APS Chiller Seminar Don Brandt, CEM-AEE, BEAP-ASHRAE ASHRAE and IEEE Life Member 3/16/2017
Agenda for today Refrigeration Cycle Chiller Types and Refrigerants Compressor Styles Chilled Water Pumping Systems Control of Chiller Plants Improving Chiller/System Efficiency Maintenance Absorption Cycle Questions & Answers Anytime
Chilled-water System air-cooled chiller pump coil control valve
Refrigeration Cycle Review of the Vapor Compression Cycle
Vapor-Compression Cycle evaporator expansion device condenser compressor
Basic Refrigeration System liquid line expansion device D A condenser evaporator C B discharge line compressor suction line
Compressor B C low-pressure refrigerant vapor from evaporator high-pressure refrigerant vapor to condenser
Condenser C refrigerant vapor D outdoor air liquid refrigerant
Expansion Device A liquid refrigerant D mixture of liquid and vapor refrigerant
Evaporator A mixture of liquid and vapor refrigerant air B refrigerant vapor
Basic Refrigeration System high-pressure C side discharge condenser line liquid line D expansion device A evaporator B compressor suction line low-pressure side
Chiller Styles Air Cooled Packaged and Split System Water Cooled Small, Medium and Large Tonnage Chillers with Evaporative Condensers Modular Chillers Packaged Chilled Water Plants
Packaged Air-cooled Chiller evaporator compressor propeller-type condenser fans air-cooled condenser
Air-cooled or Water-cooled Low-ambient Operation air-cooled chiller
Air-cooled Condenser propeller fan condenser coil subcooler outdoor air
Packaged Air-Cooled Chiller air-cooled chiller
Remote Evaporator Barrel condensing unit remote evaporator refrigerant piping
Components of a Helical-rotary Water Chiller oil supply system oil separator compressor motor liquid/vapor separator condenser control panel evaporator starter
Condenser refrigerant vapor baffle cooling tower water tube bundle liquid refrigerant
Evaporator tube bundle liquid refrigerant chilled water return liquid distributor eliminator orifice system
Water-cooled Condenser 95ºF [35ºC] hot, refrigerant vapor cooling water 85ºF [29ºC] subcooled, liquid refrigerant subcooler
Shell-and-Tube Evaporator chilled water supply baffles chilled water return refrigerant vapor tube bundle liquid/vapor refrigerant
Shell-and-Tube Evaporator baffles
Cooling Tower propeller fan sprays fill outdoor air sump 85ºF [29ºC] to condenser from condenser 95ºF [35ºC]
Evaporative Condenser fan refrigerant vapor condenser coil liquid refrigerant sump subcooler pump
Air-cooled or Water-cooled Comparison air-cooled Lower maintenance Packaged system Better low-ambient operation watercooled Greater energy efficiency Longer equipment life
Modular Chillers Typically Water-Cooled, some Air- Cooled Modules piped in Parallel from a water flow standpoint Compressors: Scroll, Screw and Centrifugal older may have Reciprocating
High-efficiency Modular Chiller Cooling Applications Only
Simultaneous Heating and Cooling Utilizing Heat Pump
Refrigerants for Chillers Scroll and Recip: HCFC-22, HFC- 407C, HFC-410A, HFC-134A Helirotor or Screw: HCFC-22, HFC- 134A Centrifugal: HFC-134A, HCFC-123 Future Refrigerants: Ammonia, HFOs Classified by ASHRAE Std 15 2016
Refrigerants of the Future HydroFluoroolefins no ozone depletion and low GWP R-514A, low pressure, replace R-123 in Centrifugal Chillers, GWP = 2 HFO-1234yf, medium pressure, replace R-134a in automotive/transportation, GWP =4 R-32, high pressure, replace R-410A in VRF, GWP = 675
Refrigerants of the Future R-452A, med pressure, replace R- 404 in various application, GWP = 1945 R-449A, high pressure, replace R-22 and R-407 in chillers and unitary, GWP=1282 R-513A, medium pressure, replace R-134a in air cooled screw chillers, GWP =573
Refrigerants of the Future R-452B, high pressure, replace R- 410A in unitary, residential and smaller HVAC equipment, GWP = 676 Suggested reading-honeywell website under Soltice refrigerants
Refrigerants of the Future Also check out websites for Chemours Dupont and Arkema ASHRAE Std 15-2016 has new classification of 2L for low flammability HFO s as it relates to safety ASHRAE just approved $1.5 Million in research for safety guidelines.
Refrigerants of the Future California just announced it will no longer allow any new equipment with R-134a in the state, starting in Jan of 2020.
Refrigerants of the Future GWP of current refrigerants. R-22, GWP = 1700,HCFC R-123, GWP = 0.02, HCFC R-134A, GWP = 1300, HFC R-11, GWP = 4000, CFC R-12, GWP = 2400, CFC
Refrigeration Compressors Reciprocating Scroll Helirotor or Screw-One, two and Three Rotor Centrifugal
reciprocating scroll helicalrotary centrifugal American Standard Inc. 2000 Air Conditioning Clinic TRG-TRC004-EN
Reciprocating Compressor discharge valve intake stroke suction valve refrigerant vapor rod piston cylinder
Reciprocating Compressor discharge valve compression stroke suction valve
Reciprocating Compressor suction opening cylinder headspace discharge opening piston rod motor crankshaft
Scroll Compressor dome scrolls discharge opening motor suction opening
Scroll Compressor stationary scroll discharge discharge port driven scroll intake motor shaft intake
Scroll Compressor journal bearing motor shaft direction of rotation driven scroll
Scroll Compressor intake discharge port intake
Scroll Compressor intake phase compression phase discharge phase
Helical-Rotary Compressor suction opening slide valve motor rotors discharge opening
Helical-Rotary Compressor female rotor male rotor housing
Helical-Rotary (Screw) Compressor
Helical-Rotary Compressor intake port pocket of refrigerant vapor
Helical-Rotary Compressor meshing point discharge port
Oil Separator refrigerant vapor to condenser refrigerant vapor and oil mixture oil return to sump
Oil Supply System oil separator rotor bearings refrigerant vapor to condenser rotor oil tank sump master solenoid valve 2 compressor 1 oil filter
Centrifugal Compressor impeller
Centrifugal Compressor refrigerant enters diffuser velocity static pressure refrigerant enters impeller refrigerant enters volute path through compressor
Centrifugal Compressor motor inlet vanes suction impeller
Centrifugal Compressor volute diffuser passages radial impeller passages blades impeller
Motor motor motor impeller geardrive directdrive impellers gears
Oil Less Centrifugal Compressor Magnetic Bearing Style Danfoss, Diakin, and York direct drive with VFD Ceramic Bearing Style Refrigerant cooled bearings with VFD
Semihermetic Compressor piston motor compressor crankshaft housing
Hermetic Compressor housing motor compressor piston
Open Compressor housing compressor crankshaft
Methods of Compressor Unloading Reciprocating Scroll Cylinder Unloaders Cycle On- Off, Digital, VFD, Ported Helical-Rotary Centrifugal Slide Valve, VFD, Ported Inlet Vanes, VFD
Cylinder Unloaders unloader solenoid valve controller unloader valve refrigerant vapor cylinder piston discharge
Digital Scrolls Provide Continuous Modulation Separation Of Scroll Elements Alternately Loads And Unloads Compressor By Controlling Separation Times, Compressor Is Precisely Operated Between 10-100% Power Linearly Related To Capacity Unloaded State Precise Temperature & Humidity Control Ideal For Light Commercial Split, Package And Chiller Applications Loaded State
Next Gen UltraTech Modulation Intermediate Cavity Pressure Communicated To Lift Chamber Via Three Way Valve (Valve De-energized) Part Load Operation Modulation Ring Moves Up, Opening Bypass Ports Part Load Full Load Bypass Ports Opened Suction Pressure Communicated To Lift Chamber Via 3-Way Valve (Valve Energized) Full Load Operation Modulation Ring Moves Down, Sealing Bypass Ports Bypass Ports Sealed
How Variable Speed Technology Works
Benefits Of Multiples Tandems And Trios Load Matching Capability Via Multiple Steps Of Capacity Compressors Operate Together Or Individually Maintains High Part & Full Load Efficiency Levels Ideal For Commercial Splits, Rooftops And Chillers
Slide Valve discharge port slide valve (closed) to suction slide valve (open) full load valve opening part load
Slide Valve discharge port housing rotors slide valve
Heli Rotor Compressor Unloader ports along the rotor that open back to the compressor suction to decrease the capacity VFDs change speed of rotors for capacity control
Inlet Vanes inlet vanes impeller
Inlet Vanes A 90 pressure difference C 10 14 25 unloading line B 36 51 63 vane position (degrees) 75 capacity
Variable Speed variable-speed drive
Equipment Rating Standards Air-Conditioning, Heating & Refrigeration Institute (AHRI) Standard 550/590 2015: centrifugal and helical-rotary water chillers Standard 560 2000: absorption water chillers
Flow Rates and Temperatures Q Btu/hr = 500 flow rate T [ Q W = 4,184 flow rate T ] equation for water only
ASHRAE Standard 15 2016 Safety standard for refrigerating systems Mechanical equipment room Refrigerant monitors Alarms Mechanical ventilation Pressure-relief piping
ASHRAE/IESNA Standard 90.1 2016 Energy standard Building design and materials Minimum equipment efficiencies HVAC system design
Std 90.1 2016 Tables Equipment FL Kw/Ton - A IPLV - A FL Kw/Ton - B IPLV - B W/C Cent Chiller >600 0.56 Kw/Ton 0.50 Kw/Ton 0.585 Kw/Ton 0.38 Kw/Ton A/C Chiller >150 10.1 EER 14.0 EER N/A N/A W/C Screw Chiller >300 0.61 Kw/Ton 0.52 Kw/Ton 0.625 Kw/Ton 0.41 Kw/Ton