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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，因此建立输气管道泄漏扩散的合理模型是正确评估输气管道事故损失后果的关键技术之一。通过分析高斯（Gaussian）模型、Sutton模型和重气模型等常见气体扩散数学模型在模拟天然气管道泄漏扩散过程中的局限性，结合天然气管道泄漏扩散过程的特殊性，在同时考虑输气管道孔口泄漏过程的射流作用和膨胀效应，以及重力作用和水平风速对天然气扩散的影响效果的基础上，建立起了适合天然气管道泄漏特点的扩散模型。该模型从考虑因素的合理性和气体泄漏边界条件的选取上都更加符合天然气管道泄漏扩散过程的实际情况。此外还对新建模型的科学合理性和使用可靠性进行了算例模拟分析检验。

STUDY ON DIFFUSION MODEL OF GAS PIPELINE LEAKING 1)

The major reason why gas pipeline accidents cause damage is leaking and diffusion of gas. So, establishing reasonable model of gas leaking and diffusion is one of the key techniques, with which the damage of gas pipeline accidents can be properly evaluated. In this paper, the usual mathematical models of gas diffusion, such as Gauss model, Sutton model and model of heavy gas and so on, are analyzed and their some disadvantages in process of stimulating gas leaking and diffusion from pipeline are found out. Based on the considerations of jetting action and ballooning effect of leak process of gas pipeline orifice, as well as effect of gravity and horizontal wind speed to gas diffusion, the diffusion model meeting the leaking characteristics of gas pipeline is set up. This model is more fitting the actual leaking and diffusion process of gas pipeline in consideration of reasonable factors and selection of gas leaking boundary conditions. A real case has been stimulated in order to analyze and demonstrate reasonableness and reliability of the new model.