A one dimensional model to track the black powder dispersion and deposition within gas transmission network

Black powder (BP) is a universal problem that occurs in sales gas pipelines all over the world. It can cause costly problems for the pipeline operation, instruments and processing industries. The main objective of the present study is to develop a novel methodology for tracking the concentration of BP within the gas transmission network taking into account the deposition of solid particles. The mathematical model is based on the 1D flow and dusty gas assumptions. The analytical solution of a one-dimensional scalar advection/reaction equation is used to track the concentration of BP within the whole gas network. The reaction term in the advection/reaction equation represents the concentration changes due to the deposition of solid particles. Different flow conditions and particle diameters are considered. The approach is tested by considering particle-laden flow in pipe segments with and without junctions which were simulated using CFD based on the discrete particle model (DPM). The 1D approach is validated with the CFD simulation for single pipe geometry. The results for the tree-shaped network shows that the sub-microns particle can be transported throughout tree shaped network, while the larger particles of diameters d_p > 1 (μm) are likely to settle rapidly near to the source, forming stratified beds. The obtained results from the present study are of significant practical interest, due to the lack of available data on BP dispersion in natural gas networks that have been reported in the literature to date. Mapping of BP distribution within the gas transmition network provides essential data that can help to identify the locations of where the filters/cyclone seperators can be installed within the gas transmission network. This leads to better options for efficienly removing and managing the BP in the gas network to protect the downstream equipments.