发电电动机通风系统全通道数值模拟

发布时间：2018-03-27 18:48

本文选题：水力机械　切入点：发电电动机　出处：《哈尔滨工业大学》2014年硕士论文

【摘要】：随着社会经济的高速发展，我国投入建设了大量火电站和核电站；为减少温室气体的排放，可再生能源陆续进入大规模开发。因此，需要加快建设配套的抽水蓄能电站，，增强电网的安全性、稳定性和调节能力。水轮发电机在运行过程中，铁耗、铜耗和摩擦损耗等都将引起部件的发热和温度上升，影响正常运行。而发电电动机转速高，尺寸小，磁极容量大，其通风冷却比常规水轮发电机难度更大。为此，有必要对发电电动机的通风冷却系统进行数值模拟研究，为改善它的通风冷却性能提供参考。为实现上述目的，本文对响水涧发电电动机发电工况下通风系统的流场进行了全通道数值模拟。并提出三种优化方案：研究转子支架辐板倾角、定子槽钢长度和槽钢安放相对位置对通风系统的影响。具体研究内容如下：对原型发电电动机在发电工况额定转速n=250r/min下的通风流场进行定常数值模拟，获得实际通风流量；得到发电电动机的风损比；分析转子支架入口及辐板间空气的流动情况，计算转子支架入口阻力系数及支架辐板压力损失系数；分析转子磁轭风沟内的流动规律，计算磁轭风沟的平均流速、散热系数和沿程损失系数；分析转子磁极风道内流体流动情况，计算流道的总压损失系数、磁极散热匝表面平均流速、散热系数和温升等；分析定子通风沟内的流动情况并计算阻力系数，获得定子铁心段线圈和端部线圈表面平均流速、散热系数和温升等。提出了三种优化方案，分别研究了支架辐板倾角在15°到40°之间变化、定子槽钢长度从减小20mm到增长14mm之间、定子槽钢按新的规律（不对称安放）安放时对发电电动机通风流场性能的影响。从增大流量、减小通风损耗，增大磁极风沟表面、磁极散热匝表面和定子线圈表面的散热效果的角度，分析了各工况下的通风流场，得到对发电电动机通风冷却更有利的支架辐板倾角、定子槽钢长度和槽钢安放规律。本文通过定常计算得到通风流场的详细情况及各个关键部位表面的流速、散热系数和温升；得到转子支架辐板最佳倾角为40o；定子槽钢长度比原型结构增加10mm对通风冷却更有利；槽钢按方案三布置较好。
[Abstract]:With the rapid development of social economy, a large number of thermal power plants and nuclear power plants have been built in China. In order to reduce greenhouse gas emissions, renewable energy has been developed on a large scale. Therefore, it is necessary to speed up the construction of supporting pumped storage power stations. During the operation of hydrogenerator, iron consumption, copper consumption and friction loss will cause the heating and temperature rise of the components, which will affect the normal operation of the generator, while the motor speed is high and the size is small. The ventilation cooling of magnetic pole is more difficult than that of conventional hydrogenerator. Therefore, it is necessary to study the ventilation cooling system of power generation motor by numerical simulation to provide a reference for improving its ventilation cooling performance. In order to achieve the above purpose, the full-channel numerical simulation of the flow field of the ventilation system under the working condition of Xiangshuijian electric motor is carried out in this paper, and three optimization schemes are proposed: to study the angle of the radial plate of the rotor support, The influence of stator channel length and relative position of channel steel on ventilation system. The steady numerical simulation of ventilation flow field of prototype generator under rated speed n=250r/min is carried out to obtain the actual ventilation flow, the wind loss ratio of the generator is obtained, and the flow of air between the rotor support and the radiating plate is analyzed. The inlet resistance coefficient and the pressure loss coefficient of the radial plate of the rotor support are calculated, the flow law in the wind ditch of the rotor yoke is analyzed, the average velocity, the heat dissipation coefficient and the loss coefficient along the path of the yoke are calculated. This paper analyzes the fluid flow in the rotor pole duct, calculates the total pressure loss coefficient of the channel, the average velocity of the magnetic pole heat dissipation turn surface, the heat dissipation coefficient and the temperature rise, and analyzes the flow situation in the stator ventilation ditch and calculates the resistance coefficient. The average surface velocity, heat dissipation coefficient and temperature rise of stator core coil and end coil are obtained. In this paper, three optimization schemes are proposed to study the variation of angle between 15 掳and 40 掳of the radial plate of the support, and the length of the stator channel steel from the reduction of 20mm to the increase of 14mm. The influence of stator channel steel placement on the ventilation flow field performance of generation motor according to the new law (asymmetric placement). From increasing the flow rate, reducing the ventilation loss and increasing the surface of the magnetic pole wind trench, From the angle of heat dissipation effect between the surface of magnetic pole heat dissipation turn and the surface of stator coil, the ventilation flow field under various working conditions is analyzed, and the inclined angle of support radiating plate, the length of stator channel steel and the regulation of channel steel placement are obtained, which are more favorable for ventilation cooling of generator motor. In this paper, the detailed situation of ventilation flow field and the flow velocity, heat dissipation coefficient and temperature rise of each key area are obtained by steady calculation. The results show that the optimum inclination angle of the spoke plate of rotor support is 40o. the length of stator channel steel is more favorable to ventilation cooling than that of prototype structure, and the channel steel is arranged better according to scheme three.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV735

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