Performance Study on Dehumidifier of Packed bed Liquid desiccant System


1 Department of Mechanical Engineering, Nour Branch, Islamic Azad University Nour, Iran

2 Faculty of Mechanical Engineering, K.N.Toosi University of Technology, Tehran, P.O. Box: 19395-1999, Iran

3 Faculty of Mechanical Engineering, slamic Azad University, Branch of Nowshahr, Nowshahr, Iran


Liquid desiccant evaporation cooling air conditioning system introduced in this paper. The dehumidifier and regenerator play the most important role in this system. For liquid-gas contact, packed towers with low pressure drop provide good heat and mass transfer characteristics for compact designs.The experimental data have been obtained from a built prototype of liquid desiccant system in a packed bed unit with a surface area per unit volume ratio of 125 m2/m3, the liquid desiccant ,viz lithium chloride. The result showed that the mean mass transfer coefficient of the packing dehumidifier was 0.02kg/ m2s Also the absorber characteristic parameter, the packing size or number of transfer units (NTU), and air-to-desiccant solution mass flow rate ratio (ASMR) are crucial parameters. These parameters are affected to humidity effectiveness and enthalpy efficiency, are introduced and defined in this paper. High efficiency could be achieved if proper values of these variables are selected. In this studyenthalpy efficiency from experimental results has been comparedwith theanalytical computation result based on optimumASMR. From analytical solution, an optimum mass flow rate ratio can be deduced for optimal design of both dehumidifiers and regenerators, but in this studybehavior of the absorberhas been considered.