破口事故下安全壳内氢气扩散与燃爆特性分析OA

When a serious accident occurs in a nuclear power plant,hydrogen gas released from the breach will spread into the containment vessel,once hydrogen gas accumulates locally and reaches a flammable concentration,it will seriously endanger the integrity of the containment vessel.This study uses numerical simulation methods,analyze the diffusion and explosion characteristics of hydrogen gas inside the containment vessel under multi-component gas conditions.The results indicate that when the mixed gas containing hydrogen is released through the breach,there will be a significant three-stage distribution of hydrogen concentration inside the containment vessel,form a high concentration accumulation zone near the breach location and generate large eddy currents in the headspace.After the mixed gas inside the containment is ignited in the later stage of the accident,detonation will occur,at this time,the flame propagation speed is greater than the speed of sound,and the flame surface is smooth and flat;During the flame propagation process,there is a significant pressure difference throughout the entire area,and the pressure wave profile highly overlaps with the flame propagation trajectory.The highest-pressure during propagation can reach 7.8×105 Pa,which can easily damage the containment structure.