Bioencrustration in the turbine cooling system at the funil hydroelectric power plant, Itatiaia, Rio de Janeiro, Brazil

Resumo

In May 2006, biofouling was found in water-cooling system of generating units at the Funil Hydroelectric Plant, state of Rio de Janeiro. This caused a perceptible decrease in heat exchanger efficiency and a consequent increase in temperature of the bearings. Encrusting biological material was found to be colonies of the euryhaline hydroid Cordylophora caspia (Pallas, 1771). Under normal operating conditions of the electricity-generating turbines, radiators are cleaned every six years and heat exchangers of the turbine guide bearing are cleaned every 18 months, according to reports of the technical team. After fouling was discovered, clogging problems in heat exchangers began to occur four months after cleaning, with a consequent increase in temperature of the system. The situation appears serious and has led to high maintenance costs and downtime, sometimes for extended periods, of equipment and generating units while the system is cleaned. Key-words: Cordylophora caspia, fouling, Hydroelectric Plant, Funil Hydroelectric Power Plant, Rio de Janeiro