Objective To address the technical bottlenecks of low accuracy and slow responsiveness in existing dynamic gas quality prediction for multi-source natural gas pipeline networks during mixed transportation, this study aims to develop a high-precision dynamic component-tracking method to support refined network operation and quality compliance.

Method Based on the domestically developed Pipeline Network Simulation (PNS) platform, a Dynamic Batch Component Tracking (DBCT) method was proposed. Physics-based criteria for fluid batch generation and transport were established to enable high-resolution tracking of component evolution under unsteady conditions. A pipeline simulation model that closely matches the physical system (simulation accuracy of 99.56%) was first established and calibrated. The DBCT approach was then validated through steady-state and transient simulation analyses.

Result Steady-state analysis quantitatively resolved source contribution weights and identified the East Trunk Line as the dominant source influencing terminal gas quality, with a contribution of 66.298%. Transient simulations successfully reproduced the propagation of upstream composition perturbations through the network and accurately characterized the terminal gas quality dynamic response across latent, transition, and new steady-state stages. Conversion of steady-state predictions to physical properties confirmed that the exported commercial natural gas under the studied operating conditions meets national quality standards.

Conclusion The proposed DBCT method substantially improves the accuracy and dynamic performance of gas quality prediction in complex pipeline networks, offering an effective technical and theoretical tool for operation optimization and quality compliance.