Performance Evaluation of a Two‐Stage Humidification‐Dehumidification Desalination Process

ABSTRACT This article conducts study on the performance evaluation of two configurations of a solar‐powered two‐stage humidification‐dehumidification (HDH) desalination system using a parabolic trough collector (PTC). The system includes the simultaneous heating of both air and seawater (feedwater), aiming in heat and mass transfer enhancement and improving overall productivity. A thermodynamic model was developed to simulate the behavior of the system under different operating conditions, including heat transfer fluid (HTF) flow rates, feedwater temperature, and salinity. Configuration I employed air heating before the first stage, while Configuration II introduced air heating between the two stages. Main findings reveal that Configuration II achieved superior performance over Configuration I, with a maximum freshwater productivity of 70 kg/h and a gain output ratio (GOR) of 0.88, whereas it was 50 kg/h and a GOR of 0.84 in Configuration I. The study also shows the influence of air characteristics and feedwater parameters on system efficiency, enlightening the optimal design strategies for solar‐driven HDH desalination units. These results demonstrate the potential of dual‐heating configurations to improve the feasibility of sustainable water production in arid regions.