不同三次风速下分解炉二相流场的数值模拟

为了优化分解炉内的气固二相流流场以提高其性能指标,基于一实际尺寸的SLC-S分解炉,分别对不同三次风速下的气固二相流场进行了数值模拟,其中对连续相、颗粒相的计算分别采用k-ε双方程湍流模型和离散相模型,对离散相与湍流之间的相互作用采用随机跟踪模型。计算所得气流场分布规律与实测值吻合较好,且颗粒相的质量浓度场分布形式与实际情况相一致。模拟结果表明:在所考察的边界条件下,当三次风速≤28 m/s时,分解炉本体压力损失较低,且物料停留时间的绝对值和料气停留时间比值皆相对很高,为适宜的三次风速范围。

Numerical simulations of gas-solid flows in a precalciner with different tertiary-air velocities

To optimize the gas-solid flows in SLC-S precalciner,the numerical simulation was carried out with tertiary-air velocity changed.In Euler coordinate system the gas phase was expressed with k-ε model,in Lagrange coordinate system the solid phase with Discrete Phase Model(DPM),and the random effects of turbulence on the particle dispersion was accounted for with Discrete Random Walk(DRW) model.The predicted gas velocity field agrees well with the measured data,and the calculated mass concentration distributions are consistent with the actul conditions.The results predict that it is optimum when the tertiary air velocity is less than or equal to 28 m/s,because not only both the solid residence-time and residence-time ratio between solid and gas are high,but also the total pressure decreases a little from the tertiary-air inlet to the outlet.