Objective As modern natural gas pipeline networks evolve into large-scale, complex and networked systems, the challenges of accurately and rapidly analyzing hydraulic and thermal changes, as well as real-time monitoring of equipment status, are intensifying.

Methods To ensure the safety and reliability of large-scale complex natural gas pipeline networks and to thoroughly investigate the mechanisms of their operating condition changes, online simulation software based on a partitioned incremental iteration-adaptive state estimation algorithm was developed, capable of meeting the online simulation needs of 2×10⁴ km-level natural gas pipeline networks. The software integrates SCADA data with mechanism models and employs a partitioned incremental iteration algorithm to decompose the entire pipeline network into smaller sub-networks for partitioned solutions. This approach transforms the global state estimation problem into highly parallelizable sub-region state estimation tasks. Different weights are assigned based on SCADA data errors, allowing a global sub-optimal solution to be achieved through iterative calculations in the sub-regions.

Results A large-scale, complex natural gas pipeline network spanning 2×10⁴ km in a specific region of China was used for testing, with simulation results verified against the measured data of the SCADA system. The results indicated that the software maintained a maximum relative error of ±5％ in predicting key process parameters such as pressure and flow, demonstrating high accuracy and reliability. It completed a full cycle of data reading, simulation calculation, and result export and display within 30 seconds, meeting real-time performance requirements. The software also exhibited robustness in handling complex situations, such as real-time data missing and anomalies, automatically correcting measurement data at both model and data levels to ensure continuity and stability in simulation calculations.

Conclusion The developed software meets industrial-grade standards for applicable scale, computational efficiency, accuracy, and stability. It establishes a robust foundation for key technologies in the intelligent operation and maintenance of natural gas pipeline networks, facilitating the digital transformation of the energy industry and providing professional simulation services to support the energy sector’s digital strategy and intelligent transformation in China.