A computer model of the nonstationary gas flow in a long multilayer-insulated high-pressure subsea gas pipeline

Abstract

For the non-stationary gas flow in a long multilayer-insulated high-pressure subsea gas pipeline, an original computer model was developed that takes into account transient heat-transfer processes in the long multilayer wall of the pipeline. These processes may influence the energy balance of the flowing gas, leading to a change in the gas temperature down to negative values, which may cause frosting of the pipe and reduction of its strength characteristics up to rupture. The adequacy of the model was checked on an industrial subsea pipeline more than 300 km long. Computational experiments on the developed computer model under essentially unsteady boundary conditions for pressure, mass flow rate, and temperature showed that the developed model gives more accurate values of flow velocity, pressure, and temperature throughout the pipeline.