Simulation of gas mixture dynamics in a pipeline network using explicit staggered-grid discretization

Journal Article · 19 September 2024 · Applied Mathematical Modelling

DOI: https://doi.org/10.1016/j.apm.2024.115717 · OSTI ID:2447960

Brodskyi, Yan  ^[1]; Gyrya, Vitaliy  ^[2]; Zlotnik, Anatoly  ^[2]

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1. Humboldt Univ. of Berlin (Germany); Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
2. Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)

Here we develop an explicit staggered finite difference discretization scheme for simulating the transport of highly heterogeneous gas mixtures through pipeline networks. This study is motivated by the proposed blending of hydrogen into natural gas pipelines to reduce end use carbon emissions while using existing pipeline systems throughout their planned lifetimes. Our computational method accommodates an arbitrary number of constituent gases with very different physical properties that may be injected into a network with significant spatiotemporal variation. In this setting, the gas flow physics are highly location- and time- dependent, so that local composition and nodal mixing must be accounted for. The resulting conservation laws are formulated in terms of pressure, partial densities and flows, and volumetric and mass fractions of the constituents. We include non-ideal equations of state that employ linear approximations of gas compressibility factors, so that the pressure dynamics propagate locally according to a variable wave speed that depends on mixture composition and density. We derive compatibility relationships for network edge boundary values that are more complex than for a homogeneous gas. The simulation method is evaluated on initial boundary value problems for a single pipe and a small network, is cross-validated with a lumped element simulation, and used to demonstrate a local monitoring and control policy for maintaining allowable concentration levels.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE Laboratory Directed Research and Development (LDRD) Program; USDOE National Nuclear Security Administration (NNSA)
• Grant/Contract Number: 89233218CNA000001
• OSTI ID: 2447960
• Report Number(s): LA-UR--24-22948
• Journal Information: Applied Mathematical Modelling, Journal Name: Applied Mathematical Modelling Vol. 137; ISSN 0307-904X
• Publisher: ElsevierCopyright Statement
• Country of Publication: United States
• Language: English