基于韦伯数的气液混输泵气相直径理论预测模型  

Theoretical prediction model of gas-phase diameter in multiphase pump based on Weber number

作　　者：刘明[1,2] 谭磊 曹树良[1,2] LIU Ming;TAN Lei;CAO Shuliang(Department of Energy and Power Engineering, Tsinghua University, Beijing 100084,China;State Key Laboratory of Hydroscience and Engineering, Tsinghua University, Beijing, 100084, China)

机构地区：[1]清华大学能源与动力工程系,北京100084 [2]清华大学水沙科学与水利水电工程国家重点实验室,北京100084

出　　处：《排灌机械工程学报》2022年第8期793-799,共7页Journal of Drainage and Irrigation Machinery Engineering

基　　金：国家重点研发计划项目(2020YFB1901401);清华大学国强研究院项目(2021GQG1003);水沙科学与水利水电工程国家重点实验室项目(2021-KY-04,sklhse-2022-Iow06)。

摘　　要：为了获得叶片式气液混输泵合理的气相直径取值,从而提高其两相流动模拟的准确性,文中从韦伯数这一决定气泡尺寸的关键参数出发,基于临界韦伯数建立了气相直径与转速、流量、含气率之间的相关关系,进而提出混输泵内气相直径的理论预测模型,并在3级叶片式气液混输泵中对该理论预测模型进行了应用.在不同流量和不同含气率的20个工况下,根据试验结果对数值模拟中的气相直径取值进行了标定,并据此拟合确定了理论预测模型中的经验系数,最终气相直径的理论预测值与数值模拟标定值的平均误差为7.28%.通过对气相直径和韦伯数在混输泵轴面流道上的分布规律进行分析,明确了高气相直径和高韦伯数的出现区域,并发现叶轮流道内高体积分数的气相会随主流运动发展,而导叶流道内高体积分数的气相则会聚集形成低速气团并堵塞流道.研究结果对提高气液混输泵两相数值模拟的准确性具有一定的帮助.In order to determine an appropriate value of gas-phase diameter to guarantee the simulation accuracy of gas-liquid flow inside multiphase pumps,from Weber number,which is a vital dimensionless value for bubble size,the relationship between gas-phase diameter and rotation speed,flow rate,gas volume fraction was established based on critical Weber number,and a theoretical prediction model for gas-phase diameter in multiphase pumps was proposed.The theoretical prediction model was applied in a three-stage rotodynamic multiphase pump.Under a total of 20 operating conditions of various flow rates and inlet gas volume fraction,the values of gas-phase diameter for numerical simulation were calibrated according to experimental results,and the empirical factors in the theoretical prediction model were fitted.Finally,the average deviation between prediction and calibration values of gas-phase dia-meter was 7.28%.According to the analysis of the distribution of gas-phase diameter and Weber number on the meridional passages inside the multiphase pump,the regions with high values of gas-phase diameter and Weber number are specified.It is also found that the gas phase of high volume fraction in the impeller passage will flow and develop along with the mainstream,but will gather to form a low-velocity pocket and block the passage of diffuser.The research results are helpful to improve the accuracy of two-phase numerical simulation of multiphase pump.

关 键 词：叶片式气液混输泵 气相直径 韦伯数 气液两相流 理论预测模型 

分 类 号：TK72[动力工程及工程热物理—流体机械及工程] S277.9[农业科学—农业水土工程]