COMPRESSOR DISCHARGE TEMPERATURE MONITOR AND ALARM

• US 20130115109A1
• Filed: 05/01/2012
• Published: 05/09/2013
• Est. Priority Date: 05/05/2011
• Status: Abandoned Application

• Current Assignee: William G. Hall
• Original Assignee: William G. Hall
• Inventors: Hall, William G.
• Application Number:
  US13/461,288
• Publication Number:
  US 20130115109A1
• Time in Patent Office: Days
• US Class Current: 417/53
• CPC Class Codes: F04B 2201/0401 Carter pressure
• CPC Class Codes: F04B 2205/03 Pressure in the compression chamber
• CPC Class Codes: F04B 2205/11 Outlet temperature
• CPC Class Codes: F04B 2207/70 Warnings
• CPC Class Codes: F04B 49/065 and making use of computers
• CPC Class Codes: F04B 49/22 by means of valves F04B49/03 takes precedence

Abstract

A compressor protection method and system capable of continuously establishing compressor discharge temperature set points based on actual in-service conditions and detecting damaged compressor valves for a given cylinder at each stage of compression. The method and system utilize sensors configured to monitor process property parameters (e.g. temperature and pressure) at the inlet section and outlet section of a compressor stage. The sensors generate monitored signals corresponding to the process property parameters. The method and system utilize a controller configured to receive and process these monitored signals. The controller executes a control logic that uses the monitored signals to either estimate or calculate compressor valve pressure losses for determining internal cylinder pressures, which are used to calculate compressor discharge temperature set points. The control logic compares the monitored temperature to the temperature set points and may generate a warning or normal operation signals based on results of the comparison.

Claims

1. A method for protecting a compressor with at least one compression stage having at least one cylinder, an inlet section configured to receive a gas wherein the inlet section comprises inlet piping and an inlet compressor valve, an outlet section configured to discharge the gas wherein the outlet section comprises outlet piping and an outlet compressor valve, sensors configured to monitor selected process property parameters at the inlet section and outlet section and generate monitored signals corresponding to the process property parameters, and a controller configured to receive the monitored signals, execute a control logic and generate signals, the control logic comprising:

a. a process property parameter collection component comprising;

i. collecting data for the monitored selected process property parameters at the inlet section and outlet section using the sensors, wherein the monitored process property parameters comprise gas inlet temperature, gas inlet pressure, gas outlet temperature, gas outlet pressure, and compressor speed;

b. an internal cylinder pressure calculation component comprising;

i. determining an inlet internal cylinder pressure;

ii. determining an outlet internal cylinder pressure;

c. a temperature set point calculation and comparison component comprising;

i. calculating a first outlet temperature set point for each cylinder;

ii. comparing the first outlet temperature set point with the monitored gas outlet temperature for each cylinder;

d. a signal component comprising;

i. generating a normal operation signal if the monitored outlet temperature is consistent with the first outlet temperature set point.

ii. generating a first warning signal if the monitored outlet temperature is inconsistent with the first outlet temperature set point.

2. A method for protecting a compressor according to claim 1 wherein:

a. the inlet internal cylinder pressure is determined by calculating a first pressure loss for the inlet compressor valve;

b. the outlet internal cylinder pressure is determined by calculating a second pressure loss for the outlet compressor valve.

3. A method for protecting a compressor according to claim 1 wherein:

a. the inlet internal cylinder pressure is determined by estimating a first pressure loss for the inlet compressor valve;

b. the outlet internal cylinder pressure is determined by estimating a second pressure loss for the outlet compressor valve.

4. A method for protecting a compressor according to claim 2 wherein the first pressure loss and second pressure loss are adjusted in proportion to the compressor speed.

5. A method for protecting a compressor according to claim 4 wherein the signal component further comprises:

a. initiating compressor shutdown if the monitored outlet temperature is inconsistent with the first outlet temperature operating range.

6. A method for protecting a compressor according to claim 5 wherein the temperature set point calculation and comparison component further comprises:

a. calculating a second outlet temperature set point for each cylinder;

b. comparing the second outlet temperature set point with the monitored outlet temperature for each cylinder.

7. A method for protecting a compressor according to claim 6 wherein the signal component further comprises:

a. generating a second warning signal if the monitored outlet temperature is inconsistent with the second outlet temperature set point;

b. initiating compressor shutdown if the outlet temperature is inconsistent with the second outlet temperature operating range.

8. A method for protecting a compressor according to claim 7 wherein the process property parameter collection component further comprises:

a. collecting data using a sensor configured to measure required properties to determine the ratio of specific heats.

9. A method for protecting a compressor according to claim 8 wherein the pressure losses are calculated using fixed operating conditions.

10. A method for protecting a compressor according to claim 8 wherein the pressure losses are continuously calculated using actual operating conditions.

11. A protection system for a compressor with at least one compression stage having at least one cylinder, an inlet section configured to receive a gas and an outlet section configured to discharge the gas, wherein the inlet section comprises inlet piping and an inlet compressor valve and the outlet section comprises outlet piping and an outlet compressor valve, wherein the protection system comprises:

a. a plurality of sensors configured to monitor selected process property parameters at the inlet section and outlet section and generate a plurality of monitored signal corresponding to the selected process property parameters;

b. a controller configured to execute a control logic, wherein the control logic comprises;

i. a process property parameter collection component;

ii. an internal cylinder pressure calculation component;

iii. a temperature set point calculation and comparison component;

iv. a signal component.

12. A protection system for a compressor according to claim 11 wherein

a. the process property parameter collection component comprises:

i. collecting data for the monitored process property parameters at the inlet section and outlet section using the sensors, wherein the monitored process property parameters comprise gas inlet temperature, gas inlet pressure, gas outlet temperature for each cylinder, gas outlet pressure, and compressor speed;

b. the internal cylinder pressure calculation component comprises;

i. determining an inlet internal cylinder pressure;

ii. determining an outlet internal cylinder pressure.

13. A protection system for a compressor according to claim 12 wherein:

a. the inlet internal cylinder pressure is determined by calculating a first pressure loss for the inlet compressor valve;

b. the outlet internal cylinder pressure is determined by calculating a second pressure loss for the outlet compressor valve.

14. A protection system for a compressor according to claim 12 wherein:

a. the inlet internal cylinder pressure is determined by estimating a first pressure loss for the inlet compressor valve;

b. the outlet internal cylinder pressure is determined by estimating a second pressure loss for the outlet compressor valve.

15. A protection system for a compressor according to claim 13 wherein the first pressure loss and second pressure loss are adjusted in proportion to the compressor speed.

16. A protection system for a compressor according to claim 15 wherein the temperature set point calculation and comparison component comprises:

a. calculating a first outlet temperature set point;

b. comparing the first outlet temperature set point with the monitored outlet temperature.

17. A protection system for a compressor according to claim 16 wherein the signal component further comprises:

a. generating a normal operation signal if the monitored outlet temperature is consistent with the first outlet temperature set point.

b. generating a first warning signal if the monitored outlet temperature is inconsistent with the first outlet temperature set point.

18. A protection system for a compressor according to claim 17 wherein the signal component further comprises:

a. initiating compressor shutdown if the monitored outlet temperature is inconsistent with the first outlet temperature operating range.

19. A protection system for a compressor according to claim 18 wherein the temperature set point calculation and comparison component further comprises:

a. calculating a second outlet temperature set point for each cylinder;

b. comparing the second outlet temperature set point with the monitored outlet temperature for each cylinder.

20. A protection system for a compressor according to claim 19 wherein the signal component further comprises:

a. generating a second warning signal if the monitored outlet temperature is inconsistent with the second outlet temperature set point;

b. initiating compressor shutdown if the outlet temperature is inconsistent with the second outlet temperature operating range.

21. A protection system for a compressor according to claim 20 wherein the process property parameter collection component further comprises:

a. collecting data using a sensor to configured to measure required properties to determine the ratio of specific heats.

22. A protection system for a compressor according to claim 21 wherein the pressure losses are calculated using fixed operating conditions.

23. A protection system for a compressor according to claim 21 wherein the pressure losses are continuously calculated using actual operating conditions.