Improving air conditioning efficiency using solar-assisted liquid desiccant systems : experimental and simulation analysis of two desiccants

Abstract

As energy demand escalates and the necessity for sustainable cooling solutions intensifies, green air handling systems emerge as promising alternatives to conventional air conditioning technologies. Liquid desiccant air conditioning systems offer considerable potential; however, challenges such as high energy consumption for desiccant regeneration and limited application scopes hinder their broader adoption. This study presents a solar-assisted liquid desiccant air conditioning system (SRLDAC) incorporating internally cooled and heated liquid desiccant technology as a pre-treatment component for air handling units, aiming to enhance system efficiency and expand its applicability. Through comprehensive experimental and simulation analyses, the technical and energy performance of two desiccants, lithium chloride (LiCl) and a deep eutectic solvent (Ethaline) are evaluated. The results demonstrate the system's capability in effective dehumidification and thermal load management. Ethaline shows slightly higher COP under certain high-flow conditions, but requires higher regeneration temperatures, leading to distinct operational trade-offs. The design achieves a solar fraction (SF) exceeding 1, peaking at 1.83, signifying exceptional solar energy utilization. Additionally, the LiCl system achieves a superior gained output ratio (GOR) of 5.5. This study underscores the energy performance benefits of solar-assisted liquid desiccant systems and their potential for sustainable cooling.