An equipment, with a plate heat exchanger, for testing seawater side fouling was operated for an extended period using seawater as the cooling heat source. The degradation of seawater side heat transfer performance with seasonal changes in seawater temperature was compared and examined. The following results were obtained: 1) The overall heat transfer coefficient decreased by 21.2% in winter and 21.9% in early summer compared to that at the start of the experiment. No significant difference was observed under the investigated experimental conditions. 2) The percentage increase in differential pressure was larger than that in overall heat transfer in both winter and early summer but the difference was still only a few kPa. 3) The estimated wall temperature at the seawater side was suitable for biological fouling in all seasons. 4) The fouling factor 30 days after the start of the experiment was 6.104×10^{-5}m^2 ・ K/W in winter and 7.01×10^{-5}m^2 ・ K/W in early summer.
Plate type heat exchanger
Biofouling
Overall heat transfer coefficient
Fouling factor
Sea water