Air-Cooled Screw Chiller

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Type
Model
100
Range [RT]
200 300 400 1000
Application
1. Application
• Comfort cooling.
• Industrial process cooling.
• Ice/thermal storage.
• Low temperature process cooling.
2. Options & Selection
High efficiency High efficiency features including cycle
optimization, high efficiency fin and enhanced
economizer. Make this unit highly efficient.
Compact model More focus on compact design and
lightness by well-organized components
Ice making The unit controls are factory set operate in
ice making mode for thermal storage applications.
High pressure water shell
Up to 21 bar (300psi)
Power Disconnect Switch
Disconnect switch to isolate the chiller from main
power can be provided.
Single Power Connection Single termination points
are available for incoming power connections.
Screw (R134a)
Air
Cooled
Water
Cooled
High
Efficiency
Compact
Standard
Efficiency
50RT 100RT 200RT 300RT 400RT
40RT 180RT 360RT 540RT
1 Comp
2 Comp
40RT
200RT
400RT
1 Comp 2 Comp
Air-Cooled Screw Chiller
2009 Series RCAW® High Efficiency model 50 to 400Tons
Compact model 40 to 540Tons
Communication interface Controlled by various
control protocols for BMS interface.
High
Efficiency
Coil protection
Louvered panels protect the condenser coils.
220RT
480RT
480RT
960RT
Access protection Coated wire mesh covers the access
area under the condenser coils.
Soft starter Voltage supply gradually increase, fit to
appropriate torque during motor initial start to full
load condition
Isolators
Neoprene isolator and Spring isolator
3. Standard provides
Flow switches
Wye-Delta starter
Suction and discharge SVC Valves
Condenser corrosion protection
Protecting the condenser in corrosive environments
Acryl coated fins, Copper to Copper. Copper to Copper
with coated.
Site conditions should be matched with the proper
condenser fin coatings to inhibit coil corrosion and
extend equipment life.
High ambient operation The high ambient option
permits operation at high ambient
(up to 125°F/52°C).
LG Electronics Air Conditioning Marketing
20 Yeouido-dong, Yeongdeungpo-gu, Seoul 150-721, Korea
Phone: 82-2-3777-1114 http://www.lgeaircon.com
May, 2009
www.lgeaircon.com

Air-Cooled Screw Chiller 2009
www.lgeaircon.com
Feature & Benefit
1. Excellent Reliability and Powerful Operation
The cutting-edge design of the series RCAW Aircooled
screw chiller accomplishes high performance
and reliability for industrial and commercial market.
LG Air-cooled screw compressors are precisely
machined from solid compound metal bar using
profound cutting process. Tolerance is maintained
within a few microns just like one-tenth hair thickness.
Robust components with highly skilled assembling
process help the compressor last long time.
LG condenser production technology is already wellknown
to worldwide air conditioning manufacturing
industries because of its leading technologies.
2. World Class High Efficiency (High efficiency
model RCAW****A**)
Top level efficiency in accordance with ARI Standard
550/590. Optimized compressor design including a
rotor and a slide valve is suitable for comfort cooling
applications. The rotor is designed to work efficiently
for different pressure ranges covering air conditioning
and refrigeration application.
The slide valve controls the cooling capacity by
controlling the position of the slide where refrigerant
suction starts using internal pressure difference
between discharge and suction. LG air cooled screw
chiller has 4 steps capacity control (100, 75, 50, 25%)
capability which is optimized for part-load condition.
Precise rotor tip clearance provides excellent energy
efficiency in the screw rotary compressor because this
reduces leakage from high pressure to low pressure
side during compression, achieving top class C.O.P.
The cooler uses internally grooved tubes having
helical angle which enhanced the water side heat
transfer performance. The outside of the tube is of
optimum shape which has highly enhanced
performance for pooling boiling and film-wise
evaporation with R134-a. The V-shape of condenser
allows the largest heat transfer surface area for the
same foot print, resulting in largest heat transfer
performance when the configuration is optimally
designed. The LG V-shape condenser coil was designed
using numerical and experimental analysis, having
optimum air flow path to optimize heat rejection
performance. Also, the enhanced condenser fin
geometry allows the optimum heat transfer
performance at small air side pressure drop, and this
reduce the fan-motor power consumption. The fin is
pre-coated to prevent corrosion at normal conditions,
and acrylic post coated fin condenser, which is
sustainable in harsh conditions, is also available as
option.
Condensor
Ejector
Evaporator
Compressor
Gas
Liquid
Gas-liquid
Separator
EJECTOR
Suction
Diffuser
Nozzle
Chamber
Motive
3. World Class Compact Design (Compact model
RCAW****B**)
The RCAW model Air-cooled screw chiller is a compact
model of LG chillers and small compare to those of
other major chiller manufacturers averages 30% in
external dimensional footprint.
This model is also very light because of its
compactness. This model is suitable for the place
where there is restriction in space and for replacement
of old chillers. All physical sizes were reduced without
any sacrifice. This compactness could be achieved by
simplifying compression chamber, modifying coil
configuration, developing new oil separator, and
optimizing oil piping configuration.
'RCAW' was designed to be a prime chiller and was
born to lead air-cooled chiller market. It is LG
technology.
4. Low Noise and Low Vibration
The unit was designed with a compact structure and
robust assembly.
The condenser fan is completed with high-efficiency
wing style axial fan and direct driven motor for low
sound level. The unit configures compressor sound
insulation box (Option), which makes LG chillers silent
and stable.
Anechoic
Noise test simulation
Chamber
5. Advanced Microcomputer Control
Adaptive Chiller Control and Higher Level Protection.
The chiller control system is based on recent PLC
(Programmable Logic Controller) technology. Because
the PLC is designed to be compatible with several
electromagnetic interference and also compatible
with severe ambient conditions, the unit has reliable
controllability in any conditions.
The adaptive chiller control is designed to operate the
unit to withstand sever conditions and maintain its
operation. Good examples are condenser fan controls
by cycling according to the temperature of condenser
refrigerant and the limitation of compressor capacity
in the case of high chilled water temperature.
Along with the adaptive control, the control also
provides higher level protection through multiple
protective devices. For example triple protective
devices are used for the detection of abnormal oil
circulation. The control system continues to monitor
the hazardous conditions of the unit, and shutdown
the unit to protect the unit safely when any condition
meets safety limit.
Rich Human Machine Interface
Full dot LCD with four-line display provides rich
human machine interface. The interface shall include
operation conditions of the unit, control outputs, and
alarm encountered. Along with the LCD display, there
are totally nine LEDs are provided to indicated the
important control status of the unit. Through the LCD
and LEDs, operator-friendly interface is achieved for
the easy control of the LGE chiller
Superior power supply monitoring function of the
control system is enabled by protective function of it
against high voltage, low voltage, power loss, phase
reverse, and phase imbalance. The superior function
of safe power supply to the unit is provided by
standard.
Standard Wye-delta Start Type and Optional Soft Start
Type The wye-delta start provides reduced starting
current by 1/3. The LGE chiller is equipped with the
wye-delta start of the compressor. Optionally, soft
start type shall be provided for soft start of the
compressor by linear voltage increase.
6. System Protection Device
All of the LG chiller supplies perfect protective devices
for reliability.
• Proper oil circulation
(triple protection)
- Oil Flow switch
- Oil level switch
- Dual pressure switch
• Anti-freezing switch
- Low chilled water cutout switch (2°C)
• Differential pressure switch
- Between evaporator and condenser
• Compressor overload relay
- Checking comp current
• Compressor internal protector
- Checking comp winding temperature.
• Flow switch
- Checking if there is water flow
7. Installation, Start-up
Small operating footprint fit most retrofit
applications. (Compact model) Factory testing for high
reliability. Factory-installed and tested controls help to
reduce start up time and minimized extra cost. Display
temperatures and pressure for each component spot.
8. Compressor Specification
Semi-hermetic twinrotor
screw compressor.
Direct-drive,low
speed/RPM. Only three
moving parts, resulting
in high reliability.
The slide valve has a
unique profile optimized
for part-load conditions.
Field serviceable and
easy maintenance.
Sauggas
Suction Gas
Gas aspiré
Precise rotor tip clearance A refrigerant dispersing
device is set internal to the compressor for motor
cooling.
1. Factory Testing
Unit Performance Testing
All LG air-cooled screw chillers are given a complete
functional test at the factory. LG computer-based
testing programs completely check the components
including sensors, wiring, electronics and microprocessor
control functions.
LG promotes factory performance tests for air-cooled
chillers and water-cooled chillers to show that we
stand behind the products which are designed and
build up.
The benefits of a performance test include verification
of performance, prevention of operational problems,
and assurance of a smooth start-up. Each compressor
is run and tested to verifying capacity and efficiency.
The result of this testing, Chiller arrives at the job site
fully tested and ready for operation. The LG test
facility is able to simulate real circumstance assuring
operation in differing climates.
ECO
Installation for Industrial usage
LG Researching Effort
CR1
CR2
CR3
Druckgas
Discharge gas
Gas de refoulement
CR4
[Air-Cooled Chiller Test Chamber]
2. Structural Strength Analysis
Structural strength evaluation simulation
3. Condenser Numerical Analysis
LG simulate heat circulation for all chiller product to
evaluate air movement to be most appropriate design.
Heat circulation evaluation simulation
4. Assembly V-Module
[Run Test for RCAW 90TON]