IDCS Dehumidifier Volumetric Air Flow Effect
Figure 5.10 shows the impact inlet air volumetric flow has on dehumidifier performance at a set inlet condition of 30 °C and 60 % relative humidity. Figure 5.10a shows the moisture removal rate increases with volumetric air flow, from 0.2058 g s-1 at 124 m3 h-1 to a maximum of 0.2978 g s-1 at 243 m3 h-1. There is little difference (<0.0116 g s-1) between the moisture removal rate achieved
Fig. 5.10 IDCS dehumidifier performance with inlet air volumetric flow between 217 m3 h-1 (fan setting 2) and 243 m3 h-1 (fan setting 3). Figure 5.10b shows that as the dehumidifier air volumetric flow increases, the change in absolute humidity of the air across the dehumidifier reduces from 0.005146 kgvapour/ kgdryair at 124 m3 h-1 to 0.003594 kgvapour/kgdryajr at 243 m3 h-1. As volumetric air flow increases, a greater mass of air is passed through the dehumidifier, and thus the capacity of the dehumidifier to reduce the air absolute humidity reduces. This relationship is in conflict with the moisture removal rate shown in Fig. 5.10a; this is because moisture removal rate is a function of air mass flow rate. Figure 5.10c shows that as the dehumidifier air volumetric flow increases, the latent (dehumidifier) effectiveness reduces from 68.52 % at 124 m3 h-1 to 37.35 % at 243 m3 h-1. Figure 5.10d shows the dehumidifier cooling output increases as the volumetric air flow increases, from a minimum of 613 W at 124 m3 h-1 to 1065 W at 243 m3 h-1. This is primarily due to a larger volume of air being conditioned.
The selection of an appropriate volumetric air flow in the dehumidifier is dependent upon the application and the desired supply air condition. However, in a tri-generation system it will be advantageous to operate the dehumidifier at the highest volumetric air flow in order to maximise the cooling output, and thus tri-generation efficiency. Across all dehumidifier tests, the maximum calculated relative uncertainties in the dehumidifier MRR, Aa>, nL and Qcooung are ±15.98, ±15.1, ±12.47, and ±15.04 % respectively.
Next, Sect. 5.3.1.3 provides the dehumidifier component evaluation conclusions.
