Numerical simulation of heat transport associated with groundwater pumping in an alluvial aquifer

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.