大流量液控单向阀动态特性分析与流场仿真

发布时间：2018-07-04 09:21

本文选题：液控单向阀 + 功率键合图　；参考：《太原理工大学》2017年硕士论文

【摘要】：随着综采工作面向大采高方向发展,液压支架的支护高度也越来越高,对其动态性能的要求也越来越高,液控单向阀对支架性能的影响起着至关重要的作用。立柱在卸载过程中液控单向阀经常会出现冲击和振动,造成液压元件损坏甚至引发安全事故。目前常用的大流量液控单向阀公称流量为480L/min,而随着7m大采高支架的出现,其有限的通流能力将对支架的动态性能造成影响,因而在大采高支架上使用大流量的液控单向阀十分必要,本文对一款公称流量为1000L/min的液控单向阀进行动态特性和流场分析。论文首先从功率流的角度分别建立液控单向阀反向打开时小阀芯和大小阀芯同步打开时的功率键合图模型,根据模型推导出对应的状态空间方程,并使用Matlab进行仿真计算,得出液控单向阀的动态特性曲线并分析。发现小阀芯在开启过程中产生约0.3s的振动现象,在此过程中系统伴随有压力冲击和振动;大阀芯打开时产生轻微的振动,此时小阀芯流量相对于大阀芯流量很小,说明液控单向阀的工作原理为小流量卸压大流量泄流。根据国标关于液控单向阀冲击试验的要求,在仿真软件AMESIM上搭建试验系统的仿真模型并仿真,对液控单向阀反向开启动态特性进行分析。通过分析发现立柱降柱初期产生约55MPa的压力冲击,液控单向阀在打开过程中发生振动,且振动分两个阶段,小阀芯打开时发生强烈的振动,大、小阀芯同步打开时阀芯发生二次振动;液控单向阀在稳定开启后的流量约为1200L/min。通过受力分析发现造成液控单向阀振动的主要原因为乳化液流过阀芯后作用在控制杆有杆腔导致控制杆波动,而大、小阀芯二次振动除受到液压力的影响外还受到稳态液动力影响。使用流场仿真软件ANSYS/FLUENT对液控单向阀的二维、三维流场进行分析,得到流场的速度分布云图、静压力分布云图、速度矢量图。通过分析,发现液控单向阀反向进油口单一入口造成阀套、阀芯径向压力分布不均,导致阀套、阀芯容易卡死;阀套上阻尼孔结构设计不合理,使得液控单向阀在反向开启初期乳化液主要作用在阀套与阀体组成的容腔而延长了小阀芯的开启时间,降低了液控单向阀的灵敏度。本论文通过对液控单向阀的动态特性和流场分析,得出其工作中可能存在的问题并提出优化方案,为今后大流量液控单向阀的设计与优化提供依据。
[Abstract]:With the development of fully mechanized mining, the support height of the hydraulic support is more and more high, and the demand for its dynamic performance is more and more high. The hydraulic control one-way valve plays an important role in the performance of the support. The hydraulic control unidirectional valve often appears shock and vibration during the unloading process, causing the damage of the hydraulic components or even the hydraulic components. At present, the common flow of large flow hydraulic control one-way valve is 480L/min, and with the appearance of 7m large stope, its limited flow capacity will affect the dynamic performance of the support. Therefore, it is necessary to use the large flow hydraulic control one-way valve on the large stope, and a nominal flow of 1000L/min is used in this paper. The dynamic characteristics and flow field analysis of the liquid controlled one-way valve are carried out. Firstly, the power bond graph model of the small valve core and the small valve core is set up simultaneously from the angle of the power flow control, and the corresponding state space equation is derived according to the model. The simulation calculation is carried out with Matlab to get the movement of the hydraulic control one-way valve. It is found that the small valve core has about 0.3s vibration during the opening process. In this process, the system is accompanied by pressure shock and vibration. When the large valve core opens, it produces slight vibration. At this time, the flow of the small valve core is relatively small compared with the large valve core flow, which indicates that the principle of the liquid controlled single valve is a small discharge pressure discharge discharge. Flow. According to the requirements of the national standard on the impact test of the liquid controlled one-way valve, the simulation model of the test system is built on the simulation software AMESIM and the dynamic characteristics of the hydraulic control one-way valve reverse opening are analyzed. Through the analysis, it is found that the pressure impact of about 55MPa at the beginning of the column descending column is found, and the vibration of the hydraulic control one-way valve is vibrated during the opening process and the vibration is vibrated. When the small valve core opens in two stages, a strong vibration occurs when the small valve is open, and the valve core has two vibrations when the small valve core is opened synchronously. The flow rate of the liquid controlled one-way valve is about 1200L/min. through the force analysis. The main reason for the vibration of the hydraulic control one-way valve is that the emulsion flows through the valve core and causes the control of the rod with the rod cavity. The rod fluctuates, and the two vibration of the small valve core is affected by the liquid pressure. The flow field simulation software ANSYS/FLUENT is used to analyze the two-dimensional and three-dimensional flow field of the liquid controlled one-way valve. The velocity distribution cloud, the static pressure distribution cloud and the velocity vector are obtained. Through analysis, the liquid controlled one-way valve is found. The single inlet of the reverse inlet causes the valve sleeve and the radial pressure distribution of the valve core is unevenly distributed, which causes the valve sleeve and the valve core to die easily. The damping hole structure on the valve sleeve is unreasonable, which makes the liquid controlled one-way valve in the initial stage of reverse opening mainly in the cavity of the valve sleeve and valve body and prolongs the opening time of the small valve core and reduces the single direction of the liquid control. In this paper, through the analysis of the dynamic characteristics and flow field of the liquid controlled one-way valve, the possible problems in the work are obtained and the optimization scheme is put forward to provide the basis for the design and optimization of the large flow and liquid controlled one-way valve in the future.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD355.4

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