECTRONICS & COMMUNICATION ENGG.

AT

N.C.COLLEGE OF ENGINEERING & TECHNOLOGYISRANA(PANIPAT)

%R&%AR&' (Y:)

*&+A

ROLL *O, ) 1-091-9

SU(M.TT&' TO:

Mr, AM.T U%%AL Mr, %AR/&&* 'A+.YA

XEN-C&I-8 A.E.E.


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This is to certify that the dissertation work done by *e!a in partial

fulfillent of the re!uireent for the award of the En"ineerin" Trainin"

in C & I# $aintenance di%ision# nit-8# '.T.'.(# ).'.*.C.+# 'anipat has

carried out si, / weeks trainin" under our super%ision and "uidance.

Nae 0 NE)A

1oll no. 0 23452356i%ision 0 C & I# $aintenance# nit-8

6ate of coenceent 0 45 7uly 42

6ate of copletion 0 49 Au"ust 42

$iss *e!a has worked under y super%ision durin" abo%e trainin" period.

I ha%e read this report. It eets our e,pectation and accurately reflects work

done by hi.

Ait ppal/ 'ar%een 6ahiya/

E,ecuti%e En"ineer Assistant E,ecuti%e En"ineer

C&I# $aintenance di%ision# nit-8# '.T.'.(# ).'.*.C.+# 'anipat


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IN E:E1; (TE'


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.*TRO'UT.O*

T)E (A+IENT =EAT1E(


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INTRODUCTION

'anipat Theral 'ower (tation is a proect of )aryana 'ower *eneration

Corporation +iited situated in 'anipat 7ind 1oad at about 22?s. =ro

'anipat >us (tand.

Total planed capacity of the '.T.'.(. is 2D4 $@. At present# four units of

224 $@# two units of 24 $@ and two units of 34 $@ each are

"eneratin" Electricity. =irst two units of 224 $@ were coissioned durin"

2583-8. nit-3 of 24 $@ capacities was brou"ht into action durin" 255

and unit- started workin" in 444. nit-9 was coissioned in 44 and

nit-8 was synchroniFed with "rid in 443.

Coal is used as priary fuel for "eneration of electricity howe%er li"ht

6iesel


7/38

T+R&& MAJOR .*%UTS TO %O3&R STAT.O*S

1; 3ater :@ater has been taken fro near by ;auna Canal. This water is lifted by

raw water pups and is sent to clarifier to reo%e turbidity of water. Theclear water is sent to water treatent plant# coolin" water syste and ser%ice

water syste. The water is deaterialiFed 6$/ by water treatent plant.

The 6$ water is stored in condensate stora"e tanks fro where it is used

in boiler.

2; Fuel Oil :The fuel oil used is of two types0

a/ +ow sulphate hi"h stock oil +()(/

b/ )i"h speed diesel oil )(6/The hi"h speed diesel oil reaches the power station throu"h the lorry tankers.

The oil is stored in lar"e tanks for the future use in the boiler.

)ea%y oil is stored in stora"e tanks in oil stora"e yard and is con%eyed to the

front throu"h a set of pups and strainers. The whole len"th of pipin" fro

the boiler front in strea traced to aintain the teperature and hence its

fluidity so that it can freely flow in the pipelines.

5; OAL :

The coal reaches the plant in the railway wa"ons. The unloadin" of coal isdone echanically by tiltin" the wa"ons by tippler. The coal is sent to the

coal stora"e yard throu"h the con%eyer belts. The crushed coal fro store is

sent to the ill bunkers throu"h con%eyer belts.

The air which takes away the coal dust passes upward into the classifier

where the direction of flow is chan"es abruptly. This causes the coarse

particle in the air coal strea to finer coal dust alon" with the priary air

lea%es the classifier onto coal transport pipin" fro where it "oes to noFFle.

'ul%eriFed coal obtained fro coal ill can not be burnt directly.


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FAM.LAR.oiler is a de%ice used for producin" stea. There are two types of boilers0

a/ =ire tube boiler

b/ @ater tube boiler

At '.T.'.(.# boilers with tan"entially fired water tubes are used. The four

walls of the boiler are constructed with water tubes and the heat produced

due to cobustion of coal in the furnace heats the water in the boiler. >oiler

is hun" with help of "irders and is free to e,pand downwards due to theral

e,pansion. It is called tan"entially fired due to the reason that direction of

fuel enterin" the furnace reains tan"ential to the fireball. The color of theflae is "olden yellow at its peak perforance.

In case the coal flae is weak# oil is inected into the coal furnace to "i%e

support to weak flae.


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There is a turbo "enerator# which "enerates electricity with the help of

D-phase alternator of 34 $@ capacity. The shaft is coupled with "enerator.

The "enerator con%erts the kinetic ener"y of the rotatin" shaft to electric

ener"y. =ield windin"s are e,cited by 6.C. power usin" e,citer.

It is 3AT&R A*' +2 =+Y'ROG&*; GAS OOL&'. Therefore it is

contained in YL.*'R.AL +AM(&R,

(haft of "enerator rotates at D444 rp speed. The turbine here has D sta"es

for rotatin" the rotor of the alternator. =irst sta"e of the turbine is called )i"h

'ressure Turbine ).'.T./# in which stea entry pressure is 234 k"cH. The

stea used here loses pressure & tep. and the e,haust of ).'. turbine "oes

into Cold 1eheat +ine C.1.)./# which is taken to the 1e-heater section in

the boiler furnace. There the stea "ains tep. & pressure throu"h waste

flue "ases of furnace and is labeled as )ot 1eheat +ine ).1.)./. The).1.). stea is brou"ht to the second sta"e of the turbine called

interediate pressure turbine I.'.T./ at about 34 k"cH. The e,haust of

second sta"e is passed on to third sta"e called low pressure turbine +.'.T./.

The e,haust of third sta"e is collected below +.'. turbine and is condensed

into water with the help of condenser. Thus the rotor of the "enerator starts

rotatin".

&O*OM.


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It is a structure of hei"ht 224 desi"ned to cool the water by natural

drou"ht. The cross sectional area is less at the center ust to create low

pressure so that the air can lift up due to natural drou"ht and can carry heat

fro spherical drops. The upper portion is also di%er"in" for increasin" the

efficiency of coolin" tower. )ence it is naed as natural drou"ht coolin"

tower.

&L&TROSTAT. %R&.%.TATOR:

It is an electronic de%ice# which reo%es the ash particles fro the soke

throu"h furnace of boiler. It helps in pre%ention of air pollution. It works on

the principle that a char"ed particle is attracted towards opposite char"e.

@hen the fly ash coes between the opposites char"ed plated it "ets char"ed

and is attracted towards the plates and then collected fro the plates by the

dischar"in" particles.

AS+ +A*'L.*G %LA*T:

Ash is not dischar"ed as such to pollute the land# air and water# but slurry of

ash is ade in ash handlin" plant and this slurry is duped in the waste

land# kept for the purpose.

S3.T+ YAR':

(witchyard is the area# which feed the "rid supply to the station transforer

and fees the "rid by the power "enerator by the unit. The power supply

control is adinistrated here and the units consued and supplies are

recorded in the control roo. The connections of 4?: >( to the station

transforer is done by usin" the isolated and "as filled circuit breakers.

3AGO* T.%%L&R:

IT I( T)E $AC)INE @)IC) I( (E6 T< TI' T)E C


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IT C


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G&*&RAL 3OR>.*G '.AGRAM

&L&TR..TY FROM OAL:


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Electric power "eneration takes place in the followin" steps0

2. Coal to stea

. (tea to echanical power

D. (witchin" and transission

OAL TO ST&AM:

The boiler burns pul%eriFed coal at rates up to 44 tonnes per hour. =ro the

coal store# fuel is carried on a con%eyor belt and dischar"ed by eans of a

coal tipper into the bunker. It then falls throu"h a wei"hed into the coal

pul%eriFin" ill where it is "round to a powder as fine as flour.

Air is drawn fro the top of the boiler house by the force drau"ht fan and

passed throu"h the air pre-heaters to the hot air duct. =ro here soe of the

air passes directly to the burners of the furnace. )ere it i,es with the restof the air and burns with "reat heat.

The boiler consists of a lar"e nuber of tubes and the heat produced raises

the tep. of the water circulatin" in the to create stea# which passes to

stea dru at %ery hi"h pressure. The stea is then heated further in the

super heater and fed throu"h outlet %al%e to the hi"h pressure cylinder of the

stea turbine.

@hen the stea has been throu"h the first cylinder hi"h pr./ of the turbine#

it is returned to the repeater of the boiler and reheated before bein" passed

throu"h the other cylinders interediate and low pr./ of the turbine.

=ro the turbine the stea passes into a condenser to be turned back into

water condensateJ. This is puped throu"h feed heaters where it aybe

heated to about 34GC to the econoiFer where the tep. is raised

sufficiently for the condensate returned to the lower half of the stea dru

of the boiler.

The flue "ases lea%in" the boiler are used to reheat the condensate in theeconoiFer and then pass throu"h the air pre-heaters to the electro-static

precipitator. =inally they are drawn by the induced drau"ht fan into the ain

flue and to the chiney.


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ST&AM TO M&+A*.AL %O3&R:

=ro the boiler# a stea pipe con%eys stea to the turbine throu"h a stop

%al%e and throu"h control %al%es that autoatically re"ulate the supply of

stea of the turbine# stop %al%e and control %al%es are located in a stea

chest and "o%ernor# dri%en fro the ain turbine shaft# operates the control

%al%es to re"ulate the aount of stea used.

(tea fro the control %al%es enters the hi"h pr. cylinder of the turbine#

where it passes throu"h a rin" of stationary blades fi,ed to the cylinder wall.

These act as noFFles and direct the stea ounted on a disc secured to the

turbine shaft. This second rin" turns the shaft as a result of the force of the

stea. The stationary and o%in" blades to"ether constitute a sta"eJ of the

turbine and in practice any sta"es are necessary. The stea passes throu"h

each sta"e in turn until it reaches the end of hi"h pr. cylinder and in its

passa"e soe of its heat ener"y is char"ed into echanical ener"y.

The stea lea%in" the hi"h pr. cylinder "oes back to the boiler for reheatin"

and is returned to the interediate pr. cylinder. )ere it passes throu"h

another series of stationary and o%in" blades.

=inally# the stea is taken to the low pr. cylinder each of which it enters at

the center flowin" outwards in opposite direction throu"h the rows of turbine

blades an arran"eent known as double flow to the e,treities of the

cylinder. As the stea "i%es up its heat ener"y to dri%e the turbine# its tep.

fall and it e,pands. The turbine shaft rotates at D444 rp at 34)F. The

turbine shaft dri%es the "enerator to "enerate alternatin" current.

@hen as uch ener"y as possible has been e,tracted fro the stea it is

e,hausted directly to the condenser. This runs the len"th of the low pr. part

of the turbine and ay be beneath or on either side of it. =ro the

condenser# the condensate is puped throu"h low pr. feed heaters by the

e,traction pup# after which its pr. is raised to boiler pr. by the boiler feed

pup. It passed throu"h the further feed heaters to the econoiFer and the

boiler for recon %ersion into stea.


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S3.T+.*G A*' TRA*SM.SS.O*:

The electricity is usually produced in the stator windin"s of the lar"e odern

"enerators at about 3#444 %olts and is fed throu"h terinal connections to

one side of a "enerator transforer that steps up the %olta"e 2D444# 4444

or 44444 %olts. =ro here conductors carry it to a series of three switches

coprisin" an isolator# a circuit breaker and another isolator.

The circuit breaker# which is a hea%y-duty switch capable of operatin" in a

fraction of a second# is used to switch off the current flowin" to the

transission line.


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O*TROL SYST&MS

There are two types of control loops in use in 'T'( nit-8 in the =C(0-


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&AM%L& ..:

Statement: ) The feeder speed has to be kept under control to aintain the

le%el to coal in the ill. E,cess of this !uantity would lead to o%erloadin" of

coal ill and inade!uate !uantity would lead to under utiliFation of the

resources.

As can be seen fro the fi"ure# there are three 'I6s in%ol%ed in the control

syste. The first one is in auto ode and the other two are in cascadedode. Cascaded ode is the one in which the set %alue is decided by

another sta"e and need not be decided by the user.

The transitter in the field indicates the coal le%el in 6'. Two readin"s are

taken and the better of the two as decided by the =C( is taken as (: for first

'I6.

The le%el of differential pressure between the dri%in" end of the ill and

non-dri%in" end of the ill is used as the set %alue for the first 'I6 auto

ode. The user# therefore# decides this (:. The $: of this 'I6 "i%es the (:

for the other two 'I6s used to control the feeder rate. Thus they are in

cascaded ode.


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&AM%L& ...:

Statement: ) $any types of e!uipent in the power plant need certain other

e!uipents in a specified condition to ensure their sooth runnin". This

e,aple co%ers =orced 6raft =an =6=/.

=or runnin" =6=# there are certain perissi%e and certain protections. The

%arious perissi%e and protections for inputs for an AN6 "ate as shown in

fi"ure. Thus it is an open loop control syste.

Another way of classifyin" perissi%e and protections is to classify the

into initial perissi%e denoted by =6I+ and those leadin" to trippin" of plant

denote by =6TT.

=6I+ 'erissi%e/ coprises of 0-

Inlet daper should be closed. +ubricatin" oil pressure should be


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nits of %ariables in ': 0-

+e%el -

Net water =low - tonneshr.

Net (tea =low - tonneshr.

The best way to ake units of all the !uantities in%ol%ed is to con%ert the

to their percenta"es0-

*AM& RA*G& %/ %&R&*TAG&

+E:E+ -D44 to D44 9.D 9.DMD44/D44MD44/

NET @ATE1

=+


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.D% O*/&RT&R

If any control si"nals has to be sent to the field by the =C( and has

ipleentation to be done by pressure# then this instruent re!uires I'

Con%erter whereby current is con%erted into pressure. In short# it is issued

for controllin" pneuatic %al%es. 'neuatic %al%es are used to control

openin" and closin" %al%es partially# which is difficult to control throu"h

electric otors. The pressure e,erts force on a diaphra" connected to a

piston# which o%es down closin" the %al%e.

3OR>.*G: ) A constant supply of air of pressure of ran"e 4-9 k"cH is

aintained at one terinal. The input si"nal is of ran"e -4 A. @hen

si"nal of A is recei%ed# the lid o%es for enou"h fro the noFFle to let

an output pressure of 4-4k"cH "i%en out throu"h the output pipe. @hen asi"nal of 4 A is recei%ed# the lid o%es near enou"h to the noFFle to let

air pressure of 2 k"cH flow throu"h the outlet. =or interediate current

%alues# pressure of ran"e 4.-2 k"cH is "i%en out for e,ertin" pressure.


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'%U (US

The 6' >us consists of electrical and optical cables and us

perforance.

'%U (US MO'UL&

The 6' >us $odule or 6>$ ana"es the work stationJs counication

with the 6' >us. It collects inforation fro 6'Js on the 6' bus#

stores it# and ultiately transfers the inforation to the appropriate

processors/ in the workstation. The collected data is coprised of alar#

e%ent# trend# historical and "eneral point inforation.The 6>$ also ana"es the transfer of data and control inforation fro

the other processors in the work station to the appropriate coponents on the

6' >us.

'.SR.(UT&' %RO&SS.*G U*.T

The 6'# the process controller# pro%ides control ad data ac!uisition

functions. It e,ecutes the confi"uration that you create usin" $AXT$s# 6's and I< odules are installed in 1eote 'rocessin" nit

cabinets. The standard 1' cabinet accoodates four and si, odules

wide Ichassis asseblies.

'&F.*.*G '.STR.(UT&' %RO&SS.*G U*.TS ='%U;

The 6'# the process controller# pro%ides control and data ac!uisition

functions for the a,6NA 6istributed Control (yste. It e,ecutes the

confi"uration that you create usin" $AXT


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to its control and data ac!uisition functions# a 6' can be linked to a

'ro"raable +o"ic Control '+C/ usin" any one of the two a%ailable 6'

serial links. ;ou ay also use the serial links to download E,cel# a $AX

Control (ystes pro"rain" lan"ua"e.

The 6' e,ecutes all control and data ac!uisition functions includin"

Control and 6ata >locks

Analo" and 6i"ital >uffers

2. (e!uential =unction Charts (=Cs/

. =unction >lock 6ia"ras =>6s/

D. +adder 6ia"ras +6/

. Instruction +ist I+/

'.STR.(UT&' %RO&SS.*G U*.T S%&.F.AT.O*S

locks for process control

and data ac!uisition.

E,ecution of user-written pro"ras usin" IEC 2 2 D 2-D Toolset.

+adder lo"ic processin".


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relay systes. All di"ital odules ha%e lo"ic state indication on the front

panel# one indication per point.


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.*TO'UT.O* OF SOM& .*STRUM&*TS

US&' .* %LA*TS

The instruents used in plant as stated abo%e is di%ided into two cate"ories0

2/ 'rocessin" instruent

/ 1ecordin" & indicatin" instruent

$ainly transitter is used as processin" instruents recorder# pen type

recorder# indicator# teperature scanner & di"ital electrolytic conducti%ity

onitor is used as recordin" and indicatin" instruents. 1T6 &

therocouple is used as sensor. >rief details of these instruents are "i%en

below and its application also0-

TRA*SM.TT&R :

There are different types of transitters are used. They all are uses for

different purposes. $ainly it is used to easure pressure. This can be done

with the help of sensin" eleents as diaphra" or below etc. It is also used

for flow and le%el easureent. =or this# orifices or other e!ui%alent de%ices

are used in conduction with the sensin" eleent.

This is a priary instruent and depends upon the displaceent of the

sensin" eleent when subected to pressure or differential pressure.

Electrically it is a differential transforer. The priary coil is connected to a

stabiliFed A.C. supply. The two secondary windin"s are differentially

connected.

OperatinE %rin@iple :

The I' differential pressure 6.'./ is con%erted into electrolytic capacitance

in the detectin" unit. The %ariation of electrolytic capacitance is then

aplified and coputed in the electronic circuit to transit


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*$te: All t!e meaurement !aCe t$ be @$nCerted t$ t$ 20 milli

ampere a t!e @$mputer in @$ntr$l r$$m @an a@@ept @urrent $ t!i

ranEe $nl, *$rmall all intrument !aCe mi@r$pr$@e$r @ard

intalled $r t!i purp$e,

OYG&* A*ALYS&R

The stea water analysis station uses o,y"en analyFer. It is desi"ned to

easure the net concentration of oth sides of disc are coated with porous etal electrodes. It ust be

operated at a re!uisite teperature# which is supplied initially by a battery.

E$= "enerated is "i%en by-

&MFB>T l$E10 =%1D%2; 4

3!ere %2 i t!e partial preure $ $?Een in t!e meaured Ea $n

$ne ide $ t!e @ell,

%1 i t!e partial preure $ $?Een in reeren@e Ea $n t!e $t!er ide

i @ell @$ntant,

> i arit!meti@ @$ntant,

The ethod used for easureent is that when the cell is at operatin"

teperature and there are une!ual o,y"en concentrations across the cell#o,y"en ions will tra%el fro hi"h partial pressure of o,y"en to lower partial

pressure side of the cell.


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ALARM A**U*.AT.O* SYST&M

The alar annunciation syste is a %ery useful syste in the workin" of

Theral 'ower 'lant that indicates any abnoral process condition. As one

enters the cabin of en"ineers operatin" the IC(s# one can see the hu"e panels

containin" display windows of this syste.

These systes work e,treely well in noisy en%ironent. It uses 1(-83

counication protocol. The circuits use hi"h speed C$


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U*.*T&RRU%T&' %O3&R SU%%LY

There are certain e!uipents# which cannot be shut down in case of power

failure. =or these %ital e!uipents# '( syste is established which ensures

uninterrupted power supply.

The coponents of '( are0-

-1ectifier and battery char"er

-'@$ in%erter utiliFin" I*>T as switchin" de%ices-Electronic (tatic >ypass switch

-$icroprocessor based data onitorin" and lo""in" syste

@ith +C6 display.

Operati$n: T!e @$ntr$lled re@tiier i @$nCertinE 5 p!ae A int$ ripple

ree ', Re@tiier !a t$ !andle #it! (atter !arEer p$#er and

inCerted rated p$#er imultane$ul,

>attery char"er decides battery char"in" odes as per battery re!uireent.

'@$ in%erter controls


34/38

Spe@ii@ati$n:

1ectifier - =ull @a%e

+oad 'ower =actor - 4.9 la" to unity within ?:A & ?@ ratin"

>attery :olta"e - D4 : 6C/

1ipple without >attery -2O

S&8U&*& &/&*T R&OR'&R A*' MAST&R LO>

A achine dedicated to the %ery purpose of recordin" occurrence of any

e%ent with the resolution of one illisecond is installed in nit called the

(e!uence E%ent 1ecorder. Thus# if any trouble pops up# a chain of

disturbances follow. This de%ice coes ost handy in such situations todecipher the epicenter of the proble the only drawback the nit-8 is that it

has a (.E.1 with a resolution of 2 illisecond.

To ake sure that all the coputers in the nit work with the sae clock

tie and any delays due to a"in" of coputers# all the processors are

connected to the $aster Clock connected to the *lobal 'ositionin" (yste.

This aster clock sends synchroniFation pulses to the processors which

updates their tiin"s e%ery second or e%ery inute or e%ery hour as per the

re!uireent.

T&M%&RATUR& M&ASUR.*G '&/.&S

Teperature easurin" de%ices used in 'T'( are 1T6 and Therocouple.

They both are suitable for autoatic teperature control. Interestin"ly# they

both look alike. =or better accuracy# 1T6 is used. These are the only

instruents which ha%e their readin" reachin" the syste cabinet directly#

not throu"h arshallin" cabinet.

The ost widely easured and controlled %ariable in the Theral 'ower'lant is teperature. Teperature is defined as the de"ree of hotness &

coldness easured on a definite scale.

Coonly used unit of tep. is de"ree Celsius GC/.

a/ =ahrenheit (cale

b/ Centi"rade (cale


35/38

T&M%&RATUR& M&ASUR.*G .*STRUM&*TS

Teperature can be easured in the followin" ways0

i/ E,pansion theroeter

ii/ Chan"e of state of theroeter

iii/ Electrical easureent of teperature.

&%A*S.O* T+&RMOM&T&R

The principle of e,pansion theroeter is based on the fact that when a

li!uid# "as or solid is heated# it e,pands and this e,pansion is fi,ed for e%ery

de"ree of teperature chan"e.

a/ +i!uid in "lass theroeter0-

The ost coon for of li!uid e,pansion theroeter is ercury

in "lass theroeter. It consists of a "lass tube with a thin wall "lass

bulb at the lower end. sually ercury is filled in the bulb. @hen the

heat is applied to the "lass bulb# it rises up the capillary colun of the

tube to indicate the tep.

As ercury freeFes at -D5GC. (o for easurin" %ery low teperatures

other li!uid like alcohol is used.

Li"uid Temp, ranEe$ercury -D to 324GC

Alcohol -84 to 9GC

=or easurin" hi"h teperature# the theroeterJs "lass ste abo%e

the ercury is char"ed with hi"h pressure nitro"en. This helps to

pre%ent of ercury. :al%e at the botto is pro%ided for "rowin" out

the "au"es for cleanin" purpose.

A'/A*TAG&S:

2. 6irect readin" is possible.. (pecial desi"ns are a%ailable for use up to D2GC & 24444psi.

'.SA'/A*TAG&S:

2. It is read where the tank is located# which is not always con%enient.


36/38

T+&RMOOU%L&:

The workin" principle of therocouple depends upon the thero-electric

effect. If two dissiilar etals are oined to"ether so as to for a closed

circuit# there will be two unctions where they eet each other. If one of

these unctions is heated# then a current flows in the circuit. This can be

detected by a "al%anoeter. The aount of current produced depends upon

the difference in the tep. between the two unction and on the

characteristics of the two etals. This was first obser%ed by (EE>AC? in

282 and is known as see back effect.

Instruent which reports the %ariation in current flow are calibrated in ters

of tep. and are known as therocouple pyroeter. The wires are oined at

the ends which for two unctions# a easurin" unction and a referenceunction. )eatin" the easurin" unction produces a %olta"e "reater than the

%olta"e of the reference unction. The difference between the two# %olta"e

easured and %olteter readin" is con%erted to its correspondin" tep. This

con%ersion table is "enerally supplied by the therocouple anufactures.

A'/A*TAG&S:

2. 1u""ed construction

. (ipler to use than resistance theroeter.

D. Absence of need for bride circuit.

. E,treely wide tep. ran"es fro -94GC to 844GC.

3. *ood accuracy.

. Calibration checkin" ade easily.

9. *ood transission distance.

8. *ood reproducibility.

'.SA'/A*TAG&S:

2. Non linearity of tep. %olta"e relationship.

. Chances of stray %olta"e pick up.

D. 1e!uired uch of an aplifier for any applications.. Need for e,pansi%e accessories for control application.


37/38

%R&SSUR& M&ASUR&M&*T

'ressure is the ost iportant echanical ser%ice %ariable & so its control is

%ital in Theral 'ower (tation. The ran"e of pressure easureent in

Theral 'ower (tation ran"es fro hi"h %acuu below atosphere

94 of )" colun/ to nearly 44 ?"cH includin" test pressure for

boiler.

/AUUM OR 'RAFT %R&SSUR&:

'ressure below atospheric is said to be de"ree of %acuu or draft. =or

easureent of pressure# the bourdon# and diaphra" and below eleents

are used because of their fle,ibility and operation of %arious. $anoeter

eleents usin" border and ercury as easurin" li!uids are used for lowerran"es. =or teleetry purpose the


38/38

Limitati$n:

In the tube anoeter the application of pressure causes the li!uid in one

le" to "o down while that in the other le" to "o up# so there is no fi,ed

reference.

(OUR'O* TU(&:

The siplicity & ru""edness of the bourdons "au"e akes it the ost

fre!uently "au"e. The reference pressure in the bourdons "au"e is

atospheric pressure. )ence the dial readin" "i%es "au"e pressure.

$ntru@ti$n:

The "au"e consists of the spark# tube encoura"e# bourdons tube# !uadrantpinion# air sprin"# case# pointer & dial.

>ourdons tube is a pressure responsi%e eleent ade of one of the aterial.

The end is to applied pressure# is soldered# braFed# welded or screw

connected to the tube encoura"e. The either end which is sealed is connected

to !uadrant %ia link.

AdCantaEe:

2. +ow cost.

. (iple construction.

D. Tie tested in application.

. )i"h accuracy# especially in relation to the cost.

'iadCantaEe:

2. +ow sprin" "radient.

. (usceptibility to shock and %ibration.

The e!uipent is e,treely sensiti%e at low concentrations as the output

si"nals are proportional to the in%erse of saple o,y"en partial pressure.

The analysis of this instruent is based on the wet testJ as the easureent

is done in the presence of all the products of cobustion# includin" water

%apor. The older apparatus is based on dryJ "as basis.

Documents

Training Report at Ptps