THERMAL SCIENCE

International Scientific Journal

Thermal Science - Online First

Authors of this Paper

External Links

Xin Wang

,

Qiang Fu

,

Changlong Wang

online first only

Study on the simplified model of vertical double U-pipe ground heat exchanger

ABSTRACT
A simplified semi-analytical model of vertical double U-pipe ground heat exchanger (VDUGHE) was established. The validity of the established model is examined by contrasting the figured outcomes with experiment data, emulation results of 3D numerical model and calculation results of infinite line-source model (ILSM) for different inlet boundary conditions and configurations. After 1 hour, the semi-analytical model's relative error is less than 0.32% under the boundary condition of given inlet fluid temperature. Under the boundary condition of given total heat input rate, the semi-analytical model's relative error after 10 hours is less than 0.11%, while the ILSM's relative error is less than 0.60%. The semi-analytical model is in good agreement with experiment and numerical model, and has higher calculation accuracy than ILSM.
KEYWORDS
verticaldouble U-pipe ground heat exchanger (VDUGHE), semi-analytical model, heat transfer, temperature distribution
PAPER SUBMITTED: 2022-09-22
PAPER REVISED: 2022-12-15
PAPER ACCEPTED: 2022-12-22
PUBLISHED ONLINE: 2023-03-11
DOI REFERENCE: https://doi.org/10.2298/TSCI220922048W
REFERENCES
  1. Li, W. X., et al., Experimental and numerical studies on the thermal performance of ground heat exchangers in a layered subsurface with groundwater , Renewable Energy, 147 (2020), Mar., pp. 620 629.
  2. Cenejac , AR., et al., Covering of heating load of object by using ground heat as a renewable energy source, Thermal Science , 16(2012), July, pp.S225 S235.
  3. Zhang, Y., Qi, Y. F., 3D numerical simulation of heat transfer for the vertical U type berried pipe of the ground source heat pump, Advanced Materials Research , 827 (2013), pp. 203 208.
  4. Chen, J . H., et al., Simulation and experimental analysis of optimal buried depth of the vertical U tube ground heat exchanger for a ground coupled heat pump system Renewable Energy , 73 (2015), Jan., pp. 46 54.
  5. Liu, Y., et al., Vertical U shaped heat exchangers for construction engineering new promises and future challenges, Thermal Science, 25 (2021), pp. 2253 2261.
  6. You, S., et al., Operation mode and heat performance of ene rgy drilled piles, Thermal Science , 25 (2021), Jan., pp.4553 4560.
  7. Raymond, J., et al., Extending thermal response test assessments with inverse numerical modeling of temperature profiles measured in ground heat exchangers , Renewable Energy 99 (2016), Dec., pp. 614 621.
  8. Sun, Z. C., et al., Research on heat transfer characteristics and borehole field layout of ground heat exchangers to alleviate thermal accumulation with groundwater advection, Thermal Science, 25 (2021), pp.2781 2794.
  9. Kayaci, N ., Demir , Numerical modelling of transient soil temperature distribution for horizontal ground heat exchanger of ground source heat pump Geothermics , 73 (2018), Jan., pp. 33 47.
  10. Gan, G. H., A numerical methodology for comprehensive assessment of the dynamic thermal performance of horizontal ground heat exchangers, Thermal Science and Engineering Progress , 11 (2019), Apr., pp. 365 379.
  11. Habibi, M., et al., A numerical study on utilizing horizontal flat panel ground heat exchangers in ground coupled heat pumps , Renewable Energy , 147 (2020), Sep., pp. 996 1010.
  12. Zeng, H. Y., et al., Heat transfer analysis of boreholes in vertical ground heat exchangers International Journal of Heat Transfer , 46 (2003), Apr., pp. 4467 4481.
  13. Conti, P., et al., Revised heat transfer modeling of double U vertical ground coupled heat exchangers Applied Thermal Engineering , 106 (2016), Aug., pp. 1257 1267.
  14. Zarrella, A., et al., Short time step analysis of vertical ground coupled heat exchangers: The approach of CaRM, Renewable Energy , 36 (2011), Sep., pp. 2357 2367.
  15. Luo, Y, Q., Xu, G . Dynamic thermal analysis of vertical double U type ground heat exchanger , Journal of Huazhong University of Science and Technology (Nature Science Edition), 49 (2021), Jan., pp. 122 127.
  16. Magran er, T., et al., Thermal response test analysis for U pipe vertical borehole heat exchangers under groundwater flow conditions, Renewable Energy , 165 (2021), Nov., pp. 391 404.
  17. Zeng, H. Y., et al., A finite line source model for boreholes in geothermal heat exchangers Heat Transfer Asian Research Research, 3131 (2002)
  18. Babak, D. B., Kukrer, E., A new 1D analytical model for investigating the long term heat transfer rate of a borehole ground heat exchanger by Green's function method. Renewable Energy , 108 (2017), pp. 615 621.
  19. Erol, S., François, B., Multilayer analytical model for vertical ground heat exchanger with groundwater flow, Geothermics , 71 (2018), Sep., pp. 294 305.
  20. Nian, Y. L., Cheng, W. L., Analytical g function for vertical geothermal boreholes with effect of borehole heat capacity, Applied Thermal Engineering , 140 (2018), May., pp. 733 744.
  21. Pan, A. Q., et al., A novel analytical multilayer cylindrical heat source model for vertical ground heat exchangers installed in layered ground, Energy 200 (2020), Apr., pp. 117545
  22. Li, M., Lai, A. C.K., New temperature response functions ( G functions) for pile and borehole ground heat exchangers based on composite medium line source theory. Energy , 38 (2012), Feb., pp. 255 263.
  23. Li, M., Lai, A. C.K., Analytical model for short time responses of ground heat exchangers with U shaped tubes: Model development and validation, Applied Energy , 104 (2013), Apr., pp. 510 516.
  24. Yang, Y., Li, M., Short time performance of composite medium lin e source model for predicting responses of ground heat exchangers with single U shaped tube, International Journal of Thermal Science , 82 (2014), pp. 130 137.
  25. Li, M., et al., Full scale temperature response function (G function) for heat transfer by borehole ground heat exchangers (GHEs) from sub hour to decades, Applied Energy , 136 (2014), pp. 197 205.
  26. Wang, C. L., et al., A simplified semi numerical model to simulate a U pipe ground heat exchanger, Numerical Heat Transfer, Part A: Application s, 77 ( Jan., pp. 482 496.
  27. Wei, J. H., et al., A new analytical model for short time response of vertical ground heat exchangers using equivalent diameter method, Energy and Buildings , 119 (2016), Mar., pp. 13 19.
  28. Su, H., et al., Fast simulation of a vertical U tube ground heat exchanger by using a one dimensional transient numerical model, Numerical Heat Transfer, Part A: Applications , 60 (2011), Aug., pp. 328 346.
  29. Diao, N. R., et al., Improvement in modeling of heat transfer in vertical ground heat exchangers, H VAC&R Research, 10 (2004), Feb., pp. 459 470.
  30. Ma, Z. D., et al., Numerical simulation on heat transfer inside and outside of vertical buried pipes based on two model order reduction methods, Numerical Heat Transfer, Part A: Applications , 79 (2021), Jan., p p. 631 655.
  31. Liao, Q., et al., Effective borehole thermal resistance of A single U tube ground heat exchanger, Numerical Heat Transfer, Part A: Applications , 62 (2012), Apr., pp. 197 210.
  32. Lee, C. K., Lam, H. N., Computer simulation of borehole ground heat exchangers for geothermal heat pump systems, Renewable Energy , 33 (2008), Aug., pp. 1286 1296.
  33. Liu, Z. Y., et al., Multilayer quasi three dimensional model for the heat transfer inside the borehole wall of a vertical ground heat exchanger, Geothermics 83 2020), Aug., pp. 101711.
  34. Al Khoury, R., Bonnier, P. G., Efficient finite element formulation for geothermal heating systems. Part II: transient, International Journal For Numerical Methods in Engineering , 67 (2006), Jan., pp. 725 745.
  35. Al Khoury , R., et al., Efficient numerical modeling of borehole heat exchangers, Computers and Geosciences , 36 (2010), Dec., pp. 1301 1315.
  36. Marcotte, B., Bernier, M., Experimental validation of a TRC model for a double U tube borehole with two independent circuits, Applied Thermal Engineering , 162 (2019), Aug., pp.
  37. Spitler, J. D., Gehlin, S. E.A., Thermal response testing for ground source heat pump system An historical review, Renewable and Sustainable Energy Reviews, 50 (2015), May., pp. 1125 1137.
  38. Li, W. X., et al., Numerical modelling of thermal response of a ground heat exchanger with single U shaped tube, Science and Technology for the Built Environment, 25 (2018), Nov., pp. 525 533.
  39. Beier, R. A., Transient heat transfer in a U tube borehole heat exchanger, Applied Thermal Engineering , 62 (2014), July, pp. 256 266.
  40. Lamarche, L., Beauchamp, B., New solutions for the short time analysis of geothermal vertical boreholes, International Journal of Heat and Mass Transfer, 50 (2017), Nov., pp. 1408 1419.
  41. Chen, J. H., A Study on layered heat transfer model of vertical double U tube ground heat exchangers, Chongqing University, 2015
PDF VERSION [DOWNLOAD]
Study on the simplified model of vertical double U-pipe ground heat exchanger