【作者】 王建凯；

【导师】 金志江；

【作者基本信息】 浙江大学 ， 化工过程机械， 2011， 硕士

【摘要】 基于先导控制的截止阀是一种利用介质压差实现启闭的新型阀门,具有结构简单、驱动能耗低、启闭快速等特点。但目前尚缺乏系统的理论研究、数值分析和试验验证,尤其在启闭特性方面缺少相关研究,而启闭特性的优劣关系直接影响阀门整体性能的体现,甚至影响整个管路系统的稳定性和安全性。为此本文采用数值模拟和实验研究相结合的方法,对先导式截止阀的流场特性、阀芯受力和运动特性以及弹簧选型等进行研究。主要研究内容和研究成果如下：1、通过先导式截止阀的稳态研究,初步验证了利用压差启闭原理的可行性和阀门结构的合理性；研究了不同条件对稳态流场的影响；分析了稳态压差液动力,为动态模拟奠定了基础。2、建立了阀芯受力方程和运动方程,并以此为依据编写了UDF程序,使新型先导式截止阀的动态模拟成为可能,为此类阀门的数值模拟奠定了基础。3、描述了先导式截止阀动态启闭过程,通过分析启闭时阀门流场和阀芯受力、位移及速度随时间的变化,对阀门的动态启闭过程有了更加全面和清晰的认识；研究了不同条件对动态启闭流场特性的影响,分别总结了开启和关闭时,不同入口压力、弹簧刚度和先导时间对阀门内部流场变化所产生的规律,为先导式截止阀的应用和设计具有指导作用；揭示了不同条件对阀芯运动特性的影响,分别总结了开启和关闭时,不同入口压力、弹簧刚度和先导时间对阀芯运动过程、阀芯稳定位移和阀芯启闭时间的规律,为先导式截止阀启闭过程的进一步优化奠定了基础。4、归纳了弹簧初步选型公式,并针对此公式进行实验研究。一方面通过实验数据得到规律,验证了数值模拟定性分析的正确性；另一方面对比实验数据与模拟数据,也证明了数值模拟定量分析的合理性。修正后的选型公式减少了设计时的盲目性,提高了设计的效率。本文研究成果对基于先导控制的新型截止阀的优化、设计以及工程应用具有重要的学术意义和工程应用价值。更多还原

【Abstract】 The pilot-operated globe valve, utilizing differential pressure to achieve the action of the valve core, is a new kind of valve with a simple structure, prompt opening and closing action and lower driving energy consumption. However, systemic theoretical research, numerical analysis and experimental verification are deficient at present, especially about the opening and closing characteristics. The relationship between opening and closing characteristics directly affects the performance of the valve even affects the stability and security of the entire pipeline system. Thus in this paper, the flow field of the pilot-operated globe valve, the characteristics of the force on valve core and the valve core motion, and the formula for selection of spring were studied via numerical simulation and experiment research. Main contents and results of this research are as follow:1. The feasibility of utilizing differential pressure to control valve opening and closing and the rationality of valve structure were initially verified; the steady flow field under different conditions was researched; the pressure force in steady state was analyzed which would lay the foundation for dynamic simulation.2. The differential equation of the force on valve core and the difference equation of the valve core motion were not only built, but also as a basis for the preparation of the UDF program, which made dynamic simulation of the new pilot-operated globe valve become possible and laid the foundation for it.3. The opening and closing processes and characteristics of the pilot-operated globe valve were studied, which were understood with a more comprehensive view through analyzing the flow field, the force on valve core, and the changes of the displacement and velocity with time. It was researched that how the flow field of the opening and closing characteristics in dynamic state would be influenced under different conditions. It was summed up that how the flow field respectively changes with inlet pressure, spring stiffness and the pilot time during the valve opening and closing process which would guide the application and the design of the pilot-operated globe valve. It is revealed that how the movement characteristics of valve core would be influenced under different conditions including the laws of the movement, the displacement and the opening and closing time of valve core changing with inlet pressure, spring stiffness and the pilot time, which provided the most basic, the most critical and the most valuable conclusions for further optimization of the valve.4. The formula for preliminary selection of spring has been summarized and tested in the experiment. On the one hand, the law was obtained from experimental data to verify the accuracy of qualitative analysis on simulation; on the other hand, comparing the experimental data and simulation data, quantitative analysis on the simulation was proved reasonably. Modified selection formula would improve the design efficiency and reduce the blindness on the design process.All in all, these results have important academic significance and value for the optimization and engineering applications of the new pilot-operated globe valve.更多还原