Heat Transfer Research, cilt.56, sa.9, ss.1-14, 2025 (SCI-Expanded)
This study examined the effects of boron nanofluid on the performance of a two-phase closed thermosyphon heat pipe. The boron nanofluid was prepared via a two-step method, using deionized water as the base fluid and boron nanoparticles at mass concentrations of 0.5%, 1%, and 2%. Alkyl polyglycoside was added as a surfactant at a constant 0.5% by mass. Thermophysical property analysis of the nanofluid showed that the boron-containing nanofluid displayed superior thermal properties compared to deionized water. Heat pipe tests were conducted at heating powers of 200 W, 300 W, and 400 W, with cooling water flow rates of 5 g/s, 7.5 g/s, and 10 g/s in the evaporator section. Temperature distributions in the evaporator and condenser sections were tracked using 8 K-type thermocouples. To evaluate the effect of nanoparticles on thermal efficiency, tests were conducted with both deionized water and nanofluid suspensions. Results showed a 20% efficiency increase with 2% boron nanofluid at 400 W heating power and a cooling water mass flow rate of 10 g/s. The highest observed improvement in thermal resistance due to boron nanofluid was 28%.