核电厂冷却塔布置对气载流出物扩散的影响

 分析了4种可能的冷却塔平面布局方案，分别为单一冷却塔布置、矩形布置、一字型布置以及S型布置。针对不同的布置方案，应用计算流体力学软件scSTREAM提供的RNG k-ε湍流模型，开展污染物大气扩散模拟分析。对于单一冷却塔布置，在释放点与冷却塔之间的距离段内，其污染物分布为标准的高斯分布，同时其浓度也高出其他3种布置方案1个数量级。除了S型布置方案，其他3种方案在冷却塔背风侧均形成阶跃效应。冷却塔背风侧污染物的分布中，单一冷却塔布置方案的浓度结果小于其他3种方案，主要是因为大量污染物进入到冷却塔体，然后从冷却塔顶部排出，造成其背风侧浓度急剧下降。

Impact of large natural draft cooling tower layout on atmospheric dispersion of airborne effluent from nuclear power plant

In terms of engineering design of nuclear power plants, four possible cooling tower layout schemes are given: single cooling tower layout, rectangular layout, inline layout and S-shaped layout, which cover most of the nuclear power plant sites. The RNG k-ε turbulence model in scSTREAM is used to simulate and analyze atmospheric diffusion of pollutants for different layout schemes. For a single cooling tower arrangement, the concentration distribution is a standard Gaussian distribution in the distance between release point and cooling tower, and its concentration is also significantly higher than those of the other three arrangements. In addition to the S-shaped arrangement, the other three solutions form a steep drop effect on the leeward side of the cooling tower. In the distribution of pollutants on the leeward side of the cooling tower, the concentration results of the single cooling tower arrangement are smaller than those of the other three schemes, mainly because a large amount of pollutants enter the cooling tower body and then discharge from the top of the cooling tower, causing a sharp concentration decrease on the leeward side.