T15: Numerical Simulation and Validation of Motor Dynamics in Reciprocating Compressor Driveline Coupled with Stiff and Soft Elastic Couplings under Continuous and Transient Operating Conditions

Abstract

Reciprocating compressor is often used in the field of gas compression industry and generates harmonic torque excitation in adriveline The objective of this paper is to simulate the dynamic torsional vibrations by considering motor as an electromechanicalsystem with real electrical characteristics and solve them numerically in order to capture the accurate torque oscillations insidecouplings The wrong selection of coupling may lead to the damage of the coupling as well as the components connected in thedriveline as they produce high level of vibrations A large deviation of torque fluctuations has been observed with two differentapproaches between simple model as spring damper and multiphysics motor model The accuracy can be achieved with a user definedelectromechanical motor model and the negative damping effect is accomplished without tuning the model Finally, the simulationresults were compared with measured experimental data The validation shows a good match The final models are based on validationconcept Two examples are presented with flexible and torsional stiff couplings in order to optimize the coupling for a higher systemreliability in a particular driveline The flexible coupling shows relatively low vibratory torque in the coupling compared to torsionalstiff coupling The damping and dynamic stiffness of rubber couplings play an important role to attenuate vibration as the couplingmode shape controls the vibration signature Moreover, the transient loading under short circuit event and energy saving valve unloaders operating conditions haven been investigated that are used in many reciprocating compressors applications