Influences of ethane on the flammable limits and explosive oxygen concentration of methane with nitrogen dilution

Abstract To comprehensively investigate the impact of ethane (C 2 H 6 ) on methane (CH 4 ) explosions, a standard test device for the flammable limits of combustible gases was used to examine the influence of C 2 H 6 on the CH 4 explosion parameters with nitrogen dilution. The flammable limits for CH 4 in air and under a nitrogen atmosphere in the presence of C 2 H 6 were obtained. Additionally, the critical index behaviors were analyzed, and the CH 4 explosive triangles at different operating modes were drawn. Using the explosive diagrams, the effects of C 2 H 6 on the location and area of the CH 4 explosive triangle were analyzed. Both the lower and upper flammable limits were reduced by the addition of C 2 H 6 . Simultaneously, the explosive hazard degree ( F value) increased. Furthermore, the inerting nitrogen concentration at the converging point for the CH 4 explosion linearly increased with the increase in C 2 H 6 , whereas the explosive oxygen concentration decreased. The CH 4 explosive triangle expanded and shifted to the left bottom corner in the presence of C 2 H 6 . The area of the explosible zone increased, while that of the no explosion zone decreased. Meanwhile, the ratio of the inert gas and combustible gas required to depress the explosion significantly increased, and more inert gas was required to maintain CH 4 in a completely inert state.