Based on the aforementioned assumptions, the packed bed is divided to some smaller elements which are shown in Fig. 1. Each AZD1283 will be small enough that the air and water properties supposed to be constant within the element and also following the assumptions could be used in modeling streams in any element.-Temperature and humidity of air stream (Tg, ω) in any element change only in the horizontal direction (in air flow direction).-Water temperature and flow rate (TL, L) in any element change only in the vertical direction (water flow direction).
As schematically shown in Fig. 2 air and water streams pass adjacent to each other separated with interface area. If dv denotes the volume of each element and a represents the specific area of the packed bed, then the heat transfer area for each element is equal to adv. Therefore, heat and mass balance equations can be written and solved for each element as a control volume.
Fig. 2. A small element of humidifier.Figure optionsDownload full-size imageDownload as PowerPoint slide