截止阀内部流动的数值模拟与试验研究

发布时间：2018-04-26 23:05

本文选题：截止阀 + 阀芯　；参考：《浙江理工大学》2012年硕士论文

【摘要】：截止阀是流体传动与控制中的重要基础元件，在实际工作中，，截止阀阀芯在启闭过程中的内部流场特性对截止阀的工作性能有着重大影响。因此，掌握流体在阀体内部的流动机理，对设计合理的截止阀阀芯结构及其节能减耗有着重要的意义。而CFD技术的快速发展为深入研究截止阀内部复杂流场提供了强有力的手段。因此，论文以截止阀为研究对象，采用数值模拟与试验研究相结合的方法，分别对截止阀阀芯改进前后两种结构，及阀芯静止和阀芯运动两种状态下，对截止阀内部流场进行了数值计算研究，并对阀门的外特性进行了试验研究。具体内容如下： 1.对截止阀阀芯结构进行了优化设计，得到了一种具有多密封及分流减压结构的截止阀阀芯结构。依据截止阀的尺寸结构，利用三维实体建模软件Pro/E，对截止阀包括阀体、阀盖、阀芯及其连接部件进行了三维实体建模。基于CFD多块网格技术，采用对复杂结构适应性强的非结构化网格对阀体流道的计算域进行离散，并运用前处理软件Gambit进行网格生成。 2.基于三维雷诺时均N-S控制方程及标准湍流模型，在阀芯不同固定开度下，对截止阀内的流动状态进行了定常的全三维数值研究。分析了不同流量工况下阀体内部的压力、速度和流线分布规律；对比分析了截止阀阀芯改进前后的阀体内部压力场和速度场的分布规律；同时也分析了阀芯改进前后阀门密封部位的速度和压力的分布规律。 3.对瞬态工况下截止阀内部流场特性进行了数值模拟研究。基于动网格技术，采用Fluent的UDF功能，定义了阀芯启闭过程的运动速度。对比分析了改进前后的截止阀阀芯在运动状态下阀体内的压力、速度和流线分布规律，揭示了阀芯在启闭过程中受到的流体挤压效应是影响截止阀性能的主要原因，对今后截止阀阀芯结构和内部流道设计有着重要的意义。 4.对截止阀进行了外特性试验研究，得到了截止阀不同开度、不同工况下外特性性能曲线，并与数值模拟结果进行了对比分析。
[Abstract]:The globe valve is an important basic component in fluid transmission and control. In practice, the internal flow field characteristics of the valve core in the process of opening and closing have a significant impact on the performance of the valve. Therefore, mastering the flow mechanism of fluid in the valve body is of great significance to the reasonable design of valve core structure and energy saving and consumption reduction. The rapid development of CFD technology provides a powerful means to study the complex flow field inside the globe valve. Therefore, the thesis takes the globe valve as the research object, adopts the method of numerical simulation and experimental study, improves the valve core before and after the two kinds of structure, and the valve core static and the valve core movement two kinds of states respectively. The internal flow field of the globe valve is numerically calculated and the external characteristics of the valve are experimentally studied. The details are as follows: 1. The valve core structure was optimized and a valve core structure with multi-seal and split pressure relief was obtained. According to the size structure of the globe valve, the three-dimensional solid modeling software Prop / E was used to model the valve including the valve body, the valve cover, the valve core and its connecting parts. Based on CFD multi-block grid technology, unstructured grids with strong adaptability to complex structures are used to discretize the computational domain of valve body flow channels, and the pre-processing software Gambit is used to generate grids. 2. Based on the three-dimension Reynolds time-averaged N-S governing equation and standard turbulence model, the flow state in the valve was studied with different fixed opening of valve core. The distribution law of pressure, velocity and streamline inside the valve body under different flow conditions is analyzed, and the distribution of pressure field and velocity field inside the valve body before and after the improvement of the valve core is compared and analyzed. At the same time, the distribution law of the speed and pressure of the valve seal before and after the improvement of the valve core is also analyzed. 3. The internal flow field characteristics of the globe valve under transient conditions are numerically simulated. Based on the technology of moving grid and UDF function of Fluent, the moving speed of the valve core during the process of opening and closing is defined. The distribution laws of pressure, velocity and streamline in the valve body under the moving state of the valve core before and after the improvement are compared and analyzed. It is revealed that the fluid extrusion effect of the valve core in the process of opening and closing is the main reason that affects the performance of the valve. It is of great significance for the design of valve core and internal runner in the future. 4. In this paper, the external characteristic curve of the globe valve under different opening and working conditions is obtained, and the results are compared with the numerical simulation results.
【学位授予单位】：浙江理工大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH134

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