中国电机工程学报
中國電機工程學報
중국전궤공정학보
ZHONGGUO DIANJI GONGCHENG XUEBAO
2014年
17期
2784-2793
,共10页
姜华伟%陈鸿伟%高建强%王洋%武振新
薑華偉%陳鴻偉%高建彊%王洋%武振新
강화위%진홍위%고건강%왕양%무진신
气固两相流%循环流化床%风帽%小波分析%均匀指数%压力波动
氣固兩相流%循環流化床%風帽%小波分析%均勻指數%壓力波動
기고량상류%순배류화상%풍모%소파분석%균균지수%압력파동
gas-solid flow%circulating fluidized bed%wind cap%wavelet analysis%homogeneous index%pressure fluctuation
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。
提齣利用採集、分析風帽壓力波動信號的方法,實現對循環流化床內氣固兩相流狀態的鑑測。藉助冷態循環流化床實驗檯,在不同一次風錶觀氣速條件下,測量瞭床內中心位置風帽的入口壓力波動信號、床內沿高度方嚮相臨測壓點的差壓信號以及繫統的顆粒循環流率。採用小波分析、均勻指數和能量加權平均頻率等方法對風帽壓力波動信號進行分析,得到信號的特徵參數。利用床內沿高度方嚮相臨測壓點的差壓信號計算床內不同位置的截麵平均顆粒濃度。然後基于壓力信號特徵參數、截麵平均顆粒濃度和繫統的顆粒循環流率等,研究瞭一次風錶觀氣速對循環流化床內氣固流態化特徵的影響。結果髮現,風帽壓力信號特徵參數能夠反映循環流化床一次風錶觀氣速變化引起的氣固流動狀態變化,錶明所提方法具有可行性。
제출이용채집、분석풍모압력파동신호적방법,실현대순배류화상내기고량상류상태적감측。차조랭태순배류화상실험태,재불동일차풍표관기속조건하,측량료상내중심위치풍모적입구압력파동신호、상내연고도방향상림측압점적차압신호이급계통적과립순배류솔。채용소파분석、균균지수화능량가권평균빈솔등방법대풍모압력파동신호진행분석,득도신호적특정삼수。이용상내연고도방향상림측압점적차압신호계산상내불동위치적절면평균과립농도。연후기우압력신호특정삼수、절면평균과립농도화계통적과립순배류솔등,연구료일차풍표관기속대순배류화상내기고류태화특정적영향。결과발현,풍모압력신호특정삼수능구반영순배류화상일차풍표관기속변화인기적기고류동상태변화,표명소제방법구유가행성。
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.