Journal of the Korean Solar Energy Society (한국태양에너지학회 논문집)

The Korean Solar Energy Society (한국태양에너지학회)
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Boiling Heat Transfer Coefficients of Nanofluids Using Carbon Nanotubes

탄소나노튜브를 적용한 나노유체의 비등 열전달계수

  • Lee, Yo-Han (Graduate School, Dept. of Mechanical Engineering, Inha University) ;
  • Jung, Dong-Soo (Dept. of Mechanical Engineering, Inha University)
  • 이요한 (인하대학교 기계공학과 대학원) ;
  • 정동수 (인하대학교 기계공학과)
  • Published : 2009.10.30
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Abstract

In this study, boiling heat transfer coefficients(HTCs) and critical heat flux(CHF) are measured on a smooth square flat copper heater in a pool of pure water with and without carbon nano tubes(CNTs) dispersed at $60^{\circ}C$. Tested aqueous nanofluids are prepared using multi-walled CNTs whose volume concentrations are 0.0001, 0.001, 0.01, and 0.05%. For dispersion of CNTs, polyvinyl pyrrolidone(PVP) is used in distilled water. Pool boiling HTCs are taken from $10kW/m^2$ to critical heat flux for all nanofluids. Test results show that the pool boiling HTCs of the nanofluids are lower than those of pure water in entire nucleate boiling regime. On the other hand, critical heat flux is enhanced greatly showing up to 200% increase at volume concentration of 0.001% CNTs as compared to that of pure water. This is related to the change of surface characteristics by the deposition of CNTs. This deposition makes a thin CNT layer on the surface and the active nucleation sites of heat transfer surface are decreased due to this layer. The thin layer acts as the thermal resistance and also decreases the bubble generation rate resulting in a decrease in pool boiling HTCs. The same layer, however, maintains the nucleate boiling even at very high heat fluxes and reduces the formation of large vapor canopy at near CHF resulting in a significant increase in CHF.

Keywords

References

  1. Eastman, J.A., Choi, S.U.S., Li, S., Thompson, L.J. and Lee, S., Enhanced Thermal Conductivity through the Development of Nano-fluids, Proc., Symposium on Nanophase and Nanocomposite materials II, Materials Research Society, Boston, Vol. 457, pp. 3-11, 1997
  2. Lee, S., Choi, S.U.S., Li, S. and Eastman, J.A., Measuring Thermal Conductivity of Fluids Containing Oxide Nanoparticles, ASME Journal of Heat Transfer, Vol. 121, pp. 280-289, 1999 https://doi.org/10.1115/1.2825978
  3. Eastman, J.A., Choi, S.U.S. and Yu, W., Anomalously Increased Effective Thermal Conductivity of Ethylene Glycol-based Nanofluids Containing Copper Nanoparticles, Applied Physics Letters, Vol. 78, pp. 718-720, 2001 https://doi.org/10.1063/1.1341218
  4. Das, S.K., Putra, N., Thiesem, P. and Roetzel, W., Temperature Dependence of Thermal Conductivity Enhancement for Nanofluids, ASME Journal of Heat Transfer, Vol. 125, pp. 567-574, 2003 https://doi.org/10.1115/1.1571080
  5. You, S.M., Kim, J.H. and Kim, K.H., Effect of Nanoparticles on Critical Heat Flux of Water in Pool Boiling Heat Transfer, Applied Physics Letters, Vol. 83, pp. 3374-3376, 2003 https://doi.org/10.1063/1.1619206
  6. Bang, I.C. and Chang, S.H., Boiling Heat Transfer Performance and Phenomena of A12O3-water Nano Fluids from a Plain Surface in a Pool, International Journal of Heat and Mass Transfer, Vol. 48, pp. 2407-2419, 2005 https://doi.org/10.1016/j.ijheatmasstransfer.2004.12.047
  7. Kim, S.J., Bang, I.C., Buongiorno, J. and Hu, L.W., Surface Wettability Chan-ge during Pool Boiling of Nanofluids and its Effect on Critical Heat Flux, International Journal of Heat and Mass Transfer, Vol. 50, pp. 4105-4116, 2007 https://doi.org/10.1016/j.ijheatmasstransfer.2007.02.002
  8. Kim, H.D., Kim, J. and Kim, M.H., Experimental Studies on CHF Charac- teristies of Nanofluids at Pool Boiling, International Journal of Multiphase Flow, Vol. 33, pp. 691-706, 2007 https://doi.org/10.1016/j.ijmultiphaseflow.2007.02.007
  9. Ajayan, P.M., Nanotubes from Carbon, Chemical Reviews, Vol. 99, pp. 1787-1799, 1999 https://doi.org/10.1021/cr970102g
  10. Dresselhaus, M.S., Dresselhaus, G. and Avouris, P., Carbon Nanotubes: Synthesis, Structure, Properties and Applications, Eds.; Springer, New York, Vol. 80, 2001
  11. Park, K.J. and Jung, D., Enhancement of Nucleate Boiling Heat Transfer Using Carbon Nanotubes, International Journal of Heat and Mass Transfer, Vol. 50, pp. 4499-4502, 2007 https://doi.org/10.1016/j.ijheatmasstransfer.2007.03.012
  12. Park, K.J., Jung, D. and Shim S.E., Nucleate Boiling Heat Transfer Coefficients of Halogenated Refrigerants Up to Critical Heat Fluxes, Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, Vol. 223, pp. 1415-1424, 2009 https://doi.org/10.1243/09544062JMES1356
  13. O'Connell, M.J. Boul, P., Ericson, L.M., Huffman, C., Wang, Y., Haroz, E., Kuper, C., Tour, J. Ausman, K.D. and Smalley, R.E., Reversible Water- solubilization of Single-walled Carbon Nanotubes by Polymer Wrapping, Chemical Physics Letters, Vol. 342, pp. 265-271, 2001 https://doi.org/10.1016/S0009-2614(01)00490-0
  14. Kline, S.J. and McClintock, F.A., Describing Uncertainties in Single-sample Experiments, Mechanical Engineer, Vol. 75, pp 3-8, 1953
  15. Bohsenow, W.M., A Method of Correlation Heat-Transfer Data for Surface Boiling of Liquids, ASME Trans., Vol. 74, pp. 969-976, 1952
  16. Stephan, K. and Abdelsalam, M., Heat Transferr Correlations for Natural Convection Boiling, International Journal of Heat and Mass Transfer, Vol. 23, pp. 73-87, 1980 https://doi.org/10.1016/0017-9310(80)90140-4
  17. Zuber, N., Hydrodynamic Aspects of Boiling Heat Transfer, AEC Report no. AECU-4439, Physics and Mathematics, 1959