高压浓相变水分煤粉输送特性及香农信息熵分析  

Flow Characteristics and Shannon Entropy Analysis of Dense-phase Pneumatic Conveying of Pulverized Coal With Variable Moisture Content at High Pressure

作　　者：梁财[1] 赵长遂[1] 陈晓平[1] 蒲文灏[1] 鹿鹏[1] 范春雷[1] 

机构地区：[1]东南大学洁净煤发电及燃烧技术教育部重点试验室,江苏省南京市210096

出　　处：《中国电机工程学报》2007年第26期40-45,共6页Proceedings of the CSEE

基　　金：国家重点基础研究发展计划项目(2004CB217702-01);东南大学优秀博士学位论文基金资助项目~~

摘　　要：在输送压力可达4.0MPa,固气比高达450kg/m3的高压气力输送试验台上,用氮气进行煤粉高压浓相气力输送试验研究。分别在不同的总输送差压、煤粉含水率、压力和表观速度等条件下进行了输送试验,考察操作参数对煤粉质量流量和固气比等气力输送特征参数的影响,用信息熵分析试验过程中采集到的压力波动时间序列,探讨流动稳定性和流型变迁过程中信息化趋势,建立信息熵和流型之间的关系。结果表明,在总输送差压增大的过程中,固气比和香农(Shannon)信息熵均增大;流动相图与Shannon信息熵之间呈现较好的规律性;不同流动形态的Shannon熵差异较大,不同流型之间的Shannon熵区分度较好。随着煤粉含水率的增大,煤粉的质量流量和压损减小,Shannon信息熵值下降。Shannon信息熵分析为研究高压浓相气力输送流型、稳定性及其转变特性提供了一种行之有效的方法。Experiments of dense-phase pneumatic conveying of pulverized coal using nitrogen were carried out in an experimental test facility with the conveying pressure up to 4MPa and the solid-gas ratio up to 450kg/m^3. The influences of the total conveying differential pressure, the moisture content, the superficial velocity and the pressure on the mass flow rate and the solid-gas ratio were investigated. Shannon entropy analysis of pressure fluctuation time series was developed to reveal the flow characteristics. Based on the distribution of the Shannon entropy in the different conditions, the flow stability and the evolutional tendency of Shannon entropy in different regimes and the regime transition processes were obtained. The relationship between Shannon entropy and flow regimes was also esiablished. The results indicate that the solid gas ratio and Shannon entropy rise with increase in the total conveying differential pressure. Phase diagram and Shannon entropy reveal preferable regularity with superficial velocity. Shannon entropy is different for the different flow regimes, and it can be used to identify the flow regimes. As the moisture content increases, the mass flow rate, the pressure drop and Shannon entropy decrease. Shannon entropy analysis is a feasible approach to research the characteristics of flow regimes, stability and flow regime transitions in Dense-phase pneumatic conveying at high pressure.

关 键 词：气力输送 高压 固气比 香农信息熵 

分 类 号：TQ51[化学工程]