Innovations in Chiller Technology

Transcription

1 Innovations in Chiller Technology Chiller Efficiency Improvement (COP) 8 Drivers Economics Legislation Emissions Refrigerant Theoretical Efficiency (COP) Indirect - Efficiency Direct - ODP/GWP Reliability, adaptability, and availability of components.

2 Today..Advanced Design Technologies Parametric Solid Models Reduce Design Cycle Time Aerodynamic Analysis - Tools for Advanced Performance Structural Analysis - Proactive Approach to Reliability Sound/Vibration and Flow Modelling - Solve noise, vibration and flow issues in the conceptual phase Collaboration of Global R&D Teams

3 Current and Emerging Technologies Permanent Magnet Motors Magnetic Bearings Hybrid Ceramic and Rolling Element Bearings Advanced Tube and Heat Exchanger Technologies

4 Evolution of Controls and Variable Speed Technologies

5 Chiller Plant Efficiency Benchmark

6 Chiller Performance Metrics IPLV is a weighted average of four specific operating points using average weather data and load profiles from 29 US Cities. AHRI 550/590 IPLV % Load Weight Condition 100% 1% 6.7 C / 29.4 C 75% 42% 6.7 C / 23.9 C 50% 45% 6.7 C / 18.3 C 25% 12% 6.7 C / 18.3 C ARI 550/590 section D2 states: The equation (IPLV) was derived to provide a representation of the average part load efficiency for a single chiller only. However, it is best to use a comprehensive analysis that reflects the actual weather data, building load characteristics, operational hours, economizer capabilities and energy drawn by auxiliaries such as pumps and cooling towers, when calculating the chiller and system efficiency. This becomes increasingly important with multiple chiller systems because individual chillers operating within multiple chiller systems are more heavily loaded than single chillers within single chiller systems.

7 Chiller Performance Metrics 500Chiller Ton 23VSS A MAP Chiller B MAP 500 Ton Centrifual IKW/Ton Tons kw Capacity 500 ECWT kw Capacity Tons IPLV Load Line IkW/KW 1 IkW/KW ECWT If both machines were 1.0 IkW/kW IPLV would you consider them equal? Equal IPLV Equal Energy Costs

8 Understanding Lift/Work Relationship Saturated Condensing Temp Condenser Approach HEAT ABSORBED Leaving Chilled Water Temp Evaporator Approach Saturated Evaporating Temp ENTHALPY Comp Lift = Refrigerant Delta P = Work (kwe) Compressor Lift Waterside Lift Leaving Cond. Water Temp LIFT PRESSURE HEAT REJECTED

9 VSD Centrifugal COP Profile 1200 kwr VSD Centrifugal Chiller COP vs ECWT % 30% 40% 50% 60% 70% IPLV Load Line % 90% 100%

10 THE CENTRIFUGAL COMPRESSOR MAP Map Boundaries STONEWALL / MAXIMUM FLOW MIN. FLOW LIFT in Deg OPERATING REGION % REFRIGERANT FLOW in CFM / CAPACITY

11 THE CENTRIFUGAL COMPRESSOR MAP Efficiency Islands Max Efficiency MIN. FLOW LIFT in Deg OPERATING REGION % REFRIGERANT FLOW in CFM / CAPACITY

12 THE CENTRIFUGAL COMPRESSOR MAP SELECTION POINT AND OPERATING LINES BAD IMPELLER GOOD IMPELLER Max Efficiency SELECTION SELECTION LIFT FACTOR CONSTANT 29.5 ARI Load Line Load Percent 25% 50% 75% 100% ECDW Temp FLOW FACTOR

13 THE CENTRIFUGAL COMPRESSOR MAP SELECTION POINT AND OPERATING LINES BAD IMPELLER GOOD IMPELLER Max Efficiency SELECTION SELECTION LIFT FACTOR CONSTANT 29.5 ARI Load Line Load Percent 25% 50% 75% 100% ECDW Temp FLOW FACTOR

14 VSD Screw COP Profile 1200 kwr VS Screw Chiller ECWT % 30% 40% 50% 60% 70% IPLV Load Line % 90% 100%

15 Applications Lift Reduction Through SCF Configuration Series Counter flow Up stream 12 C 35 C Down stream 6 C 29 C Both chillers designed to operate at 12/6 C 29/35 C. Downstream chiller cools 9 6 C /29-32 C Upstream chiller cools 12 9 C/ C. Net Operating Savings of 5-15% with same equipment in Parallel Configuration! 9 C 32

16 Series Counter flow Reduces Lift Upstream Chiller SCT 35 C SAT. LIQUID 12 C 9 C 32 C 6 C 29. C Pressure SST System SST SCT Lift Parallel SCF US 5 C 8 C 36 C 36 C 31 k 28 k Heat Rejection Reduced Lift Refrigerant Effect (Capacity) Enthalpy Lower Lift = Less Work = Lower kw SAT. VAPOR

17 Series Counter flow Reduces Lift Downstream Chiller SCT 35 C SAT. LIQUID 12 C 9 C 32 C 6 C 29. C Pressure 36 SST System SST SCT Lift Parallel SCF DS 5 C 5 C 36 C 33 C 31 k 28 k Heat Rejection 33 Reduced Lift 8 Refrigerant Effect (Capacity) Enthalpy Lower Lift = Less Work = Lower kw SAT. VAPOR

18 SCF Hydronic Considerations As Evaporator Delta T Increases the lift on upstream machine decreases System Design DS 6.0 US 9.0 ( = 26.0 K ) ( = 24.5 K) Series Design Chillers tend to have higher Delta T (Single pass HX and low flow improves pump kw)

19 SCF Hydronic Considerations Variable Primary Flow has synergistic effect with series evaporators. VPF DS Lvg US Lvg Return 100% % % % 6.0 Off 15.0 With constant speed pumping delta T falls with load Const. Flow DS Lvg US Lvg Return 100% % % 25% Off 8.3 Utilising VPF Series Configuration the leaving chilled water temperature of the upstream chiller stays warmer longer, increasing chiller system efficiency over constant primary flow

20 Chiller System Design Decisions Leverage system design for significant energy savings IkW/kW Full Load Part Load COP FL 7.04 IPLV VS Screw Parallel 6.0 / 12.0 VS Screw SCF 6.0 / 12.0 VS Screw SCF VPF 6.0 / 12.0 VS Screw SCF VPF 6.0 / 15.0 >11% FL and 15.5% IPLV Improvement

21 Sydney Weather Dry Bulb ECWT >25 C ECWT C ECWT <21 C ECWT < 15 C 25 % of hours 59 % of hours 16 % of hours? % of hours Data by BAC/Chiller System Optimizer Constant Flow/Constant Range (Constant Load) Ent. Cond Water (C) Hours of Operation 24 hr Operation - 8,760 hours

22 Sydney Weather Dry Bulb ECWT >25 C ECWT C ECWT <21 C ECWT < 15 C 56 % of hours 39 % of hours 5 % of hours? % of hours Data by BAC/Chiller System Optimizer Constant Flow/Constant Range (Constant Load) Ent. Cond Water (C) Hours of Operation Business Hours (6am 7pm M-F) 3,393 hours

23 Optimised Cooling Tower Control Chiller + Tower Estimated Annual Energy Consumption 1200 kw Water Cooled Chiller Minimum Temperature Design CW WB + 3 Optimised

24 Variable Water Flow Effect of tower water flow and air flow on chiller system power input 60% load with 16 C WB

25 Integration for Chiller System Control OEM Provided Plant System Manager (PSM) Full system factory engineered plus customised strategies and algorithms for coordination of chillers, towers and pumps Direct access to internal chiller control variables allowing for chiller plant energy optimisation Cooling Tower Control Optimal load/temperature or combined staging strategies Chilled Water Reset and Demand Limit Variable Flow Control SCF chiller system control Supports non-oem chillers & equipment Capability to track/trend and display real time efficiency Web browser and WAP access through I-Vu BACnet and Modbus Communication Protocols Web Browser Internet i-vū Pro Server PC Firewall

26 End Thank You