Analysis of the flow and condensation characteristics of hydrogen-blended natural gas containing water vapour in a regulating valve

Hydrogen-blended natural gas containing water vapour is susceptible to condensation in the regulating valve with risks of clogging and corrosion. However, there is a lack of targeted research and analysis on the condensation characteristics of the regulating valve. A regulating-valve model is constructed to analyse the pressure, temperature distribution, and condensation process of hydrogen-blended natural gas containing water vapour using the computational fluid dynamics method. The arc cone-valve core regulating valves have a larger flow area than the straight and flat-bottomed cone-valve cores for the same opening and also have a lower pressure decrease and condensation rate. The condensation rate is reduced by 18.31 % when the hydrogen blending volume ratio is increased from 5 % to 90 %. The smaller the opening, the greater the condensation rate in regulating valve. With an increasing opening, the magnitudes of the decreases in temperature, pressure, condensation rate after the flow of hydrogen-blended natural gas through the valve core were greater at openings smaller than 30 %. The magnitudes of these changes decrease when the opening is greater than 30 %. The study complements the lack of research on the flow and condensation characteristics and provides a reference for the safe operation in hydrogen-blended natural gas projects.