Method and system for monitoring a reciprocating compressor valve

A system for monitoring a condition of at least one valve positioned with respect to at least one of a first chamber and a second chamber of a reciprocating compressor, said system configured to:

• collect data by generating a crank angle degree variable and incrementally increasing the crank angle degree variable by a 0.5° increment from 0° to 359.5° during each of a plurality of rule processing cycles to establish a compressor operation cycle;
• plot a pressure measured within the first chamber and a pressure measured within the second chamber during the compressor operation cycle as a function of a crank angle;
• plot a gas load and an inertial load measured within at least one of the first chamber and the second chamber during the compressor operation cycle as a function of the crank angle;
• plot a combined load comprising the summation of the measured gas load and the measured inertial load;
• plot an acceleration waveform sample including a cylinder acceleration during the compressor operation cycle as a function of the crank angle;
• analyze the combined load to determine at least one rod reversal event that includes at least a first rod reversal event that occurs with the crank angle at about 40 degrees and at least a second rod reversal event;
• analyze the acceleration waveform sample to establish a first compressor operation cycle segment wherein the at least one valve is closed and a second compressor operation cycle segment wherein the at least one valve is closed;
• set an acceleration baseline level for each of the first compressor operation cycle segment and the second compressor operation cycle segment from the pressure measured during the compressor operation cycle;
• determine a maximum value and a minimum value of the acceleration waveform sample for each of the first compressor operation cycle segment and the second compressor operation cycle segment;
• and
• diagnose a valve leak condition during the compressor operation cycle at a valve closing event wherein the at least one compressor valve is closed by comparing the maximum and minimum values of the acceleration waveform sample against the acceleration baseline level;
• and
• diagnose a restricted flow condition during the compressor operation cycle at a valve opening event wherein the at least one compressor valve is open.

A computer program embodied on a computer readable medium for monitoring a condition of at least one valve positioned with respect to at least one of a first chamber and a second chamber of a reciprocating compressor, said computer program comprising a code segment configured to:

• generate a crank angle degree variable at each 0.5° increment for each of a plurality of rule processing cycles within a range of 0° to 359.5° ;
• simulate a cylinder pressure for at least one of the first chamber and the second chamber for each of the generated crank angle degree variables;
• estimate a crank angle and a corresponding cylinder pressure at a valve opening event using at least one of a static suction input and a discharge pressure input;
• determine the crank angle and the corresponding cylinder pressure for at least one valve closing event during a compressor operation cycle using the generated crank angle degree variables;
• determine at least one rod reversal event during the compressor operation cycle using at least one of the simulated cylinder pressure, the estimated valve opening event cylinder pressure, and the determined valve closing event cylinder pressure, wherein the at least one rod reversal event includes at least a first rod reversal event that occurs with the crank angle at about 40 degrees and at least a second rod reversal event;
• diagnose a valve leak condition during the compressor operation cycle at the at least one valve closing event;
• analyze an acceleration waveform sample to establish a first compressor operation cycle segment wherein the at least one valve is closed and a second compressor operation cycle segment wherein the at least one valve is closed;
• set an acceleration baseline level for each of the first compressor operation cycle segment and the second compressor operation cycle segment using the simulated cylinder pressure;
• determine a maximum value and a minimum value of the acceleration waveform sample for each of the first compressor operation cycle segment and the second compressor operation cycle segment;
• and
• diagnose a restricted flow condition during the compressor operation cycle at the valve opening event by comparing the maximum and minimum values of the acceleration waveform sample against the acceleration baseline level.