Numerical Investigation On Heat And Mass Transfer Characteristics Of Salt Water Falling Film With Air Counterflow Contacted

Inorder to adapt the condition of the urgent of water resources which is now a global energy crisis.this text endeavor in investigating the water conservation in cooling tower in heat-engine plant who is one of the top manufacture industry with water deprivation. Giving intensive study about mass and transfer mechanism, efficiency and influence factor,and then research the water conservation mechanism, give a water saving modification to cooling tower.Therefore, a tow-phase flow model using the volume of fluid(VOF),method is presented meanwhile take shear force as well as surface tension in the interface into account, two important momentum source terms working on the film flow are considered, the influence of some remarkable factors such as liquid entrance velocity,gas entrance velocity and structures of plate on water film flow were analyzed with variation of film thickness were taken into account. according to calculation routine show some graphical expression about film flow,and doing visualized research.A mass and heat transfer model in also presented based on the two-phase flow model.The interfacial water evaporation and heat transfer which is arise from water evaporation are considered, mass and energy source terms were introduced into calculation model of falling film to represent the influence of latent heat transfer to total heat transfer.heat and mass transfer with different gas entrance humidity along a variety of types of plate was analysed. The simulation results indicated that heat transfer efficiency of flow on rough surface is larger than flow along smooth plate, but mass transfer efficiency is lesser.for validating the corresponding computational method, Chun and Seban experimental correlation is selected.the result shows that the model proposed here can well predicte the mass and heat transfer at gas and liquid interface. Subsequently.Nu*is fitted under the analysis about influence of water-vapor mass fraction in gas flow to total heat transfer.Select optimum plate structure and entrance velocity on the basis of water film flow calculation forementioned, the model of CaCl2/H2O solution is established which focuses on the analysis and numerical simulation of heat and mass transfer in the condition of CaCl2/H2O solution film falling down in vertical plate,it also studies the influence of concentration of solution on heat transfer.it shows that total heat transfer efficiency is less than water film flow as reduction of amount of water evaporation, owing to the decrease of vapor pressure difference which is relate to concentration of solution. this comparison descripte water saving principle that is saving water by adjust concentration of solution.