Effect of BC powder on hydrogen/methane/air premixed gas deflagration

Abstract

In order to evaluate the inhibition ability of BC powder to hydrogen/methane premixed gas explosion and explore the deflagration characteristics of premixed gas, the experimental study was carried out on a small scale experimental platform built by ourselves when the equivalence ratio of premixed gas was 1. The results show that turbulence can promote the deflagration of gas when the addition ratio of hydrogen is less than 70%. When the hydrogen addition ratio is less than 80%, the peak explosion pressure changes slowly with the increase of hydrogen content in the premixed gas, but when the hydrogen addition ratio is more than 80%, the explosion peak pressure increases rapidly. In turbulent state, the flame front is wrinkled, and decreases with the increase of hydrogen addition ratio, and the variation of flame front with time is basically the same both Turbulence and quiescence. The optimum inhibitory concentration of BC powder to methane/air premixed gas is 200 g/m3. From the view of flame propagation speed and deflagration pressure peak value, BC powder has a better inhibition effect on the premixed gas with lower hydrogen addition ratio. When the ratio of hydrogen is more than 80%, the BC powder of 200 g/m3 has no inhibitory effect on hydrogen/methane/air premixed gas. With the change of BC powder concentration, the effect of BC powder on the peak deflagration pressure of premixed gas with different hydrogen addition can be divided into three categories. When the hydrogen content is 20%, 30%, 40%, the best explosion suppression concentration of BC powder is 200 g/m3, 280 g/m3, 320 g/m3; continuously increasing the concentration of BC powder has no inhibitory effect on the deflagration of premixed gas with hydrogen content more than 80%. This study can provide theoretical support for the safe use of hydrogen/methane/air premixed fuel.