Study on the thermodynamic mechanism of external magnetic field on gas explosion characteristics

Abstract

To investigate the thermodynamic mechanism of the magnetic field on the explosion characteristics of gases, experiments were carried out to study the influence of the applied magnetic field of 300 mT on the explosion characteristics of 5.7 % C2H6, 6.5 % C2H4 and 7.7 % C2H2 by volume. CHEMKIN-PRO software was used to simulate the three kinds of gas explosion chain reaction process. The chemical bond strength, stability and bond energy of the three gases were calculated and analyzed by Materials Studio software to derive the strength of chemical bond stability of the three gas molecules in the explosion process. The results show that the magnetic field weakened the breaking rate of CC, CC, and CC, the maximum explosion pressures of C2H6, C2H4, and C2H2 were reduced by 12.14 %, 16.47 %, and 18.71 %. The three gases carbon–carbon bond strength was weaker than the strength of the carbon-hydrogen bond, carbon-hydrogen bond was not easy to break, which in turn reduced the rate of generation of ·H in the chain initiation stage of the cleavage reaction, thus presenting a significant inhibitory effect of the magnetic field on C2H6, C2H4, and C2H2 explosions. The COOP of CC is 0.377 Ha, and the bond energy is 839 KJ/mol, which was greater than CC and CC, so the number of free radicals generated in the C2H2 cleavage reaction was lower, leading to a slower chain reaction rate which led to a stronger inhibitory effect of the magnetic field on C2H2 explosions than that on C2H6 and C2H4.