摘要
制冷离心压缩机采用制冷剂作为润滑介质,不仅能保证整个制冷系统无油,而且可以显著提高制冷能效。以离心压缩机中分别采用R410A和R407C润滑的径向波箔动压气体轴承为研究对象,基于有限差分法对定常雷诺方程和气膜厚度方程进行耦合迭代求解,通过数值计算得到了承载力和摩擦力矩随转速、偏心率和名义半径间隙的变化规律。结果表明:工质为R410A和R407C时,承载力和摩擦力矩均随转速和偏心率的增大而增大,随名义半径间隙的增大而减小。偏心率越大,承载力增大的梯度越大。在相同的蒸发温度条件下,工质为R410A时的承载力更大。名义半径间隙较小时,两种工质的承载力相差较大,但随着名义半径间隙的增大,承载力之间的差值逐渐减小。摩擦力矩是压力流和剪切流的共同作用,工质的动力粘度对摩擦力矩有着直接的影响,动力粘度越大,摩擦力矩也越大。
The appplication of refrigerant as lubricant in centrifugal refrigerating compressor can not only keep the refrigeration system oil-free,but also improve the energy efficiency of system significantly.The bump foil journal gas bearings lubricated with R410 A and R407 C in centrifugal compressors were chosen as the research targets.Based on the finite difference method,the Reynolds equation and the gas film thickness equation were solved by coupling iterations.The variations of bearing capacity and friction torque with rotational speed,eccentricity and nominal radius clearance were obtained by numerical calculation.The results show that with two refrigerants,the bearing capacity and friction torque both increase with the increase of rotational speed and eccentricity,but decrease with the grow of nominal radius clearance.The greater the eccentricity is,the faster the bearing capacity increases.At the same evaporation temperature,the bearing capacity of R410 A is greater.When the nominal radius clearance is small,the difference between bearing capacities of two refrigerants is large.But with the increase of the nominal radius clearance,the difference decreases gradually.The friction torque is the result of interaction of pressure flow and shear flow.The dynamic viscosity of working medium has a direct effect on the friction torque,and the greater dynamic viscosity will result in greater friction torque.
作者
化文灿
杨山举
冶文莲
马斌
罗晶晶
王顺喜
Hua Wencan;Yang Shanju;Ye Wenlian;Ma Bin;Luo Jingjing;Wang Shunxi(College of Mechanical and Electronic Engineering,Northwest A&F University,Yanling 712100,China;China Aerodynamics Research and Development Center,Mianyang 621000,China;Changqing Oilfield(Yulin)Oil and Gas Co.,Ltd.,Yulin 719000,China)
出处
《低温与超导》
CAS
北大核心
2022年第3期31-39,共9页
Cryogenics and Superconductivity
基金
国家自然科学基金(52106027)资助。
