The natural draft dry cooling tower (NDDCT) has been increasingly used for cooling in power generation in arid area. As crosswind affects the performance of a NDDCT in a complicated way, and the basic affecting mechanism is unclear, attempts have been made to improve the performance of a NDDCT based on limited experiences. This paper introduces a decoupled method to study the complicated crosswind effects on the inlet and outlet of a NDDCT separately by computational fluid dynamics (CFD) modeling and hot state experiments. Accordingly, the basic affecting mechanism of crosswind on the NDDCT performance is identified. Crosswind changes the inlet flow field of a NDDCT and induces mainstream vortices inside the tower, so as to degrade the ventilation. Besides, low crosswind deflects the upward plume at the outlet to further degrade the ventilation, while high crosswind induces the low pressure area at the outlet to reduce the ventilation degradation.

中文翻译：

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识别侧风对自然通风干式冷却塔性能影响机制的解耦方法

自然干旱干式冷却塔（NDDCT）已越来越多地用于干旱地区的发电冷却。由于侧风会以复杂的方式影响NDDCT的性能，并且基本的影响机制尚不清楚，因此，基于有限的经验，人们已尝试改善NDDCT的性能。本文介绍了一种解耦方法，通过计算流体动力学（CFD）建模和热态实验分别研究NDDCT入口和出口的复杂侧风效应。因此，确定了侧风对NDDCT性能的基本影响机理。侧风改变了NDDCT的入口流场，并在塔内引起主流涡流，从而降低了通风。此外，低侧风会使出口处的向上羽流偏转，从而进一步降低通风性能，