摘要
在全空冷水轮发电机长期运行下,由于转子磁轭长期反复地受到磁应力和热应力的作用,造成了转子磁轭通风沟结构的形变。由于全空冷水轮发电机的冷却效果直接影响了电机的性能和经济指标,因此研究转子磁轭通风沟结构的形变对全空冷水轮发电机的影响十分重要。本文以一台250MW全空冷水轮发电机为例,根据该电机特殊的通风冷却结构,确定转子旋转情况下的计算区域,并分别建立在转子磁轭通风沟结构发生形变和未发生形变时的转子三维流体-温度场的耦合计算模型。在给定相应的基本假设条件与边界条件下,采用有限体积法对全空冷水轮发电机的通风和散热问题进行计算与分析。重点研究转子磁轭通风沟结构形变对磁极间隙内空气流动速度和温度以及励磁绕组温度的影响,并得出相应的变化规律。同时,在转子磁轭通风沟结构未发生形变时,将转子励磁绕组平均温度的计算结果与实测数据进行对比来验证方法的正确性。
Under the long term operation of a full air-cooled hydro-generator, due to the repeated magnetic and thermal stress on the rotor yoke, the rotor yoke ducts are deformed. As the cooling effect of the hydro-generator directly affects the performance and economic indicators. Therefore, it is important to study the influence of the ducts deformation on the a full air-cooled hydro-generator. Taken a 250 MW air-cooled hydro-generator as an example, according to the special ventilation structure, the calculation area of the rotor was determined. The three dimensional coupling calculation models of rotor with deformed and normal ducts were respectively established. When the assumed and boundary conditions were given, the finite volume method is used to analyze the ventilation and heat dissipation of a hydro-generator. The regularities of influence of the rotor yoke ducts deformation on the fluid flow state and the excitation winding temperature were analyzed. When the ventilation ducts are normal, the calculation result of the excitation winding average temperature is compared with the measured data, and the method is verified.
出处
《电工技术学报》
EI
CSCD
北大核心
2017年第A02期42-49,共8页
Transactions of China Electrotechnical Society
基金
国家自然科学基金资助项目(51477049
51477005)
关键词
全空冷水轮发电机
转子
磁轭通风沟
温度场
流体场
Full air-cooled hydro-generator, rotor, ventilation ducts, temperature field, fluid field
