循环流化床压力波动信号的间歇性分析

用小波变换模极大值的方法对循环流化床靠近床层底部和顶部压力波动时间序列进行多重分形分析，确定相应的压力波动信号的间歇性指数.结果表明循环流化床内气-固流动具有多重分形的特性，由间歇性参数随操作气速的变化可判断出由快速流化床向密相气力输送的改变，提出了新的判断循环流化床流型转变的方法，指出流型的转变沿提升管轴向并不是均匀一致同时改变，床层底部的转变要滞后于床层顶部.

INTERMITTENCE ANALYSIS OF PRESSURE FLUCTUATION SIGNAL OF CIRCULATING FLUIDIZED BED

The multifractal analysis for pressure fluctuation signal in bottom region and upper region of circulating fluidized bed(CFB) was performed by using the wavelet transform modulus maxima method.The intermittence index of the signals can be calculated with this method.Results show that the gas-solid flow in CFB is shown to possess a multifractal character.A new method is also proposed to identify the regime transition in CFB.The lower turning point of intermittence index curve can be used to determine the transition of flow regimes from fast fluidization to dense pneumatic conveying.The transition of flow regime in CFB is not homogeneous along the axis of riser, the transtion in bottom region may be later than in upper region, and the transport velocity based on this method is also compared with that calculated by some empirical equations.