冷却塔内冷却水特性三维数值模拟研究

Three-Dimensional Numerical Simulation of Cooling Water Characteristics

采用三维数值模拟方法对自然通风逆流湿式冷却塔塔内的流场特性进行模拟,可为冷却塔设计改进提供参考。基于Fluent软件和传热传质学原理,应用欧拉-拉格朗日法及标准壁面函数法,采用标准k-ε湍流模型进行封闭,建立了逆流式自然通风冷却塔三维热态数学模型。以9000m^2的自然通风逆流式冷却塔为例,对无侧风工况塔内空气动力场的三维流场进行数值仿真模拟。首先,对冷却塔出塔水温进行模拟,将计算值与实测数据进行对比,吻合良好,证明所建模型正确合理;继而对塔内冷却水的分布特性进行了三维数值模拟研究,得出水滴下降速度和水滴温度随时间和位置高度的变化及填料层、集水池液面水温分布情况,所得结果有助于塔内配水系统的优化设计。

Using the three-dimensional numerical simulation method to simulate the flow field characteristics of natural draft counter-flow wet cooling tower,can provide reference for improving the design of the cooling tower.Based on the heat and mass transfer theory and the characteristics of the FLUENT software,applying Euler-Lagrange method and the standard wall function,using the standard k-ε turbulence model for closure, a three-dimensional numerical simulation platform was established. For 9 000 m2 natural draft counter-flow wet cooling tower as an example, with no lateral aerodynamic field, the three-dimensional flow field of the tower was simulated. First of all,the cooling towers outlet water temperature was simulated. After validation with measured data, the calculated value is proved correctly. So the model is reasonable. Then using the platform,the cooling water distribution characteristics was simulated. it is concluded the change process curve of droplet temperature and velocity along with the time and location and the Temperature Distribution in fill layer and collecting tank .the results help to the optimization of water distribution system of tower.