Energy Efficiency - Innovation, Experience Workshop Oil ...

1 1 Energy Efficiency - innovation , Technology & Experience WorkshopOil-Free Magnetic Bearing Compressors for Air-Conditioning Plants19 November 20082 All the technical details in this presentation material are from an internal study and are for information only; The data and conclusion of the presentation do not represent theofficial opinion or stance of The Energy Efficiency Office of The Electrical and Mechanical Services Department; While we have tried our endeavour to ensure the accuracy of the contents therein, The Energy Efficiency Office of The Electrical and Mechanical Services Departmentwould not be responsible for any consequence or loss arising from the use of or making reference to the presentation material by any other person or partyDisclaimer3 Electricity Consumption of Chiller EquipmentElectricity End-uses of 2006It was roughly estimated that chiller equipment alone consume about 50%-70% electricity of the HVAC systemIt was roughly estimated that chiller equipment alone consume about 50%-70% electricity of the HVAC system4 The Basic Principle of

2 ChillerCompressorExpansion ValveEvaporatorCondenserCooling Load in BuildingHeat Rejection to OutdoorPositive-displacement compressorsDynamic compressors5 Type of CompressorsPositive-displacement compressors increase pressure of refrigerant vapor by reducing the volume of the compression chamber through work applied to the compressors Examples include reciprocating, screw, scroll extracted from EsourcePhoto extracted from Air Conditioning and Refrigeration Journal April-June 2000 issue6 Volute CasingImpeller WheelImpellersRefrigerant DischargeRefrigerant SuctionType of CompressorsDynamic compressors increase the pressure of refrigerant vapour by a continuous transfer of angular momentum from the rotating member to the vapour followed by the conversion of this momentum into a pressure rise Example is centrifugal compressorGraphics extracted from Chiller Manufacturer s O&M Manual7 Type of CompressorsMore moving parts.

3 Vibrations; (water cooled) - (air cooled) 1 400 RTReciprocatingWide operating range;Relatively small and light;Response well to reductions in condenser water (water cooled) (air cooled)40 1,100 RTScrewMature technology; Subject to surge at low loads;Gear-driven or - 7100 1,500 RTCentrifugalRemarksTypical Full-load Chiller COPT ypical Size RangeType of CompressorSources: Manufacturer s Data8 Innovative Oil-Free Magnetic Bearing Compressor9 Innovative Oil-Free Magnetic Bearing Compressor2 Stages Centrifugal TypeMagnetic Bearing No lubrication oil circuitDC Permanent Magnet MotorVariable Speed Drive DrivenElectronics Integration10 Innovative Oil-Free Magnetic Bearing CompressorPressure and temperature sensorsInverter speed controlSynchronous brushless DC motorMotor and bearing controlInlet guide vanes2 stage centrifugal compressorSource.

4 Manufacturer s Literatures11 Innovative Oil-Free Magnetic Bearing CompressorCentrifugal Design for Small to Medium Size ChillerSource: Manufacturer s Literatures12 Innovative Oil-Free Magnetic Bearing CompressorMagnetic Bearing SystemSource: Manufacturer s Literatures13 Innovative Oil-Free Magnetic Bearing CompressorMagnetic Bearing SystemSource: Manufacturer s Literatures14 Innovative Oil-Free Magnetic Bearing CompressorMagnetic Bearing SystemAdvantagesNo physical contactLow and predictable frictionNo lubrication requirementSmooth operationSuitable for high speed operationDisadvantagesBulky in sizeExpensive15 Innovative Oil-Free Magnetic Bearing CompressorMagnetic Bearing SystemAdvantagesNo physical contactLow and predictable frictionNo lubrication requirementSmooth operationSuitable for high speed operationDisadvantagesBulky in sizeExpensiveQuestion to thinkWhat will happen if there is a

5 Power failure or electronics failure?16 Innovative Oil-Free Magnetic Bearing CompressorMagnetic Bearing SystemProblems associate with LubricationDisadvantagesBulky oil sump in chillerNeed oil heater to maintain oil temperature at about 40 CMaintenance issueRegular oil analysisOil migration affecting chiller efficiencyOil return problem at low chiller load19 Innovative Oil-Free Magnetic Bearing CompressorDisadvantages20 Innovative Oil-Free Magnetic Bearing CompressorDisadvantagesSource: ASHRAE research project - 601 TRPOil Content Found in Samples of Older CFC Centrifugals Tested 10 Machines Range from to Average was 12%Impact% Oil % Efficiency Loss1% 2%4% 9%9% 15%21 Innovative Oil-Free Magnetic Bearing CompressorDisadvantagesSource.

6 ESourcePermanent MagnetRotorStatorStator windingsPermanent Magnetic DC MotorMore efficient over a wide speed and load rangeVariable speed capability improve load control and precisionShows slight advantage for nearly constant operation at moderate to high load Large advantage for systems with varying load including significant low-load operation22 Innovative Oil-Free Magnetic Bearing CompressorDisadvantagesSource: ESourcePermanent Magnetic DC DC Motor Motor Oil-Free Magnetic Bearing CompressorDisadvantagesSource: Manufacturer s LiteraturesVariable Speed DriveVaries the frequency between 300 800 HzCompressor running at 18,000 48,000 rpm24 Innovative Oil-Free Magnetic Bearing CompressorDisadvantagesSource: Manufacturer s LiteraturesVariable Speed Drive25 Innovative Oil-Free Magnetic Bearing CompressorDisadvantagesSource: Manufacturer s LiteraturesVariable Speed Drive26 Innovative Oil-Free Magnetic Bearing CompressorDisadvantagesSource: Distributor s LiteraturesVariable Speed Drive27 Innovative Oil-Free Magnetic Bearing CompressorDisadvantagesSource.

7 Manufacturer s LiteraturesTT300 (STD) vs. Screw02468101225%50%75%100%CapacityCOPT urbocorScrewVariable Speed DriveIPLV COP approaching 10 for water cool and 6 for air cool chillersOil free compressors allows chiller to off load to a very low percentage (15%). IPLV COP approaching 10 for water cool and 6 for air cool chillersOil free compressors allows chiller to off load to a very low percentage (15%). 28 Innovative Oil-Free Magnetic Bearing CompressorDisadvantagesFor reference onlyVariable Speed Drive29 Innovative Oil-Free Magnetic Bearing CompressorDisadvantagesFor reference onlyVariable Speed Drive30 Innovative Oil-Free Magnetic Bearing CompressorDisadvantagesSource.

8 Manufacturer s LiteraturesApplicationCan be used in Air Cooled Chillers or Water Cooled Chillers31 Innovative Oil-Free Magnetic Bearing CompressorDisadvantages32 Innovative Oil-Free Magnetic Bearing CompressorDisadvantagesData Logging starts in October Results from 1-17 November (for reference only):More data will be collected for Condensing Water In/Out Temp: CAverage Chilled Water In/Out Temp: CAverage % Loading of Chiller:~53%Average Chiller COP As Recorded By CCMS: ~ ( ~ 5-6 of atypical conventionalcentrifugal chiller)Performance33 End Of Presentatio