Abstract:

With the increasing demand for natural gas, the stable operation and safety of the natural gas pipeline network system need to pay more and more attention. Reliability management, as a further refinement of integrity management, provides a more comprehensive evaluation and management system for the functional status of both local and overall system components. It can promote the safe and stable operation of large-scale natural gas pipeline networks. Reliability allocation is an indispensable component of reliability management. By allocating system reliability indicators to each unit and clarifying the reliability requirements for each unit, it can provide reliability assurance and guidance for the operation management and maintenance of natural gas pipeline network system. But no effective reliability allocation method has been proposed for the natural gas pipeline network system with complex topology. According to the structure and process characteristics of the natural gas pipeline network system, the analytic hierarchy process (AHP) is improved to propose the hierarchical reliability allocation method for the complex structure natural gas pipeline network system in this work. Based on the functional level of “pipeline network system-pipeline system-unit”, the hierarchical model of the natural gas pipeline network system is established. The importance of supply security and the severity of consequence have been incorporated as influence factors for system gas supply reliability. Through quantitatively evaluating the factors affecting the reliability of system gas supply, the reliability allocation index of the natural gas pipeline network system is allocated to each unit step by step, to determine the reliability allocation plan for complex structure natural gas pipeline network systems. Finally, the proposed method is applied to an actual natural gas pipeline network system. Results indicate that the value of reliability allocation for compressor station units is lower than that for adjacent pipeline segment units. The value of reliability allocation for pipeline segment units is related to the distance from the demand point. Pipeline A exhibits the highest reliability requirements, with relatively balanced unit reliability allocation values and fewer critical gas supply impact units. Pipeline B has the lowest overall reliability requirements. Pipelines C and D are similar, featuring significant variations in unit reliability allocation values and a large number of critical gas supply impact units. This study proposes a hierarchical reliability allocation method suitable for complex structured natural gas pipeline systems, which improves the theoretical system of pipeline system reliability and provides the scientific basis for enhancing the reliability of pipeline systems.

Key words: natural gas pipeline network, complex topology structure, reliability allocation, hierarchical structure model, analytic hierarchy process, gas supply reliability

摘要：

随着天然气需求的不断增长，天然气管网系统的稳定运行和安全性越来越受到重视。可靠性管理作为完整性管理的进一步深化，对系统局部及整体的功能状态有着更全面的评价管理体系，能够促进大型天然气管网系统的安全平稳运行。可靠性分配是可靠性管理中不可或缺的一环，通过将系统可靠性指标合理地分配至各单元，明确各单元可靠性要求，能够为管网系统的运行管理和维修维护提供可靠性保障和指导。对于拓扑结构复杂的管网系统目前还没有有效的可靠性分配方法。本文根据管网系统结构与工艺特点，改进层次分析法，建立复杂结构天然气管网系统递阶式可靠性分配方法。根据“管网—管道—单元”功能层级建立天然气管网系统递阶层次模型；加入保供重要度和后果严重度补充供气可靠性影响因素，通过对系统供气可靠性影响因素进行量化评估，将系统可靠性分配指标逐级分配至各单元，确定复杂结构天然气管网系统可靠性分配方案。最后将本文提出的方法应用于某实际天然气管网系统，结果表明压气站单元的可靠性分配值低于相邻管段单元，管段单元可靠性分配值的大小与距离需求点的位置有关。管道A具有最高的可靠性要求，单元可靠性分配值较为均衡，关键供气影响单元数量较少；管道B整体可靠性要求最低；管道C和管道D相近，单元可靠性分配值差异大，关键供气影响单元数量多。本研究建立的递阶式可靠性分配方法适用于复杂结构天然气管网系统，完善了管网系统可靠性理论体系，为增强管网系统可靠性提供了科学依据。

关键词: 天然气管网, 复杂拓扑结构, 可靠性分配, 递阶层次结构模型, 层次分析法, 供气可靠性

CLC Number: 

• TE832

• TE88