Thermo-active diaphragm walls have proved their effectiveness in the thermal conditioning of buildings and infrastructures. However, some aspects still need to be investigated in order to tailor methods and tools for ...Thermo-active diaphragm walls have proved their effectiveness in the thermal conditioning of buildings and infrastructures. However, some aspects still need to be investigated in order to tailor methods and tools for an accurate prediction of their energy and structural performance. In this perspective, some issues are addressed that concern the definition of models for the numerical analysis, in particular issues about the modelling of geometry and thermal boundary conditions. Taking advantage of a monitoring programme on a real full-scale structure, this research focuses on the assessment of heat transfer process and thermal response of diaphragm wall and soil mass on the basis of field data. Understanding of the heat transfer process contributes to the definition of the time-dependent thermal boundary conditions at the excavation side. From the analysis of thermal gradients in the wall, the condition at the excavation side is recognised as a major factor that influences the heat transfer process, governing the direction of the heat flux in different seasons of operation of the geothermal system.展开更多
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 u...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.展开更多
基金the support of COST Action TU1405 GABI (Geothermal Applications for Building and Infrastructures)
文摘Thermo-active diaphragm walls have proved their effectiveness in the thermal conditioning of buildings and infrastructures. However, some aspects still need to be investigated in order to tailor methods and tools for an accurate prediction of their energy and structural performance. In this perspective, some issues are addressed that concern the definition of models for the numerical analysis, in particular issues about the modelling of geometry and thermal boundary conditions. Taking advantage of a monitoring programme on a real full-scale structure, this research focuses on the assessment of heat transfer process and thermal response of diaphragm wall and soil mass on the basis of field data. Understanding of the heat transfer process contributes to the definition of the time-dependent thermal boundary conditions at the excavation side. From the analysis of thermal gradients in the wall, the condition at the excavation side is recognised as a major factor that influences the heat transfer process, governing the direction of the heat flux in different seasons of operation of the geothermal system.
基金the support of the European Commission via the Marie Skłodowska-Curie Innovative Training Networks(ITN-ETN)project TERRE’Training Engineers and Researchers to Rethink Geotechnical Engineering for a Low Carbon Future’(H2020-MSCA-ITN-2015-675762).
文摘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.
