Chiller Types & Applicatio Applications ns A Trane Air Conditioning Clinic
ACES Training K Y Yow 23 Jan 2015
Chiller Types By Compress Compressor or Type & Heat Rejecti Rejection on Mode
W/C Centrifugal
Centrifugal
Screw
Scroll
A/C Centrifugal
150-4000rt e p y T r o s s e r p m o C
W/C Screw
A/C Screw
50-500rt
50-400rt
W/C Scroll
A/C Scroll
15-70rt
5-200rt
Reciprocating Heat Water-Cooled
Rejection Air- Cooled
Vapour Compression
NON-Vapour Compression
W/C Centrifugal
absorption W/C Screw
A/C Screw & Scroll
Centrifugal Water Chillers
components of a
Centrifugal Water Chiller compressor
motor
condenser
control panel evaporator
starter
Impeller
blades
centrifugal compressor
Energy Conversion refrigerant enters diffuser
y t i c o l e v
e r u s s e r p
refrigerant enters impeller
c i t a t s
path through compressor
refrigerant enters volute
Multistage Compressor
Condenser refrigerant vapor baffle
cooling tower water tube bundle
liquid refrigerant
expansion device
Orifice Plates
orifice plates H1
to evaporator
Evaporator tube bundle liquid refrigerant
chilled water return liquid distributor
eliminator
orifice system
Motor motor
gear-drive impeller motor
impellers
direct-drive gears
Hermetic Motor Cooling stator
rotor
liquid refrigerant
drain
Controls and Starter
control panel
starter
Starters line power
line power
control power wiring
starter
control power wiring
remote-mounted
unit-mounted
Comparison of LV Starters
2-stage centrifugal chiller
Refrigeration Cycle 2-stage compressor
economizer
condenser
evaporator expansion devices
2-stage centrifugal chiller
Refrigeration Cycle
e r u s s e r p
Pc P1 Pe
condenser
6 expansion devices 8
5
economizer 7
4
2
3
10 9
1
evaporator C
B
enthalpy
A
2-stage compressor
Refrigerant Operating Pressures HCFC-22 HFC-134a
( High Pressure 40/140 psig)
e r u s s e r p
HCFC-123 ( Low Pressure vac/8 psig
atmospheric pressure temperature
Centrifugal Water Chillers Compressor Capacity Control
Inlet Vanes
inlet vanes impeller
Multistage Compressor impellers
inlet vanes
Impeller Dynamics R
Vr
Vr
refrigerant flow rate
Vt
rotational speed × diameter
Vt diameter rotational speed
refrigerant flow rate
Compressor Unloading R Vt
full load
Vr R Vt
part load
Vr
Surge Vr R Vt
Vr < static pressure
Compressor Map
90 e c n e r e f f i d e r u s s e r p
75
51 10
14
25
36
refrigerant flow rate
63
vane position (degrees)
compressor map for a
2-Stage Compressor A 90 e c n e r e f f i d e r u s s e r p
75
B
C
51 10
14
25
36
unloading line
refrigerant flow rate
63
Centrifugal Water Chillers period five
Application Considerations
Adjustable-Frequency Drives
3-4% Losses
Kw/rt
inlet vanes only
AFD + inlet vanes AHRI Temp Relief
load AFD Centrifugal Chiller Requires LIFT Reduction to Save Energy
guidance
VSD or High Efficiency? Guidance Factors
High efficiency
Significant demand charges
Humid climates
Multiple chillers in the plant
Economizer(airside or free cooling) that reduces low load/low lift operating hours
VSD
Many hours at low condenser water temperature—and low load
Perhaps only on one chiller
Factor in replacement of VSD when performing life cycle assessment
FL vs PL efficiency VSD Chiller or Hi-E Chiller ( Fixed Drive) SAME Price Option
Full Load (kW/ton)
IPLV (kW/ton)
a) VSD
0.572
0.357
b) High Efficiency (Fixed Drive)
0.501
0.430
(700 RT Chiller)
VSD Option typically cost around 30% more. Alternatively, this same investment $ can be used to Upgrade efficiency with larger heat exchangers
VSD Application on Chillers Understand its Applications… Benefits vs Cost LIFT Reduction (Min for Trop ics) for VSD Centrifugal chiller Capacity Reduction for VSD Screw ROI - Efficiency gain vs Higher $Investment & potential higher service cost
equipment certification standards
ARI Standard 550/590
Standard rating conditions Common Fouling
system conditions for published ratings
factor
Integrated Part Load Value (IPLV) Part-load Based
efficiency rating
on an “average” single-chiller installation
Standard
operating conditions
ASHRAE STD 90.1 ( 2013) Current 2013 version (first published 1975) Most Building Codes, Guides & STDs Draw Reference to ASHRAE 90.1 STD
Mandatory: Chiller Efficiency as of 2015 (Centrifugal chillers) Chiller type/size
Index Rating AHRI Definition of Integrated Part Load Value (IPLV/NPLV)
1 IPLV =
1% A
+
42% B
+
A = kW/Ton @ 85°F (30°C) @ 100% Load
45% C
+
12% D
B = kW/Ton @ 75°F(24°C) @ 75% Load C = kW/Ton @ 65°F(18°C) @ 50% Load D = kW/Ton @ 65°F(18°C) @ 25% Load
Temp eratures: Expected Entering Tower Water /7° C) AHRI Conditio ns: Chilled Water: 54 /44° F (12° Con dens er Water: 3 GPM/Ton (0.054 L/S/kW) °
1%
85°F
(30°C)
42%
57%
75° (24°C) 65° (18°C)
IPLV does NOT represent Real Efficiency
Use of IPLV or NPLV (AHRI 550/590 Appendix D, D2.1 Scope)
This appendix is for equipment covered by this standard. The IPLV equations and procedure are intended to provide a consistent method for calculating a single number part load performance number for water chilling products. The equation was derived to provide a representation of the average part load efficiency for a sing le ch iller only . However, it is best to us e a c o m p r e h en s i v e a n al y s i s that reflects the actual weather data, building load characteristics, operational hours, economizer capabilities and energy drawn by auxiliaries such as pumps and cooling towers, when calculating the c h i l l er a n d s y s t e m efficiency . This becomes increasingly important with multiple chiller systems because indiv idual chillers operating within m u l t i p l e chiller system s are m ore heavily loaded than sin gle within single chiller systems. chillers
Superior IPLV does not represent Superior Energy Savings
equipment certification standards
AHRI 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
Selection Printout
Factory Test to AHRI 550/590
Helical-Rotary Water Chillers A Trane Air Conditioning Clinic
Direct Expansion Evaporator (aircooled) chilled water supply baffles
chilled water return
refrigerant vapor liquid refrigerant tube bundle
Controls and Starter
control panel starter
helical-rotary water chiller
Refrigeration Cycle
condenser
5 e r u s s e r p
3
4
expansion device
liquid/vapor separator
7 6
2
evaporator
enthalpy
compressor 1
helical-rotary water chillers…
Refrigerants
HFC-134a ( Currently most commonly applied)
HF0 – XXX ( Next generation )… Low GWP
Helical-Rotary Water Chillers p e r io d f i v e
Application Considerations
RTHD AFD Water cooled Screw Chiller with Adaptive Frequency™ Driver
Application for Variable Speed Screw Chiller Investment $ : +30-40%
Efficiency Improvement : 5-10%
Constant Condenser Temperature 30C
200 180 160 140 120 100 80 60 40 20 0
Illustration Only
STD
AFD Type
20
30
40
50
60
70
80
90
100
AFD Type typically improves overall efficiency by 5-10% vs STD.
VSD Application on Screw Chillers Understand its Applications… Benefits vs Cost LIFT Reduction (Min for Trop ics) for VSD Centrifugal chiller Capacity Reduction for VSD Screw ROI - Efficiency gain vs Higher $Investment & potential higher service cost
condenser types…
Air-Cooled or Water-Cooled
air-cooled or water-cooled
Comparison
air-cooled
water-cooled
Lower maintenance
Greater energy efficiency
Packaged system
Longer equipment life
Better low ambient operation
ASHRAE STD 90.1 ( 2013) Current 2013 version (first published 1975) Most Building Codes, Guides & STDs Draw Reference to ASHRAE 90.1 STD
Addendum CH
Mandatory: Chiller Efficiency as of 2015 (SCREW Chiller) Chiller type/size
Path A
Path B
Air cooled < 150 tons
10.1 EER and 13.7 IPLV
9.7 EER and 15.9 IPLV
Air cooled >= 150 tons
10.1 EER and 14.0 IPLV
9.7 EER and 16.1 IPLV
WC pos. disp. < 75 tons
0.750 kW/ton & 0.600 IPLV
0.780 kW/ton & 0.500 IPLV
WC pos. disp. 75 < 150 tons
0.720 kW/ton & 0.560 IPLV
0.750 kW/ton & 0.490 IPLV
WC pos. disp. 150 < 300 tons
0.660 kW/ton & 0.540 IPLV
0.680 kW/ton & 0.440 IPLV
WC pos. disp. 300 < 600 tons
0.610 kW/ton & 0.520 IPLV
0.625 kW/ton & 0.410 IPLV
WC pos. disp. >= 600 tons
0.560 kW/ton & 0.500 IPLV
0.585 kW/ton & 0.380 IPLV
equipment certification standards
AHRI 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
Summary
Types of chillers – Overview Centrifugal chiller - components, controls and application Screw chiller – Components, controls and applications VSD application considerations & Benefits vs cost ASHRAE 90.1 Min EFF Standard AHRI 550 Rating Standard for chillers
