Instantaneous angular speed and power for the diagnosis of single-stage, double-acting reciprocating compressor

Advance condition monitoring systems that use cylinder pressure as a primary feedback variable have been developed. Application has been limited by the cost and difficulties associated with the intrusive cylinder pressure sensor installation. Non-intrusive measurements, the instantaneous angular speed (IAS) and power, have been performed to incorporate the effect of faults in a single-stage, single-cylinder double-acting reciprocating compressor. The study simulates a hydrogen make-up compressor to define a diagnosis criterion that may be used for the condition monitoring of a reciprocating compressor. It involves the development of mathematical models for three physical conditions: excess clearance, cylinder pressure variation, and variation of valves flow area. The simulation is conducted using the torque balance, energy equation, valve dynamics, and flow through the valves. The simulation produced unique effects for each of the physical conditions. The results predicted by the model are validated with the data from the hydrogen make-up compressor located in a Kerosene Desulphurization Unit using the pressure-volume diagram (PV) analysis. This paper presents IAS and power as non-intrusive diagnosis tools. Results showing the effect of faults on the IAS and power trends are presented.