Water vapour condensation behaviour within hydrogen-blended natural gas in laval nozzles

Hydrogen-blended natural gas (NG) pipeline network transport is the most effective approach for solving the problem of large-scale hydrogen use. Hydrogen-blended NG that contains water vapour is prone to water vapour condensation when it passes through complex NG pipeline networks, leading to pipeline network failures. To analyse the condensation behaviour of hydrogen-blended NG containing water vapour in a Laval nozzle, a condensation model of water vapour was established. A computational fluid dynamics approach was used to calculate the condensation process of hydrogen-blended NG containing water vapour in Laval nozzles for four countries: Iran, USA, Russia, and Australia. Hydrogen-blended NG components affect the flow characteristics of the gas mixture in the nozzle. The gas components have the greatest effect on the Mach number. The difference between the maximum and minimum Mach numbers at the outlet was 0.02 Mach. Hydrogen-blended NG containing water vapour condenses downstream of the throat of the Laval nozzle. Hydrogen-blended NG from Russia had the largest condensation ratio (79.63 %). The largest droplet radius and liquid mass fraction were observed in the hydrogen-blended NG from Australia. The condensation process can accelerate the future research and engineering application of water vapour into hydrogen-blended NG.