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An efficient borehole heat exchanger model for the analysis of transient thermal response: comparison with some existing models

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An efficient borehole heat exchanger model for the analysis of transient thermal response: comparison with some existing models

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dc.contributor.author Witte, Henk J.L. es_ES
dc.contributor.author Cazorla-Marín, Antonio es_ES
dc.contributor.author Corberán, José M. es_ES
dc.date.accessioned 2019-10-25T12:07:53Z
dc.date.available 2019-10-25T12:07:53Z
dc.date.issued 2018
dc.identifier.isbn 978-975-487-218-7
dc.identifier.uri http://hdl.handle.net/10251/129575
dc.description.abstract For the analysis of the dynamic behaviour of a complete ground source heat pump system, computationally efficient models of the borehole heat exchanger are needed. Moreover, as we are moving towards system controllers using model predictive control, such a model needs to be potentially implemented in relatively simple hardware. At the same time, it is essential that a number of key physical processes and parameters are included in the model. These include at least the thermal capacity of the fluid moving through the heat exchanger, the thermal resistance between the fluid and the ground, the heat flow and temperature change in the surrounding ground volume as well as factors such as the near-surface temperature gradient. Within the scope of the EU funded H2020 project Geotech (GA 656889), Groenholland developed a numerically efficient heat exchanger model (GHBM, GroenHolland Borehole Model) that includes the mentioned key-processes. Essentially it is a model of plug fluid flow in the heat exchanger pipe with the heat flow to the surrounding ground as a function of temperature difference and borehole resistance (which is introduced as a parameter in the model). The radial heat flow in the ground is essentially calculated using a lumped capacitance thermal resistance network with a fixed far field temperature at the furthest node. Although relatively simple in formulation, there are also some key parameters that can be fairly easily included, these include: 1) Vertical temperature gradient, as initial temperatures for the ground nodes as well as the undisturbed ground temperature 2) Different thermal characteristics of different ground layers, for instance contrast between saturated and unsaturated zone. The iteration scheme implemented to solve the equations de-couples the time step in the model from the time step used in the encompassing model (e.g. TRNSYS system model). The time step for the borehole model is selected based on the plug flow velocity, borehole length and vertical discretisation. This allows the encompassing system model to run with a simulation time step that is larger than the time step required for the plug flow model without losing accuracy. In this paper we describe the model developed and compare it with different existing models (B2G, SBM, DST) using data from a thermal response test on a concentric heat exchanger with a special geometry. The comparison focusses on the difference between the model solutions with different selections of horizontal and vertical discretisation and also on running the model with or without the iteration scheme. Results show that the GHBM model is the fastest of the models compared, the root mean square error of temperature is only better in the B2G model and the error in the heat transfer is the smallest in the GHBM. es_ES
dc.description.sponsorship The work in this paper was financially supported by the European Union, within the scope of the Geotech H2020 research project (Grant Agreement GA 65889) es_ES
dc.format.extent 11 es_ES
dc.language Inglés es_ES
dc.publisher IEA CES es_ES
dc.rights Reserva de todos los derechos es_ES
dc.subject Borehole heat exchanger es_ES
dc.subject Simulation es_ES
dc.subject Capacitance model, thermal network model es_ES
dc.subject Transient response es_ES
dc.subject.classification MAQUINAS Y MOTORES TERMICOS es_ES
dc.subject.classification TERMODINAMICA APLICADA (UPV) es_ES
dc.title An efficient borehole heat exchanger model for the analysis of transient thermal response: comparison with some existing models es_ES
dc.type Capítulo de libro es_ES
dc.type Comunicación en congreso es_ES
dc.relation.projectID info:eu-repo/grantAgreement/EC/H2020/658897/EU es_ES
dc.rights.accessRights Cerrado es_ES
dc.contributor.affiliation Universitat Politècnica de València. Departamento de Termodinámica Aplicada - Departament de Termodinàmica Aplicada es_ES
dc.description.bibliographicCitation Witte, HJ.; Cazorla-Marín, A.; Corberán, JM. (2018). An efficient borehole heat exchanger model for the analysis of transient thermal response: comparison with some existing models. IEA CES. 1-11. http://hdl.handle.net/10251/129575 es_ES
dc.description.accrualMethod S es_ES
dc.relation.conferencename International Conference on Energy Storage (EnerSTOCK) es_ES
dc.relation.conferencedate Abril 25-28,2018 es_ES
dc.relation.conferenceplace Adana, Turkey es_ES
dc.description.upvformatpinicio 1 es_ES
dc.description.upvformatpfin 11 es_ES
dc.type.version info:eu-repo/semantics/publishedVersion es_ES
dc.relation.pasarela S\362466 es_ES
dc.contributor.funder European Commission es_ES


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