Performance Evaluation of Boiling Chamber With Microchannel Chip and Taper Microgap

Area of Science:

• Thermal Management
• Heat Transfer
• Fluid Dynamics

Background:

• High-performance computing (HPC) demands advanced cooling due to increasing power densities.
• Effective thermal management is crucial for operational stability and energy efficiency in AI and cloud computing.
• Microchannel heat sinks offer potential for enhanced heat dissipation.

Purpose of the Study:

• To evaluate the cooling performance of a simulated copper microchannel chip against a plain chip.
• To investigate the impact of dual taper microgaps on heat transfer in a boiling chamber.
• To analyze the effects of microgap geometry and coolant temperature on critical heat flux (CHF) and subcooled boiling.

Main Methods:

• Experimental investigation of a 1.5U simulated copper microchannel chip and a plain chip.
• Utilized microchannels (500μm wide × 400μm deep) with 200μm fins.
• Tested various dual taper microgap configurations (inlet gaps 0.5-4mm, taper lengths 8.25mm & 16.5mm, 3° taper angle) and coolant temperatures (20-30°C).

Main Results:

• Microchannels significantly outperformed plain surfaces, with or without microgaps.
• Smaller inlet gaps (0.5-1mm) and longer taper lengths (16.5mm) enhanced nucleate boiling and delayed CHF.
• Optimal configurations improved vapor escape and utilized submerged condensation, but vapor agglomeration could lower CHF.
• An 80% fill ratio microchannel chip achieved the highest CHF due to enhanced liquid replenishment.

Conclusions:

• Microchannel heat sinks with optimized dual taper microgaps are effective for advanced thermal management.
• Geometric parameters like inlet gap and taper length critically influence boiling dynamics and CHF.
• Lower coolant temperatures and specific fill ratios further enhance cooling efficiency by managing vapor and promoting condensation.