电磁卸荷阀动态特性仿真及流场数值模拟

发布时间：2019-01-04 08:36

【摘要】：随着我国机械化采煤的快速发展,对乳化液泵站在压力控制和过载保护的要求越来越高。泵站传统卸荷阀由于其本身存在的一些不足,不能很好的满足这种要求。电磁卸荷阀的应用解决了这一难题。电磁卸荷阀作为乳化液泵站压力控制和过载保护的关键部件,电磁卸荷阀的研究已经受到足够重视。为了满足电磁卸荷阀在卸载时灵敏、稳定及大流量的要求。论文分析了电磁卸荷阀的结构和工作原理,运用流体力学、流体动力学相关知识建立了阀腔的流量特性方程和阀芯的运动微分方程,完成了阀的动态数学模型。并对卸荷阀关键尺寸参数进行了设计计算。运用AMESim仿真软件,建立了电磁卸荷阀的仿真模型,分析了卸荷阀中不同参数对卸荷阀动态特性的影响。仿真结果表明：主阀芯阻尼孔直径越小,主阀流量越大；主阀芯上腔容积越小,先导阀压力超调量越大,振荡次数较多；主阀上腔容积越大,液控先导阀开启时间就越早,超调量越小；主阀芯弹簧刚度越大,阀芯振荡次数越少,位移超调量也越小；卸荷阀在电磁控制时较机械式控制时,主阀阀口压力波动较小,主阀开启卸荷时间较早,达到稳态卸荷时间较短。运用CFD软件FLUENT建立了卸荷主阀和先导阀的二维流场流道模型。仿真结果表明：高压流体在节流口处是速度突变最大和压降最大的地方,在节流口区域处很容易观察到有气穴和漩涡现象发生。论文对卸荷主阀的结构进行了优化改进,并对比了改进前后卸荷主阀的压力、速度分布图和漩涡强度的大小,结论表明改进结构后的阀能够得到更好的流场特性。论文进行的研究工作对电磁卸荷阀的结构设计和优化设计提供了理论参考价值,对保证乳化液泵站稳定、可靠地运行有一定的现实意义。
[Abstract]:With the rapid development of mechanized coal mining in China, the requirements of pressure control and overload protection for emulsion pumping stations are becoming higher and higher. The traditional unloading valve of pumping station can not meet this requirement because of its shortcomings. The application of electromagnetic unloading valve solves this problem. As a key component of pressure control and overload protection of emulsion pumping station, the study of electromagnetic unloading valve has been paid enough attention. In order to meet the electromagnetic unloading valve in unloading sensitive, stable and large flow requirements. This paper analyzes the structure and working principle of the electromagnetic unloading valve, establishes the flow characteristic equation of the valve cavity and the differential equation of movement of the valve core, and completes the dynamic mathematical model of the valve by using the knowledge of fluid dynamics and hydrodynamics. The key dimension parameters of unloading valve are designed and calculated. The simulation model of electromagnetic unloading valve is established by using AMESim software, and the influence of different parameters in unloading valve on the dynamic characteristics of unloading valve is analyzed. The simulation results show that the smaller the diameter of the damping hole in the main valve core, the larger the flow rate of the main valve, the smaller the volume of the upper cavity of the main valve core, the larger the pressure overshoot of the pilot valve, and the more the number of oscillations. The larger the volume of the upper cavity of the main valve, the earlier the opening time of the hydraulic pilot valve and the smaller the overshoot, the greater the spring stiffness of the main valve core, the less the oscillation frequency of the valve core and the smaller the displacement overshoot. When the unloading valve is controlled by electromagnetic control, the pressure fluctuation of the main valve port is smaller, the unloading time of the main valve is earlier, and the time of steady unloading is shorter. A two-dimensional flow channel model of unloading main valve and pilot valve is established by using CFD software FLUENT. The simulation results show that the high pressure fluid is the place where the velocity change is the biggest and the pressure drop is the biggest at the throttle, and the cavitation and swirl can be easily observed in the throttle region. In this paper, the structure of the unloading valve is optimized and improved, and the pressure, velocity distribution and swirl intensity of the main valve before and after the improvement are compared. The conclusion shows that the valve with improved structure can obtain better flow field characteristics. The research work in this paper provides the theoretical reference value for the structure design and optimization design of the electromagnetic unloading valve. It is of practical significance to ensure the stability and reliable operation of the emulsion pump station.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH134

【相似文献】