A novel cycle for adsorption desalination system with two stages-ejector for higher water production and efficiency

In this paper, a novel hybridization between adsorption desalination cycle and two ejectors is proposed to increase the freshwater productivity by several folds. Silica gel/water is used as a working pair for this integration. The proposed hybrid system, donated as AD2EJ, has two sorption beds, two evaporators, two condensers, and two ejectors. Performance of the hybrid cycle is evaluated numerically in terms of specific daily freshwater production (SDWP) and Coefficient of Performance (COP). Mathematical models of the adsorption desalination cycle and ejectors are validated. The numerical results reveal that the optimal half-cycle time is about 400 s, at which the SDWP of the AD2EJ system is calculated as 23.0 m(3) per ton of silica gel at a COP of 1.64 using a regeneration temperature of 85 degrees C. This amount of freshwater is 3 times higher than that of the basic adsorption desalination system (ADS). Further enhancement is achieved by linking the condenser and evaporator of the AD2EJ cycle via an internal heat recovery circuit. The SDWP of this system (AD2EJ-HR) is found to be 79.4 m(3)/ton at a COP of 2.22 at a regeneration temperature of 95 degrees C and 400 s half-cycle time.