Environmental Engineering Reference
In-Depth Information
55
(a)
Crystal
line
ξ
= 60%
55%
50%
50
45%
ξ
= 40%
45
40
35
20%
40%
60%
80%
30
ϕ
= 100%
Isoconcebtration line
Iso-
25
ϕ
line
20
0
0.01
0.02
Humidity ratio/(kg/kg)
0.03
0.04
0.05
55
(b)
Crystal
line
40%
ξ
= 50%
50
30%
ξ
= 20%
45
40
35
20%
40%
60%
80%
30
ϕ
= 100%
Isoconcebtration line
Iso-
25
ϕ
line
20
0
0.01
0.02
Humidity ratio/(kg/kg)
0.03
0.04
0.05
Figure 16.2.3
Status of the commonly used liquid desiccants (absorbents) in the psychrometric chart:
a) Lithium Bromide (LiBr); b) Lithium Chloride (LiCl) (Liu et al., 2010).
16.3 SOLID-BASED SYSTEM
16.3.1 Basic concept
Solid desiccant air-conditioning systems are primarily based on the application of solid-
based desiccant materials in controlling air moisture content. The sorption mechanism
in the solid material is either through absorption or adsorption. Cooling by means of
heat recovery, evaporative cooling or other means is applied to the system.
The design of the system is based on the fixed-bed type in alternative operation
of moisture sorption and desorption. When the encapsulated phase change materials
(EPCM) in the desiccant bed are applied, this absorbs the heat of sorption released
during the dehumidification process and lowers the air temperature. However, its
humidity is higher compared to the pure desiccant (Rady et al., 2009). For building
Search WWH ::
Custom Search