Dehumidifier Inlet Air Velocity Effect
Figure 3.17 presents the effect varying the inlet air velocity has on the performance of the dehumidifier. The investigated range of inlet air velocity in each channel is 0.7-2.5 m s-1, this equates to a volumetric air flow range of 111— 397 m3 h-1 through the whole dehumidifier. Figure 3.17a demonstrates that as the air inlet velocity increases the difference in the air absolute humidity difference reduces, however, the cooling output increases. With constant dehumidifier geometry, as the inlet air velocity increases it means a greater mass of air is passed through the dehumidifier, and thus the absolute humidity of supply air is higher. However, the cooling output increases because there is a greater mass of conditioned air. Figure 3.17b demonstrates that increasing the inlet air velocity from 0.7 to 2.5 m s-1 reduces both the latent and enthalpy effectiveness from 77.03 and
Fig. 3.17 a, b Inlet air velocity effect on the dehumidifier performance
78.82 to 21.57 and 23.49 % respectively. The desiccant solution outlet mass concentration remains constant.