Prytula N. Mathematical modelling unsteady mass transfer in gas transmission networks and underground gas storage facilities

The dissertation deals with the solution of the actual scientific and applied problem of development of algorithms, numerical methods and mathematical models of gas flow in complex systems of gas transmission, storage and distribution, which allowed to build effective methods and algorithms for calculation and optimization of gas flows. The paper proposes a mathematical model of the gas transmission system, which connects the models of flow diagrams with variable topology and various mathematical models of facilities. This made it possible to build methods, iterative procedures and algorithms for finding the parameters of unsteady gas flows for existing types of the structural organization of gas networks, existing technologies for transmission, storage, control and distribution of gas flows. A system of formation, analysis and synthesis of graph flow diagrams of gas transmission systems and a set of algorithms for automatic formation of the model of its work and initial-boundary conditions for solving problems of mathematical physics have been developed. Algorithms for minimizing energy resources for complex gas transmission and gas storage systems are proposed, and theoretical studies and numerical experiments are conducted to substantiate approaches for effective control of filtration and gas dynamic flows. According to the results of research, complexes of programs for scheduling the modes of operation of gas transmission systems and underground gas storage facilities in real conditions of daily balancing of gas transportation, distribution and storage systems have been developed and put into commercial operation.