Cool Ideas for your Refrigeration System Zaid Al-Chalabi, P.Eng Energy Management Consultant Dr. Constantin Pitis, P.Eng Specialist Engineer
Up to 00 5% 10% 15% 20% 25% 30% 35% 40% 45% 50% 55% 60% 65% 70% 75% of Refrigeration LOAD is Non-Productive Varies based on facility type and operating conditions
Presentation Objectives 1. Understanding Refrigeration Systems 2. Benchmarking your Facility Energy Segregation based on Facility types Equipment Segregation Refrigeration Loads Energy Usage Intensity (EUI) New Concept: Benchmark Energy Factor (BEF) 3. Energy Efficiency Opportunities
Industrial Refrigeration in BC Estimated Energy consumption for Cooling & Refrigeration Systems 485 GWh/year or about 50,000 homes Facility Types: Cold Storage, Distribution, Processing Estimated Energy Savings Potential 75 GWh/year $4,500,000 per year Extrapolated based on BC Hydro Conservation Potential Report (CPR) 2007
Vapor-Compression Cycle Ambient conditions Refrigerant Line Waste Heat High pressure high temp. vapor C Insulated Walls Low pressure low temp. vapor Cold Storage Conditioned Environment Battery Charging for forklifts Compressor Condenser Coils Outdoor Fan Warm Air High Pressure Side Expansion Valve Low Pressure Side Cold Air Indoor Fan Evaporator Coils Indoor Lighting Underfloor Heating (Freezers) High pressure high temp. liquid Low pressure low temp. liquid + vapor Access Doors Refrigeration Energy Heat Load Infiltration Load Product Heat Load Product Product
Equipment Segregation Refrigeration Energy Compressor Condenser + Fan motor Evaporator + Fan motor Special Refrigerated Processes (i.e. cooling tunnels) if applicable Cold Storage Lighting Expansion Valve (metering device) Non-Refrigeration Energy Office Space HVAC/Lighting Dry Storage HVAC/Lighting Non-refrigerated Processes (if applicable) Forklift Battery Chargers Underfloor Heating (freezers) Other Access Doors
Energy Segregation Minimum Energy Required to meet refrigeration load Total Metered Energy Total Metered Energy Refrigeration Energy Essential Energy Wasted Energy Product Cooling Non-Refrigeration Energy (10 50%) Wasted Energy can be reduced by applying Energy Conservation Measures Non-Refrigeration Energy varies based on Facility Type Based on internal pilot testing on sample site
Energy Segregation on Facility Types Facility Type Refrigeration Energy (%) Non-Refrigeration Energy (%) 1 Distribution Facility 60 40 2 Storage Warehouse 90 10 3 Processing + Storage 80 20 4 Refrigerated Processing + Storage 65 35 Based on internal pilot testing on sample sites
Refrigeration Load for Distribution Facilities Product (14 20%) Refrigeration Energy (Load) Envelope/Infiltration (56 70%) Lighting (8 12%) Evaporator Fan (8 12%) Based on internal pilot testing on sample site
Product Load: Volume Vs Weight Fruit Cases Meat Cases Product load TWICE as high Volume = 1 m 3 Weight = 300 kg C = 3.4 kj/kg.c ΔT = 3 о F Volume = 1 m 3 Weight = 700 kg C = 3.6 kj/kg.c ΔT = 3 о F Product cooling load Weight C T Heavier products costs more to cool!
Energy Use Intensity (EUI) Traditional approach in assessing facility performance: kwh per cubic foot EUI = Total Metered Energy Space Volume = Refrig. Energy + Non. Refrig. Energy Varies based on Facility Type (10% 50%) EUI does NOT accurately assess your facility s performance because: Assumes Total Metered Energy = Refrigeration Energy Does not take into account Independent Variable Parameters: Facility Type and Layout Product Type and Quantity (kg) Product and Space Temperatures
Benchmark Energy Factor (BEF) New approach in assessing facility performance: Unit-less Value BEF = Refrigeration Energy Essential Energy = Total. Metered. Energy Non. Refrig. Energy Minimum Energy required to meet refrigeration load BEF method takes into account Independent Variable Parameters such as: Facility Type Product Type and Weight Facility Layout and Location Operating hours Space and Product Temperatures Example Site No.* BEF = Refrig. E Essential E. EUI = Total E. Volume 1 4.8 (Poor Efficiency) 0.46 (Good Efficiency?) 2 3.5 (Good Efficiency ) 0.85 (Poor Efficiency?) *Based on internal pilot testing for sample sites
kwh Monitoring Energetic Performance 700,000 ECM implemented 600,000 Before (2013) 500,000 400,000 300,000 200,000 Wasted Energy After (2014) 100,000 Essential Energy 0 May June July August September October November December January February March April Month Energy Conservation Measure: VFDs on Evaporator Fan Motors Energy Savings = 206,000 kwh (4 month period) Based on internal pilot testing on sample site
Refrigeration Energy Efficient Measures Energy Efficient Measure Potential System Energy Savings Cost to Implement Floating head pressure control 3-12% Low Central Control System 5-15% Low-Medium Variable Frequency Drives (or EC Motors) on Evaporator/Condenser Fans 2-5% Low-Medium Variable Frequency Drives on Compressor 10-20% High High Efficiency Lighting and Controls 5-20% Medium High Speed Doors 2-10% Low Potential Refrigeration Energy Savings: up to 45% Sources: (1) Historical Power smart Projects. (2) Wisconsin State Utilities
Non-Refrigeration Energy Efficient Measures Energy Efficient Measures Potential Energy Savings Cost to Implement Dry Storage/Other Areas Lighting Upgrade 5-10% Medium Dry Storage/Other Areas HVAC Upgrades 5-15% Medium Forklift Battery Chargers 5-15% Low-Medium Heat Recovery for Underfloor Heating (freezers) 5-10% Low-Medium (new plant) Potential Non-Refrigeration Energy Savings: up to 35% Source: (1) Historical Power smart Projects. (2) California Utility Company
Energy Efficiency Benefits Energy efficiency can deliver a range of savings, such as: Reduced energy costs Reduced operation and maintenance costs Improved system reliability Improved safety Increased productivity Matching of refrigeration load and equipment capacity a better working environment
Summary of Cool Ideas 1. Total Metered Energy = Refrig. Energy + Non.Refrig. Energy 2. Non-Refrigeration Energy varies based on Facility Type 3. Essential Energy = Minimum energy required to meet Refrig. load 4. Product weight is equally important to know as type and quantity 5. Energy Use Intensity (EUI) is not an accurate method to assess facility performance 6. New Concept: Benchmark Energy Factor (BEF) takes into account independent variable parameters
Thank You! Zaid Al-Chalabi, P.Eng Email: zaid.al-chalabi@bchydro.com Dr. Constantin Pitis, P.Eng Email: constantin.pitis@bchydro.com #psforum15