管道内预混可燃气体爆炸及其泄爆的数值模拟

发布时间：2018-01-14 19:35

本文关键词：管道内预混可燃气体爆炸及其泄爆的数值模拟　出处：《中北大学》2017年硕士论文　论文类型：学位论文

【摘要】：可燃气体爆炸是工业生产和生活中爆炸灾害的主要形式之一。为了更好地预防和控制易燃气体爆炸事故,本文利用气体爆炸模拟软件AutoReaGas对管道内预混可燃气体爆炸及其泄爆特性进行数值模拟研究,揭示甲烷掺混氢气比例、初始条件、障碍物以及泄爆条件等因素对爆炸特性的影响规律,主要研究工作和成果如下:研究了管道内甲烷掺混氢气比例对爆炸峰值超压和温度的影响规律。峰值超压随着掺氢比的增加而增加。当掺氢比为75%时,最大峰值超压为27.03bar,达到掺氢比25%时产生的最大峰值超压5.571bar的4.85倍。随着掺氢比的增加,爆炸峰值温度具有明显增大的趋势。当掺氢比从25%增加到75%时,得到的爆炸峰值温度从3170K增加到4791K,提高了1621K。研究管道内初始压力和初始温度对预混燃气/空气混和物爆炸压力的影响规律。爆炸峰值超压随初始压力的增加呈线性增加。此外,初始压力对爆炸峰值超压的影响越来越大始温度的升高逐渐减弱。初始温度25oC和50oC时,初始压力每升高1bar,得超压峰值增加到59kpa和53kpa,分别。爆炸峰值超压随着初始温度的升高而逐渐减小,初始温度对爆炸峰值超压的影响与初始压力的大小密切相关。初始温度对爆炸峰值超压的影响随着初始压力的增加而增大。研究了内置障碍物管道内障碍物数量,阻塞比等因素对预混甲烷/空气混合气体爆炸压力的影响规律。爆炸峰值超压随着障碍物数的增加而增加。当障碍物的数量增加到13时,在管内最大峰值超压达到882.0kpa,为无障碍物时管内最大峰值超压19.1kPa的46.2倍。峰值超压随着阻塞比的增大而增大,但随着阻塞率的增加,其峰值不单调增加,但当阻塞比达到一定程度时,峰值超压将逐渐减小。当阻塞比为75%峰值超压达到最大值489.5kPa,为无障碍物时最大峰值超压的25.6倍。研究了泄爆膜位置和泄爆压力等条件对管道中甲烷/空气混合气体爆炸超压以及温度等参数的影响规律。泄爆膜位置对爆炸峰值超压和温度均有显著影响。当泄爆膜位置在Ⅱ(管道中间)时,管内最大峰值超压和温度达到最小,泄爆效果最好。泄爆压力对压力波传播有较大影响。泄爆压力越大,压力波沿管道传播过程中超压的衰减速率越慢,曲线也越平缓。泄爆压力的变化对管道峰值温度的影响程度不大。
[Abstract]:Flammable gas explosion is one of the main forms of explosion disaster in industrial production and daily life. In order to prevent and control flammable gas explosion accidents better. In this paper, gas explosion simulation software AutoReaGas is used to simulate the explosion characteristics of premixed combustible gas in pipeline, and the initial conditions of methane mixing hydrogen are revealed. The influence of obstacles and explosion discharge conditions on the explosion characteristics. The main work and results are as follows: the effect of hydrogen ratio of methane mixing in pipeline on the explosion peak overpressure and temperature is studied. The peak overpressure increases with the increase of hydrogen doping ratio, and when the hydrogen ratio is 75. The maximum peak overpressure is 27.03 bar. which is 4.85 times of the maximum peak overpressure of 5.571bar when the hydrogen ratio is 25. The peak temperature of explosion increases from 3170K to 4791K when the ratio of hydrogen to hydrogen increases from 25% to 75. The effect of initial pressure and temperature on the explosion pressure of premixed gas / air mixture is studied. The peak explosion overpressure increases linearly with the increase of initial pressure. The effect of the initial pressure on the explosion peak overpressure decreases gradually, and the initial pressure increases by 1 bar at the initial temperature of 25oC and 50oC. The overpressure peak increases to 59kpa and 53kpa, respectively. The explosion peak overpressure decreases with the increase of the initial temperature. The effect of the initial temperature on the explosion peak overpressure is closely related to the initial pressure, and the effect of the initial temperature on the explosion peak overpressure increases with the increase of the initial pressure. . The effect of blocking ratio on the explosion pressure of premixed methane / air mixture gas. The explosion peak overpressure increases with the increase of the number of obstacles, when the number of obstacles increases to 13:00. The maximum peak overpressure in the tube reaches 882.0 KPA, which is 46.2 times of the maximum peak overpressure of 19.1kPa without obstruction. The peak overpressure increases with the increase of blocking ratio. However, with the increase of blocking rate, the peak value does not increase monotonously, but when the blocking ratio reaches a certain degree, the peak overpressure will gradually decrease, and when the blocking ratio is 75%, the peak overpressure reaches the maximum 489.5 KPA. It is 25.6 times of the maximum peak overpressure without obstacles. The influence of the location of venting film and the pressure of venting on the explosion overpressure and temperature of methane / air mixture gas in pipeline are studied. The explosion peak overpressure and temperature are significantly affected. In the middle of the pipe. The maximum peak overpressure and temperature in the pipe reach the minimum, and the effect of explosion is the best. The larger the pressure is, the slower the attenuation rate of pressure wave is in the process of propagating the pressure wave along the pipeline. The curve is more gentle, and the change of explosion pressure has little effect on the peak temperature of pipeline.
【学位授予单位】：中北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.221

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