球阀启闭动态特性的数值模拟和实验研究

发布时间：2018-01-13 14:18

本文关键词：球阀启闭动态特性的数值模拟和实验研究　出处：《浙江理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：球阀具有流通能力大、密封性能好、结构紧凑等优点，被广泛地应用在石油炼制、化工、制药行业。通常球阀最适宜直接做开闭使用，但是近年来随着球阀使用越来越广泛，球阀也逐渐用于节流和调节流量的作用。而在调节过程中，球阀的动态过程会使球阀及其周围管路产生漩涡或水击等，甚至会影响和阀门相连的管路系统。因此，本文对球阀启闭动态过程进行数值模拟和实验研究，分析球阀启闭动态过程对球阀性能曲线及内部流场的影响，为球阀的设计与使用提供参考和依据。主要内容如下：（1）运用三维造型软件UG对球阀及其内部流场进行三维实体建模，，并利用GAMBIT对内部流道的三维模型进行网格划分。基于球阀启闭过程的外特性实验测试，获得四种不同开启和关闭时间（18s、23s、34s和70s）及稳态工况（认为稳态工况是启闭时间接近无穷大的工况）下流量和阀门进出口压力随时间的变化曲线，作为数值模拟的进出口边界条件。采用滑动网格技术对球阀启闭过程进行数值模拟。（2）分析实验获得的不同启闭时间下的流量和进出口压力变化，得到了不同启闭时间对球阀流量及进出口压力的影响。并对比分析四种不同开启和关闭时间及稳态工况下阀门压差和流阻系数的实验与数值模拟结果。揭示球阀开启和关闭过程的压差与流阻特性随开启和关闭时间的变化规律以及球阀开启和关闭过程的差异性。（3）对启闭过程中20%、40%和70%时球阀内部流场进行研究，分析了球阀在20%、40%、70%开度下的压力和速度场，得到了启闭时间对启闭过程内部流场的影响。同时，对34s开启和关闭工况下，球阀开启和关闭过程的压力及速度场进行对比，揭示了球阀开启和关闭过程内部流动的差异性。
[Abstract]:Ball valve is widely used in petroleum refining, chemical industry and pharmaceutical industry because of its advantages such as large circulation capacity, good sealing performance and compact structure. Usually ball valve is the most suitable for direct opening and closing. But in recent years, with the more and more extensive use of ball valves, ball valves are gradually used to throttle and adjust the flow rate. In the process of adjustment, the dynamic process of ball valves will make the ball valve and its surrounding pipeline produce whirlpool or water hammer. Therefore, numerical simulation and experimental study on the dynamic process of the ball valve opening and closing are carried out to analyze the influence of the dynamic process of the ball valve on the performance curve and internal flow field of the ball valve. To provide reference and basis for the design and use of ball valves. The main contents are as follows: 1) 3D modeling software UG is used to model the ball valve and its internal flow field. GAMBIT is used to mesh the three-dimensional model of the internal flow channel. Based on the experimental test of the external characteristics of the opening and closing process of the ball valve, four different opening and closing times of 18s ~ (23 s) are obtained. Flow and valve inlet and outlet pressure curves under 34 s and 70 s) and steady state conditions (which are considered to be close to infinite opening and closing time). As the inlet and outlet boundary condition of numerical simulation, the sliding grid technique is used to simulate the opening and closing process of ball valve. 2) analyzing the flow rate and the pressure change of inlet and outlet under different opening and closing time. The effects of different opening and closing time on the flow rate and inlet and outlet pressure of ball valve are obtained. The experimental and numerical simulation results of pressure difference and flow resistance coefficient of valve under four different opening and closing times and steady condition are compared and analyzed. The variation of the pressure difference and the flow resistance characteristics with the opening and closing time and the difference of the opening and closing process of the ball valve. The internal flow field of the ball valve at 20% and 70% during the opening and closing process is studied, and the pressure and velocity fields of the ball valve under the opening degree of 20% and 70% are analyzed. The influence of the opening and closing time on the internal flow field of the opening and closing process is obtained. At the same time, the pressure and velocity fields of the opening and closing process of the ball valve under 34s open and close conditions are compared. The difference of internal flow between the opening and closing process of ball valve is revealed.
【学位授予单位】：浙江理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TH134

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