Phase-Change Cold Plate&Hybrid Air-Liquid Cooling
Publish Time: 2025-06-11 Origin: Site
Phase-Change Cold Plate Technology: Revolutionizing High-Density Cooling
Core Principle: Fluorinated coolants (e.g., R134a, R513A, R1234yf, 3M Novec HFE-7000) serve as working fluids in cold plates. Upon absorbing heat from high-power chips like GPUs/CPUs, these coolants undergo phase change (liquid-to-vapor), significantly enhancing heat transfer efficiency. Key advantages include:
Safety: Leaked fluorinated fluids vaporize into non-conductive gases, eliminating electrical hazards.
Performance: Supports up to 2.5 kW/GPU and 175 kW/rack, with heat dissipation capacity reaching 8 W/(cm²·℃).
System Architectures:
Gravity-Driven Thermosyphon:
Mechanism: Utilizes temperature gradients to circulate coolant without pumps.
Benefits: Zero moving parts, maintenance-free, and ideal for edge computing. Achieves PUE ≤ 1.07 and supports 100 kW/rack densities.
Example: SEGUENTE’s passive loop design.
Pump-Driven Thermosyphon (Active):
Mechanism: Employs refrigerant pumps for flexible heat exchanger placement, enabling multi-rack scalability.
Status: Primarily in R&D (e.g., NVIDIA’s prototype); limited commercial deployment.
Hybrid Air-Liquid Cooling: Adaptive Solutions for Diverse Data Centers
Hybrid systems address three critical scenarios:
Legacy Facility Retrofits: Reuse existing air-cooling infrastructure.
Space-Constrained New Builds: Avoid complex piping in limited-floor-area facilities.
Outdoor Unit Consolidation: Merge cooling towers/condensers for air and liquid systems.
Innovative Hybrid Solutions:
| Scenario | Solution | Key Products/Approaches |
|---|---|---|
| Legacy Retrofits | Air-Cooled CDUs | - CoolIT AHx Series: 2–100 kW capacity. - TOP-C Rack CDU: 110 kW capacity. - Inspur Variants: Integrated, rack-mounted, or rear-door designs. |
| Space Limitations | Air-Liquid Hybrid Terminals | OCP’s Chilled Door + CDU: 27°C supply water cools air via rear doors → heated to 34°C → feeds CDU for liquid cooling → returns at 44°C. |
| Outdoor Unit Sharing | Unified Air-Liquid Sources | Nortek SPLC: Uses microporous hydrophobic membranes to isolate water/air while achieving near-dew-point temperatures. |
Future Outlook & Challenges
Phase-Change Cold Plates: Need optimization for vapor-liquid separation and flow resistance reduction in microchannels.
Hybrid Systems: Require standardization to simplify deployment.
Sustainability: Fluorinated fluid management and PUE optimization remain focal points.
Conclusion: Phase-change cold plates and hybrid cooling represent pivotal advancements for AI-driven, high-density data centers. While gravity thermosyphons excel in edge reliability, hybrid solutions bridge legacy and modern infrastructure gaps—enabling sub-1.1 PUE and scalable heat reuse.