笼套式节流阀气动噪声研究及结构改进
发布时间：2018-11-13 15:14
【摘要】：笼套式节流阀常用于高压气井的开采工作,是地面节流系统的核心部件,高压天然气流经节流阀时产生的超高噪声严重影响了井场的正常运行。针对笼套式节流阀的气动噪声问题,本文采取数值模拟的方法对气动噪声的产生机理以及噪声特性进行了研究,得到了相应的结论,为生产低噪声节流阀提供理论支撑。首先,建立流体域三维模型,采用计算流体力学软件Fluent对其进行稳态和瞬态模拟;稳态模拟得到了不同压比下流体经过阀门时的流动状态,分析了结构对流场的具体影响,并为瞬态模拟提供基本的流场信息;对具有代表性的工况采用大涡模拟法进行瞬态模拟,得到了流场的时变特性,瞬态结果在细节上更加精确的展现了流场分布特性;从涡流噪声和射流噪声出发分析了阀门气动噪声的产生机理,分析了激波对流场以及声场的作用。其次,运用FW-H声类比法进行声学模拟,研究了阀门内不同区域噪声的频谱特性,得到阀门气动噪声的分布规律以及传播特性;结合阀门流场分布,分析了阀门结构和工况对气动噪声的影响,得到了射流噪声和湍流噪声的主要贡献频率,同时得到了超音速射流和亚音速射流引起的气动噪声的差异;然后,采用workbench软件对阀门管汇系统结构模态进行了分析,并找出了阀门管汇系统中气动噪声传播的优势结构模态;采用virtual lab软件分析了节流阀阀门腔体的声学模态,得到声腔模态频率以及模态振幅,并结合流场以及声场的分布情况,得到其中引起声学共鸣的优势模态;最后,基于气动噪声的产生和声学特性的研究结论,对笼套式节流阀提出结构改进,改变了阀门的流道结构,并从流场和声场上分析了新型结构的降噪效果。研究结果表明:阀门的节流作用导致流体的压力能大部分转化为动能形成超音速射流,射流在笼套内相互碰撞与掺混,加上激波影响,使得该区域湍流程度最为剧烈,是引发节流阀强烈气动噪声的根本原因。节流阀的气动噪声具有宽频特性,上游不同点声噪声压级基本不变;下游噪声声压级远远高于上游,沿着流动方向射流噪声的影响迅速减弱,总声压级也降低,主要噪声频带向低频带转移。节流阀的第5阶和第11阶结构模态为优势模态;声学模态中3、7阶为优势模态。改变笼套节流孔的入射角度可以改变流进气体的流动状态,减小其流动参数脉动程度,从噪声源上控制了噪声的产生强度,具有较好的优化效果。
[Abstract]:Cage jacketed throttle valve is often used in the production of high pressure gas wells and is the core component of the surface throttling system. The ultra-high noise produced when high pressure natural gas flows through the throttle valves seriously affects the normal operation of the well site. Aiming at the aerodynamic noise of cage type throttle valve, the mechanism and characteristics of pneumatic noise are studied by numerical simulation method, and the corresponding conclusions are obtained, which provide theoretical support for the production of low noise throttle valve. Firstly, the three-dimensional model of fluid domain is established, and the steady and transient simulation is carried out by using the computational fluid dynamics software Fluent. The steady state simulation obtained the flow state of the fluid passing through the valve under different pressure ratio, analyzed the concrete influence of the structure flow field, and provided the basic flow field information for the transient simulation. The time-varying characteristics of the flow field are obtained by using the large eddy simulation method, and the transient results show the distribution of the flow field more accurately in detail. The mechanism of valve aerodynamic noise is analyzed from eddy current noise and jet noise, and the effect of shock wave flow field and sound field is analyzed. Secondly, the FW-H acoustic analogy method is used to simulate the frequency spectrum of the noise in different regions of the valve, and the distribution and propagation characteristics of the aerodynamic noise in the valve are obtained. According to the distribution of valve flow field, the effects of valve structure and working conditions on aerodynamic noise are analyzed. The main contribution frequencies of jet noise and turbulent noise are obtained, and the difference of aerodynamic noise caused by supersonic jet and subsonic jet is obtained. Then, the structural modal of valve manifold system is analyzed by workbench software, and the dominant structural mode of pneumatic noise propagation in valve manifold system is found out. The acoustic modes of throttle valve cavity are analyzed by virtual lab software. The modal frequency and modal amplitude of the cavity are obtained, and the dominant modes which cause acoustic resonance are obtained by combining the flow field and the distribution of sound field. Finally, based on the conclusion of the research on the generation of aerodynamic noise and acoustic characteristics, the structure of cage sleeve throttle valve is improved to change the flow channel structure of the valve, and the noise reduction effect of the new structure is analyzed from the flow field and sound field. The results show that the throttling of the valve causes the pressure energy of the fluid to be converted into kinetic energy to form supersonic jet, and the jet collides and mixes with each other in the cage sleeve, and the impact of shock wave makes the turbulence degree in the region most intense. It is the root cause of the strong aerodynamic noise of throttle valve. The aerodynamic noise of throttle valve has wide frequency characteristic, and the noise pressure level at different points in upstream is basically unchanged. The downstream noise pressure level is much higher than that of upstream, the influence of jet noise along the flow direction is weakened rapidly, the total sound pressure level is also reduced, and the main noise frequency band is transferred to the low frequency band. The fifth and eleventh structural modes of the throttle valve are dominant modes, while the 37-order acoustic modes are dominant modes. Changing the incidence angle of the nozzles can change the flow state of the inlet gas, reduce the pulsation degree of the flow parameters, control the intensity of the noise from the noise source, and have a better optimization effect.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE921.5;TB535
[Abstract]:Cage jacketed throttle valve is often used in the production of high pressure gas wells and is the core component of the surface throttling system. The ultra-high noise produced when high pressure natural gas flows through the throttle valves seriously affects the normal operation of the well site. Aiming at the aerodynamic noise of cage type throttle valve, the mechanism and characteristics of pneumatic noise are studied by numerical simulation method, and the corresponding conclusions are obtained, which provide theoretical support for the production of low noise throttle valve. Firstly, the three-dimensional model of fluid domain is established, and the steady and transient simulation is carried out by using the computational fluid dynamics software Fluent. The steady state simulation obtained the flow state of the fluid passing through the valve under different pressure ratio, analyzed the concrete influence of the structure flow field, and provided the basic flow field information for the transient simulation. The time-varying characteristics of the flow field are obtained by using the large eddy simulation method, and the transient results show the distribution of the flow field more accurately in detail. The mechanism of valve aerodynamic noise is analyzed from eddy current noise and jet noise, and the effect of shock wave flow field and sound field is analyzed. Secondly, the FW-H acoustic analogy method is used to simulate the frequency spectrum of the noise in different regions of the valve, and the distribution and propagation characteristics of the aerodynamic noise in the valve are obtained. According to the distribution of valve flow field, the effects of valve structure and working conditions on aerodynamic noise are analyzed. The main contribution frequencies of jet noise and turbulent noise are obtained, and the difference of aerodynamic noise caused by supersonic jet and subsonic jet is obtained. Then, the structural modal of valve manifold system is analyzed by workbench software, and the dominant structural mode of pneumatic noise propagation in valve manifold system is found out. The acoustic modes of throttle valve cavity are analyzed by virtual lab software. The modal frequency and modal amplitude of the cavity are obtained, and the dominant modes which cause acoustic resonance are obtained by combining the flow field and the distribution of sound field. Finally, based on the conclusion of the research on the generation of aerodynamic noise and acoustic characteristics, the structure of cage sleeve throttle valve is improved to change the flow channel structure of the valve, and the noise reduction effect of the new structure is analyzed from the flow field and sound field. The results show that the throttling of the valve causes the pressure energy of the fluid to be converted into kinetic energy to form supersonic jet, and the jet collides and mixes with each other in the cage sleeve, and the impact of shock wave makes the turbulence degree in the region most intense. It is the root cause of the strong aerodynamic noise of throttle valve. The aerodynamic noise of throttle valve has wide frequency characteristic, and the noise pressure level at different points in upstream is basically unchanged. The downstream noise pressure level is much higher than that of upstream, the influence of jet noise along the flow direction is weakened rapidly, the total sound pressure level is also reduced, and the main noise frequency band is transferred to the low frequency band. The fifth and eleventh structural modes of the throttle valve are dominant modes, while the 37-order acoustic modes are dominant modes. Changing the incidence angle of the nozzles can change the flow state of the inlet gas, reduce the pulsation degree of the flow parameters, control the intensity of the noise from the noise source, and have a better optimization effect.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE921.5;TB535
【相似文献】
相关期刊论文 前10条
1 苏强,李伟,陈花玲,黄协清;电机气动噪声治理研究[J];环境工程;1997年03期
2 KamW·Ng ,黎金;控制阀气动噪声的产生和消除[J];石油化工设备;1985年06期
3 张师帅;罗亮;;空调用贯流风机气动噪声预测的研究[J];流体机械;2007年12期
4 万剑峰;杨爱玲;戴韧;;开式叶轮气动噪声信号离析方法和运用[J];流体机械;2013年11期
5 邱成东;;电梯井道气动噪声问题的分析与研究[J];机械工程师;2014年03期
6 张，
本文编号：2329538
本文链接：https://www.wllwen.com/guanlilunwen/gongchengguanli/2329538.html
