On-line continuous monitoring of high pressure reciprocating compressors
- Motor current, Voltage & Phase Angle sensors
- Smart accelerometers
- Ultra sound probes
- Thermocouple probes
- Control data from, for example, PI of OSIsoft inc
- Thermodynamic analysis of compressor process
- On line signal processing
- System customization
- Aggregation of different tags into Software Diagnostics Sensors.
- Automatic trend tracking and the early discovery of minor disturbances
Prognosis of time when a tag or a Software Sensor value reaches a threshhold value.
Example: “O” ring problem diagnostics:
Procedure 1. Using low inertia temperature probes located in cylinder suction heads. Temperatures vary in the course of compressor operation. O-ring leakage causes growth of the mean temperature values and changes in the temperature signatures. The PSE software detects and tracks these changes.
Procedure 2. “O” ring wear causes the emission of ultrasound signals in the range of 40-200 kH. Our wireless ultrasound sensors registers these signals, measure its frequency and amplitude and monitors these changes relative to the base line conditions in a specific cylinder
The “O” ring failure model (Failure Factor) aggregates the key diagnostics parameters extracted from temperature and acoustical emission signatures. The result is one indicator signalling “O” ring health.
The system trends the Failure Factor and sends alarms when the “O” ring wear grows through alert values
Failures detected Method of detection
|Compressor valve flatter Spectral analysis of motor current and phase angle|
|Compressor valve leakage Ultra sound probes installed on the cylinder heads|
|O-ring wear Thermodynamic analysis of temperatures before and after cylinders|
|Shaft bearing malfunction Ultra sound probes|
|Loose foundation Phase angle and vibration analysis|
|Rod wear Spectral analysis of motor current & phase angle and vibration analysis|
|Short windings in electrical motors Unbalance of motor current|
|VFD improper performance Spectral analysis of voltage SINE in three phases|
|Rotor-stator gap problems Phase Angle fractals|