50684234 centrifugal water chillers
TRANSCRIPT
A Trane Air Conditioning Clinic
Centrifugal Water Chillers
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
ChilledWaterSystem
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
absorption centrifugal
helical-rotary
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
Centrifugal Water Chillers
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
Centrifugal Water Chillers
period one
Components
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
condencondenserser
compressorcompressor
controlcontrolpanelpanel
evaporatorevaporator
components of a
Centrifugal Water Chiller
starterstarter
motormotor
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
Compressor
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
Impeller
bladesblades
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
volutevolute
diffuserdiffuserpassagepassage
impeller impeller passagepassagess
Centrifugal Compressor
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
centrifugal compressor
Energy Conversionrefrigerarefrigerant enters nt enters diffuserdiffuser
path through path through compressorcompressor
velo
c ity
velo
c ity
stati
c st
ati
c pre
ssu
repre
ssu
re
refrigerantrefrigerant enters enters impellerimpeller
refrigeranrefrigerant enters t enters volutevolute
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
Multistage Compressor
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
Condenser
bafflebaffle
tubetubebundlebundle
liquid liquid refrigerarefrigerantnt
refrigerant refrigerant vaporvapor
coolincooling g
tower tower waterwater
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
totoevaporatorevaporator
orifice platesorifice plates
HH11
expansion device
Orifice Plates
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
expansion device
Orifice Plates
HH22
totoevaporatorevaporator
orifice platesorifice plates
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
2-stage chiller
Economizer
refrigerant refrigerant vapor to vapor to second stagesecond stageof of compressioncompression
liquid liquid refrigerant refrigerant to to evaporatorevaporator
orificeorificeliquid liquid refrigerant refrigerant from from condensercondenser
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
3-stage chiller
Economizer
liquid liquid refrigerant refrigerant to to evaporatorevaporator
orificeorifice
orificeorifice
refrigerant refrigerant vapor to vapor to second stagesecond stageof of compressioncompression
refrigerant refrigerant vapor to third vapor to third stagestageof of compressioncompression
liquid liquid refrigerant refrigerant from from condensercondenser
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
Evaporator
eliminatoeliminatorr
liquidliquiddistributdistributoror
orifice orifice systemsystem
liquid liquid refrigerantrefrigerant
tube bundletube bundle
chilled chilled water water returnreturn
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
Motor
impellersimpellers
impellerimpeller
motormotor
motormotorgear-drive
direct-drive
gearsgears
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
Hermetic Motor Cooling
statorstator
rotorrotor
draindrainliquidliquidrefrigerarefrigera
ntnt
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
Controls and Starter
controlcontrolpanelpanel
starterstarter
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
Starters
remote-mounted
starterstarter
line line powerpower
control control power wiringpower wiring
unit-mounted
line line powerpower
control control power wiringpower wiring
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
Centrifugal Water Chillers
period two
Refrigeration Cycle
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
2-stage centrifugal chiller
Refrigeration Cycle
condenscondenserer
evaporatevaporatoror
expansion expansion devicesdevices
economieconomizerzer
2-stage2-stagecomprescompres
sorsor
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
Pressure-Enthalpy (p-h) Chart
enthalpyenthalpy
subcooledsubcooledliquidliquid mixture mixture
of liquid of liquid and and vaporvapor
15.5 15.5 Btu/lbBtu/lb[201.0 [201.0 kJ/kg]kJ/kg]
pre
ssure
pre
ssure
superheatedsuperheatedvaporvapor
BA5 psia5 psia[0.034 [0.034
MPa]MPa]
92.4 92.4 Btu/lbBtu/lb[380.4 [380.4 kJ/kg]kJ/kg]
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
2-stage centrifugal chiller
Refrigeration Cycle
11
2233
4466
77pre
ssu
repre
ssu
re
enthalpyenthalpy
evaporaevaporatortor
condenscondenserer
2-stage 2-stage compresscompressoror
expansiexpansion on devicesdevices88
99PPee
PPcc
PP11
55economizeconomizerer
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
2-stage centrifugal chiller
Refrigeration Cycle
11
22pre
ssu
repre
ssu
re
enthalpyenthalpy
evaporaevaporatortor
condenscondenserer
PPee
PPcc
PP11
C B A
66
77
99
55
2-stage 2-stage compresscompressoror
economizeconomizerer
33
44expansiexpansion on devicesdevices
1010
88
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
pre
ssure
pre
ssure
temperaturetemperature
HCFC-HCFC-2222
HCFC-HCFC-123123atmospheatmosphe
ricricpressurepressure
Refrigerant Operating Pressures
HFC-HFC-134a134a
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
Low-Pressure Chillers
compressorcompressorsuction suction
elbowelbow
evaporatorevaporator
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
Purge System
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
Purge Operation
filtratiofiltration n canistercanister
refrigerrefrigerant ant
vapor vapor from from
condencondenserser
to to condensecondenserr
filter filter drierdrier
purge purge evaporaevapora
tor coiltor coil
purge purge tanktank to to
chiller chiller vent vent lineline
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
Centrifugal Water Chillers
period three
Compressor Capacity Control
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
Inlet Vanes
inlet inlet vanesvanes impellerimpeller
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
Multistage Compressor
inlet vanes inlet vanes
impellers impellers
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
VVrrRR
VVtt
Impeller
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
Impeller Dynamics
diametediameterr
VVrr ∝ refrigerant flow refrigerant flow
raterate
VVt t ∝ rotational speed × rotational speed ×
diameterdiameter
rotatiorotational nal speedspeed
VVrrRR
VVtt
refrigerrefrigerant flow ant flow raterate
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
Compressor Unloading
VVrrRR
VVtt
VV
rrVVtt
full load part load
RR
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
VVrr
VVtt
Surge
VVr r < static < static
pressurepressure
RR
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
Compressor Map
2525
7575
1010 1414
6363
pre
ssu
re
pre
ssu
re
diffe
r en
cediffe
r en
ce
refrigerant flow refrigerant flow raterate
surgesurge
vane vane positionposition
(degrees)(degrees)
9090
3636
5151
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
Operating Pointpre
ssu
re
pre
ssu
re
diffe
r en
cediffe
r en
ce
refrigerant flow refrigerant flow raterate
operatioperatingngpointpoint
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
compressor map for a 2-Stage Compressor
2525
7575
1010 1414
6363
pre
ssu
re
pre
ssu
re
diffe
r en
cediffe
r en
ce
refrigerant flow refrigerant flow raterate
surgesurge 9090
3636
5151
operatioperatingngpointpoint
vane vane positionposition
(degrees)(degrees)
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
compressor map for a 2-Stage Compressor
2525
7575
1010 1414
6363
pre
ssu
re
pre
ssu
re
diffe
r en
cediffe
r en
ce
refrigerant flow refrigerant flow raterate
surgesurge 9090
3636
5151
C B
A
unloading unloading lineline
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
Adjustable-Frequency Drivespow
er
pow
er
con
sum
pt i
on
con
sum
pt i
on
loadload
inlet vanes inlet vanes onlyonly
AFD + inlet AFD + inlet vanesvanes
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
Centrifugal Water Chillers
period four
Maintenance Considerations
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
Maintenance Considerations
▲ Operating log
▲ Mechanical components
▲ Heat-transfer surfaces
▲ Fluid analysis
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
operating log
ASHRAE Guideline 3▲ Chilled water inlet and outlet
temperatures and pressures
▲ Chilled water flow
▲ Evaporator refrigerant temperature and pressures
▲ Evaporator approach temperature
▲ Condenser water inlet and outlet temperatures and pressures
▲ Condenser water flow
▲ Condenser refrigerant temperature and pressures
▲ Condenser approach temperature
▲ Oil pressures, temperature, and levels
▲ Addition of refrigerant
▲ Addition of oil
▲ Vibration levels
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
maintenance considerations
Mechanical Components
▲ Required maintenance◆ Compressor and motor: no maintenance required
◆ Controls: no maintenance or calibration required
▲ Recommended maintenance◆ Visually inspect overall unit
◆ Inspect safety controls and electrical components
◆ Tighten electrical connections
◆ Check for leaks
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
▲ Other design-specific requirements◆ Change oil when oil analysis dictates
◆ Replace oil filter periodically
◆ Replace filter drier periodically
◆ Clean oil strainers annually
◆ Check shaft alignment annually
◆ Check coupling annually
◆ Replace shaft seal every 2 to 4 years
◆ Compressor teardown inspection every 5 to 10 years
maintenance considerations
Mechanical Components
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
maintenance considerations
Heat Transfer Surfaces
▲ Recommended maintenance◆ Use a qualified water treatment
specialist
◆ Clean condenser tubes as needed
◆ Clean water-side strainers
◆ Test tubes every 3 years
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
Fluid Analysis
▲ Oil analysis◆ Conduct annual analysis to verify
system integrity
◆ Measure oil pressure drop to determine if filter needs changing
◆ Measure charge
▲ Refrigerant charge◆ Conduct analysis of refrigerant
◆ Inspect purge system
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
Oil Analysis
▲ Why perform regular oil analysis?◆ Helps reduce maintenance costs
◆ Detects problems without compressor disassembly
◆ Extends service life of oil charge
◆ Reduces environmental problems related to oil disposal
◆ Helps maintain compressor efficiency and reliability
◆ Helps lower refrigerant emissions
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
Centrifugal Water Chillers
period five
Application Considerations
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
Condensing Temperature Control
2525
7575
1010 1414
6363
pre
ssu
re
pre
ssu
re
diffe
r en
cediffe
r en
ce
refrigerant flow refrigerant flow raterate
surgesurge 9090
3636
5151
B
AC
vane vane positionposition
(degrees)(degrees)unloading unloading lineline
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
condensing temperature control
Cooling Tower Bypass
condensercondenser
bypassbypass
cooling towercooling tower
55°F55°F[13°[13°
C]C]
40°40°FF
[4°[4°C]C]
65°F65°F[18°C[18°C]]
divertindivertinggvalvevalve
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
evaporator water flow
Constant or Variable Flow
variablvariable- e- speed speed drivedrive
chilledchilledwater water pumppump
evaporatevaporatoror
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
variable evaporator water flow
Limitations
▲ Maintain minimum and maximum water flow rates through the chiller evaporator
▲ Rate at which the evaporator water flow changes must be kept below the corresponding limit to:◆ Maintain the chilled water set point control
◆ Keep the chiller on line
◆ Protect the chiller from damage
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
Short Evaporator-Water Loops
loadload
chilledchilledwater water pumppump
evaporatorevaporator
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
Short Evaporator-Water Loops
loadload
chilledchilledwater water pumppump
evaporatorevaporator
tanktank
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
Heat Recovery
heat-heat-recovery recovery
condensercondenser
coolincooling g
tower tower waterwater
standarstandard d
condenscondenserer
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
heat-recovery(dual) condenser
auxiliarycondenser
◆ No extra condenser
◆ Large base heating loads or continuous operation
◆ High hot water temperatures
◆ Controlled
◆ Chiller efficiency preserved
◆ Second, full-size condenser
◆ Large heating loads
◆ High hot water temperatures
◆ Controlled
◆ Degrades chiller efficiency
◆ Second, smaller size condenser
◆ Preheating loads
◆ Moderate hot water temperatures
◆ Uncontrolled
◆ Improves chiller efficiency
heat pump
Heat-Recovery Chiller Options
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
air-sideeconomizer
strainercycle
◆ Potential fouling limited to heat exchanger
◆ Requires additional heat exchanger, piping, valves, and controls
◆ Can operate simultaneously with chiller
◆ Most efficient
◆ Requires larger outdoor air, return, and exhaust duct systems
◆ Coldest water temperatures
◆ Potential fouling in chilled water loop
◆ Requires additional piping, valves, and controls
plate-and-frame heat exchanger
Free Cooling
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
free cooling
Refrigerant Migration
from from comprescompres
sorsor
to to comprescompres
sorsorevaporatevaporatoror
condenscondenserer
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
equipment certification standards
ARI Standard 550/590
▲ Purpose◆ Establish definitions, testing,
and rating requirements
▲ Scope◆ Factory designed and
prefabricated water chillers
◆ Vapor-compression refrigeration
◆ Air-cooled and water-cooled condensing
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
equipment certification standards
ARI Standard 550/590
▲ Standard rating conditions◆ Common system conditions for published ratings
◆ Fouling factor
▲ Integrated Part Load Value (IPLV)◆ Part-load efficiency rating
◆ Based on an “average” single-chiller installation
◆ Standard operating conditions
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
Centrifugal Water Chillers
period six
Review
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
Review—Period 1
condencondenserser
compressorcompressor
controlcontrolpanelpanel
evaporatorevaporator
starterstarter
motormotor
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
Review—Period 2
11
2233
4466
77pre
ssu
repre
ssu
re
enthalpyenthalpy
evaporaevaporatortor
condenscondenserer
2-stage 2-stage compresscompressoror
expansiexpansion on devicesdevices88
99PPee
PPcc
PP11
55economizeconomizerer
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
Review—Period 3
inlet vanes inlet vanes
impellers impellers
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
Review—Period 4
▲ Maintenance considerations◆ Operating log
◆ Mechanical components
◆ Heat-transfer surfaces
◆ Fluid analysis
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999
Review—Period 5
▲ Application considerations ◆ Condensing temperature control
◆ Constant or variable evaporator-water flow
◆ Short evaporator-water loops
◆ Heat recovery
◆ Free cooling
◆ Equipment certification standards
Air Conditioning Clinic TRG-TRC010-ENAir Conditioning Clinic TRG-TRC010-EN© American Standard Inc. 1999