Corrosion and biofouling of OTEC heat exchangers: IFREMER researches

For the French OTEC program, an experimental study is carrying on to select heat exchangers materials and biofouling countermeasures. Aluminium alloys, stainless steels, titanium are tested comparatively in a marine test station. Test cells with several tubes have been developped to be representative of heat exchangers flow. Influence of mechanical cleaning and chlorination can be evaluated. Corrosion of materials is analysed with visual examination and some electrochemical measurements. Specific devices and analysis methods have been developped in order to measure heat exchange coefficient, bacterial and biochemical composition of slime. These methods allow a better understanding of biofilm settlement. Results obtained in the different fields are presented.