往复式压缩机管系振动与气流脉动的模拟分析及实验研究

发布时间：2018-03-01 15:05

本文关键词： 声学模拟气流脉动管道振动赫姆霍兹共鸣器 DSPS系统　出处：《兰州交通大学》2014年硕士论文　论文类型：学位论文

【摘要】：本文主要研究了气柱固有频率、管道结构固有频率对压缩机管道系统脉动的影响，同时分析了赫姆霍兹共鸣器对气柱固有频率的影响以及不同约束点对结构固有频率的影响。利用平面波动理论，推导出气柱固有频率的有限元刚度矩阵方程，采用模态分析法中的非对称计算方法对复杂管道气柱固有频率进行数值计算，并且利用声学振动模拟试验，对计算结果进行验证。同时，利用子空间迭代法计算了管道结构固有频率，并且在实验现场利用DSPS实验测试系统测量了管道的结构固有频率值，对子空间迭代法的计算结果也进行了验证。本文利用经典波动理论，建立起气柱固有频率的有限元刚度矩阵方程，通过有限元软件建立起复杂管道的气柱模型，应用声学模态分析法进行模拟计算，获得了管道的气柱固有频率。并且针对压缩机管道系统的产生根源气流脉动，着重分析了赫姆霍兹共鸣器的减震作用。本文针对往复式压缩机的气流脉动产生机理，对赫姆霍兹共鸣器对气流脉动的消减作用进行了探究，并且对于赫姆霍兹共鸣器对管道气流脉动消减效果进行了计算机模拟，肯定了赫姆霍兹共鸣器对压缩机阀腔内的气流脉动具有衰减作用。实验结果表明：赫姆霍兹共鸣器对压缩机阀腔内的衰减效果比较好，而对缓冲罐以后的管道排气系统的气流脉动衰减效果不再明显。文中对往复压缩机的管道结构固有频率采用了子空间迭代法进行了模拟分析与计算，采用DSPS系统进行了压缩机管道的现场实验结果测试，并对模拟计算值进行了验证。实验结果表明：不同约束点对管道的结构固有频率具有重要影响，改变管道的约束，可以有效调节结构固有频率值，从而有效避开压缩机的激发频率，避免管道共振的发生。通过本文的研究，验证了非对称计算法对气柱固有频率计算的可靠性，以及子空间迭代法计算管道结构固有频率的有效性。实验结果表明了声学模拟对于气柱固有频率具有可操作性，并且DSPS系统对于现场测试结构固有频率值具有实用性。因此，利用声学模拟及DSPS测试系统，，可以很好的获得气柱固有频率值及管道结构固有频率值，从而为压缩机管道系统的设计，提供了一定的理论基础。
[Abstract]:In this paper, the influence of the natural frequency of the gas column and the natural frequency of the pipeline structure on the pulsation of the compressor pipeline system is studied. At the same time, the influence of the Hem Hortz resonator on the natural frequency of the gas column and the influence of different restraint points on the natural frequency of the structure are analyzed. The finite element stiffness matrix equation of the natural frequency of the gas column is derived by using the plane wave theory. The unsymmetrical calculation method in modal analysis is used to numerically calculate the natural frequency of gas column in complex pipeline, and the acoustic vibration simulation test is used to verify the calculated results. The natural frequency of pipeline structure is calculated by subspace iteration method, and the natural frequency of pipeline structure is measured by DSPS test system. The results of subspace iteration method are also verified. In this paper, the finite element stiffness matrix equation of natural frequency of gas column is established by using classical wave theory, and the gas column model of complex pipeline is established by finite element software, and the simulation calculation is carried out by means of acoustic modal analysis method. The natural frequency of the gas column of the pipeline is obtained, and the vibration absorption of the Hem Hortz resonator is emphatically analyzed in view of the source flow pulsation of the pipeline system of the compressor. In this paper, the mechanism of air pulsation in reciprocating compressor is studied, and the effect of Hem Hortz resonator on air pulsation is studied, and the effect of Hem Hortz resonator on the reduction of pipeline airflow pulsation is simulated by computer. It is affirmed that Hem Hortz resonator can attenuate the flow pulsation in the compressor valve cavity. The experimental results show that Hem Hortz resonator has a better attenuation effect on the compressor valve cavity. However, the attenuation effect of air pulsation on the pipe exhaust system after the buffer tank is no longer obvious. In this paper, the natural frequency of pipeline structure of reciprocating compressor is simulated and analyzed by subspace iteration method, and the field experiment result of compressor pipeline is tested by DSPS system. The experimental results show that the different constraint points have an important effect on the natural frequency of the pipeline structure. Changing the constraints of the pipeline can effectively adjust the natural frequency value of the structure. Thus effectively avoid the excitation frequency of the compressor and avoid the occurrence of pipeline resonance. Through the research in this paper, the reliability of the asymmetric calculation method for calculating the natural frequency of the gas column is verified. The experimental results show that the acoustic simulation is feasible for the natural frequency of the gas column, and the DSPS system is practical for the in-situ testing of the natural frequency of the structure. By using the acoustic simulation and DSPS test system, the natural frequency value of the gas column and the natural frequency value of the pipeline structure can be obtained well, which provides a certain theoretical basis for the design of the compressor pipeline system.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TH45

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