📋 Case Study

Pharmaceutical Lyophilization Cold Storage Hybridization

Cryo-condenser load peaks (−55°C) during primary drying exceed chiller capacity; require sub-zero TES

🏗️ Project Overview

Pfizer sterile manufacturing site, Singapore

🎯 Challenge

Cryo-condenser load peaks (−55°C) during primary drying exceed chiller capacity; require sub-zero TES

🔧 Design Approach

Eutectic salt hydrate PCM (Na₂SO₄·10H₂O + KCl) in stainless steel panels integrated into condenser manifold

📐 Design Diagram

AI-generated project design illustration

📐 Key Calculations

Sub-Zero PCM Supercooling Mitigation

ΔT_sc_max = 0.042 × (d_particle_um)^{0.33}

Result: 1.8°C

Kept nucleation delay within acceptable 2.5°C limit

Cold Exergy Retention

Ė_retained = ṁ·(h_0 − h_T) − T₀·(s_0 − s_T)

Result: 86.4 kW

Enables 100% chiller off-cycle during 45-min drying phase

📊 Results

Chiller runtime reduced by 63%, condenser temperature stability ±0.3°C, validated per FDA 21 CFR Part 11 data integrity requirements

💡 Lessons Learned

• •Sealed double-wall PCM panels prevented hydration drift over 12,000 cycles
• •Real-time exergy telemetry was mandatory for GMP audit trail

✅ Key Takeaways

• 1Sealed double-wall PCM panels prevented hydration drift over 12,000 cycles
• 2Real-time exergy telemetry was mandatory for GMP audit trail