Exploration And Experimental Research On Air Dehumidification Method Using Electrodialysis

With the rapid development of society and economy, higher request are put forward to the environment temperature and humidity, and air conditioning technology has developed rapidly. Independent humidity control is very important for building and industrial energy-saving, which is widely used in air conditioning and other industrial fields. So it is necessary and urgent to explore a high-efficiency and low energy consuming air dehumidification method. This paper introduced the basic knowledge of electrodialysis, on the base of which an experimental setup was developed to study the performance of electrodialysis regenerator for liquid desiccant. Besides, air dehumidification implementation schemes based on electrodialysis were proposed upon discussion of electrodialysis and direct air dehumidification. Given this research is total new explorations in this field, series of experimental studies are necessary. The detailed results are shown as follows:Firstly, an experimental setup was developed to study the performance of electrodialysis regenerator for liquid desiccant based on the theoretical research of this regeneration process. The results show that the mass-volume concentration of the regeneration chamber will increase with time while that of the diluting chamber will decrease with time. Also, the largest mass-volume concentration difference between regenerated desiccant solution at the entrance and the exit of the ED regenerator is 0.123g/L, and the largest mass-volume concentration difference between regenerated desiccant solution at start and end of the experiment is 0.337g/L. Meanwhile, the largest current utilization of the experimental system of ED regenerator is 55%. Among all flow rate ratios, the current utilization and the mass flow rate of regenerated desiccant solution will be largest with the flow rate ratio of 1:1. Moreover, the current utilization and the mass flow rate of regenerated desiccant solution will increase with the flow rate of desiccant solution.Secondly, two air dehumidification systems using electrodialysis were developed considering the link between basic theory of electrodialysis and the essence of air dehumidification process. And the principles of these schemes were introduced.In addition, an experimental program in order to explore the dehumidification feasibility of electrodialysis applied to air was proposed. Then the test platform was built and a series of experiments were conducted. To analyze the law of motion of the water vapor molecules in the low electric field, the relative humidity of the air at different times at different positions was measured. Based on the results, the experimental system and the improved one of the low pressure air dehumidification was set up. The experimental results show that the influence of the low voltage on the temperature and humidity of air can be neglected. But these experiments provide important ideas and guidance for the study of the following system.Lastly, the experimental system of the proposed high voltage discharge air dehumidification method based on electrodialysis was set up, along with the improved experimental system. The results show that under the condition of high voltage discharge, the humidity of air in discharged electrode increased, which reveal that water vapor molecules can be charged and gathered in discharged electrode. Besides, optimization scheme of this new method was carried out.