| Reciprocating compressor,as a general mechanical device to transport gas and improve gas pressure,plays an important role in aviation,national defense,petrochemical and many other industrial fields.The periodic movement of compressor piston will cause periodic fluctuation of gas pressure and flow,which will lead to pulsation of gas flow in pipeline system and vibration of auxiliary pipeline.A large number of engineering practices and experimental studies have shown that the gas pulsation is the main reason for the vibration of the reciprocating compressor pipeline system,and the severe gas pulsation will threaten the safe operation of the equipment.Therefore,the research on the gas pulsation of compressor pipeline system has important theoretical significance and engineering practice value.In this paper,the problems of gas pulsation existing in the reciprocating compressor pipeline system are studied as follows:(1)Starting from the structure and working mode of reciprocating compressor,the generation principle of gas flow pulsation and the mechanism of gas flow pulsation exciting pipeline vibration are analyzed.Based on the plane wave principle,the plane wave equation of air flow pulsation in the pipeline is derived,the pulsation transfer matrix of the pipeline system is established,the calculation method of natural frequency and pressure pulsation of the air column is obtained,and the evaluation method of pressure pulsation is proposed.(2)Study on the suppression device of airflow pulsation.The principle of orifice plate and buffer tank to reduce airflow pulsation is analyzed.The influence of aperture ratio parameters of orifice plate structure on pulsation suppression effect is numerically simulated by using Fluent,and the optimal design parameters of orifice plate are obtained.Based on the impedance transfer method in acoustic theory,the effects of different structure parameters of buffer tank on the reduction of air flow pulsation are studied.The research results have practical significance for engineering design.(3)Study on the gas pulsation and dynamic response of compressor piping system.Using Bentley PULS software,a pulsating acoustic model of the first stage inlet and outlet pipeline system of a labyrinth reciprocating compressor is established,and the distribution law of the pipeline airflow pulsation is mastered;The natural frequency and dynamic response of the pipeline structure are analyzed and calculated by using CAESARII software.Based on the comprehensive calculation results and engineering requirements,it was checked according to API-618 standard.Aiming at the location where the pipeline pressure pulsation of the compressor unit exceeded the standard and the maximum displacement value of the pipeline dynamic response vibration,an optimization scheme for the gas flow pulsation was proposed,which realized the control of the non-uniformity of the pulsating pressure and the dynamic response.It was determined that the excessive gas flow pulsation was the main reason for the excessive pipeline vibration.(4)The compressor pipeline vibration experiment was carried out,and the vibration frequency and maximum vibration displacement of the pipeline system were obtained.By comparing the results of the experiment and simulation analysis,the reasons for the experimental error were analyzed,and the accuracy of the air flow pulsation analysis scheme and the calculation model was verified,which provided a reference for the further study of the effect of the air flow pulsation of the reciprocating compressor on the pipeline system vibration. |
