Transient heat transfer in a U-tube borehole heat exchanger

Abstract A transient heat transfer model has been development for a thermal response test (TRT) on a vertical borehole with a U-tube. Vertical borehole heat exchangers are frequently coupled to ground source heat pumps, which heat and cool buildings. The model provides an analytical solution for the vertical temperature profiles of the circulating fluid through the U-tube, and the temperature distribution in the ground. The model is verified with data sets from a laboratory sandbox and field TRTs, as well as a previously reported numerical solution. Unlike previous analytical models, the vertical profiles for the circulating fluid are generated by the model without any assumption of their functional form.

[1]  B. Palm,et al.  Distributed thermal response tests on pipe-in-pipe borehole heat exchangers , 2013 .

[2]  José Acuña,et al.  Distributed Thermal Response Test on a U-Pipe Borehole Heat Exchanger , 2009 .

[3]  P. Mogensen.  Fluid to duct wall heat transfer in duct system heat storages , 1983 .

[4]  Z. Fang,et al.  Heat transfer analysis of boreholes in vertical ground heat exchangers , 2003 .

[5]  S. Rees,et al.  A three-dimensional numerical model of borehole heat exchanger heat transfer and fluid flow , 2013 .

[6]  J. P. Hartnett,et al.  Handbook of Heat Transfer Fundamentals (Second Edition) , 1986 .

[7]  H. S. Carslow,et al.  Conduction of Heat in Solids, Second Edition , 1986 .

[8]  J. Spitler,et al.  Reference data sets for vertical borehole ground heat exchanger models and thermal response test ana , 2011 .

[9]  Weibo Yang,et al.  A two-region simulation model of vertical U-tube ground heat exchanger and its experimental verification , 2009 .

[10]  Burkhard Sanner,et al.  Thermal Response Test - Current Status and World-Wide Application , 2005 .

[11]  Å. Melinder.  Thermophysical Properties of Aqueous Solutions Used as Secondary Working Fluids , 2007 .

[12]  Murray R. Spiegel,et al.  Applied Differential Equations , 1967 .

[13]  J. Claesson,et al.  New Analytical and Numerical Solutions for the Short-term Analysis of Vertical Ground Heat Exchangers , 2011 .

[14]  S. Kavanaugh,et al.  Simulation and Experimental Verification of Vertical Ground-coupled Heat Pump Systems , 1985 .

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

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

[17]  J. C. Jaeger,et al.  Conduction of Heat in Solids , 1952 .

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

[19]  José Acuña,et al.  Distributed thermal response tests : New insights on U-pipe and Coaxial heat exchangers in groundwater-filled boreholes , 2013 .

[20]  René Lefebvre,et al.  A Review of Thermal Response Test Analysis Using Pumping Test Concepts , 2011, Ground water.

[21]  D. P. Sekulic,et al.  Fundamentals of Heat Exchanger Design , 2003 .

[22]  Jeffrey D. Spitler,et al.  Field Validation of a Short Time Step Model for Vertical Ground-Loop Heat Exchangers , 2001 .

[23]  Stuart W. Churchill,et al.  Comprehensive Correlating Equations for Heat, Mass and Momentum Transfer in Fully Developed Flow in Smooth Tubes , 1977 .

[24]  Hongxing Yang,et al.  Vertical-borehole ground-coupled heat pumps: A review of models and systems , 2010 .

[25]  R. Beier,et al.  Borehole thermal resistance from line-source model of in-situ tests. , 2002 .

[26]  H.-J. G. Diersch,et al.  Transient 3D analysis of borehole heat exchanger modeling , 2011 .

[27]  Richard A. Beier,et al.  Vertical temperature profile in ground heat exchanger during in-situ test , 2011 .