Advanced Valve Actuator With True Flow Feedback

• US 20140261714A1
• Filed: 03/14/2014
• Published: 09/18/2014
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: Schneider Electric Buildings Americas Incorporated (Schneider Electric SE)
• Original Assignee: Schneider Electric Buildings LLC (Schneider Electric SE)
• Inventors: Burt, Alan
• Granted Patent: US 9,658,628 B2
• Time in Patent Office: Days
• US Class Current: 137/10
• CPC Class Codes: F24D 19/0095 Devices for preventing damage by freezing
• CPC Class Codes: F24F 11/83 by controlling the supply of heat-exchange fluids to heat-exchangers
• CPC Class Codes: F24F 11/84 using valves
• CPC Class Codes: G05D 23/1919 characterised by the type of controller
• CPC Class Codes: Y10T 137/0368 By speed of fluid
• CPC Class Codes: Y10T 137/1963 Temperature
• CPC Class Codes: Y10T 137/7759 Responsive to change in rate of fluid flow

Abstract

A valve and actuator assembly that includes a valve configured to control a flow of liquid into a coil or heat exchanger. The valve and actuator assembly further includes a valve actuator configured to control opening and closing of the valve via positioning of a valve closure member. The valve actuator is further configured to provide both a maximum flow rate and a minimum flow rate of the liquid through the valve. In an embodiment, the valve actuator includes a valve closure member position sensor configured to determine the position of the valve closure member based on a flow rate of the liquid through the valve.

Claims

1. A valve and actuator assembly comprising:

a valve configured to control a flow of liquid into a coil or heat exchanger; and

a valve actuator configured to calculate the fluid volume flowing through the valve and control opening and closing of the valve via positioning of a valve closure member, and further configured to provide both a maximum flow rate and a minimum flow rate for freeze protection of the liquid through the valve, the valve actuator having a valve closure member position sensor used to calculate the flow rate of the liquid through the valve.

2. The valve and actuator assembly of claim 1, wherein the valve actuator includes a valve flow rate meter that measures the flow rate of liquid through the valve.

3. The valve and actuator assembly of claim 2, wherein the valve has a valve body, and wherein the entire valve flow rate meter is located inside of a valve body.

4. The valve and actuator assembly of claim 1, wherein the valve actuator has a communications module configured to facilitate communication with the valve actuator over a network, the communications module configured to allow both remote monitoring of the flow through the valve, and remote control of the valve actuator.

5. The valve and actuator assembly of claim 4, wherein a valve closure member position sensor is coupled to the communications module such that data from the valve closure member position sensor can be accessed remotely.

6. The valve and actuator assembly of claim 1, wherein the valve actuator includes a zone air temperature controller that determines a position for the valve actuator based on a sensed zone temperature and a desired zone temperature, wherein the position for the valve actuator is verified based on data from the valve closure member position sensor.

7. The valve and actuator assembly of claim 6, wherein the valve actuator has a plurality of adjustable operating parameters.

8. The valve and actuator assembly of claim 7, wherein the plurality of adjustable operating parameters can be adjusted either locally or remotely.

9. The valve and actuator assembly of claim 7, wherein the plurality of adjustable operating parameters comprises an integral setting for the zone air temperature controller, wherein the integral setting provides positive or negative adjustment factors for the valve actuator to determine a correct the position for valve actuator when the actual flow rate through the valve does not match the desired flow rate through the valve.

10. The valve and actuator assembly of claim 7, wherein the plurality of adjustable operating parameters comprises a derivative setting for the zone air temperature controller, wherein the derivative setting provides positive or negative adjustment factors for the valve actuator to determine a correct the position for valve actuator in the event of an abrupt change to the flow rate through the valve.

11. The valve and actuator assembly of claim 1, wherein the valve actuator further comprises an anti-cavitation module configured to determine if the liquid flowing through the valve is likely to cavitate, wherein the anti-cavitation module determines a likelihood that cavitation in the valve will occur based on water temperature in the valve, valve inlet pressure, and valve outlet pressure, and wherein data from the valve closure member position sensor is used to adjust the flow rate of liquid through the valve to prevent cavitation.

12. The valve and actuator assembly of claim 1, wherein the valve actuator further comprises a diagnostics module configured to provide diagnostic information on operation of the valve and actuator assembly to a remote location.

13. The valve and actuator assembly of claim 12, wherein the diagnostics module provides diagnostic information regarding an actual flow rate through the valve versus a desired flow rate through the valve.

14. The valve and actuator assembly of claim 13, wherein the valve actuator is configured to retentively store the diagnostics information.

15. The valve and actuator assembly of claim 1, wherein the valve actuator further comprises a fluid temperature sensor, a valve inlet pressure sensor, and a valve outlet pressure sensor.

16. The valve and actuator assembly of claim 15, wherein data from the fluid temperature sensor, valve inlet pressure sensor, and valve outlet pressure sensor is accessible either locally or remotely.

17. The valve and actuator assembly of claim 1, wherein the valve actuator comprises:

a motor and geartrain coupled to the throttling closure member by a linkage assembly; and

a circuit board having control circuitry to regulate operation of the motor and geartrain, and communications circuitry to enable the actuator to communicate with a building management system via a serial communications bus.

18. The valve and actuator assembly of claim 1, wherein the valve actuator is configured to operate the valve as either a pressure-independent valve or a pressure-dependent valve.

19. A method of calculating a fluid flow rate through a valve, the method comprising the steps of:

storing a static force or torque value for a valve closure member in a memory of a valve actuator;

using the stored static force or torque value to calculate a value for dynamic force or torque on the valve closure member;

determining a closure member geometry factor and storing the geometry closure member factor in the memory of the valve actuator;

determining the valve closure member position via a valve closure member position sensor;

calculating the fluid flow rate using the dynamic force or torque value, the closure member geometry factor, and the valve closure member position;

comparing the fluid flow rate to a calculated minimum flow rate for freeze protection; and

adjusting valve operation when the fluid flow rate is below the calculated minimum flow rate for freeze protection.

20. The method of claim 19, wherein the valve closure member moves linearly between an open position and a closed position.

21. The method of claim 20, further comprising:

calculating a closure member seating force value;

storing the closure member seating force value in the memory of the valve actuator; and

using the closure member seating force value and the static force value to calculate the dynamic force value.

22. The method of claim 19, wherein determining a closure member geometry factor comprises determining a closure member geometry factor by means of a lookup table stored in the memory of the valve actuator, or by means of a polynomial based on a variables expression of valve stem positions.

23. The method of claim 19, wherein the valve closure member moves rotationally between an open position and a closed position.

24. The method of claim 23, further comprising:

storing one or more dimensions for the valve closure member in the memory of the valve actuator;

storing a bearing friction factor in the memory of the valve actuator;

using the one or more stored dimensions, the stored bearing friction factor, and the static torque value to calculate the dynamic torque value.

25. A method of calculating a fluid flow rate through a valve, the method comprising the steps of:

determining a pressure differential between an inlet of a valve and an outlet of the valve;

calculating a flow coefficient factor based on a position of the valve closure member;

calculating the fluid flow rate using the low coefficient factor, and the pressure differential;

comparing the fluid flow rate to a calculated minimum flow rate for freeze protection; and

adjusting valve operation when the fluid flow rate is below the calculated minimum flow rate for freeze protection.

26. The method of claim 25, further comprising:

measuring a temperature of a fluid flowing through the valve;

using the temperature to determine a specific gravity of the fluid;

using the specific gravity to calculate the fluid flow rate.