温度场对供料器管道内颗粒分布影响的CFD模拟

Influence of temperature field on particle distribution in feeder pipeline with CFD simulation

建立供料器管道内气固两相流的物理和数学模型,采用Fluent 2020 R2软件中的离散相模型(DPM)模拟供料器管道中温度场、压力流场和颗粒分布情况,搭建气力式混合机实验平台进行压力测试验证,并将考虑温度场和不考虑温度场影响时的仿真结果进行对比,研究温度场对供料器内颗粒分布的影响规律。结果表明:在供料器管道中,气相与颗粒相初始温度不同,气固两相流进行热量交换后温度逐渐趋向一致;考虑温度场影响时管道内的绝对压降大于不考虑温度场影响时,而且与实验测量值的误差仅为16%左右;在两侧管道出口段,随着Z轴向距离的增加,颗粒质量浓度分布从管道圆截面中心处低、壁周面高逐渐变为整个管道圆截面上近似均匀分布;相较于不考虑温度影响时的情况,考虑温度场影响时管道圆截面中心处的颗粒质量浓度降低了3.0%~8.7%,在管道圆截面上形成稳定均匀的颗粒质量浓度分布所需要的Z轴向距离要长。

Physical and mathematical models of gas-solid two-phase flow in the feeder pipeline were established.The discrete phase model(DPM)in Fluent 2020 R2 software was used to simulate the temperature field,pressure flow field and particle distribution in feeder pipeline.A pneumatic mixer test platform was built to test and verify the pressure.The effect of temperature field on particle distribution in feeder was studied by comparing the simulation results with and without temperature field.The results show that the initial temperature of gas phase and particle phase is different in feeder pipeline,and the temperature gradually tends to be the same after the heat exchange between gas and solid phase flow.The absolute pressure drop in pipeline with the influence of temperature field considered is greater than that without the influence of temperature field,and the error between measured value and experimental value is only about 16%.At the outlet section of both sides of pipeline,with the increase of Z-axis distance,the distribution of particle mass concentration gradually changes from low in the center of the circular section of the pipeline and high in the wall surface to approximately uniform distribution on the entire circular section of the pipeline.Compared with the condition without considering the influence of temperature,the particle mass concentration at the center of the circular cross section of pipeline decreases by 3.0%~8.7%and the Z-axis distance required to form a stable and uniform particle mass concentration distribution on the circular cross section of pipeline is longer when considering the influence of temperature field.