Experimental Study on Two-reactor Silica gel-water Adsorption Desalination System Using Low-temperatures

In this study, a two-reactor model was designed and tested to investigate the silica gel-water adsorption desalination system. We found that the present two-reactor model adequately elucidates the possibility of using an adsorption desalination system just as the single-reactor model does. The two-reactor model system has been developed to exploit low temperature sources such as solar thermal energy and waste heat. Our work was mainly aimed at improving the energy conversion efficiency harnessing solar thermal energy for cooling and desalination. This reduced energy loss and hence improved the energy conversion efficiency. This paper focuses on the two-reactor silica gel-water adsorption desalination technology. This system has four chambers. Plate fin heat exchangers were adopted as evaporator, two-reactor and condenser. In this study, temperature conditions were 70 to 80℃ (hot water), 10 to 20℃ (cool water), and 20 to 30℃ (tap water inlet). The pressure was 15torr. A parametric analysis is presented in this study where the effects of inlet temperature, adsorption/desorption cycle time and switching time are reported in terms of cooling capacity and coefficient of performance. The results confirm that this kind of adsorption desalination system is an effective cooling and desalination machine though its performance is not as fine as was predicted. Also, it is effectively driven by a low-grade heat source. Therefore, its applications to the low-grade heat source are much attractive. And it can be concluded that the two-reactor model can lucidly explain the adsorption desalination system scheme just as the single-reactor model. In addition the production time of a two-reactor model is much shorter than that of a single-reactor model. This facilitates the rapid mass production of freshwater. Therefore the two-reactor model can be reliably used to predict the performance and provide useful information for the design of adsorption desalination system.