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Ibrahim Fibres Limited (Polyester Plant)Production DepartmentUtilities Process

Date: 21.12.2002

Chillers ( CVGF)

Two-stage, hermetic centrifugal liquid chillers, water cooled

!hiller is a de"ice #hich is used to cool li$uids at desired temperatures.

%#o&sta'e hermetic centri u'al li$uid chillers #ater cooled installed in IFL has the

ollo#in' characteristics.

*ptimi+ed or the alternati"e re ri'erant ,F! 1- a.

!oolin' capacities rom /-0 to 000 .

,ermetic t#o&sta'e centri u'al compressor #ith economi+er cycle.

icroprocessor based control and protection system.

Description :

In !hiller re ri'eration cycle is used to cool #ater.

It consist o a shell and tube e"aporator desi'n #ith re ri'erant e"aporatin' on

shell side and #ater lo#in' inside tubes that ha"e enhanced heat trans er sur aces.

%he compressor is a t#o&sta'e centri u'al compressor. %he motor is a li$uid

re ri'erant cooled motor that operates at economi+er temperature under continuous

ull and part load operatin' conditions. n oil mana'ement system pro"ides oil ree

re ri'erant to the shells to ma3imi+e heat trans er per ormance #hile pro"idin'lubrication to 'ears and bearin's. %he lubrication system ensures lon' compressor li e

. !alibrated ori ice de"ices maintain pressure di erential and meter re ri'erant lo#

rom the condenser to the e"aporator.

unit mounted control panel on chiller pro"ides accurate chilled

#ater control as #ell as monitorin' protection and adapti"e limit unctions.

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Cycle Description :

%he re ri'eration cycle o the !45F chiller can be described usin' the

pressure enthalpy dia'ram sho#n belo#.

schematic o the system illustratin' re ri'erant lo# is 'i"en in i'ure.

Evaporator:

li$uid "apor re ri'erant mi3tures enters the e"aporator at state point 1. Li$uid

re ri'erant is "apori+ed to state point 2 as it absorbs heat rom the system coolin'

load. %he "apori+e re ri'erant lo#s into the compressor irst sta'e.

Compressor first stage:

6e ri'erant "apor is dra#n rom the e"aporator into the irst sta'e compressor. %he

irst sta'e impeller accelerates the "apor increasin' its temperature and pressure to

state point -.

Compressor second stage:

6e ri'erant "apor lea"in' the irst sta'e compressor is mi3ed #ith cooler re ri'erant

"apor rom the economi+er. %his mi3in' lo#ers the enthalpy o the "apor enterin' the

second sta'e. %he second sta'e impeller accelerates the "apor urther increasin' its

temperature and pressure to state point .

Condenser:

6e ri'erant "apor enters the condenser #here the system coolin' load and heat o

compression are re7ected to the condenser #ater circuit. %his heat re7ection cools and

condenses the re ri'erant "apor to a li$uid at state point 8.

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Economizer and refrigerant orifice system:

Li$uid re ri'erant lea"in' the condenser at state point 8 lo#s throu'h the irst ori ice

and enters the economi+er lashin' a small amount o re ri'erant at an intermediate

pressure labeled P1. Flashin' some li$uid re ri'erant cools the remainin' li$uid to

state point 9.

nother bene it o lashin' re ri'erant is to increase the total e"aporator

re ri'eration e ect rom 6 ; to 6 . %he economi+er pro"ides around < ener'y

sa"in's compared to chillers #ith no economi+er.

%o complete the operatin' cycle li$uid re ri'erant lea"in' the economi+er at

state point 9 lo#s throu'h a second ori ice. ,ere re ri'erant pressure and

temperature are reduced to e"aporator conditions at state point 1.

In desi'n eature o the !45F chiller is ma3imi+in' the e"aporator

heat trans er per ormance #hile minimi+in' re ri'erant char'e re$uirements. %his is

accomplished by the %rane patented allin' ilm e"aporator desi'n. %he amount o

re ri'erant char'e re$uired in !45F is less than that in comparably si+ed chillers o

looded e"aporator desi'n.

Compressor Description:

%he !45F compressor consist o three distinct sections: the t#o sta'e

centri u'al compressor the motor and the 'ear bo3 #ith inte'ral oil sump.

Compressor:

%he centri u'al compressor is t#o sta'e #ith hi'h stren'th aluminum alloy ully

shrouded impellers. %he impellers are tested at 28 < o"er desi'n operatin' speed. %he

rotatin' assembly is dynamically balanced or "ibration o less than 8.1 mm ; second

at nominal operatin' speeds. %he control system a ords 100 = 20 percent capacity

modulation usin' electrically actuated 'uide "ane upstream o each impeller.

Driven Train:

%he dri"e train consist o helical bull and pinion 'ears. 5ear tooth sur aces are case

hardened and precision 'round. %he one piece impeller sha t is supported by

hydrodynamic thrust and radial bearin's.

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Motor:

%he motor is hermetic li$uid re ri'erant cooled t#o pole lo# slip s$uirrel ca'e

induction motor. radial hydrodynamic bearin' and duple3 an'ular contact ball

bearin' support the rotor assembly. indin' embedded sensors pro"ide positi"e

thermal protection.

High Lift nloading Valve ( HL V ) :

hi'h li t unloadin' "al"e is standard e$uipment on the 00 > 800 ton !45F units.

this is a solenoid "al"e located bet#een the condenser and the economi+er #hich

#hen ener'i+ed allo#s re ri'erant 'as to lo# rom the condenser to the economi+er.

%he "al"e is either open or closed #ith no modulation capability. %his "al"e allo#s

smooth operation #hile unloadin' do#n to a minimum load #ithout re$uirin'

condenser relie .