Back to Basics Chiller Plant Applications Melbourne 28 th April 2016 - PowerPoint PPT Presentation

Back to Basics Chiller Plant Applications Melbourne 28 th April 2016 Johnson Controls - Proprietary

Many Considerations Climate Accessibility Comfort Redundancy Criticality Water Energy Noise Indoor space Outdoor space Marketing Codes/Standards 2 Johnson Controls - Proprietary

Chiller Plant Operating Costs = Consumables + Water + Maintenance + ENERGY Energy Cost of Plant = Rate X X X Load Hours Efficiency Structure Holistic Chiller Plant Approach 3 Johnson Controls - Proprietary

Automation is a key component of the optimization process but optimization is not just smart controls Maintain Measure & Verify Operating Decisions Optimize System Automate System Apply components effectively, optimally Design Decisions Select components effectively, optimally Design system infrastructure to max efficiency potential Johnson Controls - Proprietary

Design Energy Vs. Annual Energy Chiller 58% Chiller Fans 33% 43% Fans Tower Tower 24% 2% Pumps Pumps 5% 22% 13% Design Performance Annual Energy Usage Flexibility Efficiency Sustainability Life Cycle Johnson Controls - Proprietary & Confidential

Air cooled vs Water cooled Heat rejection medium Air Water Performance dry bulb based wet bulb based Full Load Efficiency Lower Higher Lower # Part load efficiency Higher Chiller Size larger baseline Water usage NO* YES Location Outdoors Indoors (plant-room) Installation Less complex More complex Maintenance Less complex More complex # Plant efficiencies are dependent on climate, control, and other factors * Power generating stations use water to produce electricity Johnson Controls - Proprietary

VSD technology unlocks efficiency benefit of natural weather conditions Constant Speed, Constant Speed, Variable Speed, Variable Speed, YK CSD Constant CEFT YK CSD AHRI Relief YK VSD AHRI Relief YMC2 AHRI Relief AHRI Relief Constant CEFT AHRI Relief AHRI Relief + oil-free 14.0 13.0 Chillers operate for 85% of the 12.0 time within this capacity range 11.0 10.0 COP 9.0 8.0 7.0 6.0 5.0 4.0 10 20 30 40 50 60 70 80 90 100 % Capacity Note: Above is based on water cooled centrifugal compressor technology Johnson Controls - Proprietary

The design process • Minimize ‘transport’ energy • Maximize the economics of high efficiency components • Optimize ‘lift’ Johnson Controls - Proprietary

Pressure- enthalpy diagram 6 5 4 3 condenser pressure Metering device compressor 1 2 evaporator enthalpy Johnson Controls - Proprietary

Water cooled chillers Standard design lift condition Pressure 35 ° C 29.4 ° C Lift or Differential Pressure 12.2 ° C 6.7 ° C Enthalpy Johnson Controls - Proprietary

What is Heat Recovery? ASHRAE Handbook (2008):  “In many large buildings, internal heat gains require year -round chiller operation. The chiller condenser water heat is often wasted through a cooling tower”…“[Heat recovery] uses otherwise wasted heat to provide heat at the higher temperatures required for space heating, reheat, and domestic water heating” Heat recovery creates and uses energy at higher chiller lift condition to improve overall building efficiency 11 Johnson Controls - Proprietary

What is Heat Recovery? Building with Energy Recovery Cooling Tower (40ºC) (35ºC) Condenser Heat Recovery Motor Compressor Expansion Valve Evaporator Example – reheat cooled and de-humidified O/A to neutral condition for use with a passive (6.7ºC) (12.2ºC) chilled beam system with site recovered energy Boiler 12 Johnson Controls - Proprietary

Why use a heat recovery chiller? Economic Advantages  Operational savings Social / Environmental Advantages  CO 2 reductions  Reduced water consumption Coincident heating and cooling Cooling capacity 680 kWr Heat rejection 820 kWr Power input 140 kWe Total COP = 1500 / 140 = 10.7 13 Johnson Controls - Proprietary

What is lift relief ? Lower tower water temps AND / OR Higher chilled water temps Less compressor work = lower input kWe 1 4 Johnson Controls - Proprietary

Reduce lift Capitalizing on ‘off - design’ conditions -most of the time Lowering Condenser Water Temperature Pressure Lowers the Lift Condenser Lift Expansion Compressor Reduces Compressor Work Evaporator Reduces Enthalpy Energy Consumption Johnson Controls - Proprietary

Reduce lift Capitalizing on ‘off - design’ conditions -most of the time Raising Chilled Water Temperature Pressure Condenser Lowers the Lift Lift Expansion Compressor Evaporator Reduces Compressor Work Reduces Enthalpy Energy Consumption Johnson Controls - Proprietary

How does lower LIFT (compression ratio) impact efficiency ? Variable Speed Chiller Energy Usage Analogy - Condenser Temp. 100% 29.4 0 C ECWT ENERGY 50% 12.8 ° C ECWT Off- Design Lift Load (weight of rock) 0% Evaporator Temp. 44 ° F (6.7 ° C) LCHWT Johnson Controls - Proprietary

1 8 Johnson Controls - Proprietary

Legionella growth is dormant below 20C York chillers can operate at low condenser water temperatures Cold tower water assists to control Legionella growth 1 9 Johnson Controls - Proprietary

Water Consumption is a function of TOTAL HEAT REJECTION. HEAT REJECTION = Cooling Capacity + Shaft Power + Condenser Pump Power Thus, Lower Shaft Power = Lower Water Consumption! 2 0 Johnson Controls - Proprietary

Benefits of Cold Cond. Water on High Temp Chiller (i.e. 14C leaving evap. YMC 2 ) 2 1 Johnson Controls - Proprietary

Opportunities for Lower Lift Lower Condenser Water Higher Chilled Water Temperature Temperature • Lower CW Design Temperatures • Higher CHW Design temperatures • Oversize Towers • Climate wet bulb relief • Climate wet bulb relief • Control strategy • Control Strategy • chilled water reset • Chiller / Tower optimization • Series & Series Counter-flow • Series Counter-flow • Multiple CHW loops • HT loop & LT loop 2 2 Johnson Controls - Proprietary

Series chillers 6 deg C 10 deg C 14 deg C Lift is reduced 4 degrees C Johnson Controls - Proprietary

Enhanced efficiency through series counter-flow Pressure Pressure Condenser Condenser 2 Compressor 2 Condenser 1 Lift 2 Evaporator 2 Compressor Lift 1 Compressor 1 Evaporator 1 Evaporator Enthalpy Enthalpy 14 0 C 10 0 C 6 0 C LCHWT ECHWT Evaporator Evaporator ECWT LCWT Condenser Condenser 35 0 C 32 0 C 29 0 C Johnson Controls - Proprietary

Parallel Chillers SCF Chillers Total Capacity (kWr) 2 x 1500 2 x 1500 Enhanced Evap Flow Total (L/s) 44.7 x 2 = 89.4 89.4 Evap DP (kPa) 82.4 78.9 efficiency Cond Flow Total (L/s) 69.8 x 2 = 139.6 138.7 through Cond DP (kPa) 76.9 54.2 R134a Charge (kg) 2 x 603 = 1206 2 x 438 = 876 series Cost ($) BASE Less than BASE counter-flow VPF Evap min (L/s) 13 22 Load (kWr) Parallel (kWe) SCF (kWe) Saving (kWe) % 3000 471.0 446.5 24.5 5.2% 2700 378.0 355.5 22.5 6.0% 2400 297.8 276.3 21.5 7.2% 2100 229.4 210.0 19.4 8.5% 1800 171.5 154.4 17.1 10.0% 1500 122.7 108.6 14.1 11.5% 1200 100.2 87.5 12.7 12.7% 900 80.9 69.5 11.4 14.1% 600 65.2 56.9 8.3 12.7% 300 75.4 66.0 9.3 12.4% Johnson Controls - Proprietary

Today’s and tomorrow’s challenge 1 Additional component-level efficiency gains will be insufficient. "...we are reaching maximum technological limits at a component level and that in the future the industry will have to look at the full HVAC system for further improvements. AHRI is in the process of forming a new working group to address systems approaches for efficiency improvements and will work closely with Standard 90.1 .” - Dick Lord, co- writer of addendum ‘ch’ to ANSI/ASHRAE/IES Standard 90.1-2010, ASHRAE Press Release, December 12, 2012 Johnson Controls - Proprietary

Primary / Secondary System Primary/Secondary System  Know the benefits and limitations of the system type  P/S System: Recommend to Size Primary Pumps for more flow than Secondary Pumps VSD & VPF System  VPF System: Pump Head of Low Load Chiller 27

VSD & VPF System Variable Chilled Water Flow 28

The role of controls in the optimization process Best-in-class algorithms that take a holistic, system-level approach All variable speed plant Johnson Controls - Proprietary

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Most Energy Efficient Chiller Plant Design + + + = 6.7 Plant COP JEM is identified as the “Greenest Building” in Singapore (2013) Johnson Controls - Proprietary

System efficiency targets … Traditional chiller plant Singapore Green Mark v4 COP Platinum rating @ 0.55 kW/Ton = 6.4 plant COP JEM Project delivering 0.527 kW/TR system efficiency: Low temp loop = 9/18 deg C with 2 x YORK YK series counter-flow CSD chiller pairs High temp loop = 15/20 deg C with 2 x YORK YK VSD chillers Johnson Controls - Proprietary

Efficient System Design Concepts applied to HVAC system … AHU(s) DOAS HT CHW loop LT CHW loop 15 C 9 C 13.5 C 18 C VPF 20 C VPF Johnson Controls - Proprietary

W.A> Today’s variable speed chillers with optimized control strategies deliver outstanding real world plant-room efficiencies ! Johnson Controls - Proprietary