Study on Explosion Safety of Storage of Alcohol/Gasoline Blend Fuels

以其为主要成分的甲醇、乙醇和酒精混合燃料有望成为可行的替代燃料。含有形成丰富混合气或超过可燃上限混合气的组分的酒精混合燃料在液体表面形成可燃混合气层的可能性通常小于纯甲醇或乙醇，因此在安全储存方面具有优势。然而，在瞬态工艺或大型容器中，仍然存在厚可燃层的可能性。因此，了解爆炸特性非常重要。本文对甲醇/汽油混合燃料采用小容器储存的爆炸安全性进行了研究。在不同的初始温度、汽化时间、火花间隙高度下，将混合物点燃。项目前半期研究了M100、M97、M95（含商品白汽油），后半期研究了M95、M90、M85（含7种纯汽油）。确定了几种典型的压力波动模式。在火花间隙高度汽化时间平面上绘制了最大升压曲线和爆炸范围。从图中可以看出，在20℃以下，当甲醇-空气平衡混合物浓度较低时，在小汽油含量范围内，爆炸范围和最大压力上升幅度首先随汽油含量的增加而增大，除该区域外，爆炸范围随着汽油含量的增加而缩小，最大压力上升幅度减小。观测到的最大压力上升至少为1atm，在通常情况下可达3至8atm。这些结果表明，如果不完全排除点火源，则容器要承受预期的压力上升，或增加汽油含量是必要的。

Methanol, ethanol, and alcohol blend fuels including them as main component are expected as feasible alternative fuels.Alcohol blend fuels that include components forming rich mixture or mixture beyond the upper flammable limit have advantages in safety storage since the possibility of forming flammable mixture layr on the liquid surface is usually smaller than that for pure methanol or ethanol. However, in transient processes or in large containers, the possibilities of thick flammable layr still remain. Therefore, it is important to understand explosion characteristics. In this study, explosion safety of storage of methanol/gasoline blend fuels was explored by using small vessels. The fuel was provided so as to cover the bottom, and for various sets of initial temperature, vaporized time, spark gap height, the mixture was ignited. In the former half of the projeic term, M100, M97, M95 including commercial white gasoline were examined, and in the latter half, M95, M90, and M85 including model gasoline consisting of seven pure components were examined. Several typical patterns of pressure fluctuation were identified. The contours of the maximum pressure rise and the range of explosion were plotted in the spark gap height-vaporized time plane. From the plots it was inferred that below 20ﾟC,where methanol-air mixtures in equilibrium are lean, within small gasoline content the range of explosion and maximum pressure rise increase with the content at first, and that except this region the exploded range is shrunk and the maximum pressure rise decreases with the increase of gasoline content. The observed maximum pressure rise is at least 1 atm and in usual cases it reaches 3 to 8 atms. These results indicate that if the ignition source is not excluded completely, the container to bear with expected pressure rise, or the increase of gasoline content should be necessary.