An experimental study of structured packing dehumidifier/regenerator operating with liquid desiccant

The present work presents an experimental investigation on the performance of the structured packing cross flow desiccant dehumidification system (DDS). This system is referred as DDS; its heart is the dehumidifier/regenerator. It is used to meet a latent heat load by air dehumidification. Calcium chloride (CaCl2) solution is used as the working desiccant material in this system. The structured packing has a density (specific surface area) of 390 m2/m3, corrugation angle of 60° and void fraction of 0.88. The effect of relevant parameters such as air flow rate, desiccant solution flow rate, desiccant solution temperature and concentration and packing thickness on the performance of the system is studied. The performance of the system is evaluated using the mass transfer coefficient, moisture removal rate (MMR), effectiveness and the coefficient of performance (COP). The remarkable increase of mass transfer coefficient and MRR for both deh/reg is observed by increasing both air and solution flow rates. Eventually, the payback period (PP) of the DDS is 11 months with annual running cost savings (ΔCRC) of about 31.24% compared with vapor compression system (VCS) dehumidification. The overall environmental impacts of DDS are nearly 0.63 of VCS. This may emphasize the need of incorporating a desiccant system along with air conditioning applications.

► A structured packing cross flow desiccant dehumidification system (DDS) is designed and experimentally tested.
► Increasing both air and desiccant solution flow rates will increase the mass transfer coefficient and MRR for DDS.
► The payback period (PP) of the DDS is 11 months.
► The DDS annual running cost savings (ΔCRC) are 31.24% compared with vapor compression system (VCS) dehumidification.
► The overall environmental impacts of DDS are nearly 0.63 of VCS.