Enhancing Performance of an Air Conditioner by Preheating and Precooling of Liquid Desiccant and Non-processed Air

Abstract

Corrosive fluids such as lithium chloride are often used in liquid desiccant air conditioners. Corrosion in enthalpy exchanger is one of the design problems. Some solutions are studied in this research, and based on them; an experimental setup is investigated. In this design, a counter-flow enthalpy exchanger is used to exchange moisture between the air and the liquid desiccant. First, the inlet air is preheated or precooled by an aluminium heat exchanger. Then, the liquid desiccant is preheated or precooled by thin-walled plastic tubes. By contacting this processed air and liquid desiccant, heat, and mass exchanging occurs. The variation of the air moisture content is investigated in laboratory conditions, and the rate of regeneration and dehumidification is studied. The results indicate that in general, the ambient air moisture content decreased around 20% during the dehumidification process and it enhanced around 14.28% during the regeneration process. Furthermore, the moisture content variation in the dehumidification process improved at least 9.92%, but the regeneration process decreased at least 10.76% compared to the previous study. In addition, utilizing the particle swarm optimization algorithm is desirable to identify the system's transient behavior and obtain the fitting parameters of a curve that is closely similar to the experimental data of the rate of dehumidification and regeneration and the average errors of the fitted curve were 10.43 and 1.52%, respectively.