化工学报 ›› 2020, Vol. 71 ›› Issue (2): 602-613.DOI: 10.11949/0438-1157.20191275

• 流体力学与传递现象 • 上一篇    下一篇

补充风对水平管高压密相气力输送影响的模拟研究

周海军(),熊源泉()   

  1. 东南大学能源热转换及其过程测控教育部重点实验室, 江苏, 南京 210096
  • 收稿日期:2019-10-25 修回日期:2019-12-04 出版日期:2020-02-05 发布日期:2020-02-05
  • 通讯作者: 熊源泉
  • 作者简介:周海军(1986—),男,博士研究生,zhounavy_0501@163.com
  • 基金资助:
    国家重点基础研究发展计划项目(2010CB227002);国家高技术研究发展计划项目(2011AA05A201)

Simulation study on influence of supplementary gas on dense-phase pneumatic conveying in horizontal pipe under high pressure

Haijun ZHOU(),Yuanquan XIONG()   

  1. Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, Southeast University, Nanjing 210096, Jiangsu, China
  • Received:2019-10-25 Revised:2019-12-04 Online:2020-02-05 Published:2020-02-05
  • Contact: Yuanquan XIONG

摘要:

针对水平管高压密相气力输送数理模型的缺陷与不足,引入Savage径向分布函数修正的颗粒动理学理论、基于Berzi摩擦压应力模型构建的摩擦应力模型以及修正的三段式曳力模型,在欧拉-欧拉方法的基础上建立了一个能同时兼顾水平管高压密相气力输送中稀相流、过渡流以及密相流输送特性的三维非稳态数理模型。并采用该数理模型考察了补充风对水平管高压密相气力输送的影响,模拟结果精准地预测了水平管压降及其随补充风的变化规律,而且其预测的水平管固相体积浓度分布与ECT图也是相吻合的,从而验证了数理模型的可靠性。模拟结果表明:随着补充风的增加,气固两相速度和湍动能以及颗粒拟温度增大,固相体积浓度减小。

关键词: 气力输送, 两相流, 密相, 介尺度, 补充风, 数值模拟

Abstract:

In view of the defects and deficiencies of the existing mathematical model, a new three-dimensional (3D) unsteady mathematical model for dense-phase pneumatic conveying in horizontal pipe under high pressure was established based on the Euler-Euler model. This mathematical model introduced the modified kinetic theory of granular flows by Savage’s radial distribution function, the frictional stress model established on Berzi’s frictional pressure stress and the modified three-zone drag model to expound the conveying characteristics of all of three flow regimes: dilute regime, intermediate regime and dense regime. Meanwhile, this mathematical model was applied to explore the effects of supplementary gas on dense-phase pneumatic conveying in horizontal pipe under high pressure. The simulation results show that the pressure drop of horizontal pipe and its variation with the supplementary gas flow rates are predicted accurately, and the predicted solids volume fraction distribution at the cross section of horizontal pipe also basically agrees with the electrical capacitance tomography (ECT) diagram, which confirm the reliability and applicability of this mathematical model. The simulation results show that as the supplementary wind increases, the gas-solid two-phase velocity and turbulent kinetic energy and particle pseudo-temperature increase, and the solid phase volume concentration decreases.

Key words: pneumatic conveying, two-phase flow, dense-phase, mesoscale, supplementary gas, numerical simulation

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