以210 t RH机械真空泵系统为例,对其主抽气管道工艺布置进行系统优化设计;引入不同位置处的气体不同物理状态,归纳出适用于容积式机械真空泵主抽气管道通径的计算公式;在基于理想气体绝热膨胀的机理研究上,提出真空抽气管道通径和长度...以210 t RH机械真空泵系统为例,对其主抽气管道工艺布置进行系统优化设计;引入不同位置处的气体不同物理状态,归纳出适用于容积式机械真空泵主抽气管道通径的计算公式;在基于理想气体绝热膨胀的机理研究上,提出真空抽气管道通径和长度的修正方法,对不同位置的管道采取不同的原则进行修正:对多级机械泵入口前的管道,采取修正管道长度的原则;对多级机械泵之间的管道,采取修正管道通径的原则。本文设计已应用于工程实践,设备稳定运行,得到用户好评。展开更多
In this study, we investigated the torque characteristics of large low-speed direct-drive permanent magnet synchronous generators with stator radial ventilating air ducts for offshore wind power applications. Magnet s...In this study, we investigated the torque characteristics of large low-speed direct-drive permanent magnet synchronous generators with stator radial ventilating air ducts for offshore wind power applications. Magnet shape optimization was used first to improve the torque characteristics using two-dimensional finite element analysis（FEA） in a permanent magnet synchronous generator with a common stator. The rotor step skewing technique was then employed to suppress the impacts of mechanical tolerances and defects, which further improved the torque quality of the machine. Comprehensive three-dimensional FEA was used to evaluate accurately the overall effects of stator radial ventilating air ducts and rotor step skewing on torque features. The influences of the radial ventilating ducts in the stator on torque characteristics, such as torque pulsation and average torque in the machine with and without rotor step skewing techniques, were comprehensively investigated using three-dimensional FEA. The results showed that stator radial ventilating air ducts could not only reduce the average torque but also increase the torque ripple in the machine. Furthermore, the torque ripple of the machine under certain load conditions may even be increased by rotor step skewing despite a reduction in cogging torque.展开更多
文摘以210 t RH机械真空泵系统为例,对其主抽气管道工艺布置进行系统优化设计;引入不同位置处的气体不同物理状态,归纳出适用于容积式机械真空泵主抽气管道通径的计算公式;在基于理想气体绝热膨胀的机理研究上,提出真空抽气管道通径和长度的修正方法,对不同位置的管道采取不同的原则进行修正:对多级机械泵入口前的管道,采取修正管道长度的原则;对多级机械泵之间的管道,采取修正管道通径的原则。本文设计已应用于工程实践,设备稳定运行,得到用户好评。
基金Project supported by the National Natural Science Foundation of China（No.51377140） the National Basic Research Program（973）of China（No.2013CB035604）
文摘In this study, we investigated the torque characteristics of large low-speed direct-drive permanent magnet synchronous generators with stator radial ventilating air ducts for offshore wind power applications. Magnet shape optimization was used first to improve the torque characteristics using two-dimensional finite element analysis（FEA） in a permanent magnet synchronous generator with a common stator. The rotor step skewing technique was then employed to suppress the impacts of mechanical tolerances and defects, which further improved the torque quality of the machine. Comprehensive three-dimensional FEA was used to evaluate accurately the overall effects of stator radial ventilating air ducts and rotor step skewing on torque features. The influences of the radial ventilating ducts in the stator on torque characteristics, such as torque pulsation and average torque in the machine with and without rotor step skewing techniques, were comprehensively investigated using three-dimensional FEA. The results showed that stator radial ventilating air ducts could not only reduce the average torque but also increase the torque ripple in the machine. Furthermore, the torque ripple of the machine under certain load conditions may even be increased by rotor step skewing despite a reduction in cogging torque.
