The Design And Experimeatal Research Of Semiconductor Refrigeration In Air Gap Membrane Distillation Modale

As a new water（Brackish water）desalination technology，Membrane distillationtechnology rely solely on the temperature difference both sides of microporous polymer filmso that the volatile components through the membrane pores，to achieve the concentration,separation purposes。In the membrane module，flux depends on the temperature differencebetween the surface of the steam and cooling，usually the lower the cold junctiontemperature or the higher processing temperature of the hot end solution, the greater itsmass flux. Given advantages of semiconductors, like that rapid cooling, noise, etc., toreplace the circulatory system used cold refrigerator of the membrane distillation system, itcan greatly simplify the structure of the membrane distillation system dilute brackish water.This paper designed a new type of semiconductor refrigeration membrane distillationsystem, took the semiconductor refrigeration cold cavity and the membrane distillationsystem heat cavity combining organic. studies have shown that： The cold cavity ofsemiconductor refrigeration membrane distillation system to achieve stability in4minutes,cooling rapidly; The temperature difference between the cooling surface of each measuringpoint was maximum only0.5℃, the cooling surface temperature uniformity; When thesemiconductor input power was smaller, the semiconductor input current affected theperformance of semiconductor refrigeration. When the semiconductor input high power, thefactors affected the performance of semiconductor refrigeration in addition to thesemiconductor input current as well as the cooling intensity of hot side of the semiconductor;The averaged flux growth of the unit temperature hydrothermal was1.8g/℃, the averagedflux growth of the unit input current was only0.6-0.8g/A, hydrothermal temperature wasthe main factor affecting the membrane flux; When the hydrothermal temperature increases,the input voltage of the semiconductor was lower.Analyzed and calculated the energy consumption of the semiconductor refrigerationmembrane distillation system. Semiconductor cooling performance and membrane fluxincreased sharply with hydrothermal temperature in high temperature hydrothermal regions,but blindly increased the temperature of the hydrothermal system would bring additionalenergy consumption; The trends of flux and energy consumption of per ton of water wassame at the same hydrothermal temperature; when the hydrothermal temperature was75℃ and the input current increases8A to12A, energy consumption of per ton of water wasalmost linear growth, the incremental of energy consumption would remain at8.5%.Determined the optimal coupling conditions of semiconductor refrigeration matchedmembrane distillation system.This study laid the foundation for theoretical and applied research of smallsemiconductor refrigeration air gap membrane distillation system. Proposed two evaluationcriteria，from the criteria we could find a larger membrane flux conditions did notnecessarily have a better economy.