Gas Pipeline Leak Detection And Location Technology Based On Transient Simulation

Along with the second pipeline of"Transporting the natural gas from the west to the east project"implementations, China's gas pipeline construction will enter a new upsurge, consecutively, more gas pipelines will put into construction and operation. In order to guarantee the safe operation of these pipelines and to minimize the hazards of gas pipeline leak accident, leak detection and location technology research is necessary, which also has extremely important practical significance and broad prospects.Pipeline leak detection is the multi-field, interdisciplinary topics related to fluid mechanics, sensing technology, weak signal detection, signal processing, and many other disciplines. The research to the pipeline leak detection has been several decades of history, but because of the complex process of pipeline operation, there has not an authoritative and reliable way to detect leakage. Being worth paying more attention is that, for gas has easily compressed and low-viscosity characteristics, making its pipeline leak detection and location is more difficult than any other pipeline. Taking into account the current continuous progress of pipeline network simulation and mature of gas SCANDA system, the paper researches gas pipeline leak detection and location technology based on transient simulation to improve the accuracy of leak detection and the precision of leakage position location.In order to improve the sensitivity of gas pipeline leak detection, the paper through theoretical analysis of different leakage quantity and different leakage position on the impact of pipeline flow parameters obtains that, different pressure ratio of the head to the end involves measure different flow parameters (pressure or flow) for leak detection. The paper also introduces the hypothesis testing ideas and constructs the binary hypothesis testing theory to improve the detection accuracy.From the establishment and calculation of the mathematical model two aspects to improve the precision of leakage position location. Establish the steady-state and transient model using the three hydrodynamics equations (Continuity equation, Momentum equation and Energy equation). By comparing different state equation, it selects the BWRS state equation which is considered the most accurate state equation in current natural gas measurement. It calculates compression factor, density and other Thermal parameters based on BWRS state equation. In Numerical solution of the steady-state and transient model, compression factor, friction coefficient and all the other Thermal parameters are recalculated in each small time step to reduce the numerical calculation error.