Nouvelle approche pour déterminer la distribution des temps de séjour dans les réservoirs d'eau potable en régime non permanent

Drinking water storage tanks are used to respond to fluctuating demand and to maintain water pressure in the distribution network. In drinking water plants, they are also used for disinfection. In both cases, a good knowledge of the residence time distribution (RTD) is important. An easy way to obtain the water RTD in a drinking water tank is to perform a tracer study. Nevertheless, "classical" tracing techniques can only be used under steady flow conditions. To cope with that, this study proposes a new approach to extend the application of tracer tests to unsteady flow conditions. This new approach is based on signal processing. It has been tested numerically and on a pilot scale model. The numerical tests have shown that this technique can be used for determining the RTD twice more rapidly than the "classical" methods. Thus, this technique allows to approach the knowledge of the RTD under unsteady flow conditions. Pilot scale tests have shown the need for other improvements to bring the quality of the r...