摘要:
乙醇液雾闪点低、蒸气压高，工业储运中易引发燃爆事故，爆炸泄放是其核心安全防护措施。为揭示乙醇液雾泄爆特征，为工业泄爆设计提供实验依据，依托20 L球形爆炸容器，集成液雾分散、点火、压力和火焰采集、爆炸泄放单元搭建实验平台，在0~800 g/m³浓度范围、3种泄爆口径、6种静态动作压力下，开展乙醇爆炸及泄爆实验研究。结果表明：500 g/m³为本研究中最猛烈爆炸浓度，对应最大爆炸压力达0.79 MPa、爆炸指数达峰值34.8 MPa·m/s；静态动作压力升高、泄爆口径减小会提升爆炸压力、抑制火焰传播，静态动作压力从320.22 kPa升至426.96 kPa时，最大爆炸压力升高31.9%、火焰平均传播速度降低25.5%；泄爆口径从60 mm扩大至100 mm时，火焰峰值速度提升15.3%；小口径使火焰射流细长、火花集中，高静态动作压力会延后火焰出现时间并增加火花生成量；基于实验数据修正NFPA68标准公式，建立适用于乙醇液雾的泄爆面积模型。研究成果可为乙醇工业储运过程中的泄爆系统优化设计提供数据支撑与实验参考。
Abstract:
Due to the low flash point and high vapor pressure of ethanol, serious combustion and explosion accidents are readily triggered during industrial storage and transportation. Explosion venting is therefore regarded as a critical safety protection measure. To reveal the explosion venting characteristics of ethanol mist and provide experimental guidance for industrial venting design, a comprehensive experimental platform was established based on a 20 L spherical explosion vessel, integrating mist dispersion, ignition, pressure and flame acquisition, and explosion venting units. Explosion and venting experiments of ethanol were conducted under a concentration range of 0~800 g/m³, with three different vent diameters and six distinct static activation pressures. The results show that an ethanol mist concentration of 500 g/m³ produces the most severe explosion under the experimental conditions investigated, with a maximum explosion pressure of 0.79 MPa and a peak explosion index of 34.8 MPa·m/s. It is clearly found that increasing the static activation pressure and reducing the venting diameter lead to higher explosion pressures and suppressed flame propagation. When the static activation pressure is increased from 320.22 kPa to 426.96 kPa, the maximum explosion pressure is increased by 31.9%, while the average flame propagation velocity is reduced by 25.5%. When the venting diameter is enlarged from 60 mm to 100 mm, the maximum flame propagation velocity is increased by 15.3%. A smaller venting diameter results in a more elongated flame jet with concentrated sparks, whereas a higher static activation pressure delays the flame appearance time and increases spark generation. Based on the experimental data, the venting area equation specified in the NFPA 68 standard is modified, and a venting area model applicable to ethanol mist explosions is established. The findings provide valuable experimental evidence and data support for the optimization and design of explosion venting systems in the industrial storage and transportation of ethanol.
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