Diagnosis of the single leakage in the fluid pipeline through experimental study and CFD simulation

The pipeline safety management system is crucial to transfer oil and gas because the phenomena of leakage commonly occurs in the long-distant pipelines. Hidden safety hazards can be caused by design and construction defects, affected by natural disasters, or corroded by the transmission fluid. Therefore, quick detection will not only reduce the loss of transported oil and gas but also can protect the local environment. In this study, we develop a new method to detect the pipeline leak by analyzing pressure distribution through the leak. Pipeline leak detection tests are operated using a flow loop. Through the experiments, four parameters which are pressures and flow rates of pipeline inlet and outlet are recorded. Then the specific location of the leak is determined by dimensionless analysis of flow parameters. To generate the solution to locate the leak, we introduce three dimensionless variables, which are dimensionless leak location, dimensionless leak rate, and dimensionless pressure drop. Then the relationship of pressure distribution and leak parameters is built through the simulation models. After running 3D computational fluid dynamics (CFD) simulations with commercial software (FLUENT), the pressure distribution in the pipeline with leakage in the experiments will be verified by the experimental data. Finally, the mathematical models are developed to detect and evaluate the leakage through the pipeline. CFD simulation results show that both the leak rate and location have significant effects on the pressure distribution through the pipe, which is identical to the outcome from the experiments. When the dimensionless leak location is smaller or the dimensionless leak rate is larger, the dimensionless pressure drop is smaller. The mathematical model which is based on these dimensionless variables can be applied in locating the leak point in the real accident.