射流对循环流化床内气固流动特性的影响

Influence of Jet on Gas-Solid Flow Characteristics in Circulating Fluidized Beds

在循环流化床试验台上进行了射流对炉内气固流动特性影响的试验,考察了不同的射流量和射流喷射高度对炉内轴向气流速度及截面平均固体颗粒浓度分布的影响.结果表明:射流的加入使得密相区气流速度降低,但利于气流整体平均速度的提升及加强气相流场的均匀性,射流对气相速度的影响主要体现在喷口以下区域;射流加入后,会在喷口附近区域形成动力阻塞区,浓相区固体颗粒浓度随着射流量的增加而提高,射流喷射高度的增加会提升浓相区的高度.

Experimental study for influence of jet on gas-solid flow characteristics in the furnace was carried out on a circulating fluidized bed （CFB） test rig. The influence of different jet ratios and spray heights on gas axial velocity and average cross section solid particle concentration were studied. Results indicate that jet decelerates the gas velocity at dense area, while it can promote average gas velocity and homogenize flow field. The influence of jet on gas velocity mainly occurs in the area below nozzle. A kinetic blocked region is formed near nozzle after jet spray, meanwhile the average solid particle concentration in dense area increases with increasing jet ratios, and the increase of spray height of jet can icrease the height of dense phase region.