their petrophysical properties. These rocks find several applications in various types of surfaces, from flooring to walls, coupled to radiant devices for indoor air conditioning or as geological target in hot dry rock geothermal systems. In order to support the thermophysical characterization, the thermal conductivity of seven granitoid rocks belonging to five different lithologies (granodiorite, tonalite, granite, gabbro, and syenite) has been analysed, as main property which must to be assessed, by comparison between traditional measurement methods and a new analytical approach. In detail, the thermal conductivity was measured directly on the bulk rock samples, evaluated by applying Quantitative Phase Analysis starting from the Digital Imaging Analysis (DIA) and Rietveld refinement associating thermal parameters to each phase, and analysed by thermal modelling. Thermal simulation obtained by the 2D modelling highlights on the dependence of the thermo-physical properties of considered rocks from the minerals content, according to the abundance of quartz, as well as to the mineral’s grain size and the geometrical grain distribution. This procedure provides a reliable estimation of the rock’s thermal behaviour considering concurrently different mineralogical and textural parameters. The comparison between different approaches to thermal conductivity evaluation of granitoids allowed to consider the validity of the predictive approach, based on thermal modelling. The methodologies here developed and compared considering the thermal properties of granitic rocks can be extended and optimized for other types of rocks.

Evaluation of plutonic rocks thermal properties based on QPA-mineral mode and numerical modelling from the micro- to the macro-scale

Alessandro Borghi;Roberto Cossio;
2021-01-01

Abstract

their petrophysical properties. These rocks find several applications in various types of surfaces, from flooring to walls, coupled to radiant devices for indoor air conditioning or as geological target in hot dry rock geothermal systems. In order to support the thermophysical characterization, the thermal conductivity of seven granitoid rocks belonging to five different lithologies (granodiorite, tonalite, granite, gabbro, and syenite) has been analysed, as main property which must to be assessed, by comparison between traditional measurement methods and a new analytical approach. In detail, the thermal conductivity was measured directly on the bulk rock samples, evaluated by applying Quantitative Phase Analysis starting from the Digital Imaging Analysis (DIA) and Rietveld refinement associating thermal parameters to each phase, and analysed by thermal modelling. Thermal simulation obtained by the 2D modelling highlights on the dependence of the thermo-physical properties of considered rocks from the minerals content, according to the abundance of quartz, as well as to the mineral’s grain size and the geometrical grain distribution. This procedure provides a reliable estimation of the rock’s thermal behaviour considering concurrently different mineralogical and textural parameters. The comparison between different approaches to thermal conductivity evaluation of granitoids allowed to consider the validity of the predictive approach, based on thermal modelling. The methodologies here developed and compared considering the thermal properties of granitic rocks can be extended and optimized for other types of rocks.
304
124612
1
13
Mineralogy Quantitative phase analysis 2D modelling Digital Imaging analysis Texture Thermal diffusivity Heat capacity Rietveld refinement Rocks
Chiara Coletti, Alessandro Borghi, Roberto Cossio, Maria Chiara Dalconi, Giorgia Dalla Santa, Luca Peruzzo, Raffaele Sassi, Arianna Vettorello, Antonio Galgaro
File in questo prodotto:
File Dimensione Formato  
Construction and Building Materials2021b.pdf

Accesso aperto

Descrizione: PDF EDITORIALE
Tipo di file: PDF EDITORIALE
Dimensione 807.15 kB
Formato Adobe PDF
807.15 kB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2318/1845212
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 1
  • ???jsp.display-item.citation.isi??? 0
social impact