利用雨区淋水势能提升超大型湿式冷却塔传热传质性能的研究

For ultra-large type natural draft wet cooling tower which is one of the cool-end equipment for 1000MW (or more) electric generating unit, it is difficult that the environmental wind enters into tower due to its larger bottom diameter and volume, which decreasing the cooling efficiency of the whole tower, then, in turn, affecting the economy of the whole unit. Thus, this project proposed to change the conventional configuration mode inside towers, and install a rotating components which will utilize sufficiently water dropping potential energy to increase airflow rate inside tower, and then enhance the heat and mass transfer performance for super-large wet cooling towers. Based on theoretical model analysis, thermal-state model experiment and numerical computation, this project will research the thermal performance and drag characteristic for wet cooling towers mounted this component, and reveal the influence mechanism of this component on thermal performance and drag characteristic. Meanwhile, the evaluation model of thermal performance and calculation model of drag characteristic will be set up according to reconstructing air dynamics field inside towers. By terms of the new thermal and drag model, the coupling mechanism and synergic relationship will be investigated between component’s configuration type and the performance enhancement of heat and mass transfer, and obtain the optimizing configuration type of this component. On this basis, the enhancement mechanism of optimizing configuration component to heat and mass transfer performance will be studied and discovered, and quantitatively achieving the improving effect of cooling towers. The project will put forward a novel idea and method for energy-saving research regarding ultra-large type wet cooling towers.

作为1000MW及以上等级发电机组冷端设备之一,超大型自然通风湿式冷却塔体积和底部直径大，环境风很难进入中心区域，降低了其冷却效率，影响机组经济性。因此，本研究打破了湿式冷却塔内的常规配置模式，在雨区增设淋水势能利用组件，充分利用雨区淋水势能，增加通风量，提升超大型湿式冷却塔传热传质性能。课题拟利用理论模型分析、热态模型实验与数值计算相结合的方法，研究增设淋水势能利用组件后湿式冷却塔的热力性能和阻力性能，揭示该组件对热力性能和阻力性能的影响机理；重新构建塔内空气动力场，建立增设组件后的热力性能评价模型和阻力性能计算模型。基于全新的热力和阻力模型，研究该组件在塔内配置形式与传热传质性能提升之间的耦合机制和协同关系，获得该组件的优化配置形式；研究并揭示优化配置的组件对超大型湿式冷却塔传热传质性能提升机理，获得该组件对热力性能的提升效果，为超大型湿式冷却塔深入的节能研究提供了新思路和新方法。

作为1000MW及以上等级发电机组冷端设备之一，超大型自然通风湿式冷却塔体积和底部直径大，环境风很难进入中心区域，降低了其冷却效率，影响机组经济性。因此，本研究打破了湿式冷却塔内的常规配置模式，在雨区增设淋水势能利用组件，充分利用雨区淋水势能，增加通风量，提升超大型湿式冷却塔传热传质性能。本项目首先对典型的超大型湿式冷却塔进行了现场测试，获得了不同工况下冷却塔的热力、阻力特性，为三维数值模型的验证提供了数据。基于淋水势能利用组件，本项目构建了利用淋水势能强制通风的新型冷却塔模型。利用理论模型分析、热态模型实验与数值计算相结合的方法，研究了增设淋水势能利用组件后湿式冷却塔的热力性能和阻力性能，揭示了该组件对热力性能和阻力性能的影响机理；重新构建了塔内空气动力场，并研究了淋水势能利用组件对塔内空气动力场的影响规律；研究了淋水势能利用组件不同配置形式与传热传质性能提升之间的耦合机制和协同关系，获得了该组件的优化配置形式；研究并揭示了优化配置的组件对超大型湿式冷却塔传热传质性能提升机理，获得该组件对热力性能的提升效果，为超大型湿式冷却塔深入的节能研究提供了新思路和新方法。