透平式能量回收一体机水润滑转子稳定性研究  

Study on stability of water lubricated rotor of turbine energy recovery integrated machine

作　　者：宁延强 李岩[1] 张德胜[1] 叶晓琰[1] 丁竞飞 NING Yanqiang;LI Yan;ZHANG Desheng;YE Xiaoyan;DING Jingfei(National Research Center of Pumps,Jiangsu University,Zhenjiang212013,China)

机构地区：[1]江苏大学国家水泵及系统工程技术研究中心,江苏镇江212013

出　　处：《流体机械》2024年第2期24-31,74,共9页Fluid Machinery

基　　金：国家重点研发计划项目(2017YFC0404201)。

摘　　要：为了保障膜法海水淡化系统中透平式能量回收一体机的稳定运行,对一体机水润滑转子的稳定性展开研究。基于流体动压滑动轴承理论,同时考虑水润滑轴承和口环间隙水膜的流体动压润滑效应,在MATLAB平台上利用有限差分法、扰动增量法求解雷诺方程,得到水润滑滑动轴承及口环的动力特性系数,并对水润滑转子系统的动力学特征方程进行求解,进而判别转子系统的稳定性,研究了临界状态下系统转速与质量的关系。结果表明:口环间隙水膜的承载力在转子稳定性分析中不可忽略,否则将产生较大误差;考虑口环产生的动压润滑效应后,滑动轴承处水膜压力约减小40%,系统动力特性系数增加,系统的临界转速相较仅考虑滑动轴承时提升了3 000 r/min,临界质量提升了8.4%;滑动轴承的主刚度系数与交叉阻尼系数受转速的影响明显高于口环处。研究结果为提高海水淡化一体机水润滑转子系统的可靠性提供了参考。In order to ensure the stable operation of the turbine energy recovery unit in the membrane seawater desalination system,the stability of the water-lubricated rotor of the unit was studied in this paper.Based on the theory of hydrodynamic pressure sliding bearing,at the same time,considering the water film lubrication bearing and mouth ring clearance of hydrodynamic pressure lubrication effect,on the MATLAB platform by using finite difference method,the perturbation incremental method to solve the Reynolds equation,get water lubricated sliding bearing,the dynamic performance of the mouth ring coefficient,and the water lubrication,the dynamic characteristic equations of the rotor system are solved.Then the stability of the rotor system is judged,and the relationship between the speed and the mass of the rotor system under the critical state is studied.The results show that the bearing capacity of the water film in the mouth ring clearance can not be ignored in the stability analysis of the rotor,otherwise it will produce a large error.After considering the hydrodynamic lubrication effect caused by the mouth ring,the water film pressure at the sliding bearing decreases by about 40%,the dynamic characteristic coefficient of the system increases,and the critical speed ratio of the system increases by 3000 r/min and the critical mass increases by 8.4%when only the sliding bearing is considered.In addition,the main stiffness coefficient and cross damping coefficient of the sliding bearing are obviously higher than that of the ring due to the influence of rotational speed.The research results provide reference for further improving the reliability of water-lubricated rotor system of seawater desalination machine.

关 键 词：透平式一体机 水润滑轴承 转子稳定性 临界质量 动力特性系数 

分 类 号：TH113.2[机械工程—机械设计及理论]