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多晶硅副产物四氯化硅泄漏后形成重气云,易与水蒸气发生反应,生成四氯化硅、氯化氢和硅酸的混合有毒气云,威胁人类安全,导致严重的生态和环境危害。针对四氯化硅泄漏后形成的重气云的三维大气扩散与反应迁移过程建立了传递转化模型并采用计算流体力学(CFD)进行模拟研究,化学反应模型采用漩涡破碎模型(Eddy-Break-UpModel)。模拟研究了四氯化硅气体与水蒸气反应过程中四氯化硅、氯化氢、硅酸等有毒物质的空间分布与迁移转化情形。四氯化硅受重力作用下沉并向周围扩展,迎风面处的四氯化硅下沉触碰到地面后向上风侧移动,但主体向下风向迁移;生成的毒害性氯化氢覆盖范围较四氯化硅广泛;反应物和生成物在近地面的浓度较大,威胁环境安全;水解反应消耗水分导致脱水效应和反应放热升温,会对该区域生态造成严重危害。研究结果为反应性化学品事故处理提供了依据。
Silicon tetrachloride, a polysilicon byproduct, forms a heavy gas cloud after it leaks. It easily reacts with water vapor to form a mixed gas cloud of silicon tetrachloride, hydrogen chloride and silicic acid, threatening human safety and causing serious ecological and environmental hazards. For the three-dimensional atmospheric diffusion and reaction migration process of heavy gas clouds formed after the leakage of silicon tetrachloride, a transfer model was established and simulated by computational fluid dynamics (CFD). The chemical reaction model was Eddy-Break-Up Model ). The spatial distribution and migration of silicon tetrachloride, hydrogen chloride, silicic acid and other toxic substances during the reaction between silicon tetrachloride gas and water vapor were simulated. Silicon tetrachloride (PCC) sinks and expands to the surrounding area under the action of gravity. The silicon tetrachloride (SCC) at the windward side touches the ground and moves toward the upwind side, but the body migrates downwards. The coverage of poisonous hydrogen chloride Chlorinated silicon is widely available; the concentration of reactants and products in the near-surface area is relatively large, threatening the environmental safety; and the consumption of water in the hydrolysis reaction leads to the dehydration effect and the exothermic heat of reaction, which can seriously endanger the ecology of this area. The results provide the basis for the handling of reactive chemical accidents.