中文摘要：

提出利用采集、分析风帽压力波动信号的方法,实现对循环流化床内气固两相流状态的监测。借助冷态循环流化床实验台,在不同一次风表观气速条件下,测量了床内中心位置风帽的入口压力波动信号、床内沿高度方向相临测压点的差压信号以及系统的颗粒循环流率。采用小波分析、均匀指数和能量加权平均频率等方法对风帽压力波动信号进行分析,得到信号的特征参数。利用床内沿高度方向相临测压点的差压信号计算床内不同位置的截面平均颗粒浓度。然后基于压力信号特征参数、截面平均颗粒浓度和系统的颗粒循环流率等,研究了一次风表观气速对循环流化床内气固流态化特征的影响。结果发现,风帽压力信号特征参数能够反映循环流化床一次风表观气速变化引起的气固流动状态变化,表明所提方法具有可行性。

英文摘要：

A new method, measuring and analyzing pressure fluctuation signals of wind caps to monitor conditions of gas-solid flow in circulating fluidized beds, was proposed. The pressure fluctuation signals of the central wind cap, the differential pressure signals of adjoining pressure taps along the riser and solid circulation rates were measured at different primary air velocities in a cold circulating fluidized bed. To obtain the corresponding characteristic parameters, which reflect the effects of primary air velocity on the gas-solid fluidization characteristics of circulating fluidized beds, the pressure fluctuation signals in the wind cap were analyzed with the methods of wavelet analysis, homogeneous index and energy weighted average frequency. The mean solids holdups at various heights were calculated based on the differential pressure signals of adjoining pressure taps along the riser. Based on the characteristic parameters of wind cap pressure fluctuations, mean solids holdups at various heights and solid circulation rates, the effects of primary air velocity on the gas-solid fluidization characteristics were analyzed. It is found that the variations of characteristic parameters of wind cap pressure fluctuations are related with the variations of the gas-solid flow condition caused by the primary air velocity change. It is proved that the proposed method is practical.