International Journal of Engineering and Technology

The humidification–dehumidification process (HDH) is a thermal technique adapted for water desalination. This technique has many advantages such as moderate installation, simplicity and operates at relatively low temperatures when compared with other commercial thermal processes. HDH process is perfectly suitable for the decentralized areas where a small-scale desalination technology uses renewable resources of energy. The aim of this paper is to present the experimental analysis of the process providing the principle of functioning and the characteristics of the process when a different key variable such as air flow rate and humidifier inlet water temperature is altered. The experiment designed, installed and operated where air flow rates tested at constant humidifier inlet water temperature. To study the influence of air flow rate variation on the system, several experimental runs are implemented at different air flow rates at constant inlet water temperature. The experiments are repeated where humidifier inlet water temperature is changed. The system evaluated after steady state operation within one hour, and the production is collected. Finally, the system analyzed to find the effect of air/water flow ratio on the system productivity, humidifier mass transfer coefficient and dehumidifier overall heat transfer coefficient. Moreover, the sensible heat from the humidifier inlet water is studied as the analysis includes the inlet water temperature effect on the process. The system best results obtained at the maximum tested air flow rate where the GOR was 0.22 and the production cost of 0.043 US$/liter.The highest productivity of the system found to be 5.424 l/hr at 50 oC humidifier inlet water temperature. The general outcome of the study provides that HDH desalination process is more favorable towards increasing the air flow rates and humidifier inlet water temperature where the mass transfer and overall heat transfer coefficients also increased. The system optimized for best economic and operating conditions.