References of "Fossoul, Frédérique"
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See detailNumerical simulation of heat transfer associated with low enthalpy geothermal pumping in an alluvial aquifer
Fossoul, Frédérique ULg; Orban, Philippe ULg; Dassargues, Alain ULg

in Geologica Belgica (2011), 14(1-2),

In a context favourable to renewable energies, various aquifers are studied to supply heating and/or cooling systems. The groundwater flow and heat transport are modelled in the alluvial aquifer of the ... [more ▼]

In a context favourable to renewable energies, various aquifers are studied to supply heating and/or cooling systems. The groundwater flow and heat transport are modelled in the alluvial aquifer of the river Meuse in providing an integrated tool for assessing the feasibility of a low energy air cooling/heating system for a large office building by pumping groundwater and discharging it in the river after being heated/cooled by using heat pumps. First, a comparative sensitivity analysis is performed using different codes for assessing the influence of coupling and non linearities on the main parameters due to the temperature evolution in function of time. Then, assuming that the aquifer temperature variation is weak enough to neglect its influence on hydrodynamics and thermal parameters, the MT3DMS and HydroGeoSphere codes are used for modelling the actual case-study. In practice, the worst case scenario considered by the project manager is the cooling of the office building during the hottest summer conditions. So, the influence of the warm water from the river Meuse is computed as it constitutes the major limiting factor. An optimisation of the pumping schema is computed to maximise the efficiency of the system. [less ▲]

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See detailModelling groundwater pumping and coupled heat transport in a alluvial aquifer: tests using different codes an optimisation
Fossoul, Frédérique ULg; Orban, Philippe ULg; Dassargues, Alain ULg

in Carrera, Jesus (Ed.) XVIII International Conference on Computational Methods in Water Resources, CMWR 2010 (2010, June 24)

Various aquifers are studied in terms of low temperature geothermal potential. The feasibility and impact studies of these systems imply very often a numerical simulation of groundwater flow and heat ... [more ▼]

Various aquifers are studied in terms of low temperature geothermal potential. The feasibility and impact studies of these systems imply very often a numerical simulation of groundwater flow and heat transport. Nowadays, some finite element or finite difference codes are able to deal with such non linear simulations. On a synthetic case study and then on a real case study, a detailed comparative sensitivity analysis is performed using three different codes (MT3DMS, SHEMAT and HYDROGEOSHERE). For low temperatures and relatively small temperature changes, it appears rapidly that the uncertainty affecting values of the main hydrodynamic parameters (i.e. hydraulic conductivity) influences more the results than taking into account any coupling or non linearity. For a case study, the pumping and associated groundwater flow and heat transport are modeled in an alluvial aquifer interacting with a main river in order to assess feasibility of a low energy air cooling /heating system for a large office building. The worst case scenario corresponds to hot summer conditions simultaneously with river maximum temperature and the model leads to an optimization with intermittent pumping in minimum 6 wells. Numerical codes are ready to simulate complex groundwater flow, solute transport and heat transport situations in aquifers, however efforts must be realized to obtain reliable experimental in-situ measured values for the hydro-thermal properties. [less ▲]

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See detailNumerical simulation of heat transport associated with groundwater pumping in an alluvial aquifer
Fossoul, Frédérique ULg; Orban, Philippe ULg; Dassargues, Alain ULg

Conference (2009, September)

In a context more favourable to renewable energies, various aquifers are studied to feed heating and/or cooling systems. The groundwater flow and heat transport are modelled in the alluvial aquifer of the ... [more ▼]

In a context more favourable to renewable energies, various aquifers are studied to feed heating and/or cooling systems. The groundwater flow and heat transport are modelled in the alluvial aquifer of the river Meuse in order to provide an integrated tool for assessing the feasibility of a low energy air cooling /heating system for a large office building by pumping groundwater and discharging in the river. First, a comparative sensitivity analysis is performed using three different codes (MT3D, SHEMAT and HYDROGEOSHERE) for assessing the influence of coupling and non linearities in the main parameters due to the temperature evolution in function of time. Then, assuming that the variations of the aquifer temperature are weak enough to neglect their influence on hydrodynamics and thermal parameters, the MT3D and HYDROGEOSPHERE codes are used for modelling the actual case-study. In practice, for cooling the office building with groundwater initially at 13°C, the main influence of the relative hot water from the river Meuse (in hot summer conditions 27°C) is computed and constitutes the major limiting factor. An optimisation of the pumping schema is computed to maximise the efficiency of the cooling/heating system. [less ▲]

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See detailEtude et modélisation d'un aquifère alluvial en vue de la mise en place d'installations géothermiques de refroidissement et de conditionnement d'air
Fossoul, Frédérique ULg

Master's dissertation (2009)

Policies against global warming are generating mechanisms favorable to renewable energies. In particular, the development of geothermal expertise has considerably increased these last years and numbers of ... [more ▼]

Policies against global warming are generating mechanisms favorable to renewable energies. In particular, the development of geothermal expertise has considerably increased these last years and numbers of various environments are henceforth studied and worked to feed heating and/or cooling systems. However numerical models, allowing to simulate these processes by integrating the maximum of the available information, are still seldom used in this domain. In this work, the basic principles of geothermal processes are first described. Then, the governing equations for heat transfer in saturated porous media are detailed and the analogies between heat transfer and solute transport are established. Due to the general lack of specific data, the currently available techniques for measuring and evaluating the two main parameters of the subsoil, the thermal conductivity λ and the specific heat capacity c, are reviewed. The main purpose of this work consists in modeling the flow and the heat transfer within the alluvial aquifer of the Meuse in Liège with the aim to set up a system of air conditioning by pumping the groundwater. Two numerical codes are used and compared: MT3D/MODFLOW (finite differences) and HGS (finite elements). The variations of the aquifer temperature are assumed to be weak enough to neglect their influence on hydrodynamics and thermal parameters. A simplified situation is however simulated by means of both previous codes and of software Processing Shemat to validate this hypothesis and to estimate the approximation it could generate in this kind of problem. [less ▲]

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