Experimental study on confinement effect of two-phase closed thermosyphon and heat transfer enhancement using cellulose nanofluid

Heat Transfer Enhancement of Small-Diameter Two-Phase Closed Thermosyphon Using Cellulose Nanofiber and Hydrophilic Surface Modification

“…It was discovered that the high conductivity of nanoparticles enhanced the BHTC at the low concentration; however, the higher the concentration, the thicker the coating of nanoparticles on the heater surface, resulting in a higher thermal resistance. In contrast, in a wire pool boiling study by Choi and Lee [ 9 ] using CNF fluid, the BHTC was lower than that of water at low concentrations (0.07, 0.1 wt%), but higher at high concentrations (0.3, 0.5 wt.%). Figure 1 shows the scanning electron microscopy (SEM) images of the wire surface after each experiment [ 9 ].…”

“…In contrast, in a wire pool boiling study by Choi and Lee [ 9 ] using CNF fluid, the BHTC was lower than that of water at low concentrations (0.07, 0.1 wt%), but higher at high concentrations (0.3, 0.5 wt.%). Figure 1 shows the scanning electron microscopy (SEM) images of the wire surface after each experiment [ 9 ]. As shown, an extremely thin coating had formed on the wire surface.…”

“…Figure 5 [ 9 ] shows a schematic illustration and photograph of the TPCT used in the experiment. The dimensions of the TPCT are as follows.…”

“…When this phenomenon occurs, the heat of the evaporator is not transferred effectively and dry out occurs rapidly; therefore, it can no longer be a heat transfer medium [ 8 ]. Choi and Lee [ 9 ] designed a TPCT experiment apparatus with a channel that satisfied Co = 0.245 using deionized (DI) water as the working fluid. They observed that the temperature at the evaporator surface oscillated regularly with a large amplitude in the steady state, thereby confirming the Geyser phenomenon.…”

“…At low concentrations, the thermal resistance increased with the thin coating. As the concentration increased, the thickness of the coating remained the same, but the bubble frequency generated on the wire surface accelerated [ 9 ] and heat transfer was enhanced.…”