复杂天然气管网系统运行期可靠性评价体系

中国天然气管道行业正朝着规模化、网络化方向发展,整个管网系统运行期的输气保障能力受到广泛关注,对其完成输送任务的可靠性进行评价显得尤为重要。为了保障大型天然气管网系统安全、高效运行与管理,对管网系统可靠性指标、系统可靠度计算、单元可靠度计算、可靠性数据及可靠性管理开展了研究。提出了包括可靠性类、维修性类以及健壮性类的3层系统可靠性评价指标体系,建立了基于管道工艺仿真的物理管网系统可靠度分布式阶梯计算模型,能够实现管网/管道/站场系统可靠度的简化、快速计算。将该计算模型在某压气站进行案例试算,按照站场系统→典型结构→基本回路→设备单元的顺序,将管网拓扑结构由上至下拆分为不同层级的可靠性框图,再利用单体设备可靠度由下至上依次计算各层级可靠度,获得该压气站在不同压缩机启停方案下的可靠度。该研究成果为今后持续开展大型天然气管网系统可靠性评价及管理奠定了基础。

A reliability evaluation system of complex gas pipeline network system in the operation period

In order to adapt to the large-scale networking development status of domestic gas pipeline industry, the gas transmission assurance capacity of the whole pipeline network system in the operation period is widely concerned, and it is particularly important to evaluate its reliability to accomplish the task of gas transmission. In this paper, pipeline network system reliability index, system reliability calculation, unit reliability calculation, reliability data and reliability management were studied focusing on the safety, efficient operation and management of large-scale gas pipeline network system. A three-layer system reliability evaluation index system was developed, including reliability, maintenance and robustness. Then, a distributed step calculation model of physical pipeline network system reliability based on pipeline process simulation technology was established to calculate the reliability of pipeline network/pipeline/station system simply and quickly. Finally, this calculation model was applied to one certain gas compressor station for case calculation. The topological structure of the pipeline network was split into reliability frameworks of different levels from the top to the bottom in the sequence of station system→typical structure→basic loop→equipment unit. Afterwards, the reliability of each level was calculated from the bottom to the top by using the reliability of individual equipment. Thus, the reliability of the gas compressor station in different compressor stop/start schemes was obtained.The research results provide the foundation for the reliability evaluation and management of large-scale gas pipeline network systems in the future.