Experimental and theoretical research on the current efficiency of the electrodialysis regenerator for liquid desiccant air-conditioning system using LiCl solution

Abstract

The liquid desiccant air-conditioning system conducts air dehumidification with liquid desiccant and is proposed as an alternative to the conventional vapor compression cooling system. The electrodialysis regeneration is suitable for the liquid desiccant, whose most important performance index is the current efficiency. In order to improve theoretical models of the liquid desiccant air-conditioning system based on ED regeneration, the current efficiency correlation of the ED regenerator is acquired based on several experiments and its effect on the system performance is researched in this paper. Current efficiencies of the ED regenerator in the experiment are among 20% and 70%. The increase of the concentration difference between regenerate and dilute desiccants, the operational current and the liquid desiccant concentration at the entrance of regenerate cells of the ED regenerator will all decrease the current efficiency. When the liquid desiccant concentration at the entrance of regenerate cells of the ED regenerator varies from 27% to 35%, the system performance coefficient increases from 4 to 6.2. The increase of the liquid desiccant concentration at the entrance of regenerate cells is harmful to the performance of the ED regenerator but beneficial to the performance of the whole system.