球形密闭容器内氢气浓度对混合 气体燃爆特性的影响

为了研究不同体积分数的氢气 空气混合气体的燃爆压力及压力上升速率，采用20 L球形容器进行实验研究，并利用Fluent软件基于Navier-Stokes方程组以及k-ε湍流模型进行数值模拟研究。通过数值模拟研究氢气燃爆过程中的压力变化、温度分布及火焰传播过程，得到的模拟结果和实验结果基本吻合。结果表明，随着氢气体积分数的增加，最大燃爆压力呈现先增大后减小的趋势，在氢气体积分数为30%时达到最大,为0.761 5 MPa；升压速率最快，为0.299 2 MPa。数值模拟获得了燃爆过程不同时刻的可燃气体组分质量浓度分布、压力场、温度场和气流速度矢量，为实际应用中防爆、抑爆提供了理论依据。

Effect of Hydrogen Concentration on Combustion and Explosion Characteristics of Mixed Gas in a Spherical Closed Vessel

In order to research the combustion pressure and pressure rise rate of hydrogen-air mixed gases with different volume concentrations, 20L spherical vessel was used for experimental study, and the Fluent software was used to carry out numerical simulation study based on Navier-Stokes equations and k-ε? turbulence model. It allows for numerical simulation of pressure change, temperature distribution and flame propagation in hydrogen explosion, in which simulation results were basically consistent with the experimental results. The results show that the maximum combustion pressure increases first and then decreases with the increase of hydrogen volume concentration, and reaches the maximum combustion pressure of 0.761 5 MPa and the maximum pressure rising rate of 0.299 2 MPa/ms when the hydrogen volume concentration is 30%. The mass concentration distribution, pressure field, temperature field and air velocity vector of combustible gas at different time during the explosion process could be determined by numerical simulation. It provides a theoretical basis for the explosion-proof and anti detonation capacities assessment in practical applications.