水轮发电机转子系统磁悬浮承重装置散热研究

Study on heat dissipation of magnetic-levitation bearing device for rotor system of hydraulic turbine-generator unit

由于水轮发电机轴向重力负荷电磁悬浮承重系统的励磁线圈密封在装置内部,无法与外界空气对流,从而会出现温升过高。为解决此问题,提出了分别在该系统电磁铁的上铁心和衔铁(推力盘)上设置一定数量的通风孔,以便使线圈表面形成对流散热。针对通风孔设计,选用适合此模型结构的对流散热数值模型,推导出对流散热系数的数值,并利用有限元分析软件Ansys进行了温度和磁场仿真分析。结果显示,在满足水轮机组承重要求的前提下,合理设计通风孔可以使电磁悬浮装置线圈温度大大降低,满足系统应用要求。

Since the excitation coils of electromagnetic-levitation bearing system for the axial load of hydraulic turbine-generator are sealed inside of the system, the heat inside is difficult to be dissipated, and then over-high temperature rise would occur therein. For solving this problem, it is put forward that a few vents are respectively arranged on both the electromagnet core and the armature （ thrust disc） of the system, so as to create a convection heat dissipation on the surface of coils. So far as the design of the vent is concerned, suitable numerical models are selected for this model along with the deduction of the coefficient of con- vection heat dissipation, and then the simulation analysis on the temperature and the magnetic field is made with the software-- Ansys. The results show that under the premise to satisfy the bearing requirement of hydraulic turbine-generator unit, the temperature of the coils can be greatly lowered with the reasonably designed vents, therefore, the application requirement of the system can be met as well.