采动工作面瓦斯流动规律的探讨

在经典瓦斯流动理论基础上，将瓦斯在采动工作面前方煤层中的流动视为流动边界不断变化的一维流动问题，利用动坐标变换，求出在这种情况下瓦斯压力分布的解析解，比较了不同的工作面推进速度对瓦斯压力分布及瓦斯涌出量的影响。     

聚合物燃烧火焰辐射及其温度的估算

受限空间中，通风对于燃烧状况和火焰辐射特性有重要影响。本文根据火焰中炭颗粒的生成及其受通风的影响，提出了关于聚合物燃烧火焰辐射和平均辐射温度的估算方法。计算了几种典型聚合物的火焰辐射及其平均辐射温度，并讨论了通风、燃料组成、炭颗粒和燃烧尺度的影响，旨在加深认识通风条件对于火焰温度及其有关辐射特性的影响，为受限空间中燃烧过程的分析提供依据。     

Flame Retardation and Smoke Suppression of PVC

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Gas screening effect caused by steam curtains

Steam curtain equipment is used to prevent leaking flammable gases from reaching ignition sources, such as furnaces. However, steam curtains are sometimes designed badly and are ineffective for preventing the leaking gas from spreading in the windward direction. The leaked gas may pass on either side of the stream curtain, it may pass between the nozzles, or it may pass on the upper side of the stream curtain. At present, data to design the best stream curtains are quite rare. It is necessary to obtain fundamental data on the entrainment of air by steam jet and on the inclination of the steam curtain caused by the strong wind. Therefore, a series of experiments to investigate the entrained air and the inclination of the steam curtain were performed, in addition to further theoretical considerations. Thus, fundamental data useful for the design of the steam curtain equipment have been obtained.     

由湿式锅炉烟气脱硫净化器耗碱量考察锅炉SO2排放总量

通过监测论证了锅炉烟气湿式碱法脱硫净化装置耗碱量与锅炉实际二氧化硫排放速率的关系,分析了净化器循环水pH值变化与锅炉的二氧化硫排放总量之间存在着定量关系,并推导出计算模式     

高压内反馈串级调速电机在除尘系统中的应用

大型除尘系统风机通常采用串液力耦合器的方式来实现风机电机的轻载启动和调速。介绍了高压内反馈串级调速系统的主要工作原理和系统构成,并通过在某钢铁集团公司除尘风机上的首次应用实例,说明了高压内反馈串级调速电机的实际节能效果及其应用前景。     

煤与瓦斯突出气体逆流影响模式研究

为预防井下瓦斯气体逆流引起瓦斯爆炸等二次伤害,促进煤矿安全生产,建立瓦斯逆流运移扩散模型,采用相似试验研究不同风速和气体量影响下的气体逆流运移规律,根据试验系统的巷道模型,运用Fluent软件建立几何模型,模拟不同风速和涌出量对气体逆流的影响模式,观察同一测点或时间下2种因素对瓦斯浓度变化的影响,并以过往案例验证结论....     

民勤沙尘源区近地面降尘特征研究

借助近地面沙尘暴监测系统进行沙尘暴监测,分析民勤沙尘源区近地面降尘分布特征.结果表明:民勤降尘量与沙尘天气发生频率密切相关,春季3,4月沙尘高发期月降尘量分别为9.0和9.5 mg/cm2.降尘随距地面高度的增加而减小,最大降尘出现在近地面1 m处,月降尘量为9.7 mg/cm2;降尘受下垫面条件影响较大,从荒漠区到绿洲边缘,风速减弱4.11%,总降尘量由25.0 mg/cm2减少到20.6 mg/cm2;绿洲内部受防护林作用,风速减弱30.45%,总降尘量增到24.6 mg/cm2,最大降尘量提高到近地面9 m处,与绿洲防护林冠层平均高度相吻合.风速对近地面20m内的降尘影响明显,平均降尘量2.5 mg/cm2.距地面9 m的高度范围内,降尘随持续时间变化迅速增加,降尘增量可达3.1 mg/cm2.      

Experimental study of flame acceleration and the deflagration-to-detonation transition under conditions of transverse venting

Results of experiments on critical conditions for flame acceleration and the deflagration-to-detonation transition in tubes with transverse venting are presented. Tests were made with hydrogen mixtures in two tubes (inner diameter of 46 and 92 mm) with obstacles. Ratios of vent area to total tube area were 0.2 and 0.4. Venting was shown to influence flame acceleration significantly. The greater the vent ratio, the more reactive the mixture necessary for development of fast flames. Critical conditions for flame acceleration in tubes with venting, expressed through a critical mixture expansion ratio σ_cr, were found to be σ_cr/σ₀1+2, where σ₀ is the critical value for a closed tube. Critical conditions for detonation onset in a vented tube were found to be very close to those in a closed tube with similar configuration of obstacles.     

瓦斯爆炸阻隔爆装置失效原因的实验研究

通过对水平管道内瓦斯爆炸的火焰结构及压力结构的实验研究 ,分析了瓦斯爆炸阻隔爆装置的失效原因。结果表明 ,瓦斯爆炸火焰是沿着管道的底部向前传播的 ,火焰长度较长 ,并具有较高的内聚力。阻隔爆装置的失效原因是由于其动作延迟时间与火焰到达装置位置所需的时间不一致 ,使释放出的抑制剂不能有效地覆盖整个火焰区 ,造成具有较高内聚力的火焰 ,在其后部巨大爆炸产物膨胀压力的推动下继续向前传播