ToolFusion
📋 Case Study

Portland General Electric (PGE) Industrial Refrigeration Load Shift

Refrigeration compressors could not tolerate frequent cycling; required >4-hour load shift window with <0.5°F temperature variance

🏗️ Project Overview

Food processing plant with 4.7 MW refrigeration load and 2.1 MW base lighting/process load

🎯 Challenge

Refrigeration compressors could not tolerate frequent cycling; required >4-hour load shift window with <0.5°F temperature variance

🔧 Design Approach

Phase-change thermal energy storage (PCM-TES) integrated with chiller staging logic and real-time weather-adjusted setpoint optimization

📐 Design Diagram

ChillerPCM-TESQ = 12.8 MWhRefrigeration LoadReal-time Weather-Adjusted Setpoint OptimizationΔT_gain = 3.7°F>4-hr shiftΔT < 0.5°FChiller Staging Logic & PCM Melting Control• Prevents compressor cycling• Synchronizes with weather forecast

AI-generated project design illustration

📐 Key Calculations

PCM Melting Latent Heat Requirement

Q = m × L_f
Result: 12.8 MWh
Size of PCM tank for 4.5-hr shift

Chiller Delta-T Optimization Gain

ΔT_gain = (T_cond − T_evap)_optimized − baseline
Result: 3.7°F
Reduces compressor runtime by 22%

📊 Results

Consistently delivered 3.9 MW for 4.2 hrs daily; reduced refrigeration energy use by 18%; qualified for PGE’s Industrial Flex Program incentives

💡 Lessons Learned

  • •PCM selection must match refrigerant brine chemistry to avoid corrosion
  • •Chiller staging logic must include ambient wet-bulb feedback to prevent condenser overload

✅ Key Takeaways

  • 1PCM selection must match refrigerant brine chemistry to avoid corrosion
  • 2Chiller staging logic must include ambient wet-bulb feedback to prevent condenser overload