输气管道潜在影响区模型关键参数取值讨论

Discussion on the Key Parameters of Gas Transmission Pipeline Potential Impact Areas Model

天然气管道的潜在影响区是指如果管道发生失效，其周边公众安全和财产可能受到明显响影的区域。泄漏速率衰减因子的取值对潜在影响区半径计算模型的准确性有着极大影响，ASME B31.8S基于对实验数据的研究，将泄漏速率衰减因子λ的取值为0.33。研究ASME B31.8S中泄漏速率衰减因子的取值方法，并根据该取值方法，对不同管道的泄漏速率衰减因子λ进行计算。计算结果表明：对于108~1219 mm管径的管道，泄漏速率衰减因子在0.14到0.32之间，泄漏速率衰减因子不随管道压力变化，而随管径的减小而减小。由此得出结论：将λ取为0.33可以满足安全管理需求，但是对于城镇燃气管道这类较小口径管道而言，可能造成潜在影响半径计算结果过大，在安全管理中难以执行且提高安全管理成本。最后将不同管道λ分别取值，计算出潜在影响区半径与原潜在影响区半径公式的计算结果进行比较。

Potential impact area of natural gas pipeline isanarea where the public security and property may be significantly affected if pipeline failures. The value of leak rate attenuation factor has a great impact on the calculation accuracy of the potential impact radius model. ASME B31.8S evaluates the leak rate decay factor λ to 0.33 based on the experimental data.In this paper,the reasonableness of the value of λ was discussed, the method to evaluate leakage rate decay factor in ASME B31.8S was studied. And then leak rate decay factor λ of different pipelines was calculated with the sophisticated leak rate calculation model according to the method. The results show： for different pipelines, leakrate decay factor is between 0.14and0.32;the leak rate decay factor does not vary with the pressure changing in the pipeline, but decreases with the diameter decreasing. It is concluded that, taking the λ as 0.33 can meet the needs of safety, but this willim prove the cost of safety management for small diameter pipeline. Finally, the radius of potential impact area of natural gas pipeline was calculated when λ was different, and the results were compared with the results when λ was taken as 0.33.