DOI QR코드

DOI QR Code

수직밀폐형 지중열교환기의 회로 과도해석 상사모델 개발

Development of an Electric Circuit Transient Analogy Model in a Vertical Closed Loop Ground Heat Exchanger

  • Kim, Won-Uk (Department of Mechanical Engineering, Graduate School of Korea University) ;
  • Park, Hong-Hee (Department of Mechanical Engineering, Graduate School of Korea University) ;
  • Kim, Yong-Chan (Department of Mechanical Engineering, Korea University)
  • 투고 : 2011.11.16
  • 발행 : 2012.04.10

초록

Several numerical or analytical models have been proposed to analyze the thermal response of vertical ground heat exchangers (GHEX). However, most models are valid only after several hours of operation since they neglect the heat capacity of the borehole. Recently, the short time response of the GHEX became important in system simulation to improve efficiency. In this paper, a simple new method to evaluate the short time response of the GHEX by using an analogy model of electric circuit transient analysis was presented. The new transient heat exchanger model adopting the concept of thermal capacitance of the borehole as well as the steady-state thermal resistance showed the transient thermal resistance of the borehole. The model was validated by in-situ thermal response test and then compared with the DST model of the TRNSYS program.

키워드

참고문헌

  1. Ingersoll, L. R. and Plass, H. J., 1948, Theory of the ground heat pipe heat source for the heat pump, Transactions of the American Society of Heating and Ventilating Engineers, pp. 199-122.
  2. Kelvin, S. W. T., 1882, Mathematical and physical papers, Cambridge University Press, Vol. 1.
  3. Carslaw, H. S. and Jaeger, J. C., 1947, Heat Conduction in Solids, Claremore Press, Oxford.
  4. Ingersoll, L. R., Zobel, O. J., and Ingersoll, A. C., 1954, Heat Conduction with Engineering, Geological and Other Applications, 2nd ed., McGraw-Hill, New York.
  5. Eskilson, P., 1987, Thermal Analysis of Heat Extraction Boreholes, Doctoral Thesis, University of Lund, Department of Mathematical Physics. Lund, Sweden.
  6. Yavuzturk, C. and Spitler J. D., 1999, A short time step response factor model for vertical ground loop heat exchangers, ASHRAE Transactions, Vol. 105, No. 2, pp. 475-485.
  7. Hellstrom, G., 1991, Ground Heat Storage Thermal Analysis of Duct Storage Systems, Part I Theory, Ph.D. thesis, University of Lund, Department of Mathematical Physics, Sweden.
  8. Huber, A. and Pahud, D., 1997, Erweiterung des Programms EWS fur Erdwarmedson-denfelder, Forschungsprogramm Umgebungs und Abwarme, Warme-Kraft-Kopplung(UAW), Bundesamt fur Energie(BFE).
  9. Young, T., 2001, Development, Verification, and Design Analysis of the Borehole Fluid Thermal Mass Model for Approximating Short Term Borehole Thermal Response, Master's thesis, Oklahoma State University, USA.
  10. SEL, 2000, TRNSYS Manual, A Transient Simulation Program, Version 15, Solar Engineering Laboratory, University of Wisconsin-Madison.
  11. Smith, D. L., 1994, Introduction to dynamic systems modeling for design, Prentice Hall International.
  12. Kavanaugh, S. P., 1985, Simulation and Experimental Verification of Vertical Ground-Coupled Heat Pump Systems, Doctoral Thesis, Oklahoma State University, Stillwater, OK, USA.
  13. Sutton, M. G., Couvillion, R. J., Nutter, D. W., and Davis, R. K., 2002, An algorithm for approximating the performance of vertical bore heat exchangers installed in a stratified geological regime, ASHRAE Trans., Vol. 108, No. 2, pp. 177-184.
  14. Paul, N. D., 1996, The Effect of Grout Thermal Conductivity on Vertical Geothermal Heat Exchanger Design and Performance, Master's thesis, South Dakota State University, USA.
  15. Incropera, F. P., DeWitt, D. P., Bergman, T. L., and Lavine, A. S., 2007, Fundamentals of Heat and Mass Ttransfer, 6th ed., John Wiley and Sons.
  16. Hayt, W. H. Jr., 2006, Engineering Circuit Analysis, 7th ed., McGraw-Hill, pp. 308-311.
  17. Kasuda, T. and Archenbach, P. R., 1965, Earth temperature and thermal diffusivity at selected stations in the United States, ASHRAE Trans., Vol. 71, No. 1.
  18. Han, J. S., Han, G. S., Han, H. S., Han, C., 2005, Geothermal heat pump HVAC system, Hanrimwon.