【作者】 李培良；

【导师】 廉自生；

【作者基本信息】 太原理工大学 ， 机械设计及理论， 2012， 硕士

【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。更多还原

【Abstract】 Along with the rapid development of mining mechanization, the demand for pressure control and overload protection for emulsion pump becomes more and more high. Because of some shortage of traditional unloading valve in pump station, it cannot meet the requirements. The difficult problems were solved by applying the electromagnetic unloading valve. The electromagnetic unloading valve was selected as the key parts for pressure control and overload protection in emulsion pump, the research of electromagnetic unloading valve has already been paid enough attention.In order to meet the characteristics of sensitivity, stability and big flow rate of electromagnetic unloading valve. The structure and working principle of the electromagnetic unloading valve were analyzed and the body cavity flow characteristics equation, kinematics differential equation were described by using fluid mechanics and fluid dynamic, lastly the dynamic mathematical model of the valve was established, the key size parameters of unloading valve was calculated.This paper used AMESim code to establish the simulation model of electromagnetic unloading valve and analyzed dynamic characteristics influenced by the different parameters of the unloading valve. The results showed that the bigger flow rate of the main valve was, the smaller core damping hole diameter of the main valve was; The pilot valve pressure overshoot was higher and the number of the valve oscillation was more greater when the main valve core on cavity volume is more smaller; The bigger cavity volume of the main valve was, the earlier the pilot valve open time is and lower pressure overshoot of the pilot valve was; The results showed that with the increase of the spring stiffness, the number of the oscillation of the valve core and the overshoots of the displacement decreased; To compared with unloading valve controlled by electromagnetic and mechanical, when unloading valve controlled by electromagnetic, the pressure fluctuation of main valve was lower, the open time of the main valve was earlier, the steady unloading time was shorter.The paper used CFD code FLUENT to establish the2d flow field simulation model of main valve and the unloading pilot valve. The simulation results showed that the high pressure fluid speed mutation and pressure drop is the largest when high pressure fluid flow through the throttle mouth place. The appearance of cavitations and eddy was easily to observe at the place of throttling mouth area. The paper optimized and improved the structure of main valve, then made the contrasts of the pressure, velocity distribution and whirlpool intensity to the original structure, results showed that the improved valve can get better flow field characteristics. The research work of electromagnetic unloading valve can provide a theoretical reference value for its structure design and optimization design, it also has a certain practical meaning to ensure the stability and reliability of the emulsion pump.更多还原