Efficient Biofouling Inhibition in Seawater Heat Exchangers by Novel Sol-Gel Coatings

There is a critical need to mitigate undesirable fouling formation on seawater-based titanium heat exchangers used in US Navy vessels.  Heat exchangers are widely used in Navy ships to cool operating fluids and seawater is the preferred cooling medium since it is readily available. However, fouling will form while ocean water circulates through the heat exchanger tubes or plates, decreasing the heat transfer efficiency and increasing fluid resistance. Further fouling eventually results in the consumption of more energy and a decrease in heat exchanger service life. To solve the fouling problem, Luna will improve the antifouling and fouling release coatings that were developed in Phase I and that proved to be excellent candidates for heat exchanger application. The objective will be to identify the optimum balance between antifouling and fouling release efficiency and durability for final demonstration in a 200-ton chiller/condenser unit. The best coating candidate will be selected through a systematic evaluation that will demonstrate its efficiency to prevent biofouling accumulation in titanium seawater heat exchangers at both static and dynamic conditions, the latter will be important to test the erosion resistance of Luna’s coating to ensure long term durability. In addition to biofouling prevention, Luna’s solution will eliminate the need for expensive chlorination systems and increase maintenance intervals.