A method and case study of thermal response test with unstable heat rate

Abstract This paper proposed a new method based on modified composite model in the thermal response test (TRT) in the variable heat rate case study. The new method considered the unsteady-state heat transfer in the borehole instead of the line-source model assumption. A Matlab program was compiled which can perform inversion calculation to obtain the ground thermal properties. The superposition principle was used to process the variable-rate problem. This new method was applied to two thermal response tests. The simulation value based on the method shows a good agreement with the measurement data of water temperature. The proposed method would save the time and reduce the cost of TRT when power fluctuation or failure occurs.

[1]  Esmail M. A. Mokheimer,et al.  First in situ determination of the ground thermal conductivity for boreholeheat exchanger applications in Saudi Arabia , 2009 .

[2]  Katsunori Nagano,et al.  Development of a design and performance prediction tool for the ground source heat pump system , 2006 .

[3]  Anna-Maria Gustafsson,et al.  Multi-injection rate thermal response test in groundwater filled borehole heat exchanger , 2010 .

[4]  Mustafa Inalli,et al.  In-situ thermal response test for ground source heat pump system in Elazığ, Turkey , 2009 .

[5]  J. Beck,et al.  Field Test of a New Method for Determining Soil Formation Thermal Conductivity and Borehole Resistance , 2000 .

[6]  A. Busso,et al.  First in situ determination of ground and borehole thermal properties in Latin America , 2004 .

[7]  H. C. Bixel,et al.  Pressure Drawdown and Buildup in the Presence of Radial Discontinuities , 1967 .

[8]  Daniel Pahud,et al.  Comparison of the thermal performance of double U-pipe borehole heat exchangers measured in situ , 2001 .

[9]  J. Beck,et al.  Determining effective soil formation thermal properties from field data using a parameter estimation technique , 1998 .

[10]  K. Lim,et al.  An experimental study on the thermal performance of ground heat exchanger , 2007 .

[11]  Z. Fang,et al.  Improvement in Modeling of Heat Transfer in Vertical Ground Heat Exchangers , 2004 .

[12]  D. Marcotte,et al.  On the estimation of thermal resistance in borehole thermal conductivity test , 2008 .

[13]  G. Florides,et al.  First in situ determination of the thermal performance of a U-pipe borehole heat exchanger, in Cyprus , 2008 .

[14]  Richard A. Beier.  Equivalent Time for Interrupted Tests on Borehole Heat Exchangers , 2008 .