System for detecting failure location in a pump

• US 10,378,537 B2
• Filed: 10/06/2016
• Issued: 08/13/2019
• Est. Priority Date: 10/06/2016
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Zhang, Yanchai, Dandibhotla, Venkata Bhagavathi, Cai, Zhijun, Dong, Zhaoxu, Hu, Xuefei
• Primary Examiner(s): McCall, Eric S.
• Assistant Examiner(s): Graves, Timothy P
• Application Number:
  US15/287,416
• Publication Number:
  US 20180100496A1
• Time in Patent Office: 1,041 Days
• Field of Search: 73 405 R
• CPC Class Codes: F04B 1/00 Multi-cylinder machines or pumps characterised by number or arrangement of cylinders machines or pumps with pistons coacting within one cylinder F04B3/00
• CPC Class Codes: F04B 2201/0201 Position of the piston
• CPC Class Codes: F04B 2205/04 Pressure in the outlet chamber
• CPC Class Codes: F04B 51/00 Testing machines, pumps, or pumping installations
• CPC Class Codes: F04B 53/10 Valves; Arrangement of valves
• CPC Class Codes: G01M 3/26 by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors

Abstract

A method for detecting a leak in a pump comprises: monitoring discharge pressure time domain signals of the pump; monitoring piston position time domain signals for each piston of a plurality of pistons; filtering the monitored discharge pressure time domain signals and the monitored piston position time domain signals of each piston of the plurality of pistons via a band pass filter; determining, at each pump revolution for each piston, a sum of product of the filtered discharge pressure time domain signals and the filtered piston position time domain signals; determine, at each pump revolution for each piston, an absolute value of each sum; determining, at each pump revolution, a largest absolute value of the determined absolute values; determining a corresponding piston of the plurality of pistons associated with the largest absolute value; and determining a cylinder of the pump associated with the determined corresponding piston as leaking.

Claims

1. A method for detecting a leak in a pump, the method comprising:

monitoring discharge pressure time domain signals of the pump;

monitoring piston position time domain signals for each piston of a plurality of pistons;

filtering the monitored discharge pressure time domain signals and the monitored piston position time domain signals of each piston of the plurality of pistons via a band pass filter;

determining, at each pump revolution for each piston of the plurality of pistons, a sum of a product between the filtered discharge pressure time domain signals and the filtered piston position time domain signals;

determining, at each pump revolution for each piston of the plurality of pistons, an absolute value of each sum;

determining, at each pump revolution, a largest absolute value of the determined absolute values;

determining a corresponding piston of the plurality of pistons associated with the largest absolute value; and

determining a cylinder of the pump associated with the determined corresponding piston as leaking.

2. The method of claim 1, wherein determining the sum of the product between the filtered discharge pressure time domain signals and the filtered piston position time domain signals includes a first step of multiplying the filtered discharge pressure time domain signals and the filtered piston position time domain signals at predetermined time intervals during the pump revolution to produce corresponding product terms, and includes a second step of summing all of the corresponding product terms.

3. The method of claim 1, further comprising determining a sign value of a piston displacement associated with the largest absolute value wherein determination of the sign value being a first sign identifies a discharge valve leak in the cylinder and determination of the sign value being a second sign identifies a suction valve leak in the cylinder.

4. The method of claim 3, wherein the first sign is positive and the second sign is negative.

5. The method of claim 4, wherein monitoring discharge pressure time domain signals of the pump further comprises monitoring discharge pressure time domain signals of the pump associated with a discharge manifold of the pump.

6. The method of claim 5, wherein the plurality of pistons includes a first through a fifth piston and, at each pump revolution for each of the first through fifth pistons of the plurality of pistons, a corresponding first through fifth sum of the product between the filtered discharge pressure time domain signals and the filtered piston position time domain signals is determined.

7. A failure location detection system for a pump, the failure location detection system comprising:

a discharge pressure sensor operatively disposed in a discharge manifold of the pump, the discharge pressure sensor configured to monitor and transmit discharge pressure time domain signals associated with the discharge manifold;

a plurality of piston sensors configured to monitor and transmit piston position time domain signals for each piston of a plurality of pistons of the pump, each piston sensor operatively associated with a corresponding piston of the plurality of pistons; and

a processor in operative communication with the discharge pressure sensor and the plurality of piston sensors, the processor configured to receive the discharge pressure time domain signals and the piston position time domain signals for each piston of the plurality of pistons for determining which cylinder of a plurality of cylinders is leaking by identifying a corresponding cylinder associated with one of the pistons of the plurality of pistons associated with a largest absolute value, the largest absolute value determined from an absolute value, determined for each piston of the plurality of pistons during a pump revolution, of a sum of a product between the discharge pressure time domain signals and the piston position time domain signals.

8. The failure location detection system of claim 7, wherein each sum of product of the discharge pressure time domain signals and the piston position time domain signals is determined by a first step of multiplying the filtered discharge pressure time domain signals and the filtered piston position time domain signals at predetermined time intervals during the pump revolution to produce corresponding product terms, and by a second step of adding all of the corresponding product terms.

9. The failure location detection system of claim 7, wherein the processor is further configured to determine leak location in the corresponding cylinder by determining a sign value of a piston displacement associated with the largest absolute value wherein the sign value being a first sign identifies a discharge valve leak in the corresponding cylinder and determination of the sign value being a second sign identifies a suction valve leak in the corresponding cylinder.

10. The failure location detection system of claim 9, wherein the first sign is positive and the second sign is negative.

11. The failure location detection system of claim 10, wherein the processor is further configured to filter, via a band pass filter, the received discharge pressure domain signals and the piston position time domain signals for each piston of the plurality of pistons.

12. The failure location detection system of claim 11, wherein the plurality of piston sensors includes first through fifth piston sensors disposed, on a corresponding first through fifth pistons of the plurality of pistons associated therewith.

13. A pump, comprising:

a plurality of cylinders disposed in fluid communication between a suction manifold and a discharge manifold, each cylinder of the plurality of cylinders comprising a housing;

a plurality of pistons, each piston of the plurality of pistons slidably disposed in the housing of a corresponding cylinder of the plurality of cylinders;

a discharge pressure sensor disposed in the discharge manifold and configured to monitor and transmit discharge pressure time domain signals associated with the discharge manifold;

a plurality of piston sensors, each piston sensor of the plurality of piston sensors operatively associated with a corresponding piston of the plurality of pistons, each piston sensor of the plurality of piston sensors configured to monitor and transmit piston positon time domain signals associated with corresponding pistons; and

a processor in operative communication with the discharge pressure sensor and the plurality of piston sensors, the processor configured to;

receive discharge pressure time domain signals from the discharge pressure sensor;

receive piston position time domain signals from each piston sensor of the plurality of piston sensors;

filter the received discharge pressure time domain signals and the received piston position time domain signals from each piston sensor of the plurality of piston sensors;

determine, at each pump revolution for each piston of the plurality of pistons, a sum of a product between the filtered discharge pressure time domain signals and the filtered piston position time domain signals;

determine, at each pump revolution for each piston of the plurality of pistons, an absolute value of each sum;

determine, at each pump revolution, a largest absolute value of the determined absolute values;

determine a corresponding piston of the plurality of pistons associated with the largest absolute value; and

determine a corresponding cylinder of the plurality of cylinders associated with the determined corresponding piston of the plurality of pistons as leaking.

14. The pump of claim 13, wherein the processor is further configured to determine the sum of the product between the filtered discharge pressure time domain signals and the filtered piston position time domain signals by a first step of multiplying the filtered discharge pressure time domain signals and the filtered piston position time domain signals at predetermined time intervals during the pump revolution to produce corresponding product terms, and by a second step of summing all of the corresponding product terms.

15. The pump of claim 13, wherein the processor is further configured to determine a sign value of a piston displacement associated with the largest absolute value wherein determination of the sign value being a first sign identifies a discharge valve leak in the determined corresponding cylinder of the plurality of cylinders and determination of the sign value being a second sign identifies a suction valve leak in the determined corresponding cylinder of the plurality of cylinders.

16. The pump of claim 15, wherein the first sign is positive and the second sign is negative.

17. The pump of claim 16, wherein each piston sensor of the plurality of piston sensors is disposed on corresponding pistons of the plurality of pistons.

18. The pump of claim 16, wherein each piston sensor of the plurality of piston sensors is disposed in the housing of corresponding cylinders of the plurality of cylinders.

19. The pump of claim 16, wherein the plurality of piston sensors comprises first through fifth piston sensors, each associated with a first through fifth piston of the plurality of pistons.

20. The pump of claim 16, wherein the plurality of piston sensors are one of proximity switches and accelerometers.