With the widespread use of ammonia in the process industry, more and more accidents were caused by ammonia leakage and dispersion. The dispersion of ammonia is determined by its physical properties, release source conditions and atmospheric environment. Full-scale numerical simulation based on CFD theory was carried out to study the dispersion law of ammonia in a food factory. It was found that ammonia concentrated on the symmetric plane and showed an upward movement near the source. Moreover, the effect of pressure on the dispersion of ammonia was explored showing that the concentration of ammonia near the source increased with the increase of pressure, while the dispersion of ammonia far from the source is mainly influenced by wind field. Last but not the least, the dangerous area completely covers the obstacle region according to the harmful concentration, but the lethal concentration range and explosion range both only existed near the release source. Correspondingly, the concentration of ammonia in the region far from the symmetric plane can be regarded as a safe area. When the accident happens, one should stay away from the release source and evacuate towards the sides in a timely manner. We hope that this work can provide an effective method in predicting the impact of ammonia dispersion and can arouse concerns over the public safety.

随着氨在加工业中的广泛使用，氨泄漏和分散引起越来越多的事故。氨气的分散度取决于其物理性质，释放源条件和大气环境。进行了基于CFD理论的全尺寸数值模拟，研究了食品厂氨气的扩散规律。发现氨集中在对称平面上并在源附近显示出向上运动。此外，研究了压力对氨气弥散的影响，结果表明，随着压力的增加，气源附近的氨浓度增加，而远离气源的氨的分散主要受风场的影响。最后但是同样重要的，危险区域根据有害浓度完全覆盖了障碍物区域，但致死浓度范围和爆炸范围仅存在于释放源附近。相应地，在远离对称平面的区域中氨的浓度可以被认为是安全区域。发生事故时，应远离泄漏源并及时向侧面撤离。我们希望这项工作能够为预测氨气扩散的影响提供有效的方法，并引起公众对安全的关注。应该远离释放源，并及时向侧面撤离。我们希望这项工作能够为预测氨气扩散的影响提供有效的方法，并引起公众对安全的关注。应该远离释放源，并及时向侧面撤离。我们希望这项工作能够为预测氨气扩散的影响提供有效的方法，并引起公众对安全的关注。