摘要
针对大型空冷汽轮发电机转子旋转状态下,转子内部流体流量和转子线圈温度难以准确测量的问题,对转子内部流体流动规律和温度分布进行了流体场和温度场研究.以一台100MW空冷汽轮发电机为例,建立了三维流体与传热耦合计算模型.基于旋转弱耦合与旋转强耦合两种有限元计算方法,对该发电机的转子进行流体场和温度场计算.弱耦合计算方法主要根据流体流动的伯努利方程与计算流体力学相关方程联合求解,强耦合计算方法主要通过计算旋转流体力学方程求解.研究了转子额定励磁电流,转速3000r/min时,转子内部通风道流体温度与转子绕组温度的相互关系.并将两种计算方法对同一转子的流体流量和线圈温升结果做了对比分析,最后将两种计算方法所得的转子线圈温度计算结果与试验实测结果对比.结果表明:弱耦合计算方法与实测值误差为4.6%,强耦合计算方法与实测值误差为2.6%,两种计算方法均能满足工程计算的误差要求,旋转强耦合计算方法计算精度高于旋转弱耦合计算方法.
Since it is difficult to measure the fluid flow and the coil temperature accurately in the rotor of large turbo-generator,the fluid field and temperature field of the rotor in large air-cooled turbo-generator are studied to conclude the fluid flow law and temperature distribution.Taking a 100 MW air-cooled turbo-generator as an example,this paper builds a three-dimensional fluid and coupling heat transfer calculation model and uses two finite element methods including rotational weak coupling and rotational strong coupling to calculate the fluid field and temperature field of the generator rotor.The weak coupling method is mainly based on the Bernoulli equation of fluid flow and the computational fluid mechanics related equations,and the strong coupling method is mainly based on the rotational fluid mechanics equation.The relationship between the fluid temperature in the ventilation duct and the temperature of the rotor winding under the rated rotor speed of 3000 r/min is studied.The fluid flowand coil temperature rise of the same rotor are compared by the two methods,the results of which are then compared with the experimental results.It is found that the error between the weak coupling calculation value and the measured value is 4.6%,the error between the strong coupling result and the measured value is 2.6%.Therefore,the two calculation methods can satisfy the error requirement of the engineering calculation,rotational strong coupling calculation method has higher calculation accuracy than rotational weak coupling calculation method.
作者
李勇
李伟力
苏营
LI Yong;LI Weili;SU Ying(School of Electrical Engineering,Beijing Jiaotong University,Beijing 100044,China;China North Vehicle Research Institute,Beijing 100072,China)
出处
《北京交通大学学报》
CAS
CSCD
北大核心
2019年第6期104-110,共7页
JOURNAL OF BEIJING JIAOTONG UNIVERSITY
基金
国家自然科学基金(51477049)~~
关键词
汽轮发电机
流体场
温度场
温升计算
转子
turbo-generator
fluid field
temperature field
temperature rise calculation
rotor
