永磁调速器的雾化冷却技术研究

发布时间：2018-03-06 07:13

本文选题：永磁调速器　切入点：雾化冷却　出处：《西安石油大学》2017年硕士论文　论文类型：学位论文

【摘要】：永磁调速器因为其结构简单、非机械连接,对中性要求低,可实现软启动、环境适应性强等优点,成为继液力耦合调速器与变频调速器之后新的电机调速装置的研究热点。永磁调速器优点突出,但是在运行过程中,由于特殊的工作原理,具有不可避免的温升问题。而永磁材料的磁性随着温度的升高而降低,当温度高于永磁材料的居里温度之后,会发生不可逆退磁。为了维护永磁调速器的使用性能以及延长其使用寿命,必须采取有效的降温措施。现有的冷却方式各有缺陷,而雾化冷却被称为当今最有发展前景的冷却方式,本文将该技术应用到永磁调速器的降温冷却中。本文通过Fluent数值仿真对永磁调速器的雾化冷却技术进行研究。首先对永磁调速器单喷嘴雾化冷却模型简进行数值模拟,在该模型中研究了喷嘴距永磁体的距离、喷嘴入口的压力、水的质量流量、喷嘴内部液膜的厚度对单个喷嘴雾化特性的影响,从而确定喷嘴相关参数设置,并应用到永磁调速器多喷嘴的雾化冷却模型中。由于永磁调速器结构较大,单个喷嘴的冷却效果对于大功率永磁调速器的降温效果十分有限。本文就永磁调速器模型提出了三种多喷嘴设置方案:等直径环向均匀分布、径向分布、以及变直径环向均匀分布。变直径环向均匀分布在方案设置上弥补了前两者受结构尺寸限制的不足。通过模拟计算发现由于径向分布时有大量的液滴喷洒在永磁体形成的环形空间内部,在旋转气流的作用下,液滴受离心力的作用贴近永磁体内壁运动,有利于冷却降温,因此冷却效果最为显著;而非等直径均匀分布考虑的喷洒面积较多,却在喷嘴设置过程中有个别喷嘴直接喷洒在环形空间外的区域,受到离心力的作用,液滴贴近永磁体外壳做旋转运动,对冷却效果贡献极少;等直径环向均布分布的一部分液滴喷洒到永磁体环形空间内部,一部分直接喷洒到永磁体上,还有一部分进入环形空间以外的区域,因此冷却效果介于前两种设置方案之间。综合分析,在喷嘴设置时,应尽量使喷洒区域位于永磁体形成的环形空间之内,或永磁体之上。本文的研究结果对永磁调速器的冷却降温提供了一种新的可能,具有十分重要的意义。
[Abstract]:The permanent magnet governor has the advantages of simple structure, non-mechanical connection, low neutral requirement, soft start, strong environmental adaptability, etc. It has become the research hotspot of the new motor speed regulating device after the hydraulic coupling governor and the frequency conversion governor. The permanent magnet governor has outstanding advantages, but in the course of operation, because of the special working principle, The magnetic properties of permanent magnetic materials decrease with the increase of temperature, when the temperature is higher than the Curie temperature of the permanent magnet, Irreversible demagnetization will occur. In order to maintain the performance of the permanent magnet governor and prolong its service life, effective cooling measures must be taken. And atomization cooling is known as the most promising cooling method. In this paper, the technology is applied to the cooling of permanent magnet governor. In this paper, the atomization cooling technology of permanent magnet governor is studied by Fluent numerical simulation. Firstly, the model of atomization cooling of single nozzle of permanent magnet governor is numerically simulated. In this model, the influence of the distance from the nozzle to the permanent magnet, the pressure at the nozzle inlet, the mass flow of water and the thickness of the liquid film inside the nozzle on the atomization characteristics of a single nozzle are studied. And it is applied to the atomization cooling model of permanent magnet governor with multiple nozzles. Because of the large structure of permanent magnet governor, The cooling effect of single nozzle is very limited to the cooling effect of high power permanent magnet governor. In this paper, three kinds of multiple nozzles are put forward for the model of permanent magnet governor: uniform distribution of equal diameter and radial distribution. The uniform distribution of variable diameter annulus makes up for the limitation of the former two by the structure size. It is found by simulation that a large number of droplets are sprayed on permanent magnet due to radial distribution. Inside the annular space formed by the body, Under the action of rotating airflow, the droplet is close to the inner wall of the permanent magnet by centrifugal force, which is beneficial to cooling and cooling, so the cooling effect is the most remarkable. However, in the process of setting the nozzle, some nozzles are sprayed directly outside the ring space, which is affected by centrifugal force, and the droplet moves close to the permanent magnet shell, which makes little contribution to the cooling effect. A portion of the droplets distributed in a uniform circular direction of equal diameter are sprayed inside the ring space of the permanent magnet, some directly on the permanent magnet, and another part into an area outside the ring space. Therefore, the cooling effect is between the first two settings. When the nozzle is set, the spray area should be located in the ring space formed by the permanent magnet. The results of this paper provide a new possibility for the cooling and cooling of permanent magnet governor and are of great significance.
【学位授予单位】：西安石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH139;TE65

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