The water vapor content in the exhaust of thermal power plants is huge

using membrane to recover the water vapor from flue gas may be a new way to save water for thermal power plants

because it has several advantages

such as simple system

high quality of recycled water

great separation factor

able to be standardized manufactured and modularized installation.This paper prepared a kind of hollow fiber membrane named PES-SPEEK56

and studied its performance of water recovery under conditions with different flue gas temperatures

velocities and water vapor activities.The results show that

the permeability coefficient performed better than the permeability flux when evaluating the membrane performance.The permeability coefficient increased with the flue gas temperature ranging from 54℃to 70℃

but it changed little when the flue gas temperature increased to above 70 ℃.An increase in flue gas velocity(0.1m/s to0.6m/s)was beneficial to the increase of the permeability coefficient

but would reduce the recovery rate.The increase of the water vapor activity decreased both the permeability coefficient and the recovery rate.Calculation for a 600 MW unit indicates that

using this method to recycle the water vapor form the flue gas has a low investment cost and large recovery rate

and can effectively alleviate the chimney's corrosion problem

which has a great application prospect.