Abstract
An improved test rig providing both the heat and cold source was used to perform thermal response test (TRT), and the line source model was used for data analysis. The principle of determining the temperature difference between the inlet and outlet of test well can keep the heating or cooling rate constant, along with a reduced size of test rig. Among the influencial factors of the line source model, the temperature difference was determined as the most important, which agreed with the test results. When the gravel was taken as the backfill material, the soil thermal conductivities of heating and cooling at the test place were 1.883 W/(m·K) and 1.754 W/(m·K), respectively, and the deviation of TRT between heating and cooling soil was 6.8%. In the case of fine sand, the thermal conductivities of heating and cooling were 1.541 W/(m·K) and 1.486 W/(m·K), respectively, and the corresponding deviation was 6%. It was also concluded that different velocities of water had less influence on TRT than the temperature difference.
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Carpentier O, Defer D, Antczak E et al. In situ thermal properties characterization using frequential methods[J]. Energy and Buildings, 2008, 40(3): 300–307
Sanner B, Hellstrom G, Spitler J et al. Thermal response test.Current status and world-wide application[C]. In: Proceedings of World Geothermal Congress. Antalya, Turkey, 2005.
Hwang S, Ooka R, Nam Y J. Evaluation of estimation method of ground properties for the ground source heat pump system[J]. Renewable Energy, 2010, 35(9): 2123–2130.
Lim Kyoungbin, Lee Sanghoon, Lee Changhee. An experimental study on the thermal performance of ground heat exchanger[J]. Experimental Thermal and Fluid Science, 2007, 31(8): 985–990.
Spitler J D, Rees S, Yavuzturk C. More comments on insitu borehole thermal conductivity testing[EB/OL]. http://www.igshpa.okstate.edu/Publications/source/1999/9902/MoreComments.html, 1999.
Gehlin S, Hellstrom G. Influence on thermal response test by groundwater flow in vertical fractures in hard rock[J]. Renewable Energy, 2003, 28(14): 2221–2238.
Gehlin S. Thermal Response Test—In-Situ Measurements of Thermal Properties in Hard Rock[D]. Department of Environmental Engineering, Luleå University of Technology, Sweden, 1998.
Gehlin S, Hellstrom G. Comparison of four models for thermal response test evaluation[J]. ASHRAE Transactions, 2003, 109: 135–146.
Hellström G. Ground Heat Storage—Thermal Analysis of Duct Storage Systems. Part I: Theory[D]. Department of Mathematical Physics, University of Lund, Sweden, 1991.
Witte H J L, van Gelder G J, Spitler J D. In situ measurement of ground thermal conductivity: A dutch perspective[J]. ASHRAE Transactions, 2002, 108: 263–272.
Kavanaugh S P. Field tests for ground thermal properties. Methods and impact on ground-source heat pump design[ J]. ASHRAE Transactions, 1992, 98(9): 607–615.
Shonder J A, Hughes P J, Beck J V. Determining effective soil formation thermal properties from field data using a parameter estimation technique[J]. ASHRAE Transactions, 1999, 105: 458–466.
Nina Mattsson, Gilbert Steinmann, Lyesse Laloui. Advanced compact device for the in situ determination of geothermal characteristics of soils[J]. Energy and Buildings, 2008, 40(7): 1344–1352.
Chiasson A D, Rees S J, Spitler J D. A preliminary assessment of the effects of groundwater flow on closed-loop ground-source heat pump systems[J]. ASHRAE Transactions, 2000, 106: 380–393.
John A S, James V B. Field test of a new method for determining soil formation thermal conductivity and borehole resistance[J]. ASHRAE Transactions, 2000, 106: 843–850.
Hikari Fujii, Hiroaki Okubo, Keita Nishi et al. An improved thermal response test for U-tube ground heat exchanger based on optical fiber thermometers[J]. Geothermics, 2009, 38 (4): 399–406.
Sharqawy Mostafa H, Said S A, Mokheimer E M et al. First in situ determination of the ground thermal conductivity for borehole heat exchanger applications in Saudi Arabia[J]. Renewable Energy, 2009, 34(10): 2218–2223.
Bo Nordell, Manfred Reuss, Goran Hellstrom. Energy conservation through energy storage (ECES) Annex: Thermal response test [EB/OL]. http://www.iea-eces.org/files/annex21_proposal.pdf, 2006.
Van Gelder G, Witte H J L, Kalma S et al. In-situ measurement of the thermal properties of the soil with heat extraction [C]. In: Proc OPET-Seminar Erdgekoppelte Warmepumpen. Berlin, Germany, 1999(in German).
Roth P, Georgiev A, Busso A et al. First in situ determination of ground and borehole thermal properties in Latin America[J]. Renewable Energy, 2004, 29 (12): 1947–1963.
Fu Wencheng, Zhu Jialing, Zhang Wei. Thermal response test for borehole thermal properties in Tianjin[J]. Transactions of Geothermal Resources Council, 2011, 35(2): 1091–1094.
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Supported by the National Natural Science Foundation of China (No.41272263).
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Fu, W., Zhu, J. & Zhang, W. Thermal response test by improved test rig with heating or cooling soil. Trans. Tianjin Univ. 20, 15–20 (2014). https://doi.org/10.1007/s12209-014-2032-1
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DOI: https://doi.org/10.1007/s12209-014-2032-1