CCPGE has successfully developed a new generation torsional study program based on time-domain analysis method for resolving torsional vibration problems of reciprocating compressor packages. The new program integrates the following functions:
- Input and output file management
- Calculation and presentation of torsional natural frequencies and modal shapes of systems
- Determination and presentation of Campbell diagram to show potential resonance frequencies
- Calculation and presentation of driving torques of motors and engines, and torque demand of compressors with crankshaft angles.
- Calculation and presentation of vibratory torque acting at coupling, stress on shafts, and vibration level of each mass of systems
The program prides itself on the following features over most of current torsional analysis programs by:
- Accurately modeling the evolution of forced torsional vibration of systems from starting to steady operating condition
- Accurately modeling the oscillation of VFD motor running speed and its effect on torsional vibration of systems
- Accurately modeling mass damping and shaft damping (i.e. damping along shafting between two masses) of systems as provided by manufacturers rather than use of assumed 1~5% of damping ratio as normally did in frequency-domain analysis, and their effect on torsional vibration of systems.