【作者】 王莹；

【导师】 赵杰； 郑学鹏；

【作者基本信息】 北京石油化工学院 ， 机械工程（专业学位）， 2015， 硕士

【摘要】 往复式压缩机在石化、电力、采矿等多个工业领域应用广泛,但是其工作原理本身引发的管道内周期性的压力脉动激励,会使管道系统产生剧烈振动,严重影响了装置的安全运行。近年来,对流固耦合的研究已经逐渐成为工程应用的热点。本文主要借助有限元分析软件ANSYS对充气管道进行流固耦合分析和工程实际问题的研究,主要做了以下五个方面的工作:1、对往复式压缩机管线的机械结构系统振动理论和管内气柱系统有限元分析理论进行了阐述。对于单独分析流体域和固体域存在的不足,引出了气固耦合理论,基于伽辽金法建立了气固耦合有限元方程,为基于ANSYS Workbench建立充气管道的流固耦合振动数值模型和边界条件的合理设置提供支撑。2、搭建了管道振动特性测试实验平台,对孔板+缓冲罐消振进行了实验研究,实验结论最佳孔板孔径比选取区间为0.4~0.5,与工程中推荐的孔径比区间相吻合。此外,通过对实验管道系统充气前后的对比分析,得出耦合因素造成的振动响应,为气固耦合仿真模拟的正确性提供验证。为后续耦合场模拟提供基础数据。3、基于上述实验系统建立数值模型,通过实验脉动值对模型施加边界条件进行仿真,验证了模拟方案的可行性。并讨论了气固耦合对典型复杂管线系统模型模态特性的影响,结果表明,随介质密度、流速、压力和弹性模量增加,固有频率显著升高,但振型基本不变。4、就工程实际中一套在役压缩机机组及进出口管线的剧烈振动问题进行了分析,基于上述分析,在可忽略耦合效应的前提下,提出了引入结合部等效参数修改的技术建立还原真实振动现场模型的思路。实测结果验证了模型的准确性,对一体化模型提出增加6个支撑的结构动力优化方案,数值验证结果表明,优化后系统最大振动位移降幅达到97%,振动能量分布均匀。更多还原

【Abstract】 Reciprocating compressors are widely used in many industrial fields of petrochemical, electric power and mining. However, the periodical gas pulsation which triggered by the working principle of the compressors will make the pipeline system severe vibration.This will seriously affect the safety of the device in operation. In recent years, the research on fluid-solid interaction has gradually become the focus of engineering application.This paper uses the finite element analysis software ANSYS to study the gas pipeline by fluid-solid interaction analysis and research the practical engineering problems. The main work of this article has five parts as follows:1、This paper has carried the elaboration to the vibration of mechanical structure system theory of pipeline in reciprocating compressor and the pipe gas column system finite element analysis theory. Leading out the gas-solid coupling theory from the shortcomings of a separate analysis of the fluid domain and solid domain, base on the Galerkin method to establish the gas-solid coupling finite element equation which support the fluid-solid interaction tube vibration numerical model on ANSYS Workbench and the reasonable setting of boundary conditions.2 、 This paper has set up a platform for the test of pipeline vibration characteristics. The decline of vibration through orifice plate and buffer tank was studied by experiment. The best selection of aperture ratio range is0.4~0.5.The experience results is similar with recommended engineering aperture ratio. Through the experimental analysis of full and no gas pipeline system, I concluded vibration response which caused by coupling factors. This will pave below for testing the validity of gas-solid coupling simulation process. In addition, providing basic data for subsequent vibration control.3 、 By building up numerical model of above-mentioned experimentsystem and setting boundary conditions to simulate the real state with experiment’s parameter, this paper verified the feasibility of simulation and discussed the effect of gas-solid coupling to modal characteristic of typical complex pipeline system. The result shows that the intrincic frequency rises with the increasing medium density, velocity, pressure and elasticity modulus,while the vibration mode stay the same.4 、 This paper has analyzed an actual compressor unit in service with severe vibration issues on import and export pipelines, based on the above analysis, on the premise of negligible coupling effect, I has illustrated the idea of modeling actual site vibration with correction technology on joint equivalent parameters. The field measurement confirmed the accuracy of models and a 6 points sustainer structure optimized solution was provided by integration model accordingly. The result shows that the optimized system maximum vibration displacement has fell to 97% and evenly vibration energy distribution.更多还原