自然通风逆流湿式冷却塔进风口导叶板结构参数优化

Optimization on Inlet Deflectors Structural Parameters of a Natural Draft Counter-flow Wet Cooling Tower

冷却塔作为火电厂冷端系统中重要的冷却设备之一,其冷却性能将直接影响电厂运行的安全稳定性和经济性。环境侧风在很大程度上影响冷却塔的冷却性能,文中采取在冷却塔进风口处安装导叶板的措施予以改善。针对某自备电厂300MW机组的自然通风湿式冷却塔,采用CFD软件Fluent,对进风口处安装导叶板的冷却塔进行塔内流动和传热特性数值模拟。模拟结果表明:导叶板能够增加塔内中心区域的空气上升速度和扰动,加强传热,改善冷却塔冷却性能。导叶板相对最佳的安装角度为45°,导叶板相对最佳的长度和安装数量分别为6 m和40块,在其他条件都相同的情况下,A型导叶板较方形导叶板有0.0546℃的降温,B、C型导叶板的降温效果不及方形导叶板。

Cooling tower is important cooling equipment, its performance that has a direct effect on security, stability and economy of a power plant can be greatly affected by the environmental cross-wind. The method of installing the deflectors in air inlet of cooling tower was taken. In the case of a natural draft wet cooling tower （NDWCT） of a 300MW power plant, based on CFD code FLUENT, the flow and heat transfer characteristics in the cooling tower with deflectors were numerical simulated. The simulation results show that： the deflectors can increase the air velocity and disturbance in center region and strengthen the heat transfer in the cooling tower, so that cooling performance can be improved. The relatively best installation angle of deflectors＇ is 45°. The optimal length and installation number of deflectors are 6m and 40 pieces respectively. Under the same situation, compared with rectangle deflector, the outlet temperature from cooling tower with type A deflector can be lowered by 0.0546℃, the cooling effect from type B and C deflectors are worse than the rectangle deflector.