定子通风槽钢结构对提高中型高压电机散热性能分析

Analysis of Stator Ventilation Channel Steel Structures to Improve Heat Dissipation Performance of Medium-sized High Voltage Motors

为降低YJK450-6、400kW中型高压电机的通风散热性能,本文对该电机不同通风槽钢结构进行了散热性能研究。首先,在现有电机的直线标准型通风结构基础上,提出单列缩放型、双列直线型、双列缩放型3种轴-径向混合通风结构形式;在SpaceClaim软件中建立电机3维温度场数值计算模型,根据基本假设和边界条件结合电机内部热量传递公式计算出电机仿真设置参数,并导入Fluent软件进行仿真模拟,其中,计算温度场所用热源通过AnsoftMaxwell平台计算的电机损耗值获取。其次,通过网格无关性和温升试验验证本文建立的电机3维温度场数值计算模型;通过仿真模拟对比分析3种轴-径向混合通风结构与直线标准型结构对电机流场和温度场的影响;采用正交试验法对轴-径向混合通风结构进行参数优化,得到最佳散热结构和参数方案;进一步探究冷却风速对双列缩放型槽钢的电机换热性能的影响;结合定子绕组温升和电机整体的温升均匀性系数,对最佳散热结构和参数方案电机进行散热效果评价。仿真结果表明:本文建立的计算模型是有效的;双列缩放型通风槽钢结构的各项散热性能指标均最好,是最优通风槽钢结构;径向风道高度为6mm且数量为13的双列缩放型通风槽钢结构为最佳散热结构和参数方案;双列缩放型通风槽钢结构两侧的平均对流换热系数随冷却风速增大而增大,且槽钢迎风面的平均对流换热系数明显大于背风面;径向风道高度为6mm且数量为13的双列缩放型通风槽钢结构电机的内/外层绕组温升分布均匀性系数比直线标准型电机分别提高88.13%、20.11%。因此,优化设计通风槽钢结构有利于电机内部空气流动和散热,可实现有效降低电机内部温升的目的。

In order to reduce the ventilation and heat dissipation performance of the YJK450-6,400 kW medium-sized high-voltage motors,the heat dissipation performance of different ventilation channel steel structures of these motors was studied in this paper.Firstly,on the basis of the linear standard ventilation structure of the existing motor,three axial-radial hybrid ventilation structure forms were proposed,those are the singlerow scaling type,the double-row linear type and the double-row scaling type.The 3D numerical calculation model of the temperature field of the motor was established in the SpaceClaim software.The simulation parameters of the motor were calculated according to the basic assumptions,the boundary conditions and the internal heat transfer formula of the motor.The simulation was carried out by Fluent software.Notably,the heat source for calculating the temperature field was obtained by the motor loss value computed by the Ansoft Maxwell platform.Secondly,the 3D numerical calculation model of the temperature field established in this paper was validated through the grid independence and temperature rise tests.A comparative analysis was conducted through simulation to assess the impact of the three axial-radial hybrid ventilation structures and the linear standard structure.The orthogonal test method was used to optimize the parameters of the axial-radial mixed ventilation structure to obtain the optimal heat dissipation structure and parameter scheme.The effect of cooling air velocity on the heat transfer performance of the double-row scaled channel steel was further explored.Combined with the temperature rise of the stator windings and the uniformity coefficient of the overall temperature rise of the motor,the heat dissipation effect of the optimal heat dissipation structure and parameter scheme of the motor was evaluated.The simulation results showed that the calculation model established in this paper is effective.The double-row scaling ventilation channel steel structure exhibit the best heat dissipation performance indexes,making it the optimal ventilation channel steel structure.The double-row scaling ventilation channel steel structure with a radial air duct height of 6 mm and a quantity of 13 is identified as the optimal heat dissipation structure and parameter scheme.The average convective heat transfer coefficient on both sides of the double-row scaling ventilation channel steel structure increases with the cooling air velocity,and the average convective heat transfer coefficient on the windward side of the channel steel is significantly higher than that on the leeward side.Compared to that of the linear standard motor,the uniformity coefficient of temperature rise distribution of the inner/outer windings of the double-row scaling ventilation channel steel structure motor with a radial duct height of 6 mm and a quantity of 13 increase by 88.13% and 20.11%respectively.Therefore,the optimal design of the ventilation channel steel structure is conducive to the internal air flow and heat dissipation of the motor,which can effectively reduce the internal temperature rise of the motor.