空冷凝汽器椭圆翅片椭圆管束外空气的流动与传热特性

Flow and Heat Transfer Characteristics of Cooling Air Outside Elliptical Tube Bundles Fixed with Elliptical Fin in Air-cooled Condenser

研究空冷凝汽器椭圆翅片椭圆管管束外空气的流动与传热特性,对火电站空冷岛的设计与运行具有重要意义.通过CFD模拟,获得了椭圆翅片椭圆管管束外冷却空气的流场和温度场,计算得到了空冷凝汽器冷却空气对流换热平均Nu和摩擦系数f随Re的变化规律,并采用最小二乘法拟合得到了相应的关联式.结果表明:随冷却空气流动Re的增大,Nu增大,f减小.

It is of great importance to investigate the flow and heat transfer characteristics of cooling air outside the elliptical tube bundles fixed with elliptical fin in air cooled condenser of power plant for the designing and operation of air-cooled system. The velocity and temperature fields of cooling air outside the elliptical tube bundles fixed with elliptical fin were presented by CFD simulation. The variations of mean Nusselt number （Nu） and friction coefficient （f） of air convection heat transfer with Reynolds number （Re） were obtained by calculation. and the concerned correlations of flow and heat transfer were established by the least squares fitting. The results show that the Nusselt number （Nu） increase and the friction coefficient （f） decrease with the cooling air＇s Reynolds number （Re） increasing.