[1] Barbier E (2002) Geothermal energy technology and current status: an overview. Renew Sust Energ Rev 6(1-2): 3-65.
[2] Kagel A, Bates D, Gawell K (2007) A guide to geothermal energy and the environment. Geothermal Energy Association, Washington.
[3] Egg J, Howard B (2011) Geothermal HVAC Green Heating and Cooling. 1st edn. McGraw-Hill, New York.
[4] Boyle G (2004) Renewable Energy: Power for a Sustainable Future. 2nd edn. Oxford University Press.
[5] Dipippo R (2008) Geothermal power plants: principles, applications, case studies and environmental impact. 3rd edn. Butterworth-Heinemann (an imprint of Elsevier), Waltham.
[6] Nalla G, Shook G, Mines L, Bloomeld K (2004) Parametric sensitivity study of operating and design variables in wellbore heat exchanger. Workshop on Geothermal Reservoir Engineering, Stanford University, Stanford, CA.
[7] Al-Khoury R, Bonnier PG, Brinkgreve BJ (2005) Efficient finite element formulation for geothermal heating systems. Part I: steady state. Int J Numer Meth Eng 63 (7): 988-1013.
[8] Al-Khoury R, Bonnier PG, Brinkgreve BJ (2005) Efficient finite element for- mulation for geothermal heating systems. Part II: transient. Int J Numer Meth Eng, 67(5): 725-74.
[9] Feng Y (2012) Numerical study of downhole heat exchanger concept geothermal energy extraction. Ph.D. Thesis, Louisiana state university.
[10] Parisch P, Mercker O, Oberdorfer P, Bertram E, Tepe R, Rockendorf G (2015) Short-term experiments with borehole heat exchangers and model validation in TRNSYS. Renew Energ 74: 471-477.
[11] Funabiki A, Oguma M, Yabuki T, Kakizaki T (2014) The effects of groundwater flow on vertical-borehole ground source heat pump systems. ASME 12th Biennial Conference on Engineering Systems Design and Analysis, June 25-27, Copenhagen, Denmark.
[12] Beier RA, Acuna J, Mogensen P, Palm B (2013) Borehole resistance and vertical temperature profiles in coaxial borehole heat exchangers. Applied Energy 102: 665-675.
[13] Sliwa T, Gonet A (2004) Theoretical model of borehole heat exchanger. J Energy Resour Technol 127(2): 142-148.
[14] Mastrulla R, Mauro AW, Menna L, Vanoli GP (2014) A model for a borehole heat exchanger working with CO2. Energ Proc 45: 635-644.
[15]Masalias MD (2011) Thermodynamic optimization of downhole coaxial heat exchanger for geothermal applications. M.Sc. thesis, Warsaw University of Technology, Faculty of Power and Aeronautical Engineering, Warsaw.
[16] Gnielinski V (2009) Heat Transfer coefficients for turbulent flow in concentric annular ducts. Heat Transfer Eng 30(6): 431-436.
[17] Menter FR (1994) Two-equation eddy-viscosity turbulence models for engineering applications. AIAA J 32(8): 1598-1605.
[18] Van Doormal JP, Raithby GD (1984) Enhancements of the SIMPLE method for predicting incompressible fluid flows. Numer Heat Transfer 7(2): 147-163.
[19] White FM (2011) Fluid mechanics. 7th edn. McGraw-Hill, New York.
[20] Bejan A, Kraus AD (2003) Heat transfer Handbook. John Wiley & Sons, New York.
[21] Bejan A, Tsatsaronis G, Moran M (1996) Thermal design & optimization. John Wiley & Sons, New York.
[22] Bergman TL, Levine AS, Incropera FP, Dewitt DP (2011) Fundamentals of heat and mass transfer. 7th edn. John Wiley & Sons, New York.
[23] Van Wylen GJ, Sonntag RE (1985) Fundamentals of Classical Thermodynamics. 3rd edn. John Wiley & Sons, New York.