Microreactor-Enabled One-Step High-Throughput Flow Synthesis of Titanium Dioxide Nanofluids for Efficient Pool...

Area of Science:

• Materials Science
• Thermal Engineering
• Nanotechnology

Background:

• Phase change cooling is vital for high heat flux applications like 5G base stations and data centers.
• Nanofluids can enhance cooling but require stable, high-throughput production and understood mechanisms.
• Current understanding of nanofluid effects on bubble behavior in pool boiling is limited.

Purpose of the Study:

• To develop a high-throughput microreactor for continuous, one-step synthesis of stable titanium dioxide (TiO2) nanofluids.
• To investigate the pool boiling heat transfer performance of the synthesized TiO2 nanofluid.
• To elucidate the mechanisms behind the enhanced heat transfer in TiO2 nanofluids.

Main Methods:

• Utilized a microreactor for continuous TiO2 nanofluid preparation at 2 L/h.
• Characterized nanofluid stability at 20 and 80 °C for 40 days.
• Conducted pool boiling experiments to measure critical heat flux (CHF) and heat transfer coefficient (HTC).
• Analyzed bubble behavior, spot-like deposition, and microlayer formation.

Main Results:

• Achieved continuous TiO2 nanofluid production (2 L/h) with narrow size distribution (28 nm) and 40-day stability.
• Observed a 17% enhancement in CHF and a 39% increase in HTC.
• Recorded a 10.3 °C reduction in wall temperature during boiling.
• Demonstrated increased nucleation site density, reduced bubble volume, and expanded microlayer area.
• Confirmed no significant silica chip temperature increase after 5 hours of operation.

Conclusions:

• The developed microreactor enables industrial-scale synthesis of stable TiO2 nanofluids.
• TiO2 nanofluids significantly enhance pool boiling heat transfer performance.
• Enhanced nucleation, altered bubble dynamics, and improved microlayer formation drive the heat transfer improvements.
• Findings offer valuable insights for applying nanofluids in electronic device cooling.