Research Of Reciprocating Compressor Piping System Vibration Fatigue Failure And Vibration Reduction Measures

Reciprocating compressor is an important facility in oil and natural gas industry,Pressure pulsation phenomenon arises for compressor's non-continuity of work,which will cause the vibration in pipe and equipment of upstream and downstream.Severe pipe vibration will result in fatigue failure and gas leak.This will cause accidents.The paper analyzes the cause of compressor pipeline system vibration and studies variation law of natural frequencies of pipe using ABAQUS software by theoretical analysis and calculation of acoustic and mechanical software.Then it presents the corresponding vibration analysis method according to the compressor anti-vibration design method developed by API,and studies the mechanism of the compressor different vibration damping measures.In the end it uses CAESAR II to analyze Sulige gas field compressor inlet pipe in mechanical and fatigue aspect.The paper also uses CAESAR II and DIMGO procedures to analyze 2D50 compressor piping system and propose corresponding measures to damp the pulsation and mitigate the vibration in piping system.Preventing the occurrence of resonance vibration which will lead to fatigue failure,ensure the piping system operating safely.The conclusion of the paper has important engineering significance.There are three main reasons for the vibration in compressor piping systems: piston's reciprocating motion drives frame and foundation vibrate;pressure pulsation caused by discontinuities of compressor suction and discharge in the pipeline motivate the gas in pipe to vibrate;shaking forces caused by the gas vibration in elbows,valves make the pipe system suffer from mechanical vibration.The simpler of the pipeline arrangement and the fewer of the number of bends,the smaller of piping natural frequency;the smaller of spacing constraint and the greater rigidity of piping,the bigger of piping natural frequency;the bigger of contact area between the tube and pipe restraints,the stronger of restraint capacity,the smaller of piping natural frequency;the natural frequency of piping system decreases when cracks arise,but the decline was not significant.In practical engineering design,selecting which anti-vibration design method is generally based on the value of the rated power of each cylinder and compressor pressure in discharge pipeline.Vibration analysis mainly involves acoustic analysis and mechanical analysis.Employ DIMGO procedures to analyze the pressure pulsation in compressor and piping system.Employ CAESAR II for static analysis,dynamic analysis and fatigue analysis of the pipe.Through the mechanical analysis of Sulige gas field compressor inlet pipeline,the operation of the pipeline is safe.Installing the buffer tank,the pulsation damper or orifice plate in the piping system are the main pulsation mitigation measures.Increase the number of pipeline supporting constraint or change the pattern of constraint is an effective measure to prevent mechanical resonance.Design pulsation and vibration mitigation method for 2D50 reciprocating compressor,through installing an orifice plate at flange in the discharge side,setting up thrust restraint and anti-vibration restraint in piping system to ensure compressor piping system go into operation successfully and operate safely.