Abstract: In this paper, to study the correlation between vacuum chamber volume and its suppression of gas explosion, a L-type pipe of gas explosion was designed, and the round plastic plate which can adjust the volume of vacuum chamber was made. In addition, a series of experiments about gas explosion suppression were carried out with the vacuum chamber volume changed in descending order. The results show that the suppression effect of gas explosion depends on the relation of vacuum chamber volume and its critical volume. When the vacuum chamber volume is greater than its critical volume, vacuum chamber has good suppression effect of gas explosion. When the vacuum chamber volume is smaller than its critical volume, the vacuum chamber has no suppression effect, furthermore, the overpressure of gas explosion is higher and flame signal strength of gas explosion is stronger in comparison with no vacuum chamber. Meanwhile, for the pipe used in these experiments, the critical volume of vacuum chamber is 0.026 m3, which is 43% of the pipe volume. This conclusion displays that when the vacuum chamber volume is greater than 43% of the experimental pipe, the vacuum chamber has the suppression effect of gas explosion. Conversely, there is no suppression effect of gas explosion.

Key words: vacuum chamber, gas explosion, critical volume, explosive flame, explosive overpressure