选煤厂暗道多热源叠加作用对通风排尘特性的影响

Analysis of multithermo-sources superimposed effect on ventilation dedusting in coal preparation plant

为探究选煤厂输煤暗道多热源叠加作用对粉尘颗粒瞬态扩散的影响,采用热-流-固三场耦合理论,利用Fluent软件对通风排尘供暖过程中空间温度分布情况和粉尘颗粒瞬态扩散过程进行模拟研究,并在平朔安家岭选煤厂2125暗道进行试验。模拟结果表明:在内部热源辐射散热的影响下,暗道空间内靠近热源区域形成了明显的温度梯度;热泳力加剧了粉尘颗粒沉积效果,粉尘颗粒更易积聚在设备表面或地面,下部区域粉尘质量浓度高达394 mg/m3。现场试验表明:暗道空间各测点温度的模拟值与实测值基本吻合,验证了热-流-固耦合方法分析封闭空间内多污染热源通风供暖排尘过程中热源散热、气流场流动和粉尘颗粒动力场的三场耦合关系是正确的;明确暗道空间粉尘颗粒逸散特征,对提高降尘效果具有重要意义。

In order to explore the influence of multithermo-sources superimposed on dust particles transient diffusion,based on the coupled thermo-hydro-mechanical model,the distribution of space temperature and the dispersion law of dust particles were studied by using Fluent software.Related experimental study was conducted in Anjialing coal preparation plant.The simulation and experimental results indicated that temperature gradient was formed quickly in the high-temperature area under the influence of thermal radiation of internal heat sources.At the same time,the thermophoresis force played a dominant role in dust particles diffusion which resulted in dust accumulation on the surfaces of equipment and ground.The dust concentration was 394 mg/m3.Through comparison of temperature from simulation results and measuring data in the postern,the modeling results have been proven to be reliable.The interrelationship and interreaction of multi-physical coupled fields,which was composed of heating dissipation,airflow field and particles dynamic field in the enclosure space,were verified by the coupledthermo-hydro-mechanical method.The research findings further revealed the dust dispersion characteristics in preparation plant and had important scientific significance in improving the efficiency of dust removal.