立式水轮发电机蒸发冷却转子振动特性研究

Study on vibration characteristics of evaporative cooling rotor of vertical hydro⁃generator

随着水轮发电机向大容量、高转速发展,对转子冷却技术提出了更高的要求。蒸发冷却技术是一种依靠冷却介质相变吸热的高效冷却技术,但目前的蒸发冷却转子方案要求在转子上存储一定量的液态冷却介质。为研究蒸发冷却转子上液态冷却介质与转子振动特性之间的关系,本文基于某水电站立式水轮发电电动机真机模型初步建立了管道内冷式转子蒸发冷却结构,研究了不同液位高度下蒸发冷却介质对转子固有频率的影响。结果表明,随着液位高度的增加,冷却介质对管道壁面的压力逐渐增大,对转子自身的固有频率无显著影响。本文所做工作对后续进行转子蒸发冷却结构优化设计以及进一步研究液态冷却介质与转子振动特性之间的耦合关系具有一定的指导意义。

With the development of hydro⁃generators towards large capacity and high speed,higher requirements have been imposed on rotor cooling technology.Evaporative cooling technology is an efficient cooling method that relies on the heat absorption during the phase transition of the cooling medium.However,current evaporative cool⁃ing rotor schemes require a certain amount of liquid cooling medium to be stored on the rotor.In order to investigate the relationship between the liquid cooling medium on the evaporative cooling rotor and the rotor vibration character⁃istics,this paper preliminarily establishes a pipe⁃cooled evaporative cooling structure based on a prototype model of a vertical hydro⁃generator.The influence of evaporative cooling medium on the natural frequency of the rotor at dif⁃ferent liquid level heights was studied.The results show that with the increase of liquid level height,the pressure of the cooling medium on the pipe wall gradually increases,and there is no significant effect on the natural frequency of the rotor itself.The work presented in this paper provides certain guidance for subsequent optimization of the e⁃vaporative cooling structure of rotors,as well as further research on the coupling relationship between liquid cooling medium and rotor vibration characteristics.