Comparison on crossover modes of parallel natural gas pipeline network

The first, second and third West-to-East Gas Pipelines have been basically completed and put into operation. In the future, it is possible to lay another gas pipelines parallel to the second and third West-to-East Gas Pipelines. The construction of crossovers between pipelines laid in parallel can connect the pipelines and improve the reliability of the system, but it will also increase the leakage frequency due to the increase of welding spots in the construction of the welded pipes. In this paper, a mathematical model for gas pipelines with crossovers was established by the software SPS to analyze the effects of different setting schemes for crossover valve chamber of parallel pipelines on the pipeline network with broken pipe, so as to obtain the optimal crossover setting solution. Then, the working conditions of parallel pipelines with broken pipe were simulated and analyzed. It is indicated that the gas supply reliability of the pipeline system with double-pipeline crossover is significantly higher than that of single-pipeline crossover. The scheme of constructing a crossover valve amber between two pressure stations has the best cost performance. It is recommended to set a crossover in the valve chamber between two stations and adopt the design scheme of setting crossovers before and after the valve, which is economically reasonable and can improve the emergency allocation capability of pipelines. (7 Figures, 8 Tables, 24 References)