基于FLACS的受限空间瓦斯爆炸数值模拟

为了对矿井瓦斯爆炸灾害进行有效防治、安全评估和事故调查，采用XKWB-1型近球型密闭式气体爆炸特性测试装置进行甲烷爆炸实验，并应用FLACS软件对该爆炸过程进行数值模拟，二者对比表明添加辐射模型的模拟与实验结果基本吻合，平均误差1.88%，说明辐射换热是瓦斯爆炸过程中除热传导和热对流外主要的热量传递方式。模拟结果表明，瓦斯爆炸燃烧波以近球面波的形式向四周传播，小空间内各点压力很快达到均匀，从容器壁面到点火源处温度梯度不断增大；当火焰面传至壁面附近时，未燃气体受壁面作用产生回流，上下、左右的回流气体相遇形成的涡旋使火焰加速，在可燃性气体燃烬时爆炸超压达到最大值。添加辐射换热模型的模拟结果误差基本满足工程需要，可应用于更复杂空间的瓦斯爆炸过程模拟。

Numerical simulation of gas explosion in confined space with FLACS

To prevent，safety assess，accident investigate the disaster of gas explosion in coal mine，experiments were conducted with the XKWB 1 nearly spherical confined gas explosion testing device and the software FLACS to simulate the gas explosion process of different concentrations of methane.The results of numeric simulation with the thermal radiation model were compared with the experimental data to see the average error of 1.88%，which proved that thermal radiation is also an important way of heat transfer besides conduction and convection in gas explosion.Combustion spreads around to form a nearly spherical wave front during gas explosion.Pressure of various points in the small space achieves uniform quickly，and temperature gradient from the vessel wall to ignition source increases gradually.When the flame front approaches the wall，reflux takes place due to reflection of the wall.When the reflected flow from different direction met turbulence formed，flame accelerated，and the explosion overpressure achieved its maximum value when the flammable gas burned out.The simulation result with radiation model basically meets the engineering requirements，can be applied to the gas explosion simulation in more complex space.