ABSTRACT

Obstacles are unavoidable in coalmine laneways and combustible gas pipeline. However, the obstacles may enhance the intensity of explosion, or change the propagation characteristic. The present paper deals with the flame propagation characteristic of explosion in the tube with a tilted obstacle (45 ~ 135°) under the condition of low initial pressure (0.2 ~ 0.35 kPa). Two models (a so-called modified model and a mathematical model) are adopted in order to describe the regularity of flame velocity for the first (i.e. after explosion at an edge of the tube) and third (i.e. before the flame reaches the end of the tube) stages, whereas some irregular phenomena are investigated during the second stage (i.e. in which the flame reaches the titled obstacle, and goes beyond it) of the whole process, i.e. explosion and flame propagation along the tube. A theoretical fitting model is built in order to describe the critical moments of the accident, i.e. explosion and propagation. It is shown that the initial pressure and obstacle, considered as governing factors, have specific influences on flameless zone and flame velocity. This research can provide a new basic study of the effects of obstacles on combustible gas explosion and a reference for actual explosion protection designs.

摘要

煤矿巷道和可燃气体管道难免存在障碍。然而，障碍物可能会增强爆炸的强度，或改变传播特性。本文研究了低初始压力（0.2～0.35 kPa）条件下，具有倾斜障碍物（45～135°）的管内爆炸的火焰传播特性。采用两种模型（所谓的修正模型和数学模型）来描述第一次（即管边缘爆炸后）和第三次（即火焰到达终点之前）的火焰速度规律。管）阶段，而在整个过程的第二阶段（即火焰到达标题障碍物并超越它），即爆炸和火焰沿管传播，研究了一些不规则现象。为了描述事故的关键时刻，即爆炸和传播，建立了一个理论拟合模型。结果表明，作为控制因素的初始压力和障碍物对无焰区和火焰速度有特定的影响。该研究可为障碍物对可燃气体爆炸的影响提供新的基础研究，为实际防爆设计提供参考。