Flow and Pressure Drop Characteristics of R22 in Adiabatic Capillary Tubes

  • Kim, Min-Soo (School of Mechanical and Aerospace Engineering, Seoul National University) ;
  • Kim, Sung-Goo (School of Mechanical and Aerospace Engineering, Seoul National University) ;
  • Ro, Sung-Tack (School of Mechanical and Aerospace Engineering, Seoul National University)
  • 발행 : 2001.09.01

초록

The objective of this study is to present flow and pressure drop characteristics of R22 in adiabatic capillary tubes of inner diameters of 1.2 to 2.0mm, and tube lengths of 500 to 2000mm. Distributions of temperature and pressure along capillary tubes and the refrigerant flow rates through the tubes were measured for several condensing temperatures and various degrees of subcooling at the capillary tube inlet. Condensing temperatures of R22 were selected as 40, 45, and 50$^{\circ}C$ at the capillary tube inlet, and the degree of subcooling was adjusted to 1 to 18$^{\circ}C$. Experimental results including mass flow rates and pressure drops of R22 in capillary tubes were provided. A new correlation based on Buckingham II theorem to predict the mass flow rate through the capillary tube was presented considering major parameters which affect the flow and pressure drop characteristcis.

키워드

참고문헌

  1. ASHRAE. 1994. ASHRAE Handbook-Refrigeration. Atlanta: ASHRAE.
  2. Bittle, R. R., Wolf, D. A. and Pate, M. B., 1998, 'A Generalized Performance Method for Adiabatic Capillary Tubes,' HVAC&R Research. Vol. 4, No. 1, pp. 27-43.
  3. Bolstad, M. M., and Jordan, R. C., 1948, 'Theory and Use of the Capillary Tube Expansion Device,' Refrigerating Engineering, vol. 56, No. 12, pp. 519-523.
  4. Chang, S. D., and Ro, S. T., 1996a, 'Pressure Drop of Pure HFC Refrigerants and Their Mixtures Flowing In capillary Tubes,' Int. J. Multiphase Flow, Vol. 22, No. 3, pp. 551-561. https://doi.org/10.1016/0301-9322(95)00082-8
  5. Chang, S. D., Ro, S. T., 1996a, 'Flow Characteristics of Refrigerant Mixtures with R32 ina Capillary Tube,' Korean Journal of Air Conditioning and Refrigeration Engineering, Vol. 8, No. 2, 177-186.
  6. Chen, S. L., Cheng, Y. R., Liu, C. H., Jwo, C. S.,2000, 'Simulation of Refrigerants Flowing Through Adiabatic Capillary Tubes,' HVA&R Research, Vol. 6, No. 2, pp. 101-115.
  7. Chen, Z. H., Li, R. Y., Lin, S., Chen, Z. Y., 1990, 'A Correlation for Metastable Flow of Refrigerant 12 through Capillary Tubes,' ASHRAE Trans., Vol. 96, No. 1, pp. 550-554.
  8. Collier, J. G., and Thome, J. R., 1996, Convective Boiling and Condensation 3rd ed., Oxford University Press Inc., New York.
  9. Cooper, L., Chu, C. K., and Brisken, W. R., 1957, 'Simple Seletion Method for Capillary Derived from Physical Flow Condition,' Refrigerating Engineering, vol. 65, No. 7, pp. 37-107.
  10. Huber, M., Gallagher, J., McLinden, M., and Morrison, G., 1996, NIST Thermodynamic Properties of Refrigerants and Refrigerant Mixtures(REFPROP), Ver 5.0, National Institute of Standards and Technology, Gaithersburg, Mary-land., U. S. A.
  11. Kim, S. G., Kim, M. S., Ro, S. T., and Youn, B., 1997, 'Performance Characteristics of R-22 and R-407 in a Capillary Tube Airconditoner,' Proc. of 10th Int, Symp. Tramsport Phenomena (ISTP-10), Nov. 30-Dec. 3, Kyoto, Japan, Vol. 2, pp. 574-551.
  12. Kim, Y. C., and Choi, J. M., 1998, 'Comparison of Refrigerant Flow through Capillary with Short Tube Orifice,' Korean Journal of Air Conditioning and Refrigerantion Engineering, Vol. 10, No. 1, pp. 118-128.
  13. Huerta, A. S., and Silvares, O. M., 1998, 'Simulation of the Effects of Oil in Capillary Tubes Considering a Seprarated Flow Model,' Proc. of Int. Refrig. Conf. Purdue University, West Lafayette, Indiana, U. S. A., pp. 443-448.
  14. Koizumi, H., and Yokoyama, K., 1980, 'Caracteristics of Refrigerant Flow in a Capillary Tube,' ASHRAE Trans., Vol. 86, No. 2, pp. 19-27.
  15. Kuehl, S. J., and Goldschmidt, V. W., 1990, 'Steady Flows of R-22 Through Capillary Tubes: Test Data,' ASHRAE Trans., Vol. 96. No. 1, pp. 719-728.
  16. Kuehl, S. J., and Goldschmidt, V. W., 1991, 'Modeling of Steady Flows of R-22 Through Capillary Tubes,' ASHRAE Trans., Vol. 97, No. 1, pp. 139-148.
  17. Li, R. Y., Lin, S., Chen, Z. Y., Chen, Z. H., 1990, 'Metastable Flow of R12 through Capillary Tubes,' Int. J. Refrig., Vol. 13, pp. 181-186. https://doi.org/10.1016/0140-7007(90)90073-6
  18. Melo, C., Ferreira, R. T. S. Neto, C. B. Goncalves, J. M. Thiessen, M. R., 1994, 'Experimental Analysis of Capillry Tubes for CFC-12 and HFC-134a,' Proc. of Int. Refrig, Conf. Purdue University, West Lafayette, Indiana, U. S. A., pp. 347-352.
  19. Meyer, J. J. and Dunn, W. E., 1998, 'New Insights into the Behavior of the Metastable Region of an Operating Capillary Tube,' HVAC&R Research, vol. 4, No. 1, pp. 105-115.
  20. White, F. M., 1994, Fluid Mechanics, 3rd ed., McGraw-Hill, New York Wijaya, H., 1992, 'Adiabatic Capillary Tube Test Data for HFC-134a,' Proc. of Int. Refrig. Conf. Purdue University, West Lafayettc, Indjana, U. S. A. Vol. 1, pp. 63-71.
  21. Wijaya, H., 1992, 'Adiabatic Capillary Tube Test Data for HFC-134a,' Proc. of Int. Refrig. Conf. Purdue University, West Lafayettc, Indjana, U. S. A. Vol. 1, pp. 63-71.