Abstract:

With the accelerated development of China’s nationwide integrated natural gas pipeline network, natural gas pipeline networks are increasingly characterized by multiple sources, multiple sinks, multiple loops, and large-scale complex topologies, imposing higher requirements on both the accuracy and computational efficiency of transient simulation. To address this challenge, this study proposes a Nets-Link-based acceleration method for transient simulation of natural gas pipeline networks. The network is spatially decomposed according to its geographical distribution and topological characteristics, while a depth-first search algorithm is employed to identify connected components and their associated attributes. A transient hydraulic model is established using an implicit central finite-difference scheme and solved by the Newton-Raphson method. At each time layer, a hierarchical iterative strategy is adopted. In the inner iteration, the operating parameters of nodes and pipelines in each subdomain are solved independently. In the outer iteration, a low-dimensional approximate Jacobian matrix for the interfaces is constructed based on the Schur complement concept, and the interface variables are iteratively corrected and updated using the Broyden formula until interface consistency among all subdomains is achieved. The solutions of all subdomains are then assembled to obtain the solution of the entire network. Results from a 24 h transient simulation case show that, compared with the TGNET benchmark, the mean relative errors of pressure and flow rate do not exceed 0.14% and 1.43%, respectively. Compared with the global iterative solution, partitioning the network into four to eight subdomains reduces the computational time by approximately 68%-78%, while the gain in computational efficiency exhibits diminishing marginal returns as the number of subdomains increases. The proposed method can significantly reduce the solution scale and computational complexity of transient simulation for large-scale and complex natural gas pipeline networks while maintaining high computational accuracy, thereby providing an efficient simulation tool for network operational analysis and cross-regional natural gas resource allocation.

Key words: natural gas pipeline network, hydraulic simulation, domain decomposition, parallel acceleration

摘要：

随着我国天然气“全国一张网”建设加速推进，天然气管网呈现多源、多汇、多环及大规模复杂拓扑特征，对瞬态仿真的精度与时效性提出更高要求。为此，本文提出一种基于Nets-Link技术的天然气管网瞬态仿真加速方法。该方法依据管网地理空间与拓扑特征进行空间分解，并采用深度优先搜索算法识别连通分量及其属性；基于隐式中心差分格式建立瞬态水力模型，采用牛顿—拉普森算法求解。在每一时层，采用分层迭代策略：内层独立求解各子域节点与管道运行参数，外层基于Schur补思想构建连接界面低维近似雅可比矩阵，并利用Broyden公式迭代修正，不断更新界面参数，直至各子域接口状态一致，最终整合各子域解获得管网整体解。24 h案例结果表明，与TGNET基准相比，压力和流量平均相对误差分别不超过0.14%和1.43%；与全局迭代相比，划分为4~8个子域时计算时间减少约68%~78%，且效率增益呈边际递减趋势。该方法可在保持较高精度的同时显著降低大规模复杂管网瞬态仿真的求解规模与计算复杂度，为管网高效运行分析及跨区域资源调配提供仿真工具。

关键词: 天然气管网, 水力仿真, 空间分解, 并行加速

CLC Number: 

• TE832.3

• TP391.9