Heat And Mass Transfer Research Of Water Film Evaporative Air Cooler And Design Program Development

Water film evaporative air cooler is equivalent to a combination of tube and shell heatexchanger and cooling tower, and its advantages are short closing cycle, high efficiency ofcooling, compact structure, energy saving and water saving, etc.The correlations of heat transfer coefficient outside the tube are mainly studied in thispaper. In order to enhancing generality of the correlations, the factors influencing theperformance of water evaporative air cooler are analyzed in this paper, and the new amountof dimensionless groups are obtained by platinum han theory, then the correlations of heattransfer coefficient outside the tube which are used more extensively are fit on the basis ofengineering data. Considering mass transfer between water film and air, the calculationmethod of the equivalent heat transfer coefficient between water film and air is studied inthis paper.Flow mechanism and heat transfer outside the tube is complex. Considering the equationsboth being solved and being close to the practice, the primary factors are reserved,andsecondary factors are neglected.The corresponding simplified assumptions are put forward inthe third chapter. The heat and mass transfer differential equations are established on thebasis of the finite volume method and the control equations are discreted by the first-orderwindward. It is reasonable that the simulation computation is iterative in the direction of thethermal fluid flow.And the method of temperature and humidity alternating iterative stringsection which has superlinear convergence rate is researched for solving differentialequations, so the basic process of the simulation calculation is determined, and then visualinterface of water evaporative air cooler is developed with the language of VB.net.Finally, combined with industrial background, the simulation software is debugged. Thecorrectness and reliability of the program is verified by industrial instances.