An ion mass transfer model of electrodialysis regenerator for inorganic salt liquid desiccants

Abstract

The solution dehumidification air-conditioning system shows great energy-saving potential in humid area, which is significant to the energy consumption in buildings as air-conditioning costs more than half energy in buildings under this climate. The electrodialysis regeneration is suitable for liquid desiccant in humid area as this method needs no heat and mass transfer with environmental air, and the heating and cooling of liquid desiccant are also not needed in this regeneration approach. In order to improve the mass transfer coefficient in electrodialysis regenerator, the ion mass transfer mechanism of liquid desiccant with ultra-high concentration is investigated in this paper. An ion mass transfer model of electrodialysis regenerator for inorganic salt liquid desiccant with ultra-high concentration is established based on the Nernst-Plank equation, which can be solved by the finite difference method. The current coefficient model is corrected and the accuracy of the ion mass transfer model of electrodialysis regenerator is verified by the experiment. Theoretical research shows that when the dehumidification requirement is met, the initial solution concentration, operating current and circulation flow rate should be reduced to achieve better performance of solution dehumidification air conditioning system.