石化企业毒气泄漏的数值模拟与危险性评估

Numerical simulation and hazard assessment of poisonous gas leakage in petrochemical works

针对石化企业中可能造成毒气泄漏的装置或设备,从工程实际出发,建立了3种毒气泄漏和扩散的数值模型。根据模型和给定的扩散条件,对毒气的泄漏和扩散进行数值模拟和动态仿真,得到毒气泄漏后人员死亡区域、危险区域和有感区域的动态变化结果。对石化企业有毒物质源进行毒性分级,并确定了相应的毒气泄漏危险性参数。通过给定的装置和设备泄漏危险性参数计算得到毒气泄漏的危险性矩阵,进而对石化企业有毒有害气体泄漏进行危险性评估。

This paper is aimed to introduce its author＇ s proposal of three numerical simulation models for poisonous gas diffusion on the basis of the Gauss model. The three models for simulating poisonous gas leakage and diffusion have been established in accordance with the devices, apparatuses and installations of petrochemical works ac- tually used in the engineering project practice. The trial application of the proposed model shows that the continuous poisonous gas leaking source tends to leak gas during the investigated period under a certain leakage velocity. In addition, the leakage and diffusion tends to keep going on steadily during the limited time （model 2 ）. Besides, the second model also works in the same way as model 1, but the time of diffusion is likely to be shorter than the investigated time. However, model 3, the transient leakage model shows that its poisonous gas source leaks in a twinkling manner. And then, no longer leaking is found with the poisonous gas. In the process of investigation of nu- merical simulation of poisonous gas leakage and diffusion, the com- monly used model is the Gauss mathematics model. Given the model, it is possible to deduce the numerical simulation and dynamic simula- t tion of poisonous gas leakage under the proliferation conditions. And in turn the dynamic change results of the deadly region, hazardous region and sensory region after the poisonous gas leakage can be ob- tained. Next, the sources of the poisonous or toxic substances of the petrochemical works can be identified and classified accordingly with likely hazard parameters of poisonous gas leakage being defined. In so doing, the risk matrix of poisonous gas leakage can be worked out based on the evaluation of the leakage dangerous parameters of de- vices and installations used. The mathematics models thus proposed by us can be accomplished on the basis of some assumed conditions. Though the corresponding results can not be totally identical with the actual evaluation practice, they have certainly proved to be applicable for prevention of the likely disastrous accidents.