Governing kwu

8/18/2019 Governing kwu

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GOVERNING SYSTEM• To regulate the speed of the Turbine at various

loads in a isolating set

• To regulate the load as per the frequen!de"and #hen #or$ing in a grid net#or$%OR toparticipate in the control of system frequency

• To prevent and protet the turbine fro" overspeeding%

• To allo# on line testing of various safet!protetions %

• To enable the tripping of TG set in the event ofatuation of protetions%

• Safe and health! loading of the TG Set


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3/21

TY&ES O' GOVERNING(I

• No))le Governing

• Throttle governing

• *!pass Governing

Governing is effeted b! var!ing the a"ount of

stea" #hih is further done b! hanging thepositions of ontrol valves%

+n! Throttling of Stea" #ill lead to losses % In

governing s!ste" along #ith the hange of

quantit! of stea" the qualit! of the stea" also

hanges% Therefore Throttling should be

"ini"u"%


4/21

THROTTLE GOVERNING NOZZLE GOVERNIMG

All the valves in a set opens or

closes simultaneously / together

The Valves in a set opens or

closes consequentially or in a

sequence

It is a Full arc AdmissionTurbine It is a Partial Arc admissionturbine except at full Load

It is most suitable for full load or

based Load plants

It is good for Lo! load or

variable load turbines

"o operational Problems #ay have operational Problem at

partial Loads


5/21

*Y&+SS GOVERNING• It is e"plo!ed in s"all apait! turbines

running on high pressure onditions and #iths"all blading di"ensions%

• ,ere the loading up to app- ./0 1 Eono"i

loading 2 is "et b! nor"al ontrol valves

feeding the 'irst stage% 'or higher loading 3 tosuppl! "ore stea" #hih is not possible due to

s"all blading di"ensions 1 an lead to

operational proble"s2 the e-tra quantit! of thestea" is fed to the inter"ediate setion of

turbine b!passing the initial high pressure

stages%


6/21

TY&ES O' GOVERNING(II

• 4onstant &ressure Mode5 ,ere pressure

upstrea" of ontrol valves is $ept onstant andhange is "ade b! hanging the position of

ontrol valves%

• Variable &ressure "ode5,ere ontrol valves arein full open position and pressure upstrea" of

ontrol valves varies proportionatel! #ith the load

require"ent%

• Response of 4onstant pressure Mode is "uh

faster than Variable pressure "ode3 but 4onstant

pressure leads to "ore losses%


7/21

TY&E O' GOVERNING (III

• Mehanial5 Transduer is "ehanial

entrifugal speed governor #hih atuatesontrols valves through "ehanial lin$ages%• ,!dro "ehanial5 ,ere transduer is a

entrifugal speed governor %It is onneted to

a ,!drauli s!ste" #here the signal isa"plified so that 4ontrol valves servo"otoran be atuated%

• ,!drauli5 ,ere speed transduer is a

entrifugal pu"p #hose disharge pressureis proportional to square of speed% This signalis sent to h!drauli onverter #hihgenerates


8/21

a signal #hih is proportional to valveopening64losure is required% *efore appl!ing it

to ontrol valves servo"otor this signal issuitabl! "odified%

• Eletro ,!drauli5,ere transduer an be

eletrial or Eletroni% The generated signalafter proessed eletroniall! and eletriall!is fed to a Eletro( h!drauli onverter #hihonverts eletrial signal into ,!drauli

signal%,!drauli signal before appl!ing toontrol valve servo"otor is suitabl! a"plified%


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REG78+TION

• Regulation 0 of Turbine is defined as

1No load Speed ( 'ull 8oad speed2 9 :// 0 1 No"inal Speed2

• It varies fro" ;%/0 to .0

• Nor"all! it is < to = 0• Turbine having less regulation #ill be "ore

sensitive in the grid and hene #ill share

"ore load and vie versa• Nor"all! base load plant has high regulationand &ea$ load plant has s"all regulation%


10/21

$%&/$&& #' L#( T)*+I",-

.V,"I". -0-T,#


11/21

F,AT)*,-


12/21

1 2ontrol oil and lube oil are

same "o F*F is used

1 It is lo! pressure governing

system 2ontrol oil is at $&

3g/cmsq


13/21

405*#,24A"I2AL -peed governor is purely

mechanical device and can

control speed in the range of

6&&7 689& rpm


14/21

"((L, .V,*"I".


15/21

IT has -I".L, 24A"",L .V,*"I".

-0-T,# "L0


16/21

2"-TA"T P*,--)*,

P*I"2IPL,


17/21

5IFF,*,"TIAT* ::::

A"TI2IPAT*0 5,VI2,::::

LA5 T4*' FF 5,VI2,


18/21

IT 4A- A55ITI"ALV,*-P,,5 405*A)LI2

P*T,2TI" AT %87%9;


19/21

2omponents1 Load /speed control pilot valve

1Follo! pilot valve

1 -ummation pilot valve

1 -peed governor

1 ,mergency governor

1 ver speed governor 1 5ifferentiator

1 Intermediate pilot valve

1 2V-#

1 ,42

1 I-P).

1 ,-V


20/21

Various il "ames

1 2ontrol oil $& 3g/cm sq1 Protection oil $& 3g/cm sq

1 2harging il $& 3g/cm sq

1 Primary oil @@ 3g/cm sq1 -econdary oil %&6 3g/cm sq

1 5ifferentiator oil B 3g/cm sq

1 #P suction oil % 3g/cm sq


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P*T,2TI"

1 ver speed %%7%9;1 Axial shift 4igh

1 Lo! Vacuum C 98& mm 4g

1 Lo! lube oil pressure C &6 3g/cmsq

1 #- temperature lo!

1 4P4 level high

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Governing kwu