摘要
纳米磁流体在水轮机主轴密封中摩擦功耗计算及其性能一直是影响装置设计与应用研究的瓶颈。以悬浮在顺磁性载液中不平衡旋度Ω≠1/2(rotυ)的纳米磁流体为研究对象,通过Langevins,Navier-Stokes方程推导,得到纳米磁流体磁粒子摩擦功耗理论计算式,并且通过试验验证,试验与计算值相符。进一步的仿真研究发现,在水轮机主轴纳米磁流体密封装置中,齿槽(波谷)与极齿(波峰)对应的磁感应强度差值ΔB_(sum)对不平衡旋度影响较大,即ΔBsum越大,此处纳米磁流体不平衡旋度越明显,纳米磁流体不平衡扭矩越大、密封压差越大、密封能力越好、摩擦功耗越大,反之亦然。
The calculation of friction power consumption and the performance of nano-magnetic fluids in sealed water turbines have proved to be hurdles in the studies on nano-magnetic fluidic device designs and applications.In this paper,we investigate the imbalanced rotationΩ≠1/2(rotυ)of a nano-magnetic fluid suspended in a paramagnetic carrier liquid.Through Langevin and Navier-Stokes equations,the formula for the theoretical friction power consumption can be calculated for the magnetic particles in the nano-magnetic fluid.The calculated value fits the test result.Further simulation indicates that in a sealed nano-magnetic fluid device in a water turbine,the magnetic field gradientΔBsum between the tooth space(wave trough)and the pole tooth(wave crest)has the most influence on the imbalanced rotation.Specifically,the larger theΔBsum is,the more evident the imbalanced the nano-magnetic fluid rotation will be at that location,and the imbalanced torque will be larger,so the seal differential pressure will be as well.As a result,the sealing capacity will be better and the frictional power consumption will be larger,and vice versa.
作者
李正贵
李博
柴芯
杨逢瑜
LI Zheng-gui;LI Bo;CHAI Xin;YANG Feng-yu(Key Laboratory of Fluid and Power Machinery of Ministry of Education,Xihua University,Xihua University,Chendu,China,Post Code:610039;Xihua University Library,Chengdu,China,Post Code:610039)
出处
《热能动力工程》
CAS
CSCD
北大核心
2020年第1期76-82,共7页
Journal of Engineering for Thermal Energy and Power
基金
国家重点研发计划专项(2018YFB0905205-05)
西华大学(xjjg2017083)
教育部重点实验室开放课题(szjj2017-089)。
关键词
水轮机
纳米磁流体
不平衡旋度
主轴密封
摩擦功耗
water turbines
Nano-magnetic fluid
imbalanced rotation
rotating machinery seal
friction power consumption
