A novel double-stage membrane regeneration method for absorption air-conditioning system

Abstract

The air-conditioning system, a huge energy consumer, must be more energy conservative and environment friendly for greener buildings. Absorption air-conditioning system is an idea option except for its low performance caused by the thermal regeneration method. That can be improved with the membrane regeneration based on electrodialysis method. However, single-stage membrane regeneration is unstable and inefficient when the concentration difference is high. Double-stage membrane system can solve the problem. Theoretical and experimental work has been done about double-stage system: Models have been developed based on the mass and energy balance equations. Analysis has been made on some influential parameters. Experiments have been conducted to test the true regeneration performance. It has revealed the influences of the solute concentration, voltages and the transferred solute mass. The experimental results show double-stage system could be a better choice as the concentration difference decreases in regenerators. Under some conditions, the maximum coefficient of performance (COP) of double-stage system can as high as 3.