Exergy analysis of a solar regenerated liquid desiccant assisted air conditioning system for hot and humid climates

Abstract

In this paper, exergy analysis of a novel solar powered liquid desiccant assisted air conditioning system is presented and simulated. The system aims to provide suitable thermal comfort conditions inside large office buildings with high internal loads situated in the hot and humid tropical/subtropical countries of the world. The system consists of process and regenerating air streams, a liquid desiccant solution loop and a cooling water loop. The primary objective of this study is to present the exergy of cooling capacity along with the overall exergy efficiency of the proposed system. The study helps to quantify the optimum operating and design parameters for system operation based on the second law of thermodynamics. For the base case, which is representative of a hot and humid climatic condition, the proposed system is able to maintain the room air conditions within the moderate thermal acceptability criterion. The exergy of cooling capacity and exergy efficiency for the base case is about 2900 W and 2 % respectively. Parametric analyses show that the system performs the best under conditions of high ambient insolation and temperature, low ambient humidity and a process air to desiccant solution mass flow rate of about 3 in the dehumidifier.