Experimental investigation and effectiveness analysis of a desiccant wheel dehumidification system with low air humidity

The desiccant wheel dehumidification system is a feasible approach to realize the deep-dehumidification process to produce supply air with dew point temperature below 0 °C in modern architecture fields. However, actual dehumidification performance of the desiccant wheel system under low humidity condition and its difference from normal humidity dehumidification process have not been experimentally demonstrated. This study, therefore, carried out experiments to investigate the dehumidification performance as well as the thermodynamic effectiveness of the desiccant wheel deep dehumidification system. The results reveal that the desiccant wheel dehumidification system show relatively higher relative dehumidification capacity under low inlet process air conditions, reaching 77.4% under the regeneration air state of 75 °C and 4 g/kg by supplying air humidity under 1 g/kg. The sensitivity of dehumidification performance varying with regeneration humidity is reduced when the desiccant wheel is operated at high regeneration temperature. The deep dehumidification process also shows much greater isenthalpic deviation and surplus temperature deviation than normal dehumidification process due to larger irreversible heat loss, and the thermodynamic effectiveness is also highly related to the regeneration parameters. The study provides theoretical and experimental reference for the effective and efficient design of the desiccant wheel assisted deep dehumidification system.