Modeling insulated borehole heat exchangers

  • Daniel Otto Schulte
  • Bastian Welsch
  • Anke Boockmeyer
  • Wolfram Rühaak
  • Kristian Bär
  • Sebastian Bauer
  • Ingo Sass
Thematic Issue
Part of the following topical collections:
  1. Subsurface Energy Storage

Abstract

In the heating sector, borehole heat exchangers have become popular for supplying renewable energy. They tap into the subsurface to extract geothermal energy for heating purposes. For advanced applications, borehole heat exchangers require insulation in the upper part of the borehole either to meet legal requirements or to improve their performance. A priori numerical heat transport models of the subsurface are imperative for the systems’ planning and design. Only fully discretized models can account for depth-dependent borehole properties like insulated sections, but the model setup is cumbersome and the simulations come at high computational cost. Hence, these models are often not suitable for the simulation of larger installations. This study presents an analytical solution for the simulation of the thermal interactions of partly insulated borehole heat exchangers. A benchmark with a fully discretized OpenGeoSys model confirms sufficient accuracy of the analytical solution. In an application example, the functionality of the tool is demonstrated by finding the ideal length of a borehole insulation using mathematical optimization and by quantifying the effect of the insulation on the borehole heat exchanger performance. The presented method allows for accommodation of future advancements in borehole heat exchangers in numerical simulations at comparatively low computational cost.

Keywords

Borehole insulation Borehole heat exchangers Borehole thermal energy storage 

References

  1. Acuña J, Palm B (2013) Distributed thermal response tests on pipe-in-pipe borehole heat exchangers. Appl Energy 109:312–320. doi:10.1016/j.apenergy.2013.01.024 CrossRefGoogle Scholar
  2. Acuña J, Mogensen P, Palm B (2011) Distributed thermal response tests on a multi-pipe coaxial borehole heat exchanger. HVAC&R Res 17:1012–1029. doi:10.1080/10789669.2011.625304 Google Scholar
  3. Ageb AE (2013) Anwendungsbilanzen für die Endenergiesektoren in Deutschland in den Jahren 2011 und 2012 mit Zeitreihen von 2008 bis 2012. Bundesministerium für Wirtschaft und Technologie, BerlinGoogle Scholar
  4. Angelino L, Dumas P, Latham A (2014) EGEC Market Report 2013/2014 Update, 4 edn. European Geothermal Energy Council—EGECGoogle Scholar
  5. Bär K, Rühaak W, Welsch B, Schulte D, Homuth S, Sass I (2015) Seasonal high temperature heat storage with medium deep borehole heat exchangers. Energy Procedia 76:351–360. doi:10.1016/j.egypro.2015.07.841 CrossRefGoogle Scholar
  6. Bauer D, Heidemann W, Müller-Steinhagen H, Diersch HJG (2011) Thermal resistance and capacity models for borehole heat exchangers. Int J Energy Res 35:312–320. doi:10.1002/er.1689 CrossRefGoogle Scholar
  7. Bauer S, Beyer C, Dethlefsen F, Dietrich P, Duttmann R, Ebert M, Feeser V, Görke U, Köber R, Kolditz O, Rabbel W, Schanz T, Schäfer D, Würdemann H, Dahmke A (2013) Impacts of the use of the geological subsurface for energy storage: an investigation concept. Environ Earth Sci 70:3935–3943. doi:10.1007/s12665-013-2883-0 CrossRefGoogle Scholar
  8. Bauer S, Pfeiffer T, Boockmeyer A, Dahmke A, Beyer C (2015) Quantifying induced effects of subsurface renewable energy storage. Energy Procedia 76:633–641. doi:10.1016/j.egypro.2015.07.885 CrossRefGoogle Scholar
  9. Boockmeyer A, Bauer S (2014) High-temperature heat storage in geological media: high-resolution simulation of near-borehole processes. Géotechnique Lett 4:151–156. doi:10.1680/geolett.13.00060 CrossRefGoogle Scholar
  10. Brent RP (1973) Algorithms for minimization without derivatives. Dover, MineolaGoogle Scholar
  11. Diersch HJG, Bauer D, Heidemann W, Rühaak W, Schätzl P (2011a) Finite element modeling of borehole heat exchanger systems: part 1. Fundam Comp Geosci 37:1122–1135. doi:10.1016/j.cageo.2010.08.003 CrossRefGoogle Scholar
  12. Diersch HJG, Bauer D, Heidemann W, Rühaak W, Schätzl P (2011b) Finite element modeling of borehole heat exchanger systems: part 2. Numer Simul Comp Geosci 37:1136–1147. doi:10.1016/j.cageo.2010.08.002 CrossRefGoogle Scholar
  13. Eskilson P, Claesson J (1988) Simulation model for thermally interacting heat extraction boreholes. Numer Heat Transf 13:149–165CrossRefGoogle Scholar
  14. Gehlin SEA, Spitler JD, Hellström G (2016) Deep boreholes for ground source heat pump systems—scandinavian experience and future prospects. Paper presented at the ASHRAE Winter Meeting, Orlando, Florida, 23–27 Jan 2016Google Scholar
  15. Haehnlein S, Bayer P, Blum P (2010) International legal status of the use of shallow geothermal energy. Renew Sustain Energy Rev 14:2611–2625. doi:10.1016/j.rser.2010.07.069 CrossRefGoogle Scholar
  16. Kolditz O, Bauer S (2004) A process-oriented approach to computing multi-field problems in porous media. J Hydroinformatics 6:225–244Google Scholar
  17. Kolditz O, Bauer S, Bilke L, Böttcher N, Delfs JO, Fischer T, Görke UJ, Kalbacher T, Kosakowski G, McDermott CI, Park CH, Radu F, Rink K, Shao H, Shao HB, Sun F, Sun YY, Singh AK, Taron J, Walther M, Wang W, Watanabe N, Wu Y, Xie M, Xu W, Zehner B (2012) OpenGeoSys: an open-source initiative for numerical simulation of thermo-hydro-mechanical/chemical (THM/C) processes in porous media. Environ Earth Sci 67:589–599. doi:10.1007/s12665-012-1546-x CrossRefGoogle Scholar
  18. Lee C, Lee K, Choi H, Choi H-P (2010) Characteristics of thermally-enhanced bentonite grouts for geothermal heat exchanger in South Korea. Sci China Ser E-Technol Sci 53:123–128. doi:10.1007/s11431-009-0413-9 CrossRefGoogle Scholar
  19. Lund JW, Freeston DH, Boyd TL (2005) Direct application of geothermal energy: 2005 Worldwide review. Geothermics 34:691–727. doi:10.1016/j.geothermics.2005.09.003 CrossRefGoogle Scholar
  20. Mansure AJ (2002) Polyurethane grouting geothermal lost circulation zones. Paper presented at the IADC/SPE Drilling Conference, Dallas, Texas, 26–28 Feb 2002Google Scholar
  21. Nakevska N, Schincariol RA, Dehkordi SE, Cheadle BA (2015) Geothermal waste heat utilization from in situ thermal bitumen recovery operations. Groundwater 53:251–260. doi:10.1111/gwat.12196 CrossRefGoogle Scholar
  22. Reddy JN, Gartling DK (2010) The finite element method in heat transfer and fluid dynamics, 3rd edn. CRC Press, Boca RatonGoogle Scholar
  23. Sass I, Brehm D, Coldewey WG, Dietrich J, Klein R, Kellner T, Kirschbaum B, Lehr C, Marek A, Mielke P, Müller L, Panteleit B, Pohl S, Porada J, Schiessl S, Wedewardt M, Wesche D (2016a) Shallow geothermal systems—recommendations on design, construction, operation and monitoring. Ernst & Sohn, BerlinGoogle Scholar
  24. Sass I, Welsch B, Schulte DO (2016b) Mitteltiefe Erdwärmesondenspeicher—Lösung für den Nutzungskonflikt Grundwasserschutz versus Geothermienutzung? Paper presented at the 7. Bochumer Grundwassertag, Bochum, 17 Mar 2016Google Scholar
  25. Schulte DO, Rühaak W, Oladyshkin S, Welsch B, Sass I (2016) Optimization of medium-deep borehole thermal energy storage systems. Energy Technol 4:104–113. doi:10.1002/ente.201500254 CrossRefGoogle Scholar
  26. The MathWorks (2015a) MATLAB 2015b. The MathWorks Inc, NatickGoogle Scholar
  27. The MathWorks (2015b) MATLAB 2015b Global Optimization Toolbox. The MathWorks Inc, NatickGoogle Scholar
  28. Welsch B, Rühaak W, Schulte DO, Bär K, Homuth S, Sass I (2015) A comparative study of medium deep borehole thermal energy storage systems using numerical modeling. In: Proceedings World Geothermal Congress, Melbourne, 19–24 Apr 2015Google Scholar
  29. Zawislanski PT, Faybishenko B (1999) New casing and backfill design for neutron logging access boreholes. Ground Water 37:33–37. doi:10.1111/j.1745-6584.1999.tb00955.x CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2016

Authors and Affiliations

  • Daniel Otto Schulte
    • 1
    • 2
  • Bastian Welsch
    • 1
    • 2
  • Anke Boockmeyer
    • 3
  • Wolfram Rühaak
    • 1
    • 2
  • Kristian Bär
    • 2
  • Sebastian Bauer
    • 3
  • Ingo Sass
    • 1
    • 2
  1. 1.Graduate School of Excellence Energy Science and EngineeringTechnische Universität DarmstadtDarmstadtGermany
  2. 2.Geothermal Science and TechnologyTechnische Universität DarmstadtDarmstadtGermany
  3. 3.GeohydromodellingChristian-Albrechts-Universität zu KielKielGermany

Personalised recommendations