Magnetic Bearing Technology: Achievements in Higher Efficiency

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1 Magnetic Bearing Technology: Achievements in Higher Efficiency

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3 Magnetic Bearing Compressor 100% Oil Freeeliminates oil system maintenance costs. R134a Refrigerantmeets Montreal protocol and is not subject to phaseout. Magnetic Bearingseliminate frictional losses. One moving partassures long service life. Unmatched Efficiencyas low as.30 kw/ton IPLV. Low 2-amp In-Rush Currentreduces installed cost and peak load. Lowest Noise- Only 70 dba.

4 The Turbocor Compressor Synchronous brushless DC motor Inverter speed control Soft-Start (<2amps Inrush) 2 stage centrifugal compressor Pressure and temperature sensors Inlet Guide Vanes Motor and bearing control

5 VFD and Inlet Guide Vane Operation The Compressors speed adjusts automatically to match the load and current operating conditions so that optimum efficiency is gained. Primary capacity control is done using the onboard VFD and only use the Inlet Guide Vanes to supplement VFD controls. IGVs prevent surge conditions at low turndown. IGVs normally operate at the 110% position. The slower the compressors, the greater the efficiency. As speeds is reduced, energy consumption is reduced by the cube of the speed

6 The Magnetic Direct-Drive System 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 are sensed and adjustments are made accordingly. Shaft is monitored and positioned 1,000 / sec.

7 The Magnetic Bearing System Permanently magnetized shaft does not require electrical power. 97% energy efficient Uses 0.5% of the energy required for conventional bearings. Eliminate high mechanical friction losses Eliminate oil-related heat transfer losses Eliminate cost of oil management systems (controls and hardware) Increase equipment life through elimination of wear surfaces

8 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% speed Energy 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 8

9 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. Emerging VFD plant controllers optimize the technology. 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. Cooling tower selections optimized for lower temp and flow. Can increase installed cost yet reduce operation costs.

10 Why Is a Magnetic Bearing Compressor so Compelling?

11 Compressor Sizes and Uses Capacity IPLV Turndown 90 tons tons 125 tons tons 150 tons tons 190 tons tons Chilled Water Range 28F to 60F 134a limited Condenser Water Range 50F to 90F Ambient Range 10F to F Rule of thumb 12 degrees minimum between LCHWT and ECT

12 Compact Size -Easy to Service 125 HP motor is in the foreground. 150 HP permanent magnet motor behind. Variable-speed, magnetic bearing Variable-speed, magnetic bearing and cooling controls.

13 High Capacity Smaller Size

14 Oil-Free Eliminates Piping Complexity No need for elaborate piping designs compared with oil management systems. No traps and risers Lower installed costs Eliminates leak sources Enables centrifugal chiller with remote condenser to be placed at greater distance.

15 Lowest Cost of Service Annually check electronics for tight connections No oil service or oil disposal - EVER. Replace capacitors every Replace capacitors every ten years

16 Lowest Noise and Vibration Levels Best in Class low sound levels. No moving mechanical part touches any part of the housing or frame to transmit acoustic energy. Tested at 70 dba at 1 meter with no sound attenuation. Other compressors, by comparison, are approximately 80 dba and higher. 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 television.

17 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 feeds power to the various controls and bearing actuators during a 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 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 entire cycle from loss of power to normal operation takes about 1-3 minutes.

18 Automatic Bearing Compensation This compressor continued to operate 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 was robust enough to handle the challenge. The compressor continued to The compressor continued to operate at 35,000 rpm with this imbalance.

19 Turbocor Monitoring Software

20 Turbocor Monitoring Software

21 The Dramatic Effects of Oil 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 3-4% 5-8% loss 5-6% 9-11% loss 7-8% 13-15% loss Percent Oil 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) 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

22 The Dramatic Effects of Oil Percent Oil ASHRAE study shows average percentages of oil present in chillers Efficiency loss in heat exchangers account for substantial operation costs Percent Oil

23 The Dramatic Effects of Oil Efficie ency lo oss - % In the ten chillers tested in the ASHRAE study, the average overcharge of oil in the system was 12.88%, this equated to an average energy loss of about 21% Percent of oil

24 The Big Deal About Oil -Before kw/ton at AHRI relief conditions CS Screw CS Centrifugal VFD Oil Centrifugal.350 Load.300 $$$ Profile.250 Arctic Centrifugal % 30% 40% 50% 60% 70% 80% 90% 100%

25 The Big Deal About Oil -After kw/ton at AHRI relief conditions CS Screw CS Centrifugal Curves Include Avg. Effect of Oil VFD Oil Centrifugal $$$ $$$ $$$.250 Arctic Centrifugal Load Profile % 30% 40% 50% 60% 70% 80% 90% 100%

26 High Cost of Chiller Maintenance Procedure Daily Weekly Quarterly Yearly Record operating conditions (log) X Check oil levels Check refrigerant levels Check oil return system Check operation of motor starter Check sump heater and thermostat operation X X X X X Inspect and adjust safety controls Leak check and repair leaks Lubricate motor X X X Check and tighten all electrical connections Megohm motor windings Perform oil analysis on compressor lube oil Replace oil filter and oil return filter/dryers Replace or clean starter air filters X X X X X

27 High Cost of Oil -Bearings Stop Operation & provide backup chiller (rental) Open the compressor and hermetic motor for inspection 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. Cost approximately $25,000 each time 5 times over 30 year service life $125,000 over life of equipment. Burnout & oil induced acid eliminated.

28 Magnetic Bearing Chillers vsscrews ARI 550/ Conditions Leading Screw WATER COOLED Magnetic Bearing Compressor WATER COOLED Load ECW F/C LCHW F/C SST F/C SCT F/C COP kw/ton SST F/C SCT F/C COP kw/ton 100% 85/ /6.7 42/5.6 98/ /5.6 98/ % 75/ / / / /5.8 85/ % 65/ / / / / / % 65/ / / / /6 70/ IPLV COP kw/ton Conclusion The magnetic bearing compressor is 45% more efficient than the leading screw compressor

29 Magnetic Bearing Chillers vsscrews ARI 550/ Conditions Leading Screw AIR COOLED Magnetic Bearing Compressor AIR COOLED Load Air F/C LCHW F/C SST F/C SCT F/C COP kw/ton SST F/C SCT F/C COP kw/ton 100% 95/35 44/ /2 122/ /2 122/ % 80/ / / / / / % 65/ / /3 86/ /3 82.5/ % 55/ /6.7 38/3.5 86/ / / IPLV COP kw/ton Conclusion The magnetic bearing compressor is 29% more efficient than the leading screw compressor

30 A/C Efficiencies Now Finally Approaching W/C F Ambient temps 85 F 75 F 65 F Typical Air-Cooled Screw Chiller Arctic Cool Air-Cooled Chiller 95 F 85 F at ambient temps 75 F 85 F Typical 80 F Screw F Water-Cooled 70 F Chiller F 60 F condenser temps % 30% 40% 50% 60% 70% 80% 90% 100% 65 F Percent of Load For fans at Gillette Stadium, Boston One of five 400 ton chillers

31 Standard Stacked Design Oil-Free design eliminates frictional losses and high cost. Lowest IPLV in the industry. Variable-speed Drive. Flooded evaporator/condenser for thermal buffer and close approach. Cleanable condensers/evaporators. NEMA 1 Panels Standard. Danfoss Controls Standard Marine Water Boxes Optional.

32 Optional Low Profile Design Standard designs include stacked, offset and low profile. Optional Economizers boost capacity and efficiency Split systems are available. Multiple Circuits available. Condenser-less and Condenser-less and Condensing Units available.

33 Water Cooled Chillers Up to eight compressors per chiller Provides the ability to use the entire heat transfer surface even when using few compressors, thereby ensuring close approach temperatures. Water cooled products from 50 to 1,500 tons.

34 Highest Efficiency and Reliability

35 Combined Duty System Off the Grid HOT WATER SUPPLY CHILLED WATER RETURN CHILLED WATER SUPPLY TURBINE INLET AIR COOLER POWER GENERATOR EXHAUST CONTROL VALVE TURBINE ABSORPTION CHILLER Base-Loaded for kw Balance MAGNETIC PART-LOAD CHILLER Energy efficient benefits include sizing and balancing the 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 system.

36 Air Cooled Chillers Dedicated Circuit per compressor up to 400 tons or 4 circuits. Assures that refrigerant is properly managed during staging and load variations. Eliminates the known issues of refrigerant migration with single circuited centrifugal compressors.

37 Modular Chillers Modules with Scroll, Screw or Turbocor Compressors. Any size. Air cooled, water cooled, freecooling and VFD pumping systems are available.

38 Heat Recovery Chillers APPLICATIONS 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 Process Hot Water VAV Reheat Swimming Pool Heating Laundry Facilities

39 Lowest Total Cost of Ownership Lowest Energy Consumption low as.30 IPLV Don t rely on just NPLV but do full energy analysis Lowest Noise Levels 70 db compressor NO Oil Maintenance Costs NO Degradation of Tubing U-Value, Min 8% NO Compressor Rebuild Cycles -High MTBF Advanced Genuine Danfoss Controls Qualifies for Deepest Rebates, LEED Points. Fuel Cell Project DC to DC lowest cost Reverse flow generator powers compressors.

40 Why Chose Magnetic Bearing? ASHRAE Expo Energy Innovation Award Canadian Energy Award Frost & Sullivan