Solar-desiccant air-conditioning systems - Solar Energy Sciences and Engineering Applications - page 523

Figure 16.4.1 Schematic diagram of the open-cycle liquid desiccant air-conditioning system either with
packed bed tower, spray tower or wetted wall column ( Jain and Bansal, 2007).
for non-isothermal conditions, with the introduction of cooling water flow equations.
Figure 16.4.1 shows the schematic design of the absorbent dehumidifier/regenerator.
16.4.3 Modified systems
Thermo-chemical storage is an option when the available source of thermal energy is
not in phase with cooling/dehumidification demand. With this scenario, conventional
energy usage can be reduced. Kessling et al. (1998) shows that the absorbency of hygro-
scopic salts such as LiCl and CalCl 2 is up to more than three times greater in energy
storage than other adsorbents such as zeolite and silica gel. The schematic diagram
in Figure 16.4.2 shows that the high storage capacity is based on the concentration
between the strong and diluted salt solutions. Furthermore, Miller (1983) reported that
energy storage via absorbents was competitive with phase-change materials, rock-bed
storage and water systems.
16.4.4 Hybrid systems
Hybrid installation of open-cycle liquid desiccant air-conditioning systems is used to
increase system performance. A two-stage open-cycle liquid desiccant air-conditioning
system with CaCl2 and LiCl has a COP and exergy efficiency of 0.73% and 23.0%
compared to the basic open-cycle liquid desiccant air-conditioning system (Xiong et al.,
2010). Figure 16.4.3 shows a multi-stage open-cycle liquid desiccant air-conditioning