Experimental Performance of a Nanofluid Pulsating Heat Pipe

The startup and operating performances of a nanofluid pulsating heat pipe are experimented. When the working fluid is selected as nanofluid instead of the base working fluid, the pulsating heat pipe can work at lower heating loads and start up more quickly and the thermal resistance between the heating section and the cooling section significantly decreases. For the nanofluid and base working fluid, the operating temperature increases with the heating load, the thermal resistance of pulsating heat pipe decreases with the operating temperature. The inclination angles of pulsating heat pipe as 30°, 60°, or 90°, have little effects on heat transfer performance. Under a vertical bottom heating mode of 100 watts and at the operation temperature of 110 °C, the thermal resistance of TiO₂/H₂O nanofluid pulsating heat pipe can be 0.11 °C/W, while it is 0.23 °C/W for the base working fluid. The mechanisms that the nanofluid pulsating heat pipe has better performance are tentatively explained as, the nano particles can form many micro nuclear centers for the boiling, and can lead to several heat transfer enhancement.