Study Of Solar Energy Membrane Distillation In Seawater Desalination Process

The energy crisis and the shortage of fresh water resources have become an important factor in the development of human society. This project studied over solar energy collector technology and membrane distillation desalination technology, realized the use of solar energy in desalination. Offered a new choice for off-shore platforms and reefs where water supply was decentralized.This paper proposed a new type of solar energy collector tube. The collector tube used the impetus which was formed by the density difference between the different areas of the collector tube to push the seawater flow in the membrane distillation system equipment. And we designed a self-driven experiment device of solar membrane distillation for seawater desalination according to the theory. Firstly we studied the effect of solar illumination, mass flow and inlet seawater temperature on the outlet seawater temperature. Proposed a computer simulation method of CFD for the new type of solar energy collector tube, and observed the seawater flow distribution and temperature distribution in it. Then we did some structure optimization for the collector tube. The outlet temperature increased about 2.3 ℃ after the optimization. After that, we studied the effect of solar illumination and mass flow on membrane freshwater flux of the whole system. The results showed that the maximum of membrane freshwater flux has an appropriate mass flow in a certain solar illumination. At last we researched the effect of wetted-wall on the temperature difference of the membrane and the membrane freshwater flux. The results showed that we can increase wetted-wall in the membrane module to strengthen the process of the membrane distillation. The largest membrane freshwater flux reached 232 g/m2·h under appropriate condition after increased the wetted-wall.