Numerical Study On Air Flow And Heat Transfer Characteristics For The Direct Air-cooled Condenser Fin

The structure,Principle of work and technological development of the direct air-cooled condenser and basic requirements and type of core components-finned tubes,which constitute the condenser,were introduced. In addition, the basic theory of numerical simulation software,for instance,meshing of the models, setting the boundary conditions,the principle of FLUENT and UDF were summarizd.For the basic forms of heat exchange components of air-cooled condenser in power plants, rectangular-finned elliptical tube and snake-like finned flat tube, the three-dimensional geometric models are established for researching the air-side flow and heat transfer characteristics , obtaining and analysising the velocity and temperature and pressure fields . The influences of air inlet velocity,fin space,fin height of the air-side flow and heat transfer characteristics were analyzed , discussing the affect between the comprehensive heat transfer performance indicators and the fin space,fin height and wind speeds and the structural parameters were optimized. Comparing flow resistance and heat transfer coefficient in the different velocity the above-mentioned two kinds of fin type,the target and direction of structural optimization were provided.The correlation of flow resistance and heat transfer coefficient with the wind velocity were also obtained by fitting the simulation results of flat steel brazing snake-like finned of the single row tube and the verification of the numerical results were presented by the comparisons of the numerical results with the designing datas,which the deviation of heat transfer coefficient was 10% and flow resistance was 6% in the same velocity. It is not only of theoretical significance for the optimization designing and economic operation ,but also of practical value for air-cooled condensers .