煤尘浓度和粒度对煤尘燃烧爆炸特性影响的实验研究

Experimental study on the impact of coal dust concentration and particles on combustion and explosion characteristics

煤尘粒度和浓度对煤尘燃烧爆炸存在重要影响,爆炸的危险性随粒度的减小而迅速增加。挥发分15%～30%和灰分小于30%的煤尘的爆炸下限随挥发分的增加而减少。实验研究发现,当燃料室中分别加入不同浓度的煤粉而发生燃烧爆炸时,混合物的爆压和爆速变化也各不相同。煤粉加入量少,爆压、爆速很低,混合物处于爆燃状态。实验中,当煤尘浓度为276g/m3、368g/m3时,煤尘出现稳定爆轰。爆压随着煤尘粒度的减小而增大,45～75μm粒度煤尘出现稳定的爆轰过程,采用此粒度等级煤尘进行燃烧爆炸特性实验研究是非常合理的。

The particle size and concentration of coal dust is very important during combustion explosion.The explosion danger is increased rapidly with the size reduction.Using volatile content between 15% and 30% and ash content less than 30%,the coal dust explosion limit is decreased with the volatile content increasing.Through the experiment,while different concentrations of coal powder are added to the fuel chamber,the mixture detonation pressure and detonation velocity are not the same.The less the addition of coal powder is,the lower the detonation pressure and velocity are,and the mixture is in deflagration.When the dust concentration is 276g/m3 or 368g/m3,stable detonation appears during coal dust explosion.The detonation pressure is increased as the coal dust particle size is decreased,and a stable detonation process is occurred with coal dust particle size of 45 to 75μm.Therefore,studying the experimental combustion and explosion characteristics is very reasonable under such conditions.