Optimización teórico-experimental de sondas de calor para intercambio geotérmico (SGE) según condiciones hidrogeológicas, características geométricas y propiedades de sus materiales

Tesis por compendio[ES] Uno de los mayores retos para el mercado de bombas de calor geotérmicas es el alto coste asociado a la perforación de los intercambiadores de calor geotérmicos. Conseguir unos intercambiadores de calor geotérmicos más eficientes reduciría dicho coste, ya que sería necesaria una menor longitud de intercambiador para obtener las mismas temperaturas de trabajo en él (misma eficiencia de la bomba de calor). La eficiencia térmica de un intercambiador de calor geotérmico está caracterizada por su resistencia térmica. Dicha resistencia térmica depende de una serie de elementos entre los que se encuentran: propiedades y caudal del fluido que recorre el intercambiador de calor, diámetro de la perforación geotérmica, geometría y materiales de la tubería del intercambiador de calor y las propiedades del material de relleno de la perforación (grouting). Cuanto mayor sea la resistencia térmica del intercambiador de calor, menor será el calor transferido entre el fluido caloportador y el terreno, traduciéndose en una necesidad mayor de longitud de intercambiador enterrado. Por lo tanto, es necesario una reducción de este parámetro al mínimo posible. En consecuencia, el objetivo principal de esta tesis doctoral consiste en, a partir de un modelo analítico comprensivo de cuantificación del impacto de los parámetros anteriores, realizar un estudio detallado para analizar su influencia combinada en la resistencia térmica del intercambiador geotérmico, pero también examinando dicho efecto en otros planos, como costes económicos de ejecución del intercambiador y de explotación (consumo eléctrico de la bomba de calor y costes de bombeo asociados).[CA] Un dels majors reptes per al mercat de bombes de calor geotèrmiques és l'alt cost associat a la perforació dels bescanviadors de calor geotèrmics. Aconseguir uns bescanviadors de calor geotèrmics més eficients reduiria aquest cost, ja que seria necessària una menor longitud de bescanviador per a obtenir les mateixes temperatures de treball en ell (mateixa eficiència de la bomba de calor). L'eficiència tèrmica d'un bescanviador de calor geotèrmic està caracteritzada per la seva resistència tèrmica. Aquesta resistència tèrmica depèn d'una sèrie d'elements entre els quals es troben: propietats i cabal del fluid que recorre el bescanviador de calor, diàmetre de la perforació geotèrmica, geometria i materials de la canonada del bescanviador de calor i les propietats del material de farciment de la perforació (grouting). Com més gran sigui la resistència tèrmica del bescanviador de calor, menor serà la calor transferida entre el fluid termòfor i el terreny, traduint-se en una necessitat major de longitud de bescanviador enterrat. Per tant, és necessari una reducció d'aquest paràmetre al mínim possible. En conseqüència, l'objectiu principal d'aquesta Tesi Doctoral consisteix en, a partir d'un model analític comprensiu de quantificació de l'impacte dels paràmetres anteriors, realitzar un estudi detallat per a analitzar la seva influència combinada en la resistència tèrmica del bescanviador geotèrmic, però també examinant aquest efecte en altres plans, com a costos econòmics d'execució del bescanviador i d'explotació (consum elèctric de la bomba de calor i costos de bombament).[EN] One of the biggest challenges for the ground source heat pump market is the high cost associated with drilling geothermal borehole heat exchangers. Achieving more efficient geothermal heat exchangers would reduce this cost, since a shorter exchanger length would be required to obtain the same working temperatures in it (same efficiency of the heat pump). The thermal efficiency of a geothermal heat exchanger is characterized by its borehole thermal resistance. This borehole thermal resistance depends on a number of parameters, mainly: properties and flow rate of the working fluid that flows through the borehole heat exchanger, diameter of the geothermal borehole, geometry and materials of the heat exchanger pipe and the properties of the borehole grouting material. The higher thermal resistance of the heat exchanger, the less heat is transferred between the heat carrier fluid and the ground, resulting in an increased requirement for the length of the buried heat exchanger. Consequently, it is essential to reduce this parameter to the minimum possible. Therefore, the main objective of this Ph. Doctoral Thesis is to carry out, based on a comprehensive analytical model of quantification of the impact of the above mentioned parameters, a detailed study to analyze their combined influence on the thermal resistance of the geothermal borehole, but also exploring this effect in other less researched areas, such as economic costs of running the exchanger and operating it (electricity consumption of the heat pump and associated pumping costs).This research has received funding from the European Union’s Horizon 2020 Research and Innovation program under grant agreement No [657982], [727583] and [792355].Badenes Badenes, B. (2020). Optimización teórico-experimental de sondas de calor para intercambio geotérmico (SGE) según condiciones hidrogeológicas, características geométricas y propiedades de sus materiales [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/160477TESISCompendi

Modelado térmico de un pilote termoactivo y validación experimental

[ES] El uso de bombas de calor acopladas al terreno en estructuras de cimentación (como por ejemplo, en pilotes, pantallas y losas) es una forma de calefacción y refrigeración de edificios respetuosa con el medio ambiente y que además, al evitar la ejecución de las perforaciones, permite ahorrar los costes en obra civil asociados a un sistema de climatización geotérmico. Con estas estructuras termoactivas es posible la transferencia de energía desde el suelo hasta el fluido que portan las tuberÍas insertadas en la armadura de la estructura y de allí al edificio (o en el sentido contrario, dependiendo del modo de funcionamiento de la bomba de calor). Para mejorar el conocimiento en el campo de las estructuras de cimentación termoactivas, se ha desarrollado una instalación experimental con el fin de caracterizar el comportamiento de un pilote prefabricado sujeto a cargas termomecánicas. El objetivo de este trabajo es realizar un modelado del comportamiento térmico de un pilote prefabricado. El pilote a modelar está enmarcado dentro del proyecto de investigación PITERM y se encuentra actualmente hincado en terrenos de la UPV. Una vez obtenido el modelo del comportamiento térmico del pilote se calculará experimentalmente su resistencia térmica, para poderlo caracterizar térmicamente. Por último, se confrontarán los resultados experimentales obtenidos en los ensayos térmicos con una simulación en TRNSYS del pilote geotérmico, para poder validar la metodología utilizada[EN] The use of Ground Coupled Heat Pumps (GCHP) in foundation structures (for example, in piles, piled walls and slabs) is a way of heating and cooling buildings that respects the environment and also prevents the execution of the drilling, saving civil work costs associated with a Geothermal HVAC (Heating, Ventilation and Air Conditioning) Systems. With these thermoactive structure, the energy is transferred from the ground to the fluid carrying pipes inserted into the frame of the structure, and then, to the building (or in the opposite direction, depending on the mode of operation of the heat pump). To improve knowledge in the field of thermoactive foundation structures, we have developed an experimental facility in order to characterize the behavior of a precast pile subjected to thermomechanical loads. The aim of this study is to model the thermal behavior of a precast pile. The pile is framed within the PITERM research project and is currently driven into the UPV (Universidad Politècnica de València). Once the thermal behavior of the pile has been designed, thermal resistence will be calculated experimentally, to be able to thermally characterize it. Finally, the experimental results obtained in the thermal tests will be compared with a geothermal pile TRNSYS simulation in order to validate the methodology applied.Badenes Badenes, B. (2013). Modelado térmico de un pilote termoactivo y validación experimental. http://hdl.handle.net/10251/37116Archivo delegad

Análisis de la estabilidad del cauce del río Llobregat tras la construcción de la autovía del Baix Llobregat

Las actuaciones humanas sobre los ríos llevan mucho tiempo produciéndose, y hasta nuestros días el sentido de éstas era mejorar la vida de los que en sus proximidades se encontraban (ya fuese para evitar inundaciones, crear vías de comunicación paralelas a los cauces, aprovechamientos hidráulicos…). Por otro lado, hay que decir que en los últimos tiempos parece que se ha despertado una conciencia medioambiental, cada vez, afortunadamente, más fuerte e insistente. Estos dos aspectos (las obras en los ríos y el respeto por el medioambiente) son los que van a marcar la dirección de este trabajo: trataremos de ver cómo afecta al estado natural del río una actuación antrópica, concretamente nos centraremos en ver cómo la construcción de la Autovía del Baix Llobregat (1998) ha interferido en el río Llobregat cuando ésta actúa como límite del cauce de avenidas. Básicamente, el aspecto que estudiaremos será la estabilidad del cauce, esto es, si a causa de la actuación, se ha producido erosión o acreción. Analizando el caso a priori, y observando los efectos sobre el río, es evidente que esa estabilidad se ha traducido en una erosión del cauce, mejor dicho: el estado en que se dejó el río tras la construcción de la autovía no era estable, lo que ha llevado a una progresiva erosión hasta la situación actual

Análisis de la estabilidad del cauce del río Llobregat tras la construcción de la autovía del Baix Llobregat

Las actuaciones humanas sobre los ríos llevan mucho tiempo produciéndose, y hasta nuestros días el sentido de éstas era mejorar la vida de los que en sus proximidades se encontraban (ya fuese para evitar inundaciones, crear vías de comunicación paralelas a los cauces, aprovechamientos hidráulicos…). Por otro lado, hay que decir que en los últimos tiempos parece que se ha despertado una conciencia medioambiental, cada vez, afortunadamente, más fuerte e insistente. Estos dos aspectos (las obras en los ríos y el respeto por el medioambiente) son los que van a marcar la dirección de este trabajo: trataremos de ver cómo afecta al estado natural del río una actuación antrópica, concretamente nos centraremos en ver cómo la construcción de la Autovía del Baix Llobregat (1998) ha interferido en el río Llobregat cuando ésta actúa como límite del cauce de avenidas. Básicamente, el aspecto que estudiaremos será la estabilidad del cauce, esto es, si a causa de la actuación, se ha producido erosión o acreción. Analizando el caso a priori, y observando los efectos sobre el río, es evidente que esa estabilidad se ha traducido en una erosión del cauce, mejor dicho: el estado en que se dejó el río tras la construcción de la autovía no era estable, lo que ha llevado a una progresiva erosión hasta la situación actual

Impact of Employing Hybrid Nanofluids as Heat Carrier Fluid on the Thermal Performance of a Borehole Heat Exchanger

[EN] In this numerical study, 4 types of hybrid nanofluid, including Ag-MgO/water, TiO2-Cu/water, Al2O3-CuO/water, and Fe3O4-multi-wall carbon nanotube/water, have been considered potential working fluid in a single U-tube borehole heat exchanger. The selected hybrid nanofluid is then analyzed by changing the volume fraction and the Reynolds number. Based on the numerical results, Ag-MgO/water hybrid nanofluid is chosen as the most favorable heat carrier fluid, among others, considering its superior effectiveness, minor pressure drop, and appropriate thermal resistance compared to the pure water. Moreover, it was indicated that all cases of Ag-MgO/water hybrid nanofluid at various volume fractions (from 0.05 to 0.20) and Reynolds numbers (from 3200 to 6200) could achieve better effectiveness and lower thermal resistances, but higher pressure drops compared to the corresponding cases of pure water. Nevertheless, all the evaluated hybrid nanofluids present lower coefficient of performance (COP)-improvement than unity which means that applying them as working fluid is not economically viable because of having higher pressure drop than the heat transfer enhancement.This research work has been supported financially by the European project GEOCOND (funded by the European Union's Horizon 2020 research and innovation program under grant agreement No 727583) and by the European project GEO4CIVHIC (funded by the European Union's Horizon 2020 research and innovation program under grant agreement No 792355).Javadi, H.; Urchueguía Schölzel, JF.; Ajarostaghi, SSM.; Badenes Badenes, B. (2021). Impact of Employing Hybrid Nanofluids as Heat Carrier Fluid on the Thermal Performance of a Borehole Heat Exchanger. Energies. 14(10):1-26. https://doi.org/10.3390/en14102892126141

Numerical Study on the Thermal Performance of a Single U-Tube Borehole Heat Exchanger Using Nano-Enhanced Phase Change Materials

[EN] To investigate the impacts of using nano-enhanced phase change materials on the thermal performance of a borehole heat exchanger in the summer season, a three-dimensional numerical model of a borehole heat exchanger is created in the present work. Seven nanoparticles including Cu, CuO, Al2O3, TiO2, SiO2, multi-wall carbon nanotube, and graphene are added to the Paraffin. Considering the highest melting rate and lowest outlet temperature, the selected nano-enhanced phase change material is evaluated in terms of volume fraction (0.05, 0.10, 0.15, 0.20) and then the shape (sphere, brick, cylinder, platelet, blade) of its nanoparticles. Based on the results, the Paraffin containing Cu and SiO2 nanoparticles are found to be the best and worst ones in thermal performance improvement, respectively. Moreover, it is indicated that the increase in the volume fraction of Cu nanoparticles could enhance markedly the melting rate, being 0.20 the most favorable value which increased up to 55% the thermal conductivity of the nano-enhanced phase change material compared to the pure phase change material. Furthermore, the blade shape is by far the most appropriate shape of the Cu nanoparticles by considering about 85% melting of the nano-enhanced phase change materiaThis research work has been supported financially by the European project GEOCOND (funded by the European Union's Horizon 2020 research and innovation program under grant agreement No 727583) and by the European project GEO4CIVHIC (funded by the European Union's Horizon 2020 research and innovation program under grant agreement No 792355).Javadi, H.; Urchueguía Schölzel, JF.; Mousavi Ajarostaghi, SS.; Badenes Badenes, B. (2020). Numerical Study on the Thermal Performance of a Single U-Tube Borehole Heat Exchanger Using Nano-Enhanced Phase Change Materials. Energies. 13(19):1-30. https://doi.org/10.3390/en131951561301319Javadi, H., Mousavi Ajarostaghi, S. S., Rosen, M. A., & Pourfallah, M. (2019). Performance of ground heat exchangers: A comprehensive review of recent advances. Energy, 178, 207-233. doi:10.1016/j.energy.2019.04.094Javadi, H., Mousavi Ajarostaghi, S. S., Pourfallah, M., & Zaboli, M. (2019). Performance analysis of helical ground heat exchangers with different configurations. Applied Thermal Engineering, 154, 24-36. doi:10.1016/j.applthermaleng.2019.03.021Javadi, H., Ajarostaghi, S. S. M., Mousavi, S. S., & Pourfallah, M. (2019). Thermal analysis of a triple helix ground heat exchanger using numerical simulation and multiple linear regression. Geothermics, 81, 53-73. doi:10.1016/j.geothermics.2019.04.005Javadi, H., Mousavi Ajarostaghi, S., Rosen, M., & Pourfallah, M. (2018). 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Energies, 13(14), 3737. doi:10.3390/en13143737Janiszewski, M., Caballero Hernández, E., Siren, T., Uotinen, L., Kukkonen, I., & Rinne, M. (2018). In Situ Experiment and Numerical Model Validation of a Borehole Heat Exchanger in Shallow Hard Crystalline Rock. Energies, 11(4), 963. doi:10.3390/en11040963Patil, M., Seo, J.-H., Kang, S.-J., & Lee, M.-Y. (2016). Review on Synthesis, Thermo-Physical Property, and Heat Transfer Mechanism of Nanofluids. Energies, 9(10), 840. doi:10.3390/en9100840Cao, S.-J., Kong, X.-R., Deng, Y., Zhang, W., Yang, L., & Ye, Z.-P. (2017). Investigation on thermal performance of steel heat exchanger for ground source heat pump systems using full-scale experiments and numerical simulations. Applied Thermal Engineering, 115, 91-98. doi:10.1016/j.applthermaleng.2016.12.098Li, B., Zheng, M., Shahrestani, M., & Zhang, S. (2020). Driving factors of the thermal efficiency of ground source heat pump systems with vertical boreholes in Chongqing by experiments. 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NUMERICAL INVESTIGATION OF MELTING PROCESS IN HORIZONTAL SHELL-AND-TUBE PHASE CHANGE MATERIAL STORAGE CONSIDERING DIFFERENT HTF CHANNEL GEOMETRIES. Heat Transfer Research, 48(16), 1515-1529. doi:10.1615/heattransres.201701554

Implementación de los Objetivos de Desarrollo Sostenible (ODS) en la asignatura optativa Geotermia de 4º Curso del Grado en Ingeniería de la Energía

[ES] El 25 de de 2015, la Organización de las Naciones Unidas de septiembre (ONU) celebró la Agenda 2030 para el Desarrollo Sostenible, un plan de acción para mejorar el planeta que incluye 17 Objetivos de Desarrollo Sostenible (ODS). Las universidades pueden convertirse en un actor clave para liderar la implementación de los ODS a través de la enseñanza, el aprendizaje y la investigación. Este artículo describe una metodología de análisis de diagnóstico para la implementación de los ODS en la optativa Energía Geotérmica en el 4º curso de la carrera de Ingeniería en Energía, a través de las siguientes acciones: (1) identificación de los ODS relacionados con la asignatura; (2) análisis de la correspondencia entre las competencias trabajadas y los ODS relacionados con el tema; (3) diseñar los ODS en cada una de las actividades de la asignatura y definir los resultados de aprendizaje asociados; y (4) modificación de los contenidos de las actividades para lograr los resultados de aprendizaje relacionados con los ODS definidos. La identificación de los nuevos resultados de aprendizaje asociados a los ODS ha permitido modificar las actividades de la asignatura para integrar los Objetivos de Desarrollo Sostenible (ODS).Investigación financiada por el Vicerrectorado de Estudios, Calidad y Acreditación de la Universitat Politècnica de València (UPV), a través del Proyecto: “Innovación y mejora educativa aplicada a los Objetivos de Desarrollo Sostenible en la ETSII" (PIME/21-22/281).Badenes, B.; Magraner, T. (2023). Implementación de los Objetivos de Desarrollo Sostenible (ODS) en la asignatura optativa Geotermia de 4º Curso del Grado en Ingeniería de la Energía. Editorial Universitat Politècnica de València. 122-130. https://doi.org/10.4995/INN2022.2022.1557012213

A Review of Recent Passive Heat Transfer Enhancement Methods

[EN] Improvements in miniaturization and boosting the thermal performance of energy conservation systems call for innovative techniques to enhance heat transfer. Heat transfer enhancement methods have attracted a great deal of attention in the industrial sector due to their ability to provide energy savings, encourage the proper use of energy sources, and increase the economic efficiency of thermal systems. These methods are categorized into active, passive, and compound techniques. This article reviews recent passive heat transfer enhancement techniques, since they are reliable, cost-effective, and they do not require any extra power to promote the energy conversion systems' thermal efficiency when compared to the active methods. In the passive approaches, various components are applied to the heat transfer/working fluid flow path to improve the heat transfer rate. The passive heat transfer enhancement methods studied in this article include inserts (twisted tapes, conical strips, baffles, winglets), extended surfaces (fins), porous materials, coil/helical/spiral tubes, rough surfaces (corrugated/ribbed surfaces), and nanofluids (mono and hybrid nanofluids).Ajarostaghi, SSM.; Zaboli, M.; Javadi, H.; Badenes Badenes, B.; Urchueguía Schölzel, JF. (2022). A Review of Recent Passive Heat Transfer Enhancement Methods. Energies. 15(3):1-55. https://doi.org/10.3390/en1503098615515

A Case Study of Thermal Evolution in the Vicinity of Geothermal Probes Following a Distributed TRT Method

[EN] To meet the stated climate change targets and to ensure the capability of meeting the current and future energy demands, there is an urgent need to develop renewable energy sources, such as geothermal systems. If geothermal systems are to be cost-efficient and are to enjoy public confidence, it is essential that they are designed and installed in accordance with the prevailing site-specific conditions. A thorough understanding of the thermal behaviour of the surrounding ground is, therefore, critical. In this work, we investigated temperature and its evolution in the vicinity of a shallow geothermal helix-shaped borehole heat exchanger (BHE). To measure the temperature close to the actual geothermal system, an additional U-tube probe was installed at the edge of the same borehole. A thermal load was then applied to the BHE, and the temperature was detected in the nearby U-tube. The temperature measurements were made with a GEOSniff monitoring device. To understand these localised temperature measurements in the context of the Valencia test site, ERT measurements were also performed. The GEOSniff device permits measurements to be made with very high depth resolution, which allows the thermal properties of the surrounding ground to be derived precisely, thus, enabling the identification of the different textural domains.This research work has been supported financially by the European Cheap-GSHPs Project (funded by the European Union's Horizon 2020 research and innovation program under grant agreement No 657982) and by the European GEO4CIVHIC Project (funded by the European Union's Horizon 2020 research and innovation program under grant agreement No 792355).Schwarz, H.; Badenes Badenes, B.; Wagner, J.; Cuevas, JM.; Urchueguía Schölzel, JF.; Bertermann, D. (2021). A Case Study of Thermal Evolution in the Vicinity of Geothermal Probes Following a Distributed TRT Method. Energies. 14(9):1-17. https://doi.org/10.3390/en14092632S11714

Theoretical and experimental cost-benefit assessment of borehole heat exchangers (BHEs) according to working fluid flow rate

[EN] In ground-source heat-pump systems, the heat exchange rate is influenced by various design and operational parameters that condition the thermal performance of the heat pump and the running costs during exploitation. One less-studied area is the relationship between the pumping costs in a given system and the heat exchange rate. This work analyzes the investment and operating costs of representative borehole heat-exchanger configurations with varying circulating flow rate by means of a combination of analytical formulas and case study simulations to allow a precise quantification of the capital and operational costs in typical scenario. As a conclusion, an optimal flow rate minimizing either of both costs can be determined. Furthermore, it is concluded that in terms of operating costs, there is an operational pumping rate above which performance of geothermal systems is energetically strongly penalized.This research work has been supported financially by the European project GEOCOND (funded by the European Union's Horizon 2020 research and innovation program under grant agreement No 727583) and by the European project GEO4CIVHIC (funded by the European Union's Horizon 2020 research and innovation program under grant agreement No 792355).Badenes Badenes, B.; Mateo Pla, MÁ.; Magraner Benedicto, MT.; Soriano Olivares, J.; Urchueguía Schölzel, JF. (2020). Theoretical and experimental cost-benefit assessment of borehole heat exchangers (BHEs) according to working fluid flow rate. Energies. 13(18):1-30. https://doi.org/10.3390/en13184925S1301318Sáez Blázquez, C., Piedelobo, L., Fernández-Hernández, J., Nieto, I. M., Martín, A. F., Lagüela, S., & González-Aguilera, D. (2020). Novel Experimental Device to Monitor the Ground Thermal Exchange in a Borehole Heat Exchanger. Energies, 13(5), 1270. doi:10.3390/en13051270Bae, S. M., Nam, Y., & Shim, B. O. (2018). Feasibility Study of Ground Source Heat Pump System Considering Underground Thermal Properties. Energies, 11(7), 1786. doi:10.3390/en11071786Bilić, T., Raos, S., Ilak, P., Rajšl, I., & Pašičko, R. (2020). Assessment of Geothermal Fields in the South Pannonian Basin System Using a Multi-Criteria Decision-Making Tool. Energies, 13(5), 1026. doi:10.3390/en13051026Lamarche, L., Raymond, J., & Koubikana Pambou, C. (2017). Evaluation of the Internal and Borehole Resistances during Thermal Response Tests and Impact on Ground Heat Exchanger Design. Energies, 11(1), 38. doi:10.3390/en11010038Vella, C., Borg, S. P., & Micallef, D. (2020). The Effect of Shank-Space on the Thermal Performance of Shallow Vertical U-Tube Ground Heat Exchangers. Energies, 13(3), 602. doi:10.3390/en13030602Javed, S., & Spitler, J. D. (2016). Calculation of borehole thermal resistance. Advances in Ground-Source Heat Pump Systems, 63-95. doi:10.1016/b978-0-08-100311-4.00003-0Serageldin, A. A., Sakata, Y., Katsura, T., & Nagano, K. (2018). Thermo-hydraulic performance of the U-tube borehole heat exchanger with a novel oval cross-section: Numerical approach. Energy Conversion and Management, 177, 406-415. doi:10.1016/j.enconman.2018.09.081Hou, G., Taherian, H., Li, L., Fuse, J., & Moradi, L. (2020). System performance analysis of a hybrid ground source heat pump with optimal control strategies based on numerical simulations. Geothermics, 86, 101849. doi:10.1016/j.geothermics.2020.101849Li, M., & Lai, A. C. K. (2013). Thermodynamic optimization of ground heat exchangers with single U-tube by entropy generation minimization method. Energy Conversion and Management, 65, 133-139. doi:10.1016/j.enconman.2012.07.013De Carli, M., Galgaro, A., Pasqualetto, M., & Zarrella, A. (2014). Energetic and economic aspects of a heating and cooling district in a mild climate based on closed loop ground source heat pump. Applied Thermal Engineering, 71(2), 895-904. doi:10.1016/j.applthermaleng.2014.01.064Lu, Q., Narsilio, G. A., Aditya, G. R., & Johnston, I. W. (2017). Economic analysis of vertical ground source heat pump systems in Melbourne. Energy, 125, 107-117. doi:10.1016/j.energy.2017.02.082Nguyen, H. V., Law, Y. L. E., Alavy, M., Walsh, P. R., Leong, W. H., & Dworkin, S. B. (2014). An analysis of the factors affecting hybrid ground-source heat pump installation potential in North America. Applied Energy, 125, 28-38. doi:10.1016/j.apenergy.2014.03.044Garber, D., Choudhary, R., & Soga, K. (2013). Risk based lifetime costs assessment of a ground source heat pump (GSHP) system design: Methodology and case study. Building and Environment, 60, 66-80. doi:10.1016/j.buildenv.2012.11.011Yoon, S., Lee, S.-R., Xue, J., Zosseder, K., Go, G.-H., & Park, H. (2015). Evaluation of the thermal efficiency and a cost analysis of different types of ground heat exchangers in energy piles. Energy Conversion and Management, 105, 393-402. doi:10.1016/j.enconman.2015.08.002Emmi, G., Zarrella, A., De Carli, M., Donà, M., & Galgaro, A. (2017). Energy performance and cost analysis of some borehole heat exchanger configurations with different heat-carrier fluids in mild climates. Geothermics, 65, 158-169. doi:10.1016/j.geothermics.2016.09.006Spitler, J. D., & Gehlin, S. E. A. (2015). Thermal response testing for ground source heat pump systems—An historical review. Renewable and Sustainable Energy Reviews, 50, 1125-1137. doi:10.1016/j.rser.2015.05.061Bandos, T. V., Montero, Á., Fernández, E., Santander, J. L. G., Isidro, J. M., Pérez, J., … Urchueguía, J. F. (2009). Finite line-source model for borehole heat exchangers: effect of vertical temperature variations. Geothermics, 38(2), 263-270. doi:10.1016/j.geothermics.2009.01.003Diao, N., Cui, P., & Fang, Z. (2002). The thermal resistance in a borehole of geothermal heat exchangers. Proceeding of International Heat Transfer Conference 12. doi:10.1615/ihtc12.3050H. Tarrad, A. (2019). A Borehole Thermal Resistance Correlation for a Single Vertical DX U-Tube in Geothermal Energy Application. American Journal of Environmental Science and Engineering, 3(4), 75. doi:10.11648/j.ajese.20190304.12Ould-Rouiss, M., Redjem-Saad, L., & Lauriat, G. (2009). Direct numerical simulation of turbulent heat transfer in annuli: Effect of heat flux ratio. International Journal of Heat and Fluid Flow, 30(4), 579-589. doi:10.1016/j.ijheatfluidflow.2009.02.018Lundberg, R. E., McCuen, P. A., & Reynolds, W. C. (1963). Heat transfer in annular passages. Hydrodynamically developed laminar flow with arbitrarily prescribed wall temperatures or heat fluxes. International Journal of Heat and Mass Transfer, 6(6), 495-529. doi:10.1016/0017-9310(63)90124-8Badenes, B., Mateo Pla, M., Lemus-Zúñiga, L., Sáiz Mauleón, B., & Urchueguía, J. (2017). On the Influence of Operational and Control Parameters in Thermal Response Testing of Borehole Heat Exchangers. Energies, 10(9), 1328. doi:10.3390/en10091328Urchueguía, J., Lemus-Zúñiga, L.-G., Oliver-Villanueva, J.-V., Badenes, B., Pla, M., & Cuevas, J. (2018). How Reliable Are Standard Thermal Response Tests? An Assessment Based on Long-Term Thermal Response Tests Under Different Operational Conditions. Energies, 11(12), 3347. doi:10.3390/en11123347Código Técnico de la Edificación de España https://www.codigotecnico.org/EED—Earth Energy Designer, v4 https://buildingphysics.com/eed-2/GMSW 28 HK https://www.ochsner.com/en/ochsner-products/product-detail/gmsw-28-hk