仓泵流态化浓相输灰数值模拟

Numerical simulation of dense phase pneumatic conveying for fluidizing transporter

为了研究某煤粉工业锅炉房布袋除尘器仓泵充气输灰阶段内部粉煤灰的流化情况,合理设置仓泵的输灰时间,节约压缩空气用量,利用Fluent软件,采取数值模拟的方法,依据工业生产实际加入边界条件,进行非稳态计算,比较0.4、1.0、1.6、2.2、2.8和3.4 s等6个时刻仓泵内部的气固两相状态。研究发现：仓泵出灰量在很短的时间内即可达到最大,时间约为1.0 s,此段时间内仓泵气相回流较多,出灰管的入口速度矢量分布无规律;此后仓泵出灰量持续减少,在3.4 s基本结束。最后,推荐仓泵合适的加压输灰流化时间为4~5 s。

In industrial pulverized coal boiler room,the fluidizing transporter of bag-type dust collector was used to transport the fly ash.In order to determine the most suitable blowing time and reduce the consumption of compressive air,the Fluent software was used to simulate the process in unsteady state and the boundary condition was set by reality in industrial production.The state of solid and gas phases of 0. 4s,1. 0 s,1. 6 s,2. 2 s,2. 8 s and 3. 4 s after the start of blowing were compared in fluidizing transporter.The results showed that the fly ash amount reached to the maximum in 1.0 s after the start of pneumatic conveying.During this period,the fluidizing transporter was occupied by back flows of gas phase and the vector distribution of entrance velocity was irregular.The fly ash amount gradually decreased and basically ended at 3.4 s.At last,the appropriate length ranged from 4 s to 5 s.