基于数值模拟的扇形水幕阻挡稀释氯气扩散的影响因素研究

Research for the influential factors of the fan-shape water spray curtain on mitigating the chlorine gaseous release via a numerical simulation

在重气储罐区内设置喷射水幕是安全隔离、控制重气泄漏后扩散和减缓事故后果严重程度的重要措施之一。为此,利用计算流体力学(CFD)模型建立了氯气泄漏扩散模型,对扇形水幕阻挡稀释氯气扩散过程进行了动态模拟及影响因素分析,分别模拟了外界风速、水幕的喷射角度、水幕距泄漏源距离、水幕流量和水幕液滴直径等参数对氯气泄漏后扩散的影响情况。结果表明,合理地设置水幕能够有效阻挡氯气的扩散、缩短危险距离和减少危害面积。在大气稳定的情况下,外界风速、水幕的喷射角度、水幕距泄漏源距离、水幕流量等参数、水幕液滴直径是影响扇形水幕阻挡氯气扩散的重要因素。其中水幕距泄漏源距离和水幕流量2个因素对阻挡稀释效果的影响比较明显,水幕距泄漏源的距离越小,水幕的动量越大,阻挡稀释效果越好,水幕流量适中时效果最好,流量过大或过小阻挡稀释效果都要差一些。因此,合理设置相关参数有利于提高水幕性能,更加有效地降低氯气泄漏事故的后果。

This paper aims to introduce a chlorine leakage diffusion model developed by its author in hoping to improve the dilution and blocking effect of the fan-like water curtain in diluting the chlorine gas diffusion.Through the said chlorine leakage diffusion model,we have simulated the dynamic blocking process of the aforementioned water curtain in a heavy gas storage tank zone so as to isolate and control the severe situation of the heavy gas leakage and the diffusion consequences through the Computational Fluid Dynamics（CFD）.It is just for the said purpose that we have investigated the influential factors,such as the external wind speed,the water curtain Witting angle,the distance between the leak source and the water curtain,in addition to the water curtain flow and the water curtain droplet diameters,with their impact given to the spreading of the chlorine leak.The simulation results demonstrate that a reasonable water-curtain setting can help to block the diffusion of chlorine effectively,in addition to shortening the risk distance and reducing die hazard sphere.Therefore,on the condition when the atmospheric pressure is stable,the following factors should be taken as the key decisive factors that may account for the blocking dilution of the water curtain,such as tbe external wind speed,the water curtain spray angle,the distance between the water curtain and the leakage source,the water curtain flow and the droplet diameter,with the last two parameters being of principal ones,that is,the distance between the leak source and water curtain,and the water curtain flow will be.What is more,the shorter the distance between the leak source and the water curtain is,the greater momentum the water curtain will be endowed with,and in turn,the more idealistic the blocking dilution effect will be.For,too large or too little water curtain flow force would fail to be conducive to the dilution and blocking effect needed except for a moderate water curtain flow.Therefore,reasonable settling of the water curtain parameters can surely be beneficial to the improvement of the water curtain capability and eventually more effective and proficient in reducing the consequences of the chlorine spill accidents.