Author(s): Jean-Marie Beckers; Jean-Jacques Van Ormelingen
Abstract: A mathematical model and numerical simulation has been used to test the validity of a water and thermal circulation scheme induced by the implementation of a new power plant in the Zeebrugge harbour. The aim of the study was to: a) verify that in the interior basin of the inner harbour, a sufficient stratification is present to allow for the capture of cold bottom waters, whereas the ejected heated water remains at the surface and is evacuated to the main harbour, b) study the way the water cools in the main harbour and to quantify the amount of thermal energy which is pumped back into the inner harbour, c) determine if the global heat excess is evacuated and if the resulting temperature increase remains within reasonable limits at the power plant pump inlet. The study, accomplished in three steps, determined the parameters that control the recirculation (e.g. atmospheric conditions) and what their relative importance is. It was shown that a stratification is created in the interior basin. In the main harbour the heat evacuation is done primarily by evaporation in the harbour and only for 20% by the outflow to the open sea. Extreme temperature increases at the pump inlet are expected to be 1,6°C and 6.6°C, but generally the temperature increase lies between 3-4°C. The actual value was found to be most sensitive to the atmospheric conditions.