System and method of determining top-dead-center (TDC) of reciprocating compressor

1. An apparatus comprising:

a pressure transducer configured to measure a pressure inside a compressor cylinder and convert the measured pressure into an asynchronous waveform; and

at least one computing device operably connected with the pressure transducer, the at least one computing device configured to:

extract a revolution data set representing piston angles over a single revolution of a piston within the compressor cylinder from the asynchronous waveform;

evaluate a property corresponding to the measured pressure at each piston angle of the revolution data set;

determine whether each piston angle of the revolution data set is an invalid piston angle that does not correspond to a top-dead-center (TDC) position of the piston within the compressor cylinder based at least in part on a comparison of the evaluated property from the respective piston angle to a respective threshold;

remove data representing invalid piston angles from the revolution data set to form a refined data set;

determine an average piston angle for the single revolution from the refined data set;

identify the average piston angle representing a data value of the refined data set as the TDC position of the piston within the compressor cylinder; and

adjust the refined data set to order the data value of the TDC position of the piston within the compressor cylinder to be a first data value in the refined data set;

wherein the at least one computing device is configured to identify the average piston angle as the TDC position of the piston within the compressor cylinder without the use of a phase-reference transducer.

2. The apparatus of claim 1 , wherein the evaluated property comprises a compression ratio of the single revolution of the piston within the compressor cylinder.

3. The apparatus of claim 1 , wherein the evaluated property comprises a volumetric efficiency of the single revolution of the piston within the compressor cylinder.

4. The apparatus of claim 1 , wherein the evaluated property comprises a clearance volume of the single revolution of the piston within the compressor cylinder.

5. The apparatus of claim 1 , wherein the asynchronous waveform includes a series of uniformly spaced time domain data points corresponding to measured pressures within the compressor cylinder.

6. The apparatus of claim 1 , wherein the at least one computing device is configured to extract the revolution data set representing the piston angles over the single revolution using a threshold-hysteresis model.

7. The apparatus of claim 1 , wherein the pressure transducer is operably connected with the at least one computing device via a wireless link.

8. A system comprising:

at least one computing device configured to identify a top-dead-center (TDC) position of a piston within a compressor cylinder by performing actions including:

extracting a revolution data set representing piston angles over a single revolution of a piston within a compressor cylinder from an asynchronous waveform indicating pressure inside the compressor cylinder;

evaluating a property corresponding to the pressure at each piston angle of the revolution data set;

determining whether each piston angle of the revolution data set is an invalid piston angle that does not correspond to the TDC position of the piston within the compressor cylinder based at least in part on a comparison of the evaluated property from the respective piston angle to a respective threshold;

removing data representing invalid piston angles from the revolution data set to form a refined data set; and

identifying a determined piston angle representing a data value of the refined data set as the TDC position of the piston within the compressor cylinder;

wherein the at least one computing device is configured to identify the average piston angle as the TDC position of the piston within the compressor cylinder without the use of a phase-reference transducer.

9. The system of claim 8 , wherein the evaluated property comprises a compression ratio of the single revolution of the piston within the compressor cylinder.

10. The system of claim 8 , wherein the evaluated property comprises a volumetric efficiency of the single revolution of the piston within the compressor cylinder.

11. The system of claim 8 , wherein the evaluated property comprises a clearance volume of the single revolution of the piston within the compressor cylinder.

12. The system of claim 8 , comprising:

determining an average piston angle for the single revolution from the refined data set;

identifying the average piston angle as the determined piston angle; and

adjusting the refined data set to order the data value of the TDC position of the piston within the compressor cylinder to be a first data value in the refined data set.

13. The system of claim 8 , wherein the asynchronous waveform includes a series of uniformly spaced time domain data points.

14. The system of claim 8 , wherein the at least one computing device is configured to extract the revolution data set representing the piston angles over the single revolution using a threshold-hysteresis model.

15. A non-transitory computer readable media comprising program code, which when executed on at least one computing device, causes the at least one computing device to identify a top-dead-center (TDC) position of a piston within a compressor cylinder by performing actions including:

obtaining an asynchronous waveform indicating measured pressures inside the compressor cylinder;

extracting a revolution data set representing piston angles over a single revolution of the piston within the compressor cylinder from the asynchronous waveform;

evaluating a property corresponding to the measured pressure at each piston angle of the revolution data set;

determining whether each piston angle of the revolution data set is an invalid piston angle that does not correspond to the TDC position of the piston within the compressor cylinder based at least in part on a comparison of the evaluated property from the respective piston angle to a respective threshold;

removing data representing invalid piston angles from the revolution data set to form a refined data set;

determining an average piston angle for the single revolution from the refined data set;

identifying the average piston angle as representing a data value of the refined data set as the TDC position of the piston within the compressor cylinder; and

adjusting the refined data set to order the data value of the TDC position of the piston within the compressor cylinder to be a first data value in the refined data set;

wherein the at least one computing device is configured to identify the average piston angle as the TDC position of the piston within the compressor cylinder without the use of a phase-reference transducer.

16. The non-transitory computer readable media of claim 15 , wherein the evaluated property comprises a compression ratio of the single revolution of the piston within the compressor cylinder.

17. The non-transitory computer readable media of claim 15 , wherein the evaluated property comprises a volumetric efficiency of the single revolution of the piston within the compressor cylinder.

18. The non-transitory computer readable media of claim 15 , wherein the evaluated property comprises a clearance volume of the single revolution of the piston within the compressor cylinder.

19. The non-transitory computer readable media of claim 15 , wherein the asynchronous waveform includes a series of uniformly spaced data points, and wherein the extracting of the revolution data set representing the piston angles over the single revolution includes using a threshold-hysteresis model.