Pressure drop modeling and performance optimization of a humidification–dehumidification desalination system

Abstract

In this study, the thermodynamic and pressure drop models of the humidification–dehumidification (HDH) system are developed and verified by the experimental results. The effect of operating parameters on the system performance is investigated. The parametric analysis indicates that the optimum point of the energy efficiency may appear in some cases. The pressure drop in the system increases with the air and liquid mass flow rates and the liquid top temperature. The influence of electric consumption on the system overall performance is evaluated from the different point of view (energy and exergy). In terms of energy consumption, the proportion of electric consumption in the total energy consumption is small with an average of 9.9%. The effect of electric energy consumption is negligible in many cases. In terms of exergy consumption, the average proportion of electric consumption is 29.4%, and the highest is 40.6%. The electric energy consumption has significant influences on the overall energy efficiency. Furthermore, numerical optimization is performed to achieve the minimum specific exergy consumption (SEXC). It can be concluded that, in the performance optimization of the HDH system, the priority is to adjust the liquid mass flow rate and liquid top temperature. The minimum values of the optimized SEXC are 222.0 kJ/kg.