典型有限空间内混氢天然气泄漏燃爆演化规律研究

Study on evolution laws of leakage,combustion and explosion of hydrogen-blended natural gas natural gas in typical confined space

为探究混氢天然气在有限空间内泄漏燃爆的演化规律,采用FLACS建立27 m^(3)立方体开口容器,分析混氢比(HBR)、点火位置、泄漏口尺寸、体积阻塞率对有限空间内混氢天然气燃爆内外压力的影响。研究结果表明:随HBR增加,容器内部压力峰值逐渐增大,外部压力在40%混氢比以上时,开始出现二次超压;中部点火导致内部压力峰值最大,前部点火导致容器外部压力峰值最大;随泄漏口尺寸减小,容器内部压力峰值逐渐增大;外部压力曲线中泄漏口宽度固定为1.2 m,长度为2 m和0.5 m时,长度为1 m和1.5 m时峰值及趋势相近;随体积阻塞率增加,容器内部压力峰值逐渐减小,8%体积阻塞率的压力峰值较4%下降明显,由166 kPa下降到87 kPa。研究结果可为城镇终端用户燃气掺氢应用提供参考。

In order to investigate the evolution of hydrogen-blended natural gas leakage and combustion in limited space,FLACS was used to establish a 27 m^(3) cubic open vessel to analyze the effects of hydrogen-blended natural gas combustion on the internal and external pressures in limited space by hydrogen blending ratio(HBR),ignition position,leakage port size,and volumetric obstruction rate.The results show that:with the increase of HBR,the vessel internal pressure peak gradually increased,the external pressure in 40%hydrogen blending ratio above,the beginning of the second overpressure.The central ignition leads to the maximum internal pressure peak,the front ignition leads to the maximum pressure peak outside the vessel.With the decrease of the leakage port size,the peak pressure inside the vessel increases gradually.In the external pressure curve,the width of the leakage port is fixed at 1.2 m,the length at 2 m and 0.5 m,and the peak value and trend are similar at 1 m and 1.5 m;With the increase of volume blockage rate,the peak pressure inside the container decreases gradually,and the peak pressure of 8%volume blockage rate decreases significantly compared with that of 4%,from 166 kPa to 87 kPa.The results of the study can provide a reference for the application of hydrogen blending in urban end-user gas.