气体扩散数学模型在安全评价方面的应用

工业生产、储运过程涉及储存大量气态和液态的危险性物质,该类物质大都易燃易爆、有毒有害。民用燃料的输送和储藏,也涉及易燃易爆。气体或液体物质发生泄漏事故,可能对附近居民和环境造成极大的危害。气体物质一旦发生泄漏,很难将其限定在一定范围内,势必造成大面积的危害。因此,事故状态下有毒气体的扩散,是安全评价中灾害后果评价的重要内容。笔者通过梯度输送理论,建立了无风条件下气体扩散的动态模型。在限定容器中气体介质是中性气体的情况下,由于中性气体在扩散过程中各向同性,扩散方程获得了简化。进一步限定容器形状为最常见的圆柱形,确定了模型的边界条件,求出了该条件下扩散方程的解析解。开发的扩散模型建立的理论依据是梯度输送理论即单位时间内物质通过单位面积的输送的通量与浓度梯度成正比。同时对建立的模型在安全评价方面的应用进行了初探,结合实例提出了该模型的应用方向。

Application of Gas Diffusion Mathematical Model to Safety Assessment

Storage of huge amount of dangerous gaseous and liquid materials is usually involved in industrial production and transportation processes. Most of them are inflammable, explosive and poisonous, in the transportation and storage of fuels for civil use, the materials are also inflammable and explosive. Once the leakage occurs, great hazardous impact could happen on the environment and residents nearby. Gaseous material once leaks, it is very difficult to control in a limited area, wide spread disaster would happen. Therefore, the accidental poisonous gas diffusion is an important content in safety assessment. A dynamic model of gas diffusion without wind is established according to the Grads Theol. Suppose the gas medium in the definite container is a neutral gas, so its diffusion is the same in different direction that diffusion equation is simplified. Further suppose the container is the general cylindrical in shape, the boundary of the model is determined, the solution of the diffusion equation is solved. The application of the model to safety assessment is preliminarily probed into; its further application is discussed.