The throughput capacity of the main gas pipeline when transporting gas-hydrogen mixtures

Purpose: To determine the effect of hydrogen concentration in the gas-hydrogen mixture on the throughput capacity of the main gas pipeline and the volume of energy transported by it. The range of molar concentrations of hydrogen in the gas-hydrogen mixture up to and including 20%, which does not require significant technical modernisation of the system, was investigated. Design/methodology/approach: Performing theoretical studies and applying mathematical modelling methods to establish the regularities of thermo hydrodynamic processes in a gas pipeline, gas turbine and centrifugal blowers while transporting gas-hydrogen mixtures. Findings: In the example of a gas turbine unit widely used in the gas transmission system of Ukraine, it was found out that the molar content of hydrogen, if it does not exceed 20%, has a negligible effect on its rated power and other energy parameters. Adding hydrogen to natural gas with the above molar content will lead to a slight decrease in the pipeline system's capacity (up to 5%) and a significant reduction in the volume of energy transportation (up to 18%). Research limitations/implications: The next stage of the study is to determine the impact of gas-hydrogen mixture properties on the pipeline capacity, taking into account changes in seasonal factors and the degree of system load. Practical implications: A method and software have been developed to predict the pipeline capacity and energy transfer volume for the transportation of gas-hydrogen mixtures, taking into account the influence of seasonal factors, gas-dynamic characteristics of blowers, and combinations of gas-pumping units at compressor stations. Originality/value: Modern international standards are used to calculate gas-hydrogen mixtures' physicochemical and thermodynamic properties under standard and operating conditions. The originality of the approach lies in the fact that the compressor station and the linear section of the gas pipeline are considered as a SLE gas-dynamic system.