双曲线型间接空间冷却塔流场的数值模拟研究

Numerical Simulation Study on the Flow Field of Hyperbolic Indirect Air Cooling Tower

间接空间冷却塔具有节约水资源的优势,适用于干旱地区电厂。本文将空冷散热器简化为面单元建立某双曲线型间接空间冷却塔及其外场的模型,基于RNG k-ε湍流模型模拟无风工况下的流场,利用中心轴线空气流速进行了网格无关性检验,分析了外场、出口截面和中心轴线的速度、压强分布。模拟结果表明位于空冷散热器高度以上的空冷塔各截面,速度分布为类抛物线型,截面中心的速度大于两侧的速度。随着空冷散热器壁面温度的升高,空冷塔进出口速度差和压差均增大,且在壁面温度32℃～52℃区间,进出口速度差、压差均与壁面温度近似呈线性关系。

Because indirect air cooling tower has the advantage of saving water resources,it is suitable for power plants in arid areas.In this paper,radiator is simplified as a surface element to establish the model of a hyperbolic indirect air cooling tower withexternal field.Based on RNG k-εturbulence model,the flow field in windless condition is simulated.The grid independence test is carried out by using the air velocity of the central axis.The velocity and pressure distributions of the external field,the outlet section and the central axis are analyzed.The simulation results show that the velocity distribution of each section above the radiator is parabolic,and the velocity at the center of the section is greater than that at both sides.With the increase of the radiatorsurfacetemperature,the velocity difference and pressure difference between the inlet and outlet of the air cooling tower increaseapproximately linearly in the range of 32-52℃of radiatorsurface temperature.