Cooling of high heat flux electronic devices using ultra-thin multiport minichannel thermosyphon

Abstract

Studying multiport minichannels as thermosyphons are considered to be of great interest compared to cylindrical and flat shaped ones with single ports. In this study, a novel multiport minichannel (MPMC) thermosyphon (hydraulic diameter of 1.18 mm, length of 200 mm with 10 internal ports with thickness 0.1 mm each) with acetone as working fluid is experimentally investigated for cooling high heat flux electronic devices. Effect of heat load (10–50 W), filling ratio (40%, 50%, and 60%) and tilt angles (45°, 60° and 90°) on thermal resistance, convective heat transfer coefficients of evaporator and condenser, vapour velocity, flooding, sonic, boiling limits and efficiency are experimentally studied. Results showed 9.31% and 22.2% reduction in evaporator wall temperature and thermal resistance at optimum filling ratio (OFR) of 50%. Enhancement in evaporator heat transfer coefficient and thermal efficiency of 30.7% and 89.8% are respectively observed at OFR. Multiports present in minichannel acts as internal fins and increases the surface area and evaporation rate. Further multiports increases surface tension of condensate at right angles to the flow direction along with the effects of gravity enhancing the rate of condensation. Thus, the obtained experimental results will be useful in cooling of miniaturized high heat flux electronic devices..