In the present work, the heat dissipation rate and thermal resistance of electronic cooling system is investigated with different coolants by two-phase closed loop thermosyphon method for both steady and unsteady state conditions. The coolants used in this study are acetone, alcohol and petrol respectively and are poured in the created test facility. A square heater of size 35 × 35 mm is fixed in the primary tank and used as a heat source. The heat input is given to the system varies from 10 to 60 W. The temperature of the experimental setup is measured by seven K-type thermocouples which are attached at various locations. Results indicate that (i) the convective heat transfer coefficient increases and thermal resistance decreases with increasing of heat input for all the coolants (ii) the acetone has high heat removal rate of 65.4 % at 60 W due to low boiling point, high latent heat of evaporation and less effect on subcooling, which directly helps in phase change process and heat extraction rate (iii) a maximum reduction in thermal resistance of about 0.523 0C/W for acetone in comparison with alcohol and petrol by virtue of its high superheat which accelerates to nucleate boiling.
electronic cooling, closed loop thermosyphon, latent heat of evaporation, thermal resistance
 Alimohammadi M, Aghli Y, Alavi ES, Sardarabadi M, Passandideh-Fard M. (2017). Experimental investigation of the effects of using nano/phase change materials (NPCM) as coolant of electronic chipsets, under free and forced convection. Applied Thermal Engineering 111: 271-279. https://doi.org/10.1016/j.applthermaleng.2016.09.028
 Huminic G, Huminic A, Fleaca C, Dumitrache F. (2016). Heat transfer characteristics of a two-phase closed thermosyphons using nanofluids based on sic nanoparticles. International Journal of Heat and Technology 34(Special Issue 2): S199-S204. https://doi.org/10.18280/ijht.34Sp0202
 Singh JK, Rohidas P, Joshi N, Begum SG. (2017). Influence of Hall and ion-slip currents on unsteady MHD free convective flow of a rotating fluid past an oscillating vertical plate. International Journal of Heat and Technology 35(1): 37-52. https://doi.org/10.18280/ijht.350106
 Boutra A, Ragui K, Labsi N, Benkahla YK. (2017). Free convection enhancement within a nanofluid’ filled enclosure with square heaters. International Journal of Heat and Technology 35(1): 447-458. https://doi.org/10.18280/ijht.350302
 Naphon P, Wiriyasart S. (2015). Thermal cooling enhancement techniques for electronic components. International Communications in Heat and Mass Transfer 61: 140-145. https://doi.org/10.1016/j.icheatmasstransfer.2014.12.005
 Krishna J, Kishore PS, Solomon, A. B. (2017). Heat pipe with nano enhanced-PCM for electronic cooling application. Experimental Thermal and Fluid Science 81: 84-92. https://doi.org/10.1016/j.expthermflusci.2016.10.014
 Palm B, Khodabandeh R. (2003). Choosing working fluid for two-phase thermosyphon systems for cooling of electronics. Transactions-American Society of Mechanical Engineers Journal of Electronic Packaging 125(2): 276-281. https://doi.org/10.1115/1.1571570
 Zhang M, Liu Z, Ma G. (2008). The experimental investigation on thermal performance of a flat two-phase thermosiphon. International Journal of Thermal Sciences 47(9): 1195-1203. https://doi.org/10.1016/j.ijthermalsci.2007.10.004
 Chang C.C, Kuo SC, Ke MT. (2010). Two-phase closed-loop thermosyphon for electronic cooling. Experimental Heat Transfer, 23(2): 144-156. https://doi.org/10.1080/08916150903402807
 Kandasamy R, Wang XQ, Mujumdar AS. (2008). Transient cooling of electronics using phase change material (PCM)-based heat sinks. Applied Thermal Engineering 28(8): 1047-1057. DOI: 10.1016/j.applthermaleng.2007.06.010
 Krishnan S, Garimella SV, Kang SS. (2005). A novel hybrid heat sink using phase change materials for transient thermal management of electronics. IEEE Transactions on Components and Packaging Technologies 28(2): 281-289. https://doi.org/10.1109/TCAPT.2005.848534
 Jandaud P, Lambourg L, Harmand S. (2016). Aero-thermal optimization of a heat sink using variable neighbourhood search. Journal of Applied Fluid Mechanics 9.
 Baby R, Balaji C. (2013). A neural network-based optimization of thermal performance of phase change material-based finned heat sinks - an experimental study. Experimental Heat Transfer 26(5): 431-452. DOI: 10.1080/08916152.2012.705573
 Casano G, Piva S. (2015). Parametric analysis of a PCM energy storage system. International Journal of Heat and Technology 33(4): 61-68. https://doi.org/10.1088/1742-6596/796/1/012029
 Naik R, Varadarajan V, Pundarika G, Narasimha KR. (2013). Experimental investigation and performance evaluation of a closed loop pulsating heat pipe. Journal of Applied Fluid Mechanics 6(2): 267-275.
 Na MK, Jeon JS, Kwak HY, Nam SS. (2001). Experimental study on closed-loop two-phase thermosyphon devices for cooling MCMs. Heat Transfer Engineering 22(2): 29-39. https://doi.org/10.1080/01457630116920
 Holman JP. (2001). Experimental Methods for Engineers. Chapter 3. seventh edition, McGraw-Hill, New York.
 Szymański P, Mikielewicz D. (2017). Experimental study of pressure rise at the evaporator of capillary pumped loop with acetone and water as working fluids. Experimental Thermal and Fluid Science 87: 161-170. https://doi.org/10.1016/j.expthermﬂusci.2017.05.004
 Han H, Cui X, Zhu Y, Sun S. (2014). A comparative study of the behavior of working fluids and their properties on the performance of pulsating heat pipes. International Journal of Thermal Sciences 82: 138-147. https://doi.org/10.1016/j.ijthermalsci.2014.04.003