安全阀排量及泄放机理仿真与实验研究

发布时间：2018-05-15 00:31

本文选题：安全阀 + 排量　；参考：《华南理工大学》2012年硕士论文

【摘要】：安全阀的安全泄放能力，即排量，是衡量安全阀性能的一个最重要指标。本文在“具有在线功能的安全阀及其检测系统”专利技术的指导下，对安全阀动态开启过程的排量检测问题及其相关流动机理进行了研究。主要研究内容包括： 1、根据喷管流动特性和理想气体等熵流动的基本流体控制方程，推导了安全阀开启排放量的计算公式，系统总结了影响安全阀开启排放能力的各种因素。提出了安全阀超压开启流场参数之间存在的相互影响机理，尤其是气体动力学参数的变化规律。 2、采用CFD软件对安全阀开启过程的三维模型进行动态数值仿真，通过仿真分析安全阀流场参数随时间变化规律，得到了阀口附近和出口流产生亚临界，临界和超临界流动的状态参数变化规律；用流线（streamline）分析法对时间和空间几何位置上安全阀开启过程流场参数的突变机理进行了分析研究，，结果表明在临界和超临界状态下，流动过程的场参数的确存在参数超音速突变，其位置位于几何截面突变处，且其流动参数的突变不仅与截面形状有关，还与自身所处的流动状态有关。 3、本文研究了非标准测试条件下安全阀排量与其模拟流量之间的关系，提出了四种安全阀排量的数值仿真计算方法与数值仿真排量系数（Kd,num）定义，分析了各种算法的优缺点。研究表明影响安全阀超压泄放能力及其泄放机理的因素包括开启高度、进出口压力比、出口直径、阀腔背压等。 4、在实验研究方面，利用阀芯检测传感器和检测法兰传感器在现场试验中分别进行了排量和其他相关的参数测试。将二维、三维数值仿真排量计算值与试验测试结果比较，研究表明仿真与试验结果较为一致，从而说明利用专用传感器来检测和计量排量具有良好的可操作性。只要数值仿真计算排量的处理方法得当，就可以较准确地预测安全阀的排放能力。
[Abstract]:The safety discharge capacity of safety valve, I. e., displacement, is one of the most important indexes to measure the performance of safety valve. Under the guidance of patent technology of "On-line safety valve and its detection system", this paper studies the problem of displacement detection and its related flow mechanism in the process of dynamic opening of safety valve. The main research contents include: 1. According to the flow characteristics of nozzle and the basic fluid control equation of ideal gas isentropic flow, the formula for calculating the opening discharge of safety valve is derived, and the various factors affecting the opening discharge capacity of safety valve are summarized systematically. The mechanism of interaction between the parameters of overpressure opening flow field of safety valve, especially the variation of gas dynamics parameters, is put forward. 2. The dynamic numerical simulation of the three dimensional model of the safety valve opening process is carried out by using CFD software. Through the simulation and analysis of the variation law of the safety valve flow field parameters with time, the subcritical flow near the valve opening and the outlet flow is obtained. The variation of state parameters of critical and supercritical flow is studied by streamline line analysis method, and the sudden change mechanism of flow field parameters in the opening process of safety valve in time and space geometry position is analyzed. The results show that in the critical and supercritical states, The field parameters of the flow process do have supersonic mutations, which are located at the abrupt position of the geometric cross section, and the sudden changes of the flow parameters are not only related to the shape of the section, but also to the flow state in which they are located. 3. This paper studies the relationship between relief valve displacement and its simulated flow under non-standard test conditions, proposes four numerical simulation methods of safety valve displacement and the definition of numerical simulation displacement coefficient (Kdnum), and analyzes the advantages and disadvantages of various algorithms. The research shows that the factors influencing the overpressure release ability and its release mechanism include the opening height, the ratio of inlet and outlet pressure, the outlet diameter, the back pressure of the valve cavity, etc. 4. In the aspect of experimental research, the displacement and other related parameters were tested by spool sensor and flange sensor respectively in the field test. By comparing the calculated displacement values of 2D and 3D numerical simulations with the experimental results, it is shown that the simulation results are in good agreement with the experimental results, which shows that it is feasible to use special sensors to detect and measure the displacement. The discharge capacity of the relief valve can be predicted more accurately if the numerical simulation method is proper.
【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH134

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