VCISR不同撞击间距下压力波动的数值模拟

Numerical simulation under pressure fluctuations of VCISR with different impact spacing

采用数值模拟的方法对VCISR(立式循环撞击流反应器)不同导流筒间距下压力波动的空间分布和时域分布进行研究,设定搅拌转速分别取为10,20和30r/s,上下两导流筒的间距分别取为60,100和140mm.结果表明:导流筒间距对压力波动的空间分布和时域分布有重大影响,同一转速下,导流筒间距为100mm时反应器内空间压力波动强度达到最大值,导流筒间距为60mm时反应器内时域压力波动强度达到最大值,微观混合效果分别达到最好;转速相同时,不同导流筒间距下时域压力波动曲线变化的趋势基本相同,即随着时间的增加先迅速下降后缓慢上升,达到一个时间分界点后时域压力值基本保持不变,导流筒间距越大达到时间分界点所需的时间越长.

The numerical simulation method was used to investigate the pressure fluctuations of the VCISR （vertical circulation impinging stream reactor） in spatial distribution and time-domain distribution under the different impact spacing. The speeds of stirring were set as 10, 20 and 30 r/s and the spacing between upper and lower draft tube were set as 60, 100 and 140 mm, respectively. The re- sults show that in the given numerical simulation parameters, under the conditions of same speed, the spatial pressure fluctuation reaches to the maximum value when impact spacing is 100 mm, and the time-domain pressure fluctuation reaches to the maximum value when tube spacing is 60 mm, which means that micro mixing effects achieve the best, respectively; under the conditions of same speed, the change trend of the pressure fluctuation in time-domain under different impact spacing is basically the same, which first decrease and then increase and then stay stable after reaches the time cut-off point. The greater the impact spacing, the longer the time required to reach the cut-off point.