【作者】 孟伟；

【导师】 喻健良；

【作者基本信息】 大连理工大学 ， 安全技术及工程， 2005， 硕士

【摘要】 本文主要研究压力波和火焰在多层丝网结构和平行狭缝结构内传播时其参数的变化规律以及参数之间的耦合关系。 组建了圆形管道内预混可燃气体爆炸及抑爆实验装置。抑制爆炸的结构为多层丝网结构和平行狭缝结构。 进行了乙炔/空气混合气和丙烷/空气混合气爆燃波在管内传播与抑制的实验研究。实验条件如下:乙炔浓度为化学计量比(7.75%),丙烷浓度为化学计量比(3.95%),爆炸初压为常压,管道内径为81mm,长度为1.4～2.9m,点火端密闭,出口端开放,实验研究了多层丝网结构和平行狭缝结构对管内传播的爆燃火焰的淬熄能力。 提出了临界淬熄量的重要概念,淬熄量可用来表示爆炸波被丝网结构转化的能量损失。得到了临界淬熄速度、临界淬熄压差、临界淬熄量(临界淬熄速度与临界淬熄压差之积)与丝网层数、丝网目数、金属丝径等几何参数之间关系的经验公式。随着丝网的几何参数(n·m·d)的增加,临界淬熄压差和临界淬熄量增加,淬熄性能越好。并得出多层丝网结构对压力波的抑制效果。并根据阻火器设计流程和本实验研究成果,提出了阻火器设计的新思路。 还对丙烷-空气预混气在平行狭缝中传播时的淬熄现象进行了实验和理论研究,得到了火焰传播速度、淬熄压差、淬熄间距和淬熄长度之间的关系。 上述工作对爆炸抑制理论的完善和爆炸抑制技术的推广应用均有积极的意义。更多还原

【Abstract】 Experimental investigations are carried out to analyze variation regulations of parameters in flow field and their couple relations as explosion waves and flame propagating along tube or through multi-layer mesh construction and narrow parallel channels construction.Experimental apparatus used for explosion and explosion suppression of flammable gases in tube are set up. The constructions of explosion suppression are multi-layer mesh construction and narrow parallel channels construction.With premixed ethyne-air gases and propane-air gases, experimental investigations about explosion waves propagating and suppression in tube are dealt with. Experimental conditions are set as follows: Stoichiometric rate and atmospheric pressure are used for initial concentration of Ethyne(7.75%), propane(3.95%) and initial pressure; the inside diameter and length of tube, which is closed at ignition end and open at the other, are 81mm and 1.4~2.9m respectively; multi-layer mesh construction made of stainless steel, is vertical to tube axle, narrow parallel channels construction is parallel to tube axle.The new important concept, critical quenching value has been put forward. This concept can be used to denote energy loss of explosion wave transformed by mesh construction. The effects of multi-layer mesh construction on flame propagation in tube are analyzed. Empirical formulas about relationship between critical values, include of quenching speed, quenching pressure difference and quenching amount (the product of quenching speed and quenching pressure difference), and geometrical parameters, such as layer, screen mesh and wire diameter, are obtained. With the increase of geometrical parameter (n·M·d) , critical quenching pressure difference and critical quenching value increased, the higher the capability of quenching is. Suppression effects of multi-layer mesh construction on explosion pressure waves are introduced. A new way to design flame arrest has been put forward basing on flow of flame arrest design and study results of the experiment.An experimental study on the quenching of explosion for propane-air mixture when the flame passes narrow parallel channels is described. The relationship of flame velocity v, quenching diameter D and quenching length Lq has been given. The principle of quenching when the flame passes narrow parallel channels is discussed.These studies have positive effect on the development of explosion suppression theory and the application of explosion suppression technology.更多还原