| Piston compressor is widely used in petroleum,chemical industry,power,natural gas transportation and other fields.The reliable operation of compressor is the basis of ensuring production safety and economic benefits.The air pulsation of pipe system and the working characteristics if air valve are important factors affecting the reliability of piston compressor unit.Therefore,in this paper,the working characteristic model of the piston compressor and the air flow pulsation model of the pipeline are studied as follows :(1)Based on the working characteristics of piston compressor and the theory of acoustics and fluctuation,the working characteristics model of piston compressor with valve chamber is established,and the program is compiled with MATLAB software to obtain the working characteristics information of compressor cylinder pressure,valve chamber pressure fluctuation,P-V diagram of calculated cylinder,compressor rod load and gas valve characteristics.On this basis,this paper analyzes and compares the factors that affect the movement characteristics of the valve.(2)Based on the plane wave theory,the natural frequency equation of the gas column and the analysis model of the gas flow pulsation in the pipeline are established.According to the acoustic boundary conditions,the natural frequency of the gas column of the pipeline system is not coincident with the exciting frequency of the compressor unit,which avoids the increase of the air pulsation amplitude caused by the resonance.Secondly,the fluctuating pressure information of the valve chamber is taken as the boundary condition of the analysis model of air flow pulsation by coupling the working characteristic model of the piston compressor.The distribution of the fluctuating pressure of the pipe system and the uneven degree of air flow pulsation at the key position are obtained by the joint solution.According to the sixth edition of API618 standard,where the pipeline pressure unevenness of a large piston compressor unit and a land piston compressor unit exceeds the standard,an improvement scheme is provided according to the calculation results and engineering requirements,so as to control the pressure unevenness within the standard range.(3)Pipeline system of high power piston compressor unit based on an enterprise,a small-scale experimental platform of air flow pulsation of piston compressor is designed and built.According to the experimental conditions,a specific experimental scheme is proposed to lay the foundation for the subsequent air flow pulsation experiment of piston compressor. |
