Skip to Main content Skip to Navigation
Theses

Modélisations physique et numérique des géostructures énergétiques

Abstract : Energy geostructures are civil engineering structures equipped with energy exchanger elements in order to store heat seasonally. The aim of this study is the use of compacted soil to store energy through installation of horizontal exchangers in an embankment. During the soil compaction, two parameters were controlled: the water content w and the dry density ρd. This parameters as well as the soil nature, the mechanical load path and the cyclic temperature variation may affect the storage capacity and the system stability. This work includes an experimental part and a modeling part. In the experimental part, the impact of the temperature variation is studied on the thermal and mechanical properties of the compacted soil. The Plaisir loam (PL) extracted from the Paris region was investigated through laboratory tests at a temperatures range of 20 to 50°C. The results showed that the thermal properties of the compacted soils increased on the dry side of the compaction curve. This evolution was clearly confirmed for higher temperatures. The application of cyclic temperature variations showed reversible evolutions in the thermal properties after one cycle. The results of unconfined compressive tests and pressuremeter tests showed that heating induces a softening of the material whereas several temperature cycles induce a stiffening of the material. Thereafter, a coupled thermo-hydraulic modeling of an embankment made of the compacted Plaisir loam is performed in order to optimize the storage system. The comparison of different modelling results, fixed the temperature sensors spacing that minimizes the interactions between them, and the optimal distance between the last sensors and the bottom of the slope. It is shown that if an appropriate thermal program is chosen, the heat storage in the embankment could be possible. A better efficiency of the storage capacity can be reached by introducing 3 temperature sensors rows in the storage and by covering the storage with a thermal insulation. The simulation of this scenario over 10 years including temperature cycles shows a heating of the embankment for several years, until to reach an equilibrium state after the 7th year
Complete list of metadata

https://hal.univ-lorraine.fr/tel-03130332
Contributor : Thèses Ul <>
Submitted on : Wednesday, February 3, 2021 - 3:01:44 PM
Last modification on : Monday, March 29, 2021 - 4:03:16 PM

File

DDOC_T_2016_0241_BOUKELIA.pdf
Files produced by the author(s)

Identifiers

  • HAL Id : tel-03130332, version 1

Collections

Citation

Ahmed Boukelia. Modélisations physique et numérique des géostructures énergétiques. Thermique [physics.class-ph]. Université de Lorraine, 2016. Français. ⟨NNT : 2016LORR0241⟩. ⟨tel-03130332⟩

Share

Metrics

Record views

153

Files downloads

621