Hydrothermal interactions in energy walls

Underground Space

Maxime Pousse¹  Alessio Ferrari²  Lyesse Laloui³  Jacopo Zannin³ 

[1] Corresponding author at: Swiss Federal Institute of Technology in Lausanne, EPFL, Laboratory of Soil Mechanics, EPFL-ENAC-IIC-LMS, Station 18, 1015 Lausanne, Switzerland.;Nobatek/INEF4, 67 rue de Mirambeau, F-64600 Anglet, France;Swiss Federal Institute of Technology in Lausanne, EPFL, Laboratory of Soil Mechanics, EPFL-ENAC-IIC-LMS, Station 18, 1015 Lausanne, Switzerland;

关键词: Geothermal energy;    Shallow geothermal structures;    Energy geostructures;    Energy infrastructures;    Hydrothermal modelling;    Non-isothermal seepage;   

DOI  :  

来源: DOAJ

【 摘 要 】

Energy geostructures (EGs) employ heat exchangers embedded in concrete geostructures, such as piles, walls, tunnels, and sewers. In this study, energy walls (EWs) are studied with an emphasis on the following objectives: (1) to understand the fundamentals of hydrothermal interactions acting in the vicinity of EWs caused by groundwater seepage in saturated soil; (2) to highlight hydraulically induced thermal effects and their consequences on the thermal performance of EWs. Extensive three-dimensional hydrothermal finite element analyses are performed considering two groundwater flow conditions: perpendicular and parallel to the EW. The thermal activation of the geostructure locally modifies the flownet with respect to the non-isothermal case because of the temperature dependency of the water properties. Mutual interactions between seepage directions and thermal activation are analyzed. Remarkable thermal interactions are detected within the heat exchangers. The thermal behavior of EGs is highly affected by an incorrect evaluation of the hydraulically induced thermal effects, which may result in an overestimation of the thermal behavior. Conversely, an efficient thermal design, which considers such interactions, may increase the thermal potential of EGs.

【 授权许可】

Unknown