化工学报 ›› 2021, Vol. 72 ›› Issue (10): 5082-5093.DOI: 10.11949/0438-1157.20210355

• 流体力学与传递现象 • 上一篇    下一篇

基于TFM-PBM耦合模型的离心泵内微气泡破碎合并的模拟研究

高颂1,2(),徐燕燕1,2,3,李继香1,2,叶爽1,2(),黄伟光1,2,3   

  1. 1.中国科学院上海高等研究院,上海 201210
    2.中国科学院大学,北京 100049
    3.上海科技大学物质科学与技术学院,上海 201210
  • 收稿日期:2021-03-09 修回日期:2021-08-15 出版日期:2021-10-05 发布日期:2021-10-05
  • 通讯作者: 叶爽
  • 作者简介:高颂(1996—),男,gaosong2018@sari.ac.cn
  • 基金资助:
    国家重点研发计划项目(2017YFE0116300);中国科学院青年创新促进会会员项目(2017353);上海市科委科研计划项目(19DZ1205700)

Simulation study of microbubbles' break-up and coalescence in centrifugal pump based on TFM-PBM coupling model

Song GAO1,2(),Yanyan XU1,2,3,Jixiang LI1,2,Shuang YE1,2(),Weiguang HUANG1,2,3   

  1. 1.Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China
    2.University of Chinese Academy of Sciences, Beijing 100049, China
    3.School of Physical Science and Technology, Shanghai Tech University, Shanghai 201210, China
  • Received:2021-03-09 Revised:2021-08-15 Online:2021-10-05 Published:2021-10-05
  • Contact: Shuang YE

摘要:

了解离心泵内微气泡的发生特性,对于优化现有基于旋转流场的微气泡发生装置的性能、提高工业废水废气的污染物去除率至关重要。在考虑气泡破碎合并的前提下,通过将双流体模型(TFM)与群体平衡模型(PBM)进行耦合,求解离心泵内气液两相旋转流场,研究了入口体积气含率(IGVF)、入口气泡尺寸对泵内气泡沿程尺寸变化、出口气泡尺寸分布的影响,并结合Luo等的破碎合并模型分析成因。结果表明,随IGVF增加,叶轮内气体聚集引起局部气含率陡升,气泡由破碎主导转变为合并主导,而后在蜗壳内气含率恢复正常,气泡又变为破碎主导,总体上出口气泡尺寸逐渐增大。另外,入口气泡尺寸对出口气泡尺寸的影响对IGVF敏感,当IGVF较低时,随入口气泡尺寸增大,出口气泡尺寸先增大后减小;而当IGVF较高时,由于泵内气体聚集,入口气泡尺寸的影响并不明显。

关键词: 离心泵, 微气泡, 气液两相流, TFM-PBM耦合模型, 气含率, 粒度分布

Abstract:

Understanding the generation characteristics of microbubbles in centrifugal pumps is essential for optimizing the performance of existing microbubble generation devices based on rotating equipment and improving the pollutant removal rate of industrial wastewater and waste gas. Recognizing bubble break-up and coalescence, this paper examines how microbubbles evolve under different inlet gas volume fraction (IGVF) and different inlet bubble size in two-phase rotating flow field by coupling two fluid model (TFM) and population balance model (PBM), which was verified to be effective through comparing with experimental head and average bubble size. The results show that gas accumulation in impeller to be the main factor affecting the performance of bubbles with IGVF increasing, which causes bubble size increase as break-up dominated turn to coalescence dominated in impeller. Furthermore, the influence of inlet bubble size on outlet bubble size is sensitive to IGVF. Outlet bubble size increases first and then decreases with inlet bubble size increasing at low IGVF, while this influence is not obvious at high IGVF by gas accumulation in impeller.

Key words: centrifugal pump, microbubble, gas-liquid flow, TFM-PBM coupling model, gas holdup, size distribution

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