高压先导轴流式天然气减压阀建模仿真与性能优化研究

发布时间：2018-03-06 03:01

本文选题：天然气减压阀　切入点：动态特性　出处：《兰州理工大学》2012年硕士论文　论文类型：学位论文

【摘要】：本论文是在课题组与企业合作项目的支持下完成的。天然气先导式减压阀是保障天然气输配、门站系统正常工作的重要自力式控制类阀门。其主要功能是调节输配管网压力，保证负载设备正常运行。研究减压阀的性能涉及到流体力学、工程热力学和自动控制等学科中的一系列基础理论问题。要改进减压阀的性能，就必须研究不同元件参数组合下减压阀所表现出来的动态特性，不同的流道结构对于减压阀流场特性的影响，以及减压阀出口压力波动及噪声问题。本论文进行了以下一系列的研究，为改进天然气先导式减压阀的性能提供了可靠的理论依据。运用Matlab软件Simulink工具箱，根据天然气先导式减压阀结构参数及工作原理建立机械系统运动方程，气体状态和流动方程以及各腔压力控制方程，绘制系统方框图。重点采用子系统和S函数模块进行动态模型仿真，得到系统动态特性，计算出天然气先导式减压阀在动态流量变化过程中各个时刻的状态量，分别绘制不同进口压力、弹簧刚度以及泄流孔直径下天然气高压先导式减压阀的动态特性响应曲线。运用Matlab软件Gatool工具箱对天然气高压先导式减压阀结构参数进优化。根据不同设计变量，建立以输出压力为目标函数的优化数学模型，，基于遗传算法理论得出最佳适应度和最佳均值轨迹，从而得到天然气高压先导式减压阀动态性能最优化的参数组合。运用Solidworks软件对天然气先导式减压阀内部流道进行三维建模及网格划分。采用天然气理想气体可压缩流体模型，设置压力进口和压力出口边界条件，应用改进的RNG k-Epsilon模型求解得到天然气先导式减压阀内压力及速度分布云图，以及压差、流量等相关参数。分析了减压阀在不同工况条件下的流场特性。对不同阀瓣形状下减压阀的流场特性进行分析，改进了阀瓣形状，提高了减压阀性能。在流场分析的基础上，利用标准IEC60534-8-3-2009《工业过程控制阀.第8-3部分:噪声的考虑.控制阀的气动噪声预测法》对高马赫数天然气高压先导式减压阀所产生的噪声进行了理论预估和分析计算。对于超过标准要求的噪声范围提出了改进要求，为今后的研究工作提供了方向。
[Abstract]:This paper is completed under the support of the project of cooperation between the research group and the enterprise. The natural gas pilot pressure reducing valve is an important self-control valve to ensure the natural gas transmission and distribution, and the gate station system works normally. Its main function is to regulate the pressure of the pipeline network, the main function of which is to regulate the pressure of the pipeline network. The research on the performance of the pressure reducing valve involves a series of basic theoretical problems in the fields of fluid mechanics, engineering thermodynamics and automatic control. It is necessary to study the dynamic characteristics of the valve under the combination of different component parameters and the influence of different flow channel structures on the flow field characteristics of the valve. As well as the pressure fluctuation and noise at the outlet of the pressure-reducing valve. In this paper, a series of studies have been carried out, which provide a reliable theoretical basis for improving the performance of the natural gas pressure-reducing valve. By using Simulink toolbox of Matlab software, the mechanical system motion equation, gas state and flow equation and pressure control equation of each cavity are established according to the structure parameters and working principle of the natural gas pilot pressure reducing valve. The block diagram of the system is drawn. The dynamic model is simulated by the subsystem and the S function module, and the dynamic characteristics of the system are obtained, and the state quantities of the natural gas pressure-reducing valve at each moment in the process of dynamic flow change are calculated. Drawing different inlet pressures, The dynamic response curves of natural gas pressure-pressure-reducing valves with spring stiffness and outlet diameter are obtained. The structural parameters of natural gas high-pressure-guide pressure-reducing valves are optimized by using the Matlab software Gatool toolbox. According to the different design variables, the dynamic response curves of the high-pressure pressure-reducing valves are obtained. An optimal mathematical model with the output pressure as the objective function is established. The optimal fitness and the optimal mean trajectory are obtained based on the genetic algorithm theory, and the parameter combination of the dynamic performance optimization of the natural gas pressure-reducing valve is obtained. Using Solidworks software, the internal flow channel of the natural gas pilot pressure reducing valve is modeled and meshed. The ideal gas compressible fluid model of natural gas is adopted, and the pressure inlet and pressure outlet boundary conditions are set up. Using the improved RNG k-Epsilon model, the pressure and velocity distribution and pressure difference in the natural gas pilot relief valve are obtained. The flow field characteristics of the pressure relief valve under different working conditions are analyzed. The flow field characteristics of the valve under different disc shapes are analyzed. The disc shape is improved and the performance of the valve is improved. On the basis of flow field analysis, Using standard IEC60534-8-3-2009 < Industrial process control valves-part 8-3: noise considerations; Pneumatic noise prediction method of control valves, the theoretical prediction, analysis and calculation of the noise generated by high Mach number natural gas high pressure pilot pressure-reducing valves are carried out. Improved requirements for noise ranges exceeding standard requirements, It provides a direction for future research work.
【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH134

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