Two-Phase Fin-Induced Turbulent Cooling for Electronic Devices Using Heat Pump Associated Micro-Gap Heat Sink

 
 
 
  • Abstract
  • Keywords
  • References
  • PDF
  • Abstract


    High energy requirement for electronic cooling is a major problem to operate high performance computers and data centres. Developing low cost thermal management systems for micro-electronic devices and micro-electro-mechanical systems (MEMS) is a cutting edge research area. A heat pump system associating micro-gap evaporator with internal micro-fins is a potential candidate for two-phase cooling of these advanced devices. Micro-fins induce pseudo-turbulence in the flow field, which escalates heat transfer rate. In this paper, the system performance of a heat pump using micro-gap evaporator has been investigated numerically and experimentally. As heat transfer rate in the micro-gap evaporator is influenced by turbulence generation, flow field in the inlet and outlet manifolds have been visualized in the numerical simulation to observe fin-induced pseudo-turbulence at the entrance and outlet of the micro-gap evaporator. The simulation has been performed using FLUENT 14.5 release. Experimental work has been carried out to validate numerical results. For experimentation purpose, a test rig has been developed, which contains a test section accommodating the micro-gap evaporator. A heater is provided at the bottom of the evaporator to supply uniform heat flux ranging 1 ~ 8 kW/m2. A pre-heater is installed at the compressor outlet to vary refrigerant temperature at the condenser inlet. The range of pre-heater temperature is 93 ~ 159°C. A variable speed compressor is used. The input frequency to the compressor is varied within the range of  20 ~ 50 Hz to run the compressor at different speeds. Experimental data show good agreement with numerical results. It is observed that in transient state, temperatures and pressures at different locations of the test apparatus fluctuate due to quasi-periodic dry out and surface rewetting nature of the flow. When pre-heater temperature is set at 159⁰C and compressor frequency is increased from 20 Hz to 30 Hz, evaporator wall heat flux escalates 118.2% and heat transfer rate of the condenser increases 65.2%. However, heat transfer rate declines with the further increment of compressor frequency. Coefficient of performance (COP) of the heat pump also increases with the frequency increment from 20 Hz to 30 Hz and declines after surpassing 40 Hz frequency.

     


  • Keywords


    Micro-gap evaporator; micro-fin; pseudo-turbulence; flow boiling; heat pump; coefficient of performance

  • References


      [1] Kakaç, S., Vasiliev, L. L., Bayazitoglu, Y., & Yener, Y. (Eds.). (2006). Microscale Heat Transfer-Fundamentals and Applications: Proceedings of the NATO Advanced Study Institute on Microscale Heat Transfer-Fundamentals and Applications in Biological and Microelectromechanical Systems, Cesme-Izmir, Turkey, 18-30 July, 2004 (Vol. 193). Springer Science & Business Media.

      [2] Bar-Cohen, A., Holloway, C., Kaffel, A., & Riaz, A. (2016). Waves and instabilities in high quality adiabatic flow in microgap channels. International Journal of Multiphase Flow, 83, 62-76.

      [3] Tuckerman, B. & Pease, R.F.W, High-performance heat sinking for VLSI, IEEE Electron. Dev. Lett. EDL-2, (1981) pp.126 –129.

      [4] Bertsch, S.S., Groll, E.A. & Garimella, S.V. (2009). Effects of heat flux, mass flux, vapor quality, and saturation temperature on flow boiling heat transfer in microchannels. International Journal of Multiphase Flow, 35(2), 142-154.

      [5] Y. Wang, and K. Sefiane (2012). "Effects of heat flux, vapour quality, channel hydraulic diameter on flow boiling heat transfer in variable aspect ratio micro-channels using transparent heating," International Journal of Heat and Mass Transfer, vol. 55, no. 9, pp. 2235-2243, 2012.

      [6] Yadigaroglu, G. (1978). Two-phase flow instabilities and propagation phenomena. In Von Karman Inst. for Fluid Dyn. Two-Phase Flows in Nucl. Reactors, (SEE N79-28497 19-34) (Vol. 2), 71.

      [7] Tadrist, L. (2007). Review on two-phase flow instabilities in narrow spaces. International Journal of Heat and Fluid Flow, 28(1), 54-62.

      [8] Alam, T., Lee, P. S., Yap, C. R., & Jin, L., (2013). A comparative study of flow boiling heat transfer and pressure drop characteristics in microgap and microchannel heat sink and an evaluation of microgap heat sink for hotspot mitigation. International Journal of Heat and Mass Transfer, 58(1), 335-347.

      [9] Kim, D. W., Rahim, E., Bar-Cohen, A., & Han, B. (2008, May). Thermofluid characteristics of two-phase flow in micro-gap channels. In Thermal and Thermomechanical Phenomena in Electronic Systems, 2008. ITHERM 2008. 11th Intersociety Conference on (pp. 979-992). IEEE.

      [10] Bar-Cohen, A., & Rahim, E. (2007, January). Modeling and prediction of two-phase refrigerant flow regimes and heat transfer characteristics in microgap channels. In ASME 2007 5th International Conference on Nanochannels, Microchannels, and Minichannels, 1141-1160.

      [11] Alam T., Lee P. S., Yap C. R., Jin L. W. & Balasubramanian K. (2012). Experimental investigation and flow visualization to determine the optimum dimension range of microgap heat sinks. International Journal of Heat and Mass Transfer, 55(25), 7623-7634.

      [12] Alam T., Lee P. S., Yap, C. R., & Jin, L. (2012). Experimental investigation of local flow boiling heat transfer and pressure drop characteristics in microgap channel. International Journal of Multiphase Flow, 42, 164-174.

      [13] Chang, W.R., Chen, C.A., Ke, J.H. & Lin, T.F. (2010). Subcooled flow boiling heat transfer and associated bubble characteristics of FC-72 on a heated micro-pin-finned silicon chip. International Journal of Heat and Mass Transfer, 53(23), 5605-5621.

      [14] Yeom, T., Simon, T., Zhang, T., Zhang, M., North, M. & Cui, T. (2016). Enhanced heat transfer of heat sink channels with micro pin fin roughened walls. International Journal of Heat and Mass Transfer, 92, 617-627.

      [15] Stehlík, P., Jegla, Z. & Kilkovský, B. (2014). Possibilities of intensifying heat transfer through finned surfaces in heat exchangers for high temperature applications. Applied Thermal Engineering, 70(2), 1283-1287.

      [16] Ahmed, S., Ismail, A. F., Sulaeman, E. & Hasan, M. H. (2016a). A critical assessment on evaporative cooling performance of micro finned micro gap for high heat flux applications. ARPN Journal of Engineering and Applied Sciences, vol. 11, no. 1, pp. 331-336.

      [17] Ahmed, S., Ismail, A. F., Sulaeman, E., & Hasan, M. H. (2016b). A Comparative Analysis of Flow Boiling in Micro-Gaps with Internal Micro-Fins of Rectangular and Triangular Profiles. International Journal of Applied Engineering Research, 11(4), 2364-2372.

      [18] Ahmed, S., Hasan, M. H., Ismail, A. F., & Sulaeman, E. (2016c). Effect of geometrical parameters on boiling heat transfer and pressure drop in micro finned micro gap. ARPN Journal of Engineering and Applied Sciences, vol. 11, no. 1, pp. 297-302.

      [19] Ahmed, S., Ismail, A.F., Sulaeman, E. & Hasan, M.H. (2016). Study on turbulent characteristics of flow boiling in a micro gap under the influence of surface roughness and micro fins. ARPN Journal of Engineering and Applied Sciences, vol. 11, no. 1, pp. 410-414, 2016.

      [20] Hirt C. W. & Nichols B. D. (1981). Volume of fluid (VOF) method for the dynamics of free boundaries. Journal of Computational Physics. 39(1), 201–225.

      [21] Brackbill J.U., Kothe D.B., Zemach C. (1992), A continuum method for modeling surface tension, Journal of Computational Physics, 100, 335-354.

      [22] Orszag S. A., Yakhot V., Flannery W. S., Boysan F., Choudhury D., Maruzewski J. & Patel B. (1993). Renormalization Group Modeling and Turbulence Simulations. International Conference on Near-Wall Turbulent Flows, Tempe, Arizona. 1031-1046.

      [23] Schrage, R. W. (1953). A theoretical study of interphase mass transfer. Columbia University Press.

      [24] Lee, W. H. (1979), A Pressure Iteration Scheme for Two-Phase Modeling.Technical Report LA-UR. Los Alamos Scientific Laboratory, Los Alamos, New Mexico, 79 -975.

      [25] Wu, H. L., Peng, X. F., Ye, P., and Gong, Y. E. (2007). Simulation of refrigerant flow boiling in serpentine tubes. International Journal of Heat and Mass Transfer, 50(5), 1186–1195.

      [26] De Schepper, S. C., Heynderickx, G. J. & Marin, G. B. (2009). Modeling the Evaporation of a Hydrocarbon Feedstock in the Convection Section of a Steam Cracker, Computers & Chemical Engineering, 33(1), 122–132.

      [27] Alizadehdakhel, A., Rahimi, M. and Alsairafi, A. A. (2010). CFD Modeling of Flow and Heat Transfer in a Thermosyphon. International Communications in Heat and Mass Transfer, 37(3), 312–318.

      [28] Patankar, S. V. & Spalding, D. B. (1972). A calculation procedure for heat, mass and momentum transfer in three-dimensional parabolic flows. International Journal of Heat and Mass Transfer, 15(10), 1787-1806.

      [29] Holman, J. P. (2001). Heat transfer, Eighth SI Metric Edition.

      [30] Vlahostergios, Z., Missirlis, D., Flouros, M., Albanakis, C., & Yakinthos, K. (2015). Effect of turbulence intensity on the pressure drop and heat transfer in a staggered tube bundle heat exchanger. Experimental Thermal and Fluid Science, 60, 75-82.

      [31] Wang, G., Cheng, P., & Bergles, A. E. (2008). Effects of inlet/outlet configurations on flow boiling instability in parallel microchannels. International Journal of Heat and Mass Transfer, 51(9), 2267-2281.

      [32] Wu, H. Y., & Cheng, P. (2003). Visualization and measurements of periodic boiling in silicon microchannels. International Journal of Heat and Mass Transfer, 46(14), 2603-2614.

      [33] Hetsroni, G., Mosyak, A., Segal, Z., & Ziskind, G. (2002). A uniform temperature heat sink for cooling of electronic devices. International Journal of Heat and Mass Transfer, 45(16), 3275-3286.

      [34] Yin, L., Jia, L., & Guan, P. (2016b). Bubble confinement and deformation during flow boiling in microchannel. International Communications in Heat and Mass Transfer, 70, 47-52.

      [35] Bertsch, S. S., Groll, E. A., & Garimella, S. V. (2008). Refrigerant flow boiling heat transfer in parallel microchannels as a function of local vapor quality. International Journal of Heat and Mass Transfer, 51(19-20), 4775-4787.


 

View

Download

Article ID: 16336
 
DOI: 10.14419/ijet.v7i3.13.16336




Copyright © 2012-2015 Science Publishing Corporation Inc. All rights reserved.