Study on the Air-Side Fouling Characteristics and Repeated Cleaning Performance of Finned-Tube Heat Exchangers Based on Fin types

This study analyzed the pressure drop characteristics of finned-tube heat exchangers, a key component of EHP systems, during repeated cycles that included fouling acceleration, cleaning, and air-blowing drying. Each cycle consisted of 60 minutes of fouling acceleration under 1.5 m/s conditions, followed by 10 minutes of cleaning and 30 minutes of drying, and was repeated three times. The pressure drop characteristics were compared based on fin spacing and fin shape. The results indicated that for a fin spacing of 16 FPI, which is relatively narrow, the pressure drop increased more significantly during fouling acceleration with each cycle, and the recovery rate of the pressure drop after cleaning was lower. While the pressure drop for louvered fin heat exchangers remained elevated during the initial phase of fouling acceleration, corrugated fin heat exchangers exhibited a sharp increase in pressure drop near the end of this phase. Additionally, the rate of pressure drop increase after cleaning was higher for louvered fin heat exchangers. Regardless of fin spacing and shape, it was observed that as the cycles were repeated, residual particles on the surface formed aggregates, leading to a gradual increase in pressure drop, which was particularly pronounced during the third cycle.