Optimal operating conditions and configurations for humidification–dehumidification desalination cycles

This article applies nonlinear programming techniques to optimize humidification–dehumidification (HD) desalination cycles for operating conditions that result in maximum gained output ratio (GOR). Closed air open water as well as open air open water cycles, each with either an air or a water heater, were considered in this analysis. Numerical optimization resulted in a substantial increase in GOR for all four cycle types compared to previous best-case conditions found using heuristic studies. The GOR of the cycles was found to decrease with increasing component terminal temperature difference (TTD). In addition, different cycles perform best at different temperature differences. Optimization also revealed that some counterintuitive design configurations can result in superior performance under the appropriate operating conditions.