Issue
Korean Journal of Chemical Engineering,
Vol.28, No.1, 49-55, 2011
Studying the influence of refrigerant type on thermal efficiency of annular two-phase flows; mass transfer viewpoint
Many parameters influence the thermal efficiency of two-phase systems; among them, the type of refrigerant employed in two-phase systems is of great importance. Carbon dioxide has been reintroduced as a possible R22 replacement, because of having more heat transfer rate and lower pressure drops, along with better environmental treatment compared with widely-used refrigerants. In the present article carbon dioxide is studied and compared with some thermophysically-different refrigerants from the viewpoint of probability of dry-out occurrence. Dry-out phenomenon in twophase systems should be avoided as far as possible to prevent sudden drops in heat transfer. Dry-out occurrence is strongly influenced by entrainment mass transfer. In the present study a semi-empirical model is proposed for simulation of entrainment mass transfer in annular flow regime of liquid-vapor in a vertical tube. The significance of entrainment phenomenon in carbon dioxide is compared with that of some other refrigerants to figure out the probability of dryout occurrence in different refrigerants. It will be demonstrated that CO2 relative to other refrigerants has much lower amounts of entrainment. This issue along with other mentioned advantages shows the prominent effectiveness of carbon dioxide among other conventional refrigerants.
[References]
  1. Qu WL, Mudawar I, Int. J. Heat Mass Transf., 46(15), 2755, 2003
  2. Qu WL, Mudawar I, Int. J. Heat Mass Transf., 46(15), 2773, 2003
  3. Chen T, Garimella SV, Int. J. Multiphase Flow., 32, 957, 2006
  4. Wen DS, Yan YY, Kenning DBR, J. App. Therm. Eng., 24, 1207, 2004
  5. Cui WZ, Li LJ, Xin MD, Jen TC, Chen QH, Liao Q, Int. J. Heat Mass Transf., 49(17-18), 2851, 2006
  6. Brutin D, Tadrist L, Int. J. Heat Mass Transf., 47(10-11), 2365, 2004
  7. Qu WL, Mudawar I, Int. J. Heat Mass Transf., 47(10-11), 2045, 2004
  8. Yu W, France DM, Wambsganss MW, Hull JR, Int. J. Multiphase Flow., 28, 927, 2002
  9. Kureta M, Akimoto H, Int. J. Heat Mass Transf., 45(20), 4107, 2002
  10. Pan L, Hanratty TJ, Int. J. Multiphase Flow., 28, 363, 2002
  11. Barbosa JR, Hewitt GF, Konig G, Richardson SM, Int. J.Multiphase Flow., 28, 943, 2002
  12. Kataoka I, Ishii M, Nakayama A, Int. J. Heat Mass Transf., 43(9), 1573, 2000
  13. Sawant P, Ishii M, Mori M, J. Nucl. Eng. Design., 238, 1342, 2008
  14. Collier JG, Thome JR, Convective boiling and condensation, Clarendon Press, Oxford, 1996
  15. Woodmansee D, Hanratty T, J. Chem. Eng. Sci., 24, 299, 1969
  16. Holowach MJ, Hochreiter FB, Int. J. Heat Fluid Flow., 23, 807, 2002
  17. Hewitt GF, Hall-Taylor NS, Annular two-phase flow, Pergamon Press, Oxford, 1970
  18. Lee PS, Garimella SV, Int. J. Heat Mass Transf., 51(3-4), 789, 2008
  19. Vashisth S, Nigam KD, J. Chem. Eng. Processing: Process Intensification., 48, 452, 2008
  20. Alekseenko S, Antipin V, Cherdantsev A, Kharlamov S, Markovich D, J. Phys. Fluids., 061701, 21, 2009
  21. Zhao LW, Kamiel SG, Zhen FZ, J. Technol., 15, 19, 2004
  22. Wongwises S, Kongkiatwanitch W, Int. Commun. Heat Mass Transfer., 28(3), 323, 2003
  23. Thomas DA, Modern geometry, Cole Publishing Co., California, 2002
  24. Utsuno H, Kaminaga F, J. Nucl. Sci. Technol., 35(9), 643, 1998
  25. Hewitt GF, Whalley PB, UKAEA Report AERE-9187, 1978
  26. Schadel SA, Leman GW, Binder JL, Hanratty TJ, Int. J.Multiphase Flow., 16, 363, 1990
  27. Okawa T, Kotani A, Kataoka I, Naito M, J Nuc. Sci. Technol., 40, 388, 2003
  28. Sawant P, Ishii M, Hazukub T, Takamasab T, Moric M, J. Nucl.Eng. Design., 238, 3528, 2008