摘要
在超临界二氧化碳布雷顿循环系统涡轮机械设计中,为提高能量转换效率,需要研究转子风阻的变化规律.针对5 MPa二氧化碳工质在不同转速、不同间隙宽度与转子半径比值以及不同定子壁面换热系数的工况进行数值计算分析.结果表明:在间隙宽度与转子半径比值相同的情况下,转子风阻随着转速的增大而增大;在转速一定的情况下,随着间隙宽度与转子半径比值的增大,转子风阻先减小后增大,在其比值为0.20时转子风阻存在最小值;转子风阻受泰勒涡影响较大,泰勒涡强度越大,摩擦系数越小;转子风阻随定子壁面换热系数的增大而增大,定子壁面换热系数的变化会导致腔室内工质温度的改变,工质热物性的改变是转子风阻随定子壁面换热能力变化的主要原因.
In the turbomachinery design of supercritical carbon dioxide Brayton cycle system,to improve the energy conversion efficiency,it is necessary to study the change rule of rotor windage.Numerical calculation and analysis are performed under the working condition of 5 MPa carbon dioxide at different rotating speeds,with different ratios of the gap width to the rotor radius,and with different convective heat transfer coefficients of the stator.The results show that the windage increases with the rotating speed increasing with the same ratio of the gap width to the rotor radius.At the same rotating speed,as the ratio of the gap width to the rotor radius increases,the windage decreases and then increases,and there is a minimum value when the ratio was 0.20.The windage is significantly affected by the Taylor vortex.The stronger the Taylor vortex is,the smaller the friction coefficient is.The windage increases as the convective heat transfer coefficient of the stator increases.It is the change of convective heat transfer coefficient of stator that makes the temperature of the working medium in the chamber change.The variation in the thermal physical properties is the main reason why windage changes with the convective heat transfer capacity of the stator.
作者
马乐
黄宏立
苏开放
梁腾和
张尧立
洪钢
MA Le;HUANG Hongli;SU Kaifang;LIANG Tenghe;ZHANG Yaoli;HONG Gang(College of Energy,Xiamen University,Xiamen 361102,China;Zhuhai Productivity Promotion Center,Zhuhai 519000,China)
出处
《厦门大学学报（自然科学版）》
CAS
CSCD
北大核心
2022年第1期74-79,共6页
Journal of Xiamen University：Natural Science
关键词
风阻
数值计算
泰勒涡
二氧化碳
windage
numerical calculation
Taylor vortex
carbon dioxide
