Experimental study on the flame acceleration of premixed hydrocarbons-hydrogen/air mixtures in tee pipes

•Flame acceleration of premixed hydrocarbons-hydrogen/air mixtures.•The explosion development in tee pipe geometry on a medium scale system.•Effectiveness of ignition positions on flame acceleration of fuels in tee pipes.

The benefits of using hydrogen as a source of fuel seem to be limited due to a number of difficulties. To overcome the drawbacks of hydrogen, hydrocarbon-hydrogen fuel mixtures are the best substitutions. However, in literature, the flame acceleration of hydrogen-hydrocarbons/air mixtures in tee pipes has not yet been fully explored. Thus, the aim of this work is to report some new experimental data and provide an understanding of the explosion development in the geometry of tee pipes. In this study, premixed C2H4-H2/air, NG-H2/air and C3H8-H2/air mixtures with different ratios of 10:90, 30:70, 50:50, 70:30 and 90:10 were ignited at six ignition positions at two tee pipe configurations. Hydrocarbon fuels were considered as the primary gases. For the overall observation, it can be said that the flame reactivity of ethylene-hydrogen/air and NG-hydrogen/air was much higher. The kinetic reaction of these mixtures contributed to the overall explosion development. However, the dynamics of flame deployment in the tee junctions had a significant effect on the recorded maximum overpressure and flame speeds along the pipes. Moreover, the obtained data show that the lower distance of tee junction to ignition point caused a higher explosion severity in terms of the rate of pressure rise.