Heat transfer and pressure drop characteristics of wet air flow in metal foam under dehumidifying conditions.

In the present study, the heat transfer and pressure drop characteristics of wet air flow in metal foam were experimentally investigated, and were compared with the airside characteristics in conventional fin-tube heat exchanger with the same size as that of metal foam. The research results show that, as the relative humidity of inlet air increases from 50% to 90%, the total heat transfer rate increases by a maximum of 67%, and the pressure drop increases by 62%; as the inlet air temperature increases, the heat transfer rate and pressure drop increase; when the pore density of metal foam increases, the pressure drop always increases, while the heat transfer rate initially decreases slightly and then increases due to the influence of condensate water; the total heat transfer rate and pressure drop decrease with the increase of cooling water temperature. Compared to the louvered fin and tube heat exchanger with the same size, the heat transfer capacity of copper foam heat exchanger is enhanced by 56%~196%under dehumidifying condition, and mass transfer rate is increased by 125%.