Through amending the SENKIN code of CHEMKIN Ⅲ chemical kinetics package

the computational model of gas explosion in a constant volume bomb was built

and the detailed reaction mechanisms (including 53 species

325 reactions) were adopted.The trends of variation of the mole fractions of reactants

activation centers in the explosion process

and the mole fractions of catastrophic gases after explosion were analyzed by using this model.Furthermore

through the sensitivity analysis of the reaction mechanisms of gas explosion

the key reactions that affected gas explosion and formation of catastrophic gases were identified.At the same time

the inhibition mechanism of H2O on gas explosion and formation of catastrophic gases were analyzed.The results showed that the temperature and pressure were 2700 K and 0.22 MPa respectively after gas explosion when the mixed gas had no water.When the mole fraction of water in the mixed gas was 10%

the temperature and pressure were 2580 K and 0.21 MPa respectively.When the mole fraction of water in the mixed gas was 15%

the temperature and pressure decreased by 180 K and 0.025 MPa respectively against the case that the mixed gas had no water.Furthermore

the water in the mixed gas would inhibit gas explosion and the formations of CO

CO2 and NO2.