Numerical investigation of condensation characteristics of a moist air-to-air plate-fin heat exchanger and experimental validation

•Numerical investigation of condensation characteristics is carried out.•The change of mcond can be divided into three stages as t mdry, increases.•The surplus potential of condensation (δ) is proposed and it is more affected by cooling air side.•Some operation strategies were proposed for the dehumidification under high temperature and high humidity. The purpose of this study is to investigate the condensation characteristics of a moist air-to-air plate-fin heat exchanger (PFHE) used for dehumidification under high temperature and high humidity. A numerical simulation model of a PFHE was developed and an experimental system was established. Good agreement was observed between predicted and experimental data from two types of PFHEs with different fins. The effects of the operating parameters of both moist air side and cooling air side on the condensation characteristics of the PFHE were discussed in detail. The surplus potential of condensation (δ) is more affected by cooling air side especially the mass flow rate of cooling side (mca). When mca = 0.09 kg/s and mca = 0.03 kg/s, δ respectively changes from 0.625 to 0.919 and from 0.780 to 0.980 as the increase of the mass flow of dry air. Multiple operation strategies for energy saving of heat exchangers were proposed for the dehumidification process under high temperature and high humidity.