基于小波模极大的循环流化床气化炉冷态试验研究

Cool Experimental Study of Circulating Fluidized Bed Gasifier Based on Wavelet Modulus Maxima

对循环流化床气化试验系统进行冷态试验研究,改变风量、颗粒粒径、组合粒径等操作参数,掌握固体循环速率Gs、空隙率的变化规律,应用小波模极大法对压差波动信号进行分析。结果表明:随着表观风速的提高,Gs逐渐增大。表观风速大于2m/s时,普通颗粒在提升管底部表现出快速区特征,其压差的模极大值线条数与顶部差不多相等。改变粒径分布范围,细颗粒能够增大Gs的同时,相当份额的粗颗粒在提升管内能表现出底部湍流区、上部快速区的特征,延长了其在床内的停留时间。对应的底部压差波动信号的模极大值线较顶部要多,但随着表观风速的增大,快速区长模极大线位置向后移动。分析结果有助于深入理解增压循环流化床气化的设计、控制和运行。

The cool experimental study was carried out on circulation fluidized beds （CFB） gasification experiment system. The change law of solid circulation rate Gs, and solids holdup were studied by the changes of the flow rate of riser, particle size and combination particle. And pressure fluctuation was analyzed by using wavelet modulus maxima method. The experimental results indicate that Gs increases gradually with the increase of riser velocity. When the velocity of superficial gas exceeds 2 m/s, the common particles express the fast area characteristics at the bottom of the riser. Its numbers of modulus maxima lines of pressure were equaled with the top. By a change of particle size distribution, fine particles can increase Gs, while coarse particles exhibit turbulence area characteristics at the bottom, and fast area characteristics in the upper of riser. Resident time of particles is prolonged. There is more number of modulus maxima lines of the bottom than the top, but long modulus maxima lines move backward with the increasing of the superficial gas of fast area. The results indicate that this study is likely to play an important guiding role to designing, controlling and operation of pressured CFB gasification system.