Hydrodynamic and thermal evaluation of fouling mitigation in hydrogenerators heat exchangers

Paper presented at the 8th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Mauritius, 11-13 July, 2011.The effectiveness of a mitigation technology for undesired formation of mineral inlay (fouling) and biological material (biofouling) in the plate heat exchangers of the bearings refrigeration system in the hydrogenerators of the power plant "Fontes Nova" (Rio de Janeiro, Brazil) was studied. These incrustations change the thermal and hydrodynamic characteristics of the system due to the increase in the pressure drop and the drastic reduction of the thermal effectivity of the heat exchangers. The technology that was object of the study "excites the flow" because of the appli-cation of an electric field generated by an electronic device. To evaluate the effectivity of the mitigation method, the plate heat exchangers was instrumented. Water quality is also studied to analyze the environmental impact and the need to explain the undesired mechanism of biofouling.pm201