Temperature evolution around four laboratory-scale borehole heat exchangers grouted with phase change materials subjected to heating–cooling cycles: An experimental studyVisa övriga samt affilieringar
2023 (Engelska)Ingår i: Journal of Energy Storage, ISSN 2352-152X, E-ISSN 2352-1538, Vol. 74, artikel-id 109302Artikel i tidskrift (Refereegranskat) Published
Abstract [en]
This article presents the experimental results from a unique laboratory test-setup used to comparative study of heat transfer conditions in borehole heat exchangers with different grouts under a controlled environment. The work was part of a larger, EU-funded project on advanced materials for borehole heat exchangers pipes and grout, GEOCOND. Four grout columns with different formulations were cast and tested under cyclic heating and cooling. One grout column was cast using high thermal conductivity grout; two columns were cast from high thermal conductivity grout with microencapsulated phase change material (MC-PCM) and one with shape-stabilised phase-change material (SS-PCM). The objective of the test was to comparatively evaluate performance of the borehole heat exchanger under a cyclic temperature regime and to investigate if the selected phase change materials (PCM) embedded in grout can be activated by cyclic heating and function steadily. Twenty-five heating-cooling cycles were performed, each lasted 24 h. The results showed clear cooling delay in grouts containing PCM associated with the crystallization heat release. The cooling delay was better expressed in grouts with SS-PCM. The PCM related cooling delay was stable throughout all the cycling in SS-PCM containing grouts, however, the effect vanished in grouts with MC-PCM. © 2023 The Authors
Ort, förlag, år, upplaga, sidor
Elsevier Ltd , 2023. Vol. 74, artikel-id 109302
Nyckelord [en]
Boreholes; Cooling; Geothermal energy; Grouting; Mortar; Thermal conductivity; Borehole heat exchangers; Cyclic heating; Heating-cooling cycle; High thermal conductivity; High thermal conductivity grout; Laboratory test; Shallow geothermal energies; Shape stabilized phase change material; Temperature evolution; Test setups; Phase change materials
Nationell ämneskategori
Energiteknik
Identifikatorer
URN: urn:nbn:se:ri:diva-67699DOI: 10.1016/j.est.2023.109302Scopus ID: 2-s2.0-85174685922OAI: oai:DiVA.org:ri-67699DiVA, id: diva2:1810047
Forskningsfinansiär
EU, Horisont 2020, 727583
Anmärkning
This work received funding from the European Union's Horizon 2020 research and innovation programme [grant agreement number No 727583 ].
2023-11-062023-11-062023-11-16Bibliografiskt granskad