Synchronous torque balance in multiple pump systems

• US 8,328,523 B2
• Filed: 12/15/2008
• Issued: 12/11/2012
• Est. Priority Date: 12/14/2007
• Status: Active Grant

• Current Assignee: ITT Manufacturing Enterprises, Inc. (ITT, Inc.)
• Original Assignee: ITT Manufacturing Enterprises, Inc. (ITT, Inc.)
• Inventors: Kernan, Daniel J., Ganzon, Nicolas W.
• Primary Examiner(s): Mai, Anh
• Assistant Examiner(s): COUGHLIN, ANDREW J
• Application Number:
  US12/335,001
• Publication Number:
  US 20090304521A1
• Time in Patent Office: 1,457 Days
• Field of Search: 417/2, 417/1, 417/5
• US Class Current: 417/5
• CPC Class Codes: F04D 13/14 the pumps being all of centrifugal type deviation valves F04D15/0016
• CPC Class Codes: F04D 15/0066 by changing the speed, e.g. of the driving engine
• CPC Class Codes: F04D 15/0072 Installation or systems with two or more pumps, wherein the flow path through the stages can be changed, e.g. series-parallel
• CPC Class Codes: F04D 15/029 for pumps operating in parallel
• CPC Class Codes: G05B 13/0205 not using a model or a simulator of the controlled system

Abstract

The present invention provides a new and unique method and apparatus for operating and running multiple pumps in a system together at a substantially synchronous torque to achieve a desired setpoint. Each of the multiple pumps may be operated with a variable speed drive. The present invention may also take the form of the system having the multiple pumps with a system controller for operating and running the multiple pumps, a pump for operating and running in such a system, a system control module for such a system controller, as well as a pump control module for running and operating such a pump.

Claims

1. A method of control in a system having multiple pumps, wherein the multiple pumps are operated and run together at a substantially synchronous torque to achieve a desired setpoint, wherein the method comprises:

responding with a controller to signaling containing information about the desired setpoint, and providing a control output signal;

responding with a lead variable speed drive to the control output signal, providing a lead variable speed drive signal for driving one of the multiple pumps, and also providing one or more torque signals; and

responding with a lag variable speed drive to the one or more torque signals, and providing a lag variable speed drive signal for driving another one of the multiple pumps;

the one or more torque signals containing information so that the lead variable speed drive and the lag variable speed drive operate and run the multiple pumps together at the substantially synchronous torque to achieve the desired setpoint.

2. A method according, to claim 1, wherein the flow of the multiple pumps is substantially balanced even when pumps have different hydraulic head curves.

3. A method according to claim 1, wherein the multiple pumps have nearly 1:

1 flow balance.

4. A method according to claim 1, wherein each respective pump is controlled by a respective variable speed device that is configured to calculate a respective torque of a respective load of the respective pump.

5. A method according to claim 1, wherein each pump is controlled by a respective suitable device that can vary the speed of the pump.

6. A method according to claim 1, wherein the method includes providing a process variable and setpoint as inputs to a system controller.

7. A method according to claim 6, wherein the system controller includes either a PLC, DCS System, SCADA System or Variable Speed Drive.

8. A method according to claim 6, wherein the system controller contains logic that recognizes an error from the process variable to the setpoint and instructs a respective pump to increase or decrease torque and/or speed to maintain a desired setpoint.

9. A method according to claim 6, wherein the system controller is configured to recognize when an additional pump should be brought online or taken offline to match the demand of the system.

10. A method according to claim 6, wherein the system controller is configured to instruct a lead pump to increase or decrease torque/speed to meet the setpoint when the multiple pumps are running.

11. A method according to claim 10, wherein lag pumps will match torques to the lead pump and operate together in a synchronous torque mode when the multiple pumps are running.

12. A system having multiple pumps, wherein the multiple pumps are operated and run together at a substantially synchronous torque to achieve a desired setpoint, wherein the system comprises:

a controller configured to respond to signaling containing information about the desired setpoint, and to provide a control output signal;

a lead variable speed drive configured to respond to the control output signal, to provide a lead variable speed drive signal for driving one of the multiple pumps, and also to provide one or more torque signals; and

a lag variable speed drive configured to respond to the one or more torque signals, and to provide a lag variable speed drive signal for driving another one of the multiple pumps,

the one or more toque signals containing information so that the lead variable speed drive and the lag variable speed drive operate and run the multiple pumps together at the substantially synchronous torque to achieve the desired setpoint.

13. A system according to claim 12, wherein the flow of the multiple pumps is substantially balanced even when pumps have different hydraulic head curves.

14. A system according to claim 12, wherein the multiple pumps have nearly 1:

1 flow balance.

15. A system according to claim 12, wherein each pump is controlled by a respective variable speed device that is configured to calculate a respective torque of a respective load of the respective pump.

16. A system according to claim 12, wherein each pump is controlled by a respective device that can vary the speed of the pump.

17. A system according to claim 12, wherein the system has a system controller that receives a process variable and setpoint as inputs.

18. A system according to claim 17, wherein the system controller includes either a PLC, DCS System, SCADA System or Variable Speed Drive.

19. A system according to claim 17, wherein the system controller contains logic that recognizes an error from the process variable to the setpoint and instructs a respective pump to increase or decrease torque and/or speed to maintain a desired setpoint.

20. A system according to claim 17, wherein the system controller is configured to recognize when an additional pump should be brought online or taken offline to match the demand of the system.

21. A system according to claim 17, wherein the system controller is configured to instruct a lead pump to increase or decrease torque/speed to meet the setpoint when the multiple pumps are running.

22. A system according to claim 21, wherein lag pumps will match torques to the lead pump and operate together in a synchronous torque mode when the multiple pumps are running.

23. A pump for forming part of a system having multiple pumps, wherein the pump comprises a module configured to operate and run the pump at, a substantially synchronous torque to achieve a desired setpoint together with one or more other pumps in the system, wherein the pump comprises:

a controller configured to respond to signaling containing information about the desired setpoint, and to provide a control output signal; and

a lead variable speed drive configured to respond to the control output signal, to provide a lead variable speed drive signal for driving one of the multiple pumps, and also to provide one or more torque signals to be received by a lag variable speed drive for driving another one of the multiple pumps;

the one or more torque signals containing information so that the lead variable speed drive and the lag variable speed drive operate and run the multiple pumps together at the substantially synchronous torque to achieve the desired set point.

24. A pump according to claim 23, wherein the flow of the pump is substantially balanced with the flow of the one or more other pumps even when the multiple pumps have different hydraulic head curves.

25. A pump according to claim 23, wherein the flow of the pump is substantially balanced with the flow of the one or more other pumps so that the multiple pumps have nearly 1:

1 flow balance.

26. A pump according to claim 23, wherein the module includes a variable speed device that is configured to calculate a respective torque of a respective load of the respective pump.

27. A pump according to claim 23, wherein the module includes a respective device that can vary the speed of the pump.

28. A pump according to claim 23, wherein the module receives signals from a system controller that receives a process variable and setpoint.

29. A pump according to claim 28, wherein the system controller is either a PLC, DCS System, SCADA System or Variable Speed Drive.

30. A pump according to claim 28, wherein the system controller contains logic that recognizes an error from the process variable to the setpoint and instructs the pump to increase or decrease torque and/or speed to maintain a desired setpoint.

31. A pump according to claim 28, wherein the system controller is configured to recognize when an additional pump should be brought online or taken offline to match the demand of the system.

32. A pump according to claim 28, wherein if the pump is a lead pump, then the system controller is configured to instruct the lead pump to increase or decrease torque/speed to meet the setpoint when the multiple pumps are running, and the module is configured to respond to that instruction.

33. A pump according to claim 32, wherein if the pump is a lag pump, then one or more lag pumps in the system will match torques to the lead pump and operate together in a synchronous torque mode when the multiple pumps are running.

34. A system control module for controlling a system having multiple pumps, wherein the system control module is configured to operate and run multiple pumps together at a substantially synchronous torque to achieve a desired setpoint, wherein the system control module comprises:

a controller configured to respond to signaling containing information about the desired setpoint, and to provide a control output signal;

a lead variable speed drive configured to respond to the control output signal, to provide a lead variable speed drive signal for driving one of the multiple pumps, and also to provide one or more torque signals; and

a lag variable speed drive configured to respond to the one or more torque signals, and to provide a lag variable speed drive for driving another one of the multiple pumps,

the one or more torque signals containing information so that the lead variable speed drive and the lag variable speed drive operate and run the multiple pumps together at the substantially synchronous torque to achieve the desired setpoint.

35. A pump control module for a pump for forming part of a system having multiple pumps, wherein the pump control module is configured to respond to a control signal from a system controller, and is configured to operate and run the pump at a substantially synchronous torque to achieve a desired setpoint together with one or more other pumps in the system, wherein the system comprises:

a controller configured to respond to signaling containing information about the desired setpoint, and to provide a control output signal; and

a lead variable speed drive configured to respond to the control output signal, to provide a lead variable speed drive signal for driving one of the multiple pumps, and also to provide one or more torque signals to be received by a lag variable speed drive for driving another one of the multiple pumps,

the one or more torque signals containing information so that the lead variable speed drive and the lag variable speed drive can operate and run the multiple pumps together at the substantially synchronous torque to achieve the desired setpoint.

36. A pump control module for a pump for forming part of a system having multiple pumps,

wherein the pump control module is configured to respond to a control signal from a system controller, and is configure to operate and run the pump at a substantially synchronous torque to achieve a desired setpoint together with one or more other pumps in the system;

and

wherein the pump control module comprises;

a lag variable speed drive configured to respond to one or more torque signals to be provided by a lead variable speed drive for driving one of the multiple pumps, and to provide a lag variable speed drive signal for driving another one of the multiple pumps,

the one or more torque signals containing information so that the lag variable speed drive and the lead variable speed drive can operate and run the multiple pumps together at the substantially synchronous torque to achieve the desired setpoint.