A LOOP THERMOSYPHON FOR LIQUID COOLED MINICHANNELS HEAT SINK WITH PULSATE SURFACE HEAT FLUX

Authors : Kays A. Al-tae’y, Ameer Abed Jaddoa, Hussain Saad Abd

Pages : 1030-1038

Doi:10.18186/thermal.931389

View : 17 | Download : 11

Publication Date : 2021-05-01

Article Type : Other

Abstract :The period operation of power electronic acts as switching element, where the power dissipated consists of pulses at certain duty cycle, the semiconductor temperature oscillates and varies as a waveform. In the present study, an experimental investigation was carried out for a loop thermosyphon order to evaluate the effect of pulsate surface heat flux on the single-phase buoyancy driven convection of ethylene glycol flow through a minichannels heat sink with hydraulic diameter 1.5 mm. An electric heater block is used to supply the heat flux to minichannels heat sink in a rectangle waveform. The study is done at different heat flux frequencies of 2.777×10-3 Hz, 8.333×10-4 Hz, 5.555×10-4 Hz and 4.166×10-4 Hz, while the heat flux amplitude (2 watt), Rayleigh number (1864) and duty cycle (50 %) are kept constant. The results revealed that for a range of the measured frequency for the complete power cycle and due to unsteady state operation conditions, the pulse heat flux pattern is close to a rectangle-wave, this generates the fluid outlet temperature pattern close to a triangle-wave. The fluid outlet temperature increases with the decreases of heat flux frequency and tends to reach to the fluid outlet temperature for a constant and continuous heat flux case. Due to closed-loop of thermosyphon, the fluid inlet temperature is changed in pattern like that the fluid outlet temperature change.
Keywords : Loop Thermosyphon, Natural Convection, Minichannels Heat Sink, Pulse Heat Flux, Single-Phase Flow, Ethylene Glycol