A New Viewpoint to Studying the Condensate Retention and Drainage Process on Air Cooling Coil

Normally simultaneous air cooling and dehumidification takes place in an air cooling coil. The condensate accumulated on the cooling coil surfaces could significantly affect its thermal and hydraulic performance. The condensate retention and drainage has bee usually regarded as a static process. The total mass of condensate retained was viewed as being influenced by the balance among gravitational, air flow drag forces and surface tension retaining force only. With fixed geometric and surface characteristics and under a constant air Reynolds Number, a cooling coil was therefore considered to have a fixed amount of condensate retained. However, some researches pointed out that the total mass of condensate retained could be influenced by system operating parameters such as temperature and moisture content of inlet air. A previously related study by authors developed a mathematic model and considered this process as being a dynamic but without giving a detailed discussion. In this paper, through a further analysis of data obtained in the previously study, a new viewpoint on condensate retention and drainage process has been suggested in order to better explain the experimental results and to provide a base for proposing some future related research work.