为理解不同典型参数对无烟煤着火特性的影响,本文建立了单颗粒煤粉着火模型。基于主要的总包非均相反应和气相反应及相应的对流和传热传质规律,模拟O2/N2燃烧方式下煤粉颗粒的着火过程,研究了不同的气流温度、O2浓度、对流条件等关键因素对无烟煤颗粒着火的影响特征,结果表明气流温度增加时煤粉颗粒着火延迟时间在不同对流条件下普遍变短,且温度较高时着火延迟时间对对流强度变化的响应有所减弱;在相同气流温度和O2浓度条件下,气流对流强度处于较低水平时,其变化对着火延迟时间的影响相对明显;当气流的温度和对流条件一定时,O2浓度增加则着火延迟时间变短,但影响较小。模型得到文献数据的有效检验。
To understand the effects of different typical factors on the ignition characteristics of the anthracite coal,a model on the ignition of a single coal particle was built.Based on principal global heterogeneous reactions and gas phase reactions,as well as related laws of convection and heat and mass transfer,the ignition was simulated in O2/N2 environment.The influence characteristics of gas temperature,concentration of O2,and convection conditions were studied in coupling.In the results,it was found that the coal particle ignition time is generally shorter for different convection intensities with a higher temperature of the flow.Meanwhile,for higher temperature,the influence of the convection on the delay time of ignition gets weaker.On the other hand,under similar air temperature and O2 concentration,and with lower convection intensity,the effect of convection is much clearer on the ignition delay time.Keeping flow temperature and convection conditions invariant,a larger O2 concentration results in a shorter ignition delay time,whereas the effect is small.The model was effectively validated by results from literature.