چكيده به لاتين
Today, the issue of providing fresh water and energy is two fundamental challenges facing the world. In recent decades, various technologies for desalinating saline water have been developed. This research focuses on a fresh water desalination plant that operates using the humidification-dehumidification (HDH) method, which is considered one of the most efficient methods among various desalination techniques for use in areas with moderate demand for fresh water, while having the least fossil energy consumption and environmental impact. In the examined system, saline water is first preheated by recovering thermoelectric heat and passing through a thermoelectric hot surface, and then it is sprayed into the packed bed humidifier. Additionally, air is heated by passing through a solar air heater and is blown into the packed bed humidifier, creating humid air. The humid air condenses by passing through a cold thermoelectric surface, producing fresh water that is stored in a tank. By developing a mathematical model of the designed system, the behavior of operational parameters and the impact of changes in parameters (including temperature and mass flow rate of the input saline water, type of packing used, model and number of thermoelectrics, length of the collector, and solar radiation intensity) on the amount of produced fresh water, efficiency, and output gain ratio (GOR) were examined. Furthermore, to optimize the design and evaluate the effectiveness of the system, the effect of the solar air heater and the addition of recovering waste heat from the thermoelectric on the performance of the designed HDH system were investigated. The results obtained from modeling in the EES software indicated that the amount of fresh water production depends on the parameters of solar collector length, solar radiation intensity, mass flow rate of input saline water, number of installed thermoelectrics, and temperature of the input water and air, while the mass flow rate of the input air has an inverse relationship. Additionally, metal packing results in the highest amount of produced fresh water. By use a solar air heater, the amount of produced fresh water in the system increases, and the GOR of the system decreases. Conversely, if waste heat recovery from the thermoelectric is utilized, both the amount of produced fresh water and the GOR of the system increase.
