Strategic optimization of borehole heat exchanger field for seasonal geothermal heating and cooling

A mathematical procedure for optimization of borehole heat exchanger (BHE) fields is presented. If heat extraction and injection is not seasonally balanced, thermal anomalies grow in the ground. These are commonly constrained by regulations and not desirable due to potential decline of the system’s performance. We demonstrate, for the case with heat extraction and only partial replenishment, how adjustment of seasonal heating and cooling workloads can mitigate local cooling of the ground. It is revealed that the benefit from mathematical optimization increases with heat extraction/injection imbalance. Evidently, strategic operation of individual BHEs in the field can to some extent compensate for the heat injection deficit. Additionally to the optimization of workloads, we inspect the required number of BHEs for a given heating/cooling demand. The idea is that by sequentially removing least effective BHEs in the field, investment cost are reduced, while the effect on the entire field performance is minimal. We show that such unfavorable BHEs exist mainly in non-optimized fields without replenishment. Thus, our work offer two ways of tuning BHE fields applied for geothermal heating and cooling: workload optimization of individual BHEs and removal of redundant BHEs for a given arrangement.

[1]  Andreas Zell,et al.  Optimization of energy extraction for closed shallow geothermal systems using linear programming , 2012 .

[2]  Philippe Pasquier,et al.  The importance of axial effects for borehole design of geothermal heat-pump systems , 2010 .

[3]  Seong-Kyun Kim,et al.  Field-scale evaluation of the design of borehole heat exchangers for the use of shallow geothermal energy , 2010 .

[4]  Apostolos Michopoulos,et al.  A new energy analysis tool for ground source heat pump systems , 2009 .

[5]  Ladislaus Rybach,et al.  Sustainability aspects of geothermal heat pump operation, with experience from Switzerland , 2010 .

[6]  Andreas Zell,et al.  Geometric arrangement and operation mode adjustment in low-enthalpy geothermal borehole fields for heating , 2013 .

[7]  Marc A. Rosen,et al.  Geothermal heat pump systems: Status review and comparison with other heating options , 2013 .

[8]  P. Blum,et al.  Evaluating the influence of thermal dispersion on temperature plumes from geothermal systems using analytical solutions , 2011 .

[9]  E. Zanchini,et al.  Long-term performance of BHE (borehole heat exchanger) fields with negligible groundwater movement , 2010 .

[10]  Benamar Bouhacina,et al.  Analysis of thermal and dynamic comportment of a geothermal vertical U-tube heat exchanger , 2013 .

[11]  Xiaosheng Qin,et al.  Investigation on potential applicability of subsurface cooling in Singapore , 2013 .

[12]  Umberto Desideri,et al.  Feasibility study and numerical simulation of a ground source heat pump plant, applied to a residential building , 2011 .

[13]  Hywel Rhys Thomas,et al.  Optimization of operating parameters of ground source heat pump system for space heating and cooling by Taguchi method and utility concept , 2014 .

[14]  Jeffrey D. Spitler,et al.  Ground-Source Heat Pump System Research— Past, Present, and Future , 2005 .

[15]  Per Eskilson.  Thermal analysis of heat extraction boreholes , 1987 .

[16]  W. H. Leong,et al.  A design methodology and analysis of combining multiple buildings onto a single district hybrid ground source heat pump system , 2014 .

[17]  Stefano Lazzari,et al.  Corrigendum to “Long-term performance of BHE (borehole heat exchanger) fields with negligible groundwater movement” [Energy (2010) 35: 4966–4974] , 2012 .

[18]  A. Lai,et al.  Thermodynamic optimization of ground heat exchangers with single U-tube by entropy generation minimization method , 2013 .

[19]  Marc A. Rosen,et al.  Examination of thermal interaction of multiple vertical ground heat exchangers , 2012 .

[20]  C. D. Rakopoulos,et al.  Cooling dominated Hybrid Ground Source Heat Pump System application , 2012 .

[21]  Thomas Kohl,et al.  Sustainability of Production from Borehole Heat Exchanger Fields , 2005 .

[22]  Michele De Carli,et al.  Analysis of short helical and double U-tube borehole heat exchangers: A simulation-based comparison , 2013 .

[23]  P. Blum,et al.  Numerical sensitivity study of thermal response tests , 2012 .

[24]  Amanda Pertzborn,et al.  Effective design and operation of hybrid ground-source heat pumps: Three case studies , 2011 .

[25]  B. Perers,et al.  Optimization of systems with the combination of ground-source heat pump and solar collectors in dwellings , 2010 .

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

[27]  Michael de Paly,et al.  Optimization of energy extraction for vertical closed-loop geothermal systems considering groundwater flow , 2013 .

[28]  Peter Bayer,et al.  Oberflächennahe Geothermie und ihre potenziellen Auswirkungen auf Grundwasserökosysteme , 2011 .

[29]  Marc A. Rosen,et al.  An analytical approach to evaluating the effect of thermal interaction of geothermal heat exchangers on ground heat pump efficiency , 2014 .

[30]  Stephen P. Kavanaugh,et al.  Ground Source Heat Pumps : Design of Geothermal Systems for Commercial and Institutional Buildings , 1997 .

[31]  Yong Chan Kim,et al.  Performance optimization of a hybrid ground source heat pump with the parallel configuration of a ground heat exchanger and a supplemental heat rejecter in the cooling mode , 2012 .

[32]  David John Booth,et al.  Sustainable development – the East Bali poverty project , 2012 .

[33]  Philipp Blum,et al.  Thermal Use of Shallow Groundwater , 2013 .

[34]  Philipp Blum,et al.  Sustainability and policy for the thermal use of shallow geothermal energy , 2013 .

[35]  Xiaosong Zhang,et al.  Soil temperature distribution around a U-tube heat exchanger in a multi-function ground source heat pump system , 2009 .

[36]  Stephen P. Boyd,et al.  Convex Optimization , 2004, Algorithms and Theory of Computation Handbook.

[37]  Daniel Pahud,et al.  Geocooling potential of borehole heat exchangers' systems applied to low energy office buildings , 2012 .

[38]  Peter Bayer,et al.  International legal status of the use of shallow geothermal energy , 2010 .

[39]  Ahmet Dagdas.  Heat exchanger optimization for geothermal district heating systems: A fuel saving approach , 2007 .

[40]  Hiep V. Nguyen,et al.  A methodology and computerized approach for optimizing hybrid ground source heat pump system design , 2013 .

[41]  Simon Arthur,et al.  Thermal modelling of large scale exploitation of ground source energy in urban aquifers as a resource management tool , 2013 .

[42]  Alessandro Casasso,et al.  Efficiency of closed loop geothermal heat pumps: A sensitivity analysis , 2014 .

[43]  Jeffrey D. Spitler,et al.  Editorial: Ground-Source Heat Pump System Research—Past, Present, and Future , 2005 .

[44]  Andreas Zell,et al.  Evaluation of the performance of evolutionary algorithms for optimization of low-enthalpy geothermal heating plants , 2012, GECCO '12.

[45]  Marco Fossa,et al.  The effect of borefield geometry and ground thermal load profile on hourly thermal response of geothermal heat pump systems , 2013 .

[46]  Jozsef Hecht-Méndez,et al.  Evaluating MT3DMS for Heat Transport Simulation of Closed Geothermal Systems , 2010, Ground water.

[47]  Burkhard Sanner,et al.  Larger geothermal heat pump plants in the central region of Germany , 2003 .

[48]  Richard Labib,et al.  A Multiple Load Aggregation Algorithm for Annual Hourly Simulations of GCHP Systems , 2004 .

[49]  Alvin C.K. Lai,et al.  Analytical model for short-time responses of ground heat exchangers with U-shaped tubes: Model development and validation , 2013 .

[50]  Andreas Zell,et al.  Optimization of the energy extraction of a shallow geothermal system , 2010, IEEE Congress on Evolutionary Computation.

[51]  Grant Ferguson.  Subsurface energy footprints , 2013 .

[52]  Enzo Zanchini,et al.  Long-term performance of large borehole heat exchanger fields with unbalanced seasonal loads and groundwater flow , 2012 .

[53]  Philippe Pasquier,et al.  Fast fluid and ground temperature computation for geothermal ground-loop heat exchanger systems , 2008 .

[54]  Paul Christodoulides,et al.  An analysis of heat flow through a borehole heat exchanger validated model , 2012 .

[55]  Grant Ferguson,et al.  Screening for Heat Transport by Groundwater in Closed Geothermal Systems , 2015, Ground water.

[56]  Stefano Lazzari,et al.  Corrigendum to “Long-term performance of large borehole heat exchanger fields with unbalanced seasonal loads and groundwater flow” [Energy (2012) 38: 66–77] , 2012 .

[57]  Tomislav Kurevija,et al.  Effect of borehole array geometry and thermal interferences on geothermal heat pump system , 2012 .

[58]  Z. Fang,et al.  Heat transfer in ground heat exchangers with groundwater advection , 2004 .

[59]  Philipp Blum,et al.  Greenhouse gas emission savings of ground source heat pump systems in Europe: A review , 2012 .

[60]  Yong Chan Kim,et al.  The cooling seasonal performance factor of a hybrid ground-source heat pump with parallel and serial configurations , 2013 .