Effect of Salt Spray Corrosion on Air-Side Performance of Finned-Tube Heat Exchanger with Hydrophilic Coating Under Dehumidifying Conditions

Abstract

In this study, the effect of salt spray corrosion on the air-side performance of finned-tube heat exchangers with hydrophilic coating under dehumidifying conditions was experimentally investigated. Artificial accelerated method of salt spray corrosion on the hydrophilic coated heat exchangers was used for simulating the corrosion process of the actual heat exchangers. The experimental results show that the contact angles of hydrophilic coated aluminum fins increase with the increase of salt spray corrosion hours, which results in the degradation of hydrophilicity of fins; the heat transfer is enhanced at lower inlet air velocity and degraded at high inlet air velocity for the pitting corroded heat exchanger with hydrophilic coating; compared with the uncorroded finned-tube heat exchanger with hydrophilic coating at the inlet air velocity ranging from 0.5 to 2.0 m/s (5905.5 to 23622.0 ft/h), the effects of salt spray corrosion on the air-side heat transfer coefficient and on the air-side pressure drop are approximately within the range of −20.5%~8.7% and 1.7%~13.1%, respectively.