On-line continuous monitoring of high pressure reciprocating compressors

Multi-disciplinary technologies

  • 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

Main Functionality

  • 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

 

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