magnetic bearing technology: achievements in higher …...magnetic bearing compressor •100% oil...
TRANSCRIPT
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Magnetic Bearing Technology:
Achievements in Higher Efficiency
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Magnetic Bearing Compressor
• 100% Oil Free eliminates oil system
maintenance costs.
• R134a Refrigerant meets Montreal • R134a Refrigerant meets Montreal
protocol and is not subject to phase-
out.
• Magnetic Bearings eliminate frictional • Magnetic Bearings eliminate frictional
losses.
• One moving part assures long service • One moving part assures long service
life.
• Unmatched Efficiency as low as .30
kw/ton IPLV.kw/ton IPLV.
• Low 2-amp In-Rush Current reduces
installed cost and peak load.
• Lowest Noise - Only 70 dBa.
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The Turbocor CompressorSoft-Start
Inverter speed 2 stage centrifugal
compressor
Soft-Start (
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VFD and Inlet Guide Vane Operation
• The Compressors speed adjusts
automatically to match the load and automatically to match the load and
current operating conditions so that
optimum efficiency is gained.
• Primary capacity control is done using • Primary capacity control is done using
the onboard VFD and only use the Inlet
Guide Vanes to supplement VFD Guide Vanes to supplement VFD
controls. IGVs prevent surge conditions
at low turndown. IGVs normally
operate at the 110% position.operate at the 110% position.
• The slower the compressors, the
greater the efficiency. As speeds is
reduced, energy consumption is reduced, energy consumption is
reduced by the cube of the speed
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The Magnetic Direct-Drive System
Magnetic bearings and sensors keep the shaft properly centered and positioned at all times. The Magnetic bearings and sensors keep the shaft properly centered and positioned at all times. The
rotor shaft is held in position with ten separately controlled electro magnetic cushions which
continually changes in strength to keep the shaft centrally positioned.
The shafts position is monitored with 10 sensor coils whose signal is fed back to a digital controller.
Movements of less than .00002”are sensed and adjustments are made accordingly.
Shaft is monitored and positioned 1,000 / sec.Shaft is monitored and positioned 1,000 / sec.
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The Magnetic Bearing System
• Permanently magnetized shaft does not require
electrical power. electrical power.
• 97% energy efficient
• Uses 0.5% of the energy required for conventional
bearings.bearings.
• Eliminate high mechanical friction losses
• Eliminate oil-related heat transfer losses
• Eliminate cost of oil management systems • Eliminate cost of oil management systems
(controls and hardware)
• Increase equipment life through elimination of
wear surfaceswear surfaces
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Leveraging Affinity Laws
Energy Used is Proportional to the Cube of the Speed of the Motor
Two pumps at 50% speed use 25% of the power of one pump at 100% speedTwo pumps at 50% speed use 25% of the power of one pump at 100% speed
Energy
100% 100%Speed
100% 100%
40% 7%
Optimizing the System involves leveraging Affinity Laws and Real-Time Tracking and Tuning of
Components to shift Load to where total PLANT ENERGY across all related components is reduced.
This is not simple PID loop feedback, but Dynamic Optimized kW Input
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This is not simple PID loop feedback, but Dynamic Optimized kW Input
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Variable Speed Factors
• Power is proportional to the speed cubed
• To achieve power reduction, the speed of fans, pumps and
compressors should be reduced at lower loads. compressors should be reduced at lower loads.
• Emerging VFD plant controllers optimize the technology.
• Flooded designs with water in tubes can limit flow range due to • Flooded designs with water in tubes can limit flow range due to
velocity and laminar flow issues. DX can be better solution in some
applications, but with efficiency loss.applications, but with efficiency loss.
•Cooling tower selections optimized for lower temp and flow. Can
increase installed cost yet reduce operation costs. increase installed cost yet reduce operation costs.
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Why Is a Magnetic Bearing Compressor so Compelling?
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Compressor Sizes and Uses
90 tons .375 17 tons
Capacity IPLV Turndown90 tons .375 17 tons
125 tons .359 28 tons125 tons .359 28 tons
150 tons .336 35 tons150 tons .336 35 tons
190 tons .342 55 tons190 tons .342 55 tonsChilled Water Range – 28F to 60F – 134a limited
Condenser Water Range – 50F to 90FCondenser Water Range – 50F to 90F
Ambient Range – 10F to 108-110F
Rule of thumb – 12 degrees minimum between LCHWT and ECTRule of thumb – 12 degrees minimum between LCHWT and ECT
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Compact Size - Easy to ServiceCompact Size - Easy to Service
125 HP motor is in the foreground.
150 HP permanent magnet motor 150 HP permanent magnet motor
behind.
Variable-speed, magnetic bearing Variable-speed, magnetic bearing
and cooling controls.
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High Capacity – Smaller Size
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Oil-Free Eliminates Piping Complexity
No need for elaborate piping
designs compared with oil designs compared with oil
management systems.
• No traps and risers
• Lower installed costs• Lower installed costs
• Eliminates leak sources
Enables centrifugal chiller
with remote condenser to be with remote condenser to be
placed at greater distance.
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Lowest Cost of Service
• Annually check electronics
for tight connectionsfor tight connections
• No oil service or oil
disposal - EVER.disposal - EVER.
•Replace capacitors every •Replace capacitors every
ten years
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Lowest Noise and Vibration Levels
• “Best in Class” low sound levels. No
moving mechanical part touches any part of moving mechanical part touches any part of
the housing or frame to transmit acoustic
energy.energy.
• Tested at 70 dBa at 1 meter with no sound
attenuation. Other compressors, by
comparison, are approximately 80 dBa and comparison, are approximately 80 dBa and
higher.
• Vibration is essentially non-existent.• Vibration is essentially non-existent.
• The chiller with 5 compressors operating
at full speed only produces 75 DB of sound
at 10 feet., about the sound level of your at 10 feet., about the sound level of your
television.
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What Happens with a Power Outage?
• In the case of a power outage, the compressor is fully protected.
• Within 0.5 of a micro-second, the motor becomes a generator which then • Within 0.5 of a micro-second, the motor becomes a generator which then
feeds power to the various controls and bearing actuators during a
controlled coast-down. The onboard capacitors have adequate power to fully controlled coast-down. The onboard capacitors have adequate power to fully
support the bearing system during the switch. Capacitors are replaced every
ten years.
•After the compressor comes to a complete stop, the rotor de-levitates
normally onto touchdown bearings. Carbon or roller touchdown bearings are normally onto touchdown bearings. Carbon or roller touchdown bearings are
also used as a back up bearing system to act as a cradle for the rotor during
the off-mode.
• The system then determines if normal power is restored, if YES, the shaft
levitates. If there is a call for cooling, the rotor will then begin to rotate. The levitates. If there is a call for cooling, the rotor will then begin to rotate. The
entire cycle from loss of power to normal operation takes about 1-3 minutes.
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Automatic Bearing Compensation
This compressor continued to operate
even though this hole saw slug was even though this hole saw slug was
embedded in the 1st stage impeller.
The compressor is not designed to pump
hole saw slugs, however when faced with
this problem, the auto-balance feature this problem, the auto-balance feature
was robust enough to handle the
challenge. The compressor continued to
challenge. The compressor continued to operate at 35,000 rpm with this imbalance.this imbalance.
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Turbocor Monitoring Software
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Turbocor Monitoring Software
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The Dramatic Effects of OilThe Dramatic Effects of OilASHRAE 601-TRP - Oil contamination can be caused by several factors, including gasket failure, ASHRAE 601-TRP - Oil contamination can be caused by several factors, including gasket failure,
but the most common cause of oil migration in comfort chillers is the continued use of a chiller at
low loads during the beginning or end of the cooling season. How much does excess oil in the
evaporator degrade performance? Table 1 gives typical ranges.
Oil in Evaporator Performance Loss
1-2% 2-4% loss
evaporator degrade performance? Table 1 gives typical ranges.
Percent Oil
1-2% 2-4% loss3-4% 5-8% loss5-6% 9-11% loss5-6% 9-11% loss7-8% 13-15% loss
ASHRAE study reached the same conclusion: “Flow boiling results have been obtained for newer
enhanced boiling tubes with R-134a. This enhanced tube shows a decrease in heat transfer with the
addition of even a small amount of oil throughout various heat loadings. Even at 1 percent (by weight) addition of even a small amount of oil throughout various heat loadings. Even at 1 percent (by weight)
oil, the heat transfer coefficient is reduced by 25 percent from its no oil baseline. At higher oil content, a
30 percent reduction has been typically measured.”
Oil causes 50% of downtime and cost
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The Dramatic Effects of OilThe Dramatic Effects of OilPercent Oil
ASHRAE study shows
average percentages of oil
Percent Oil
average percentages of oil
present in chillers
Percent OilEfficiency loss in heat
exchangers account for Percent Oilexchangers account for
substantial operation costs
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The Dramatic Effects of Oil
In the ten chillers tested in
the ASHRAE study, the the ASHRAE study, the
average overcharge of oil in
the system was 12.88%, this
equated to an average
Eff
icie
ncy
loss
-%
equated to an average
energy loss of about 21%
Eff
icie
ncy
loss
E
ffic
ien
cy lo
ss
Percent of oilPercent of oil
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The Big Deal About Oil - Before
kW/Ton at AHRI relief conditions.650
.600
kW/Ton at AHRI relief conditions
CS Screw.550
.500 CS Centrifugal
CS Screw
VFD Oil.450
.400
CS Centrifugal VFD OilCentrifugal
.350
.300 $$$ LoadProfile.300
.250
.20020% 30% 40% 50% 60% 70% 80% 90% 100%
Arctic Centrifugal
$$$ Profile
.20020% 30% 40% 50% 60% 70% 80% 90% 100%
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The Big Deal About Oil - After
.650kW/Ton at AHRI relief conditions
CS Screw.600
.550CS Centrifugal
CS Screw
Curves Include.500
.450VFD Oil Centrifugal
Curves IncludeAvg. Effect of Oil
.400
.350$$$
$$$
$$$
.300
.250 Arctic Centrifugal
$$$$$$
LoadProfile
.250
.20020% 30% 40% 50% 60% 70% 80% 90% 100%
Arctic Centrifugal
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High Cost of Chiller Maintenance
Procedure Daily Weekly Quarterly Yearly
Record operating conditions (log) X
Check oil levels X
Check refrigerant levels X
Check oil return system X
Check operation of motor starter X
Check sump heater and thermostat operation X
Inspect and adjust safety controls X
Leak check and repair leaks X
Lubricate motor XLubricate motor X
Check and tighten all electrical connections X
Megohm motor windings XMegohm motor windings X
Perform oil analysis on compressor lube oil X
Replace oil filter and oil return filter/dryers XReplace oil filter and oil return filter/dryers X
Replace or clean starter air filters X
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High Cost of Oil - BearingsHigh Cost of Oil - Bearings
Stop Operation & provide backup chiller (rental)
Open the compressor and hermetic motor for inspectionOpen the compressor and hermetic motor for inspection
In addition to normal annual maintenance, inspection occurs every 40,000 hrs of In addition to normal annual maintenance, inspection occurs every 40,000 hrs of
operation or every 5 years, whichever occurs first. 5 times during a 30 year
service life. Screw chillers not optional!
Shutdown, disassemble motor,
replace bearings, replace seals.replace bearings, replace seals.
Cost approximately $25,000 each
time 5 times over 30 year service time 5 times over 30 year service
life $125,000 over life of equipment.
Burnout & oil induced acid eliminated.
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Magnetic Bearing Chillers vs Screws
ARI 550/590-1998 Conditions
Leading ScrewWATER COOLED
Magnetic Bearing CompressorWATER COOLED
Load ECWF/C
LCHWF/C
SSTF/C
SCTF/C
COP kW/Ton SSTF/C
SCTF/C
COP kW/Ton
100% 85/29.5 44/6.7 42/5.6 98/36.7 5.33 0.64 42/5.6 98/36.7 5.56 0.63100% 85/29.5 44/6.7 42/5.6 98/36.7 5.33 0.64 42/5.6 98/36.7 5.56 0.63
75% 75/23.9 44/6.7 42.3/5.8 89.6/32 5. 73 0.6 42.3/5.8 85/29.5 7.31 0.48
50% 65/18.3 44/6.7 42.5/5.9 89.6/32 5.49 0.64 42.5/5.9 72.2/2.2 11.38 0.3050% 65/18.3 44/6.7 42.5/5.9 89.6/32 5.49 0.64 42.5/5.9 72.2/2.2 11.38 0.30
25% 65/18.3 44/6.7 42.8/6. 89.6/32 4.11 0.845 42.8/6 70/21.1 10.86 0.32
IPLV COP kW/Ton 5.4 .65 9.55 0.36
Conclusion – The magnetic bearing compressor is 45% more efficient
than the leading screw compressor
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Magnetic Bearing Chillers vs Screws
ARI 550/590-1998 Conditions
Leading ScrewAIR COOLED
Magnetic Bearing CompressorAIR COOLED
Load AirF/C
LCHWF/C
SSTF/C
SCTF/C
COP kW/Ton SSTF/C
SCTF/C
COP kW/Ton
100% 95/35 44/6.7 35.5/2 122/50 3.19 1.10 35.5/2 122/50 3.08 1.13
75% 80/26.7 44/6.7 36.5/2.5 104/40 4.20 0. 83 36.5/2.5 104/40 4.44 0.79
50% 65/18.3 44/6.7 37.5/3 86/30 5.26 0.69 37.5/3 82.5/28 7.23 0. 48
25% 55/12.8 44/6.7 38/3.5 86/30 3.98 0.88 38/3.5 66.2/19 9.77 0.35
IPLV COP kW/Ton 4.6 0.76 6.32 0. 55
Conclusion – The magnetic bearing compressor is 29% more efficient
than the leading screw compressor
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A/C Efficiencies Now Finally Approaching W/C
2.5
3.0
95°F Ambient temps
1.5
2.0Typical Air-Cooled
Screw Chiller
85°F
75°F
65°F
.80
.90
1.0
Arctic Cool
Chiller
at ambient temps
Air-Cooled
.60
.70
.80
85°F
80°F
75°F
TypicalScrew
Water-Cooled
95°F 85°F75°F
at ambient temps
.40
.50
.60 75°F70°F
65°F
60°F
ChillerWater-Cooled
condenser temps
65°F
For fans at Gillette Stadium, Boston
Percent of Load
20% 30% 40% 50% 60% 70% 80% 90% 100%.30
For fans at Gillette Stadium, Boston
One of five 400 ton chillers
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Standard Stacked Design
• Oil-Free design eliminates frictional
losses and high cost. losses and high cost.
• Lowest IPLV in the industry.
• Variable-speed Drive.• Variable-speed Drive.
• Flooded evaporator/condenser for
thermal buffer and close approach.thermal buffer and close approach.
• Cleanable condensers/evaporators.
• NEMA 1 Panels Standard.• NEMA 1 Panels Standard.
• Danfoss Controls Standard
• Marine Water Boxes Optional.• Marine Water Boxes Optional.
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Optional Low Profile Design
Standard designs include
stacked, offset and low stacked, offset and low
profile.
Optional Economizers Optional Economizers
boost capacity and
efficiency
Split systems are Split systems are
available.
Multiple Circuits Multiple Circuits
available.
Condenser-less and Condenser-less and
Condensing Units
available.
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Water Cooled Chillers
• Up to eight compressors • Up to eight compressors
per chiller
• Provides the ability to use • Provides the ability to use
the entire heat transfer
surface even when using
few compressors, thereby few compressors, thereby
ensuring close approach
temperatures.temperatures.
•Water cooled products
from 50 to 1,500 tons.
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Highest Efficiency and ReliabilityHighest Efficiency and Reliability
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Combined Duty System – Off the GridCombined Duty System – Off the Grid
�
HOT WATER SUPPLY
� CHILLED WATER SUPPLYCHILLED WATER RETURN
TURBINE INLETAIR COOLER EXHAUST
CONTROL
ABSORPTIONCHILLER
Base-Loadedfor kW Balance
CONTROLVALVE
POWERGENERATOR
TURBINE
for kW Balance
MAGNETIC PART-LOAD CHILLERGENERATOR
Energy efficient benefits include sizing and balancing the
absorption chiller to the base load to assure steady-state absorption chiller to the base load to assure steady-state
output, and using the variable-speed magnetic chiller to meet
varying load demands above and below base load, and to
provide system redundancy for the absorption and power provide system redundancy for the absorption and power
system.
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Air Cooled Chillers
• Dedicated Circuit per • Dedicated Circuit per
compressor up to 400
tons or 4 circuits.
• Assures that
refrigerant is properly
managed during staging managed during staging
and load variations.
•Eliminates the known •Eliminates the known
issues of refrigerant
migration with single
circuited centrifugal circuited centrifugal
compressors.
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Modular Chillers
• Modules with Scroll, Screw or
Turbocor Compressors. Any size.Turbocor Compressors. Any size.
• Air cooled, water cooled, free-
cooling and VFD pumping systems cooling and VFD pumping systems
are available.
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Heat Recovery Chillers
APPLICATIONS
• Sites with constant chilled and hot water demand.• Sites with constant chilled and hot water demand.• Hospitals, Hotels, Nursing Homes, Universities• Process Heating and Cooling Loads
HEAT RECOVERY USES
• Building Heating Loops• Domestic Hot Water• Domestic Hot Water• Process Hot Water• VAV Reheat• VAV Reheat• Swimming Pool Heating• Laundry Facilities
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Lowest Total Cost of OwnershipLowest Total Cost of Ownership
• Lowest Energy Consumption – low as .30 IPLV• Lowest Energy Consumption – low as .30 IPLV
• Don’t rely on just NPLV but do full energy analysis
• Lowest Noise Levels – 70 dB compressor• Lowest Noise Levels – 70 dB compressor
• NO Oil Maintenance Costs
• NO Degradation of Tubing U-Value, Min 8%• NO Degradation of Tubing U-Value, Min 8%
• NO Compressor Rebuild Cycles - High MTBF
• Advanced Genuine Danfoss Controls• Advanced Genuine Danfoss Controls
• Qualifies for Deepest Rebates, LEED Points.
• Fuel Cell Project – DC to DC lowest cost
•Reverse flow generator powers compressors.
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Why Chose Magnetic Bearing?
ASHRAE Expo Canadian ASHRAE Expo
Energy Innovation
Award
Canadian
Energy Award
Award
Frost & Sullivan