Analysis of a Wet Surface Finned-tube Evaporator of an Air Source Heat Pump

  • Baik, Young-Jin (Thermal/Fluids Control Research Center, Korea Institute of Science and Technology) ;
  • Chang, Young-Soo (Thermal/Fluids Control Research Center, Korea Institute of Science and Technology) ;
  • Kim, Young-Il (Thermal/Fluids Control Research Center, Korea Institute of Science and Technology)
  • Published : 2002.12.01

Abstract

In this study, in-situ performance test of a wet surface finned-tube evaporator of an air source heat pump which has a rating capacity of 20 RT is carried out. Since test conditions, such as indoor and outdoor air conditions cannot be controlled to satisfy the standard test conditions, experiments are done with the inlet air conditions as they exist. From the experimental data, air side heat and mass transfer coefficients were calculated by the well known heat and mass transfer analogy and tube-by-tube method. Since current procedure underpredicted the experimental sensible heat factor (SHF), a proper empirical parameter was introduced to predict the experimental data with satisfactory results. This study provides the method of evaluating the heat and mass transfer coefficients of a wet surface finned-tube evaporator of which in-situ performance test is necessary.

Keywords

References

  1. Park, H, Y., Park, D. K. and Lee, K. S., 1989, Modeling of fin-tube heat exchanger, Transactions of the Korean Society of Mechanical Engineers, Vol. 13, No. 5, pp. 952-961
  2. Yun, J. Y. and Lee, K. S., 1996, Heat transfer characteristics of fin and tube heat exchangers with various interrupted surfaces for air conditioning application, Transactions of the Korean Society of Mechanical Engineers B, Vol. 20, No. 12, pp. 3938-3948
  3. Hiller, C. C. and Glicksman, L. R., 1976, Improving heat pump performance via compressor capacity control-analysis and test, MIT Energy Lab.
  4. Fischer, S. K. and Rice, C. K., 1980, The Oak Ridge heat pump models: I. A steady-state computer design model for air-to-air heat pumps, ORNL/CON-80/R1, Oak Ridge National Lab.
  5. Domanski, P. A., 1989, EVSIM-An evaporator simulation model accounting for refrigerant and one dimensional air distribution, NISTIR 89-4133, U. S. Dept. of Commerce, NIST, Maryland 20899
  6. Han, C. S. and Kim, K. W., 1996, The air side heat transfer coefficient on the wetted surface of fin and tube heat exchanger, Air-Conditioning and Refrigeration Engineering, SAREK, Vol. 25, No. 2, pp.161-173
  7. McQuiston, F. C. and Parker, J. D., 1997, Heating, ventilating, and air conditioning: analysis and design, 4th ed., John Wiley & Sons, Inc., pp. 543-547
  8. Kim, N. H., Kim, J. S., Cho, J. P., Yun, J. H., Peck, J. H., Lee, S. G., Nam, S. B. and Kwon, H. J., 1997, Wet surface performance test of fin-tube heat exchangers with slit-wavy fin, Korean J. of Air-Conditioning and Refrigeration Engineering, Vol. 9, No. 2, pp.153-162
  9. Yoon, B., Yoo, K. C., Park, H. Y. and Kim, Y. S., 1996, Modeling of cross-flow fin-tube evaporator, The Korean Society of Mechanical Engineers Symposium Series: Thermal and Fluid Engineering Section, pp. 73-81
  10. Yoon, B., Park, H. Y., Yoo, K. C. and Kim, Y. C., 1999, Air-conditioner cycle simulation using tube-by-tube method. Korean Journal of Air-Conditioning and Refrigeration Engineering, Vol. 11, No. 4, pp. 499-510
  11. Hartnett, J. P., Koh, J. C. Y. and Mccomas. S. T., 1962, A Comparison of predicted and measured friction factors for turbulent flow through rectangular ducts, Trans. ASME J Heat Transfer, pp. 82-88
  12. SAREK, 1999, TAB. Standard for HVAC applications
  13. Kandlikar, S. G., 1990, A general correlation for saturated two-phase boiling heat transfer inside horizontal and vertical tubes, Trans. ASME J. Heat Transfer, Vol. 112, pp, 219-228
  14. Gnielinski, V., 1976, New equations for heat and mass transfer in turbulent pipe and channel flow, International Chemical Engineering, Vol. 16, No. 2, pp. 359-368
  15. Sheffield, J. W., Wood, R. A. and Sauer, Jr., H. J., 1989, Experimental investigation of thermal conductance of finned tube contacts, Experimental Thermal and Fluid Science, Vol. 2, pp. 107-121
  16. Schmidt, T. E., 1949, Heat transfer calculations for extended surface, Journal of the ASRE, Refrigerating Engineering, Vol. 4, pp. 351-357
  17. Threlkeld, J. L., 1970, Thermal environmental engineering, Prentice-Hall, New York, pp. 257-259
  18. Hwang, Y. J., 2000, The optimum design of heat pump system with refrigerant distributor, The Society of Air-Conditioning and Refrigerating Engineers of Korea Symposium Series: Refrigeration Section, pp. 93-99