Research On Pipeline Vibration And Fluid-structure Coupling Characteristics Of Reciprocating Compressor

Reciprocating compressor,as a typical equipment in manufacturing industry,plays a key role in many fields such as chemical industry,metallurgy,aerospace and so on.With the attention of the state and society to the green development of manufacturing industry,the vibration problem of reciprocating compressor pipeline needs to be effectively controlled.At the same time,the influence of fluid-solid coupling on the vibration characteristics of pipeline system should be considered to avoid low production efficiency and safety accidents caused by pipeline vibration.In this paper,theoretical analysis,experimental research,simulation research and design of new shock absorber are studied.The research contents are as follows:(1)This paper studies the vibration effect of reciprocating compressor pipeline system,expounds the economic harm and safety hazard caused by the vibration phenomenon in the actual use of compressor and pipeline system,so it is necessary to study the vibration of pipeline system and consider the influence of fluid-solid coupling on the vibration characteristics.The main causes of pipe system vibration are also introduced.Based on the different vibration reasons,the corresponding vibration control technologies are proposed,including three ways of reducing vibration:reducing pressure pulsation,eliminating resonance and transferring vibration energy.After vibration control of structural system,the effect of vibration reduction is measured by specific standards.Vibration control standards are divided into two parts:pipeline standard and compressor standard.Vibration standards of pipeline and compressor under different working frequencies are described respectively.(2)The theory of vibration characteristics of pipeline system is studied,and the description and modeling methods of pipeline vibration system are expounded and deduced.The discrete method is usually used to describe the vibration system,and the damping theory of dissipating vibration energy in structural system is analyzed,including the form of damping and the influencing factors.The basic theory of fluid-solid coupling,including fluid,should be studied first to study the effect of fluid-solid coupling on pipeline system.The flow of the system obeys the laws of mass conservation,momentum conservation and energy conservation.The stress and displacement at the interface of fluid and solid should be transferred normally in order to ensure the fluid-solid coupling to play its role and solve.In the theory of vibration characteristics,modal analysis method and harmonic response analysis method are also described.The above analysis realizes the trend and process of structural vibration.For the optimization design of vibration control,the mathematical expression is constructed by defining the optimization variables,objective functions and constraints in the optimization problem,which provides theoretical support for the subsequent parameter optimization.(3)Vibration experiment research of pipeline system is carried out based on the comprehensive test platform of pipeline vibration of reciprocating compressor.Firstly,the basic working conditions of the pipeline were tested to understand the vibration response of the experimental platform under three on-off working conditions,and the vibration displacement of the measured points exceeded the standard.Therefore,the vibration of the pipeline was further analyzed and controlled.Secondly,a comparative experiment of fluid-solid coupling is carried out to make the pipelines under uncoupled and coupled conditions respectively.The effect of fluid-solid coupling on the vibration characteristics of pipelines is compared.The results show that the coupling effect on the vibration characteristics of pipelines under the experimental conditions is not obvious.Similarly,experiments of different vibration absorbers were carried out to explore the optimal restraint position and vibration reduction effect of the device.The optimal position of the butterfly spring clamp is 13,the optimal position of the ordinary spring clamp is 6,and the maximum reduction of the pipe damper is 23.6%.After vibration reduction,the system meets the requirements of the vibration standard,and the vibration reduction effect of the pipe damper is the best under this condition.(4)The vibration characteristics of pipelines are simulated by finite element method.Ansy Workbench is used to simulate the vibration of pipelines.The effects of fluid-structure interaction,pipeline modal analysis module,harmonic response analysis module and parameterized vibration control are studied.The maximum displacement and stress of pipeline system under 0.6Mpa working pressure are obtained by using the method of one-way coupling simulation.The coupling effect has some influence on the solid system of pipeline,but is not obvious,which is consistent with the experimental results.The modal analysis is carried out by coupling and uncoupling.The results show that the former increases the natural frequency slightly,but does not affect the vibration mode trend of pipelines.Harmonic response analysis simulates resonance by using different frequency doubling excitation frequencies of compressors,and obtains the corresponding relationship between frequency and vibration response.When the excitation frequency is 350.3Hz,the vibration response reaches the maximum,which provides a reference for the frequency that vibration control needs to avoid.By using the parameter optimization method,the optimal vibration reduction position of the pipeline damper is simulated at 0.069m.The obtained pipeline vibration deformation cloud is consistent with the experimental results,which shows that the finite element simulation is the correct method to study the effect of the vibration reduction device.(5)The design of new dampers for pipelines is studied.The structure of new dampers is selected from the aspects of working principle and control means.The main parts are designed and calculated.The design of new dampers is tested by finite element simulation method.The effect of vibration reduction is simulated by parameter optimization method.At the same time,the optimal restraint position of new dampers is obtained.Compared with the vibration response data before and after pipeline restraint,the vibration displacement of the new damper decreases by 9.93%compared with the original damper.Although the maximum stress of the new damper increases compared with the original damper,it is still within the scope of need,which shows that the vibration reduction effect of the new damper meets the target requirements.It provides method reference and solution for vibration control of reciprocating compressor pipeline.