城市天然气高压输配管网风险评价

城市天然气管网由城市边缘超高压、高压天然气主干管线与市内次高压、中压天然气管网构成。由于天然气主干管和市内天然气输配管网的风险影响因素不完全相同，而且城市高压天然气管线的设计、新建成、运行阶段的风险特征也有所不同。因此，有必要建立基于不同阶段的风险评价体系。为此， 通过风险因素分析，分别建立了3个阶段的风险评价模型，运用指数评分法进行风险分析，并基于风险评价体系进行风险等级划分。针对风险等级较高的评价对象，根据实际情况和专家咨询意见，对各影响因素给出相应的风险缓解措施。风险评价结果有助于城市天然气高压管网的设计、新建成、运行阶段的修正、维护及管理。

RISK ASSESSMENT ON URBAN HIGH PRESSURE NATURAL GAS PIPELINE NETWORK

As to urban natural gas pipeline network, including gas trunk lines at superhigh pressure or high pressure and distribution network of small pipelines at intermediate pressure, corresponding risk assessment systems should be established due to different risk factors at different stages of gas pipeline network. This paper discussed risk factors and established risk assessment models of urban high pressure natural gas pipeline network at three stages, including design stage, newly built stage, and operational stage. Applying the exponential risk assessment method, the risk of natural gas pipeline network was analyzed, and the degree of risk was defined based on the risk assessment system. In order to mitigate risks of the evaluated pipelines, relevant measures of various factors leading to risk were put forward according to practical situations and experts' suggestions. The results of the risk assessment are helpful to both maintenance and management of urban high pressure natural gas pipeline network.