DOI QR코드

DOI QR Code

Development of a Numerical Modeling Technique for Predicting Groundwater flow and Heat Transport in a Standing Column Well

수주지열정의 지하수 유동 및 지열 이동 예측을 위한 수치 모델링 기법 개발

  • Received : 2016.10.24
  • Accepted : 2016.12.10
  • Published : 2016.12.30

Abstract

Numerical modules based on a conventional thermo-hydrological numerical model, TOUGH2, are developed to provide a numerical modeling technique for a standing column well (SCW). Cooling and heating operations for two different types of SCW are then simulated using these modules. Modeling showed these operations to be significantly influenced by heat exchange and fluid mixing between the SCW and the adjacent geologic formation and groundwater. The results also reveal that heat exchange between the oppositely flowing outflow and inflow in the PVC or PE pipe and the SCW borehole is an important factor. Overall, the numerical modeling technique developed here can reasonably simulate fluid flow and heat transport phenomena in the complex internal structures of a SCW. The proposed technique can be used practically for the quantitative analysis of heat exchange in a SCW at the design, construction, and operation stages.

수주지열정의 지하수 유동 및 지열 이동 현상을 모사할 수 있는 수치 모델링 기법을 제시하기 위하여 열-수리학적 모델인 TOUGH2를 기반으로 한 모듈을 개발하였고 두 유형의 수주지열정에서의 냉방 및 난방 운영을 수치 모의하였다. 수치 모델링 결과들은 수주지열정의 냉난방 운영이 주변 지층 및 지하수와의 열교환 및 유체 혼합에 크게 영향을 받으며, 특히 PVC 또는 PE 파이프 내부와 수주지열정 내부에서 서로 반대방향으로 유동하는 유입수와 유출수 간의 열교환이 중요한 요소임을 보여준다. 또한 본 연구에서 개발 및 제안된 수치 모델링 기법이 수주지열정의 내부 구조 및 유체 유동과 열 이동 현상을 합리적으로 모사할 수 있음을 보여준다. 이러한 수치 모델링 기법은 수주지열정의 설계, 시공 및 운영 단계에서 열교환 성능을 정량적으로 분석할 때 유용하게 활용될 수 있을 것으로 기대된다.

Keywords

References

  1. Chen, N., 1979, An explicit equation for friction factor in pipe, Industrial and Engineering Chemistry Fundamentals, 18(3), 296-297. https://doi.org/10.1021/i160071a019
  2. Deng, Z., 2004, Modeling of standing column wells in ground source heat pump systems, Ph.D. Thesis, Oklahoma State University, 303pp.
  3. Hahn, J. S., Han, H. S., Hahn, C., Kim, H. S., and Jeon, J. S., 2006, Design guidelines of geothermal heat pump system using standing column well, Economic and Environmental Geology, 39(5), 607-613.
  4. Hahn, J. S., Han, H. S., Hahn, C., Kim, H. S., 2007, Estimation of optimal spacing between standing column wells for geothermal heat pump system (1): A hydrogeological point of view, Korea Journal of Geothermal Energy, 3(2), 60-68.
  5. Hahn, J. S., Han, H. S., Hahn, C., Kim, H. S., 2008, Estimation of optimal spacing between standing column wells for geothermal heat pump system (2): Focused on the design of SCW, Korea Journal of Geothermal Energy, 4(1), 62-70.
  6. Hahn, J. S., Han, H. S., and Hahn, C., 2010, Geothermal Energy, Hanrimwon Publishing Co., Seoul, Korea, 1093pp.
  7. Hwang, G., 2013, Open loop underground heat exchanger development with stability, functionality and efficient maintenance, Final Report 11TRPI-C057631-01, GGK Inc., 161pp.
  8. IPCC (International Panel on Climate Change), 2014, Climate Change 2014: Synthesis Report, the fifth assessment report, IPCC, Geneva, Switzerland, 151pp.
  9. KIGAM (Korea Institute of Geoscience and Mineral Resources), 2005, Mid- and long-term planning of research and development on geothermal resources utilization technologies, Final Report 2004-R-NC02-P-01-0-000, KIGAM, Daejeon, Korea, 104pp.
  10. Kwon, K. S., Lee, J. Y., and Mok, J. K., 2012, Update of current status on ground sources heat pumps in Korea (2008- 2011), Journal of the Geological Society of Korea, 48(2), 193-199.
  11. Lindeburg, M. R., 2013, Mechanical Engineering Reference Manual for the PE Exam, 13th edition, Professional Publications Inc., Belmont, CA, USA, 1488pp.
  12. Munson, B. R., Young, D. F., and Okiishi, T. H., 1998, Fundamentals of Fluid Mechanics, third edition, Wiley, New York, USA, 877pp.
  13. Narasimhan, T. N. and Witherspoon, P. A., 1976, An integrated finite difference method for analyzing fluid flow in porous media, Water Resources Research, 12(1), 57-64. https://doi.org/10.1029/WR012i001p00057
  14. Olson, R. M. and Wright, S. J., 1990, Essentials of Engineering Fluid Mechanics, fifth edition, Harper and Row Publishers, New York, USA, 638pp.
  15. Park, D. H., Kim, K. K., Kwak, D. Y., Chang, J. H., and Park, S. S., 2010a, Numerical simulaton of standing column well ground heat pump system, Part I: Validation of the numerical model, Journal of the Korean Geotechnical Society, 26(2), 33-43.
  16. Park, D. H., Kim, K. K., Kwak, D. Y., Chang, J. H., and Na, S. M., 2010b, Numerical simulaton of standing column well ground heat pump system, Part II: Parametric study for evaluation of the performance of standing column well, Journal of the Korean Geotechnical Society, 26(2), 45-54.
  17. Park, Y., Mok, J. K., Jang, B. J., Park, Y. C., and Lee, J. Y., 2013, Influence of open and closed loop geothermal cooling and heating systems on hydrogeological properties, Journal of the Geological Society of Korea, 49(6), 649-659. https://doi.org/10.14770/jgsk.2013.49.6.649
  18. Park, Y., Mok, J. K., Jang, B. J., Lee, J. Y., and Park, Y. C., 2015, Influence of closed loop ground source heat pumps on groundwater: a case study, Journal of the Geological Society of Korea, 51(2) 243-251. https://doi.org/10.14770/jgsk.2015.51.2.243
  19. Pruess, K., Oldenburg, C., and Moridis, G., 1999, TOUGH2 user's guide, version 2.0, Technical Report, No. LBNL- 43134, Lawrence Berkeley National Laboratory, Berkeley, CA, USA, 198pp.
  20. Sutera, S. P. and Skalak, R., 1993, The history of Poiseuille's law, Annual Review of Fluid Mechanics, 25(1), 1-19. https://doi.org/10.1146/annurev.fl.25.010193.000245
  21. Titow, W. V., 1984, PVC Technology, Springer, New York, USA, 1260pp.

Cited by

  1. 수주지열정 지열원 열펌프 시스템의 집단주거시설 적용을 위한 기반 기술 분석 vol.15, pp.3, 2016, https://doi.org/10.17664/ksgee.2019.15.3.014
  2. Numerical modeling of prediction and evaluation of groundwater flow and heat transport in production well for enhanced geothermal system vol.57, pp.2, 2016, https://doi.org/10.14770/jgsk.2021.57.2.243