基于事故防治的含尘瓦斯气流爆炸传播流场结构演化过程实验研究

Based on accident prevention and control, this research is to study temporal and spatial characteristics of shock wave structures and flow field pressure, temperature, and flame in the process of explosion propagation of dust-containing gas. The main contents are as follows: (1) the coupling effects of coal dust and methane gas during explosion propagation; The dust concentration of gas and coal are measured by absorption spectra and high-speed schlieren in shock tube. With the aid of transient spectrum, high-speed laser schlieren and PLIF measurements, the explosion pressure, flame and its structural evolution, shock wave generation and propagation are discussed and compared under the conditions of single coal dust and single gas explosion. (2) the influence of built-in obstacles on the flow field structures of dust-containing gas explosion; By means of optical measurement such as laser schlieren, PLIF imaging and OH and CH spontaneous spectra, the interaction of shock wave and flame with built-in obstacle like diffraction and convergence are considered into analysis. (3) the scale effect of dust-containing gas explosion flow field; Experiments are conducted on large and small pipelines respectively to compare results in different pipeline sizes and explore the influences of scale effect on flow field structures.The research objectives primarily include the establishment of a flow field measurement system for dust-containing gas explosions; and a deep understanding of mechanism in dust-containing gas explosions accidents through the inversion between evolution of flow field structures and explosion characteristics of dust-containing gas.

本项目基于事故防治，研究含尘瓦斯气流爆炸传播过程中冲击波波系结构及流场压力、温度、火焰时空变化特征。主要内容为：（1）含尘瓦斯气流爆炸传播过程中煤尘和甲烷气体在爆炸传播过程中的耦合效应。在激波管利用吸收光谱和高速纹影测量瓦斯和煤尘浓度分布。结合瞬态光谱、高速激光纹影和PLIF测量，研究爆炸压力、火焰及其结构演化、冲击波生成和传播，并与单一煤尘与单一瓦斯气体爆炸工况进行比较。（2）内置障碍物对含尘瓦斯气体爆炸流场结构影响研究。利用激光纹影、PLIF成像和OH、CH自发光谱等光学测量，研究冲击波和火焰与内置障碍物绕射、汇聚等相互作用现象。（3）含尘瓦斯气体爆炸流场尺度效应。分别在大、小尺寸管道开展实验研究，比较不同尺寸管道的实验结果，探索尺度效应对流场结构的影响。主要目标包括：建立含尘瓦斯气体爆炸流场测量系统，通过流场结构演化反演含尘气流瓦斯爆炸特征，深度掌握含尘瓦斯爆炸事故发生机理。

瓦斯（煤尘）爆炸事故包含多项复杂物理、化学变化的热力学过程，受多种因素影响。爆炸传播过程由于激波和剧烈燃烧现象的存在，以及爆炸气流卷吸作用形成含尘瓦斯，导致流场结构极为复杂，压力、温度、火焰速度瞬息巨变。本项目以实验研究为主要手段，搭建及改进了基于光学测试的气体粉尘爆炸实验平台。仿照井下条件，设置障碍物，在不同瓦斯浓度、煤尘浓度、不同数目障碍物作用下，利用激光纹影技术重点研究了含尘瓦斯气流爆炸传播流场结构演化过程，获得了含尘瓦斯爆炸压力、火焰耦合演化过程及障碍物对含尘瓦斯爆炸产生激励效应的物理机制。研究成果对于预防矿井瓦斯煤尘爆炸事故、掌握瓦斯煤尘爆炸事故发生的真实原因，提高事故调查水平以及爆炸事故的应急救援具有重要意义。