IEA Solar Heating and Cooling Programm - NachhaltigWirtschaften.at

IEA SHC Task 38 Solar Air Conditioning and Refrigeration Subtask C1 Report, 31 October 2010
Figure 24: Schematic diagrams of different liquid desiccant distributors; channel concept
(upper) and outlet concept integrated into the heat and mass transfer plate (lower). Hublitz
[118].
Another option is to provide cooling through an internal evaporative cooler. In such systems,
as proposed by Saman and Alizadeh [119] and shown in Figure 25, the desiccant and
evaporating water flow on opposite sides of the same wall. The air to be conditioned flows on
the desiccant side. The scavenging air, which can also be the exhaust air from the building,
flows on the water side. These absorbers are potentially more economical and compact than
the water channel cooled varieties. The additional stream of air and the coupled evaporative
cooler, however, make its construction significantly more complex. The additional complexity
comes from building an absorber with two streams of air, one stream of desiccant and one
stream of water, and ensuring no leakages/contamination between the two air streams.
Figure 25: Schematic of an evaporatively cooled absorber. Source: Saman and Alizadeh
[119].
The main disadvantages and challenges of the plate-type liquid desiccant heat and mass
exchanger are:
1. Difficult to construct, especially when internally cooled designs are used in a
“three-way heat exchanger”. Here, a mixing of the different fluids has to be
prevented
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