风力对天然气管道泄漏后扩散过程的影响研究

天然气管道发生泄漏扩散是输气管道事故危害的根本原因，而风力是影响泄漏后天然气扩散过程的一个极为重要的因素，建立有风条件下天然气泄漏扩散的位移量计算模型是正确评估输气管道事故损失后果的关键技术之一。通过风速与风压关系的研究，确定了风速分布关系式；并结合管道泄漏扩散过程的特殊性,在考虑管道孔口泄漏过程的射流作用和膨胀效应,以及重力作用影响效果的基础上, 重点考虑了水平风速的影响，给出了在风力作用下泄漏后天然气团偏移量的计算公式，建立了三维空间内的位移量计算模型，并进行了实例计算。结果表明，风力的存在将加剧天然气的扩散，使泄漏的天然气团顺风向偏移，其偏移尺寸远大于其他两个方向，大大增加了天然气泄漏后的危害面积。

STUDY ON WIND INFLUENCE OF WIND ON GAS DIFFUSION PROCESS DURING GAS PIPELINE LEAKAGE EMERGENCY

The major reason why gas transmission pipeline accident causes damage is gas leakage and diffusion. Wind is one of the main contributors. Thus, it is significant to establish calculation model for displacement vector of natural gas mass to evaluate the loss of pipeline leakage accident. By researching the relationship between wind velocity and wind pressure, the wind velocity distribution equation was determined. Considering the particularity of gas pipeline and based on the considerations of jetting action and ballooning effect of leak process of gas pipeline orifice, as well as effect of gravity to gas diffusion, the effect of horizontal wind velocity was well considered. The calculation equation for drift vector of natural gas mass affected by wind was provided. Furthermore, the calculation model for displacement vector in three-dimensional space was gained. Meanwhile, the results were showcased in an example. The results indicated that the existence of wind will strengthen the diffusion of gas, make it drift along the wind direction and increase the acreage which might be plagued.