Fluid Flow Measurement and Control

• US 20140262159A1
• Filed: 03/07/2014
• Published: 09/18/2014
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: Trane International Inc. (Trane Technologies plc)
• Original Assignee: Trane International Inc. (Trane Technologies plc)
• Inventors: Solberg, David Pierce Whitten, Sanders, Earl Orel
• Granted Patent: US 10,036,568 B2
• Time in Patent Office: Days
• US Class Current: 165/104.31
• CPC Class Codes: F24F 11/30 for purposes related to the operation of the system, e.g. for safety or monitoring
• CPC Class Codes: F24F 11/62 characterised by the type of control or by internal processing, e.g. using fuzzy logic, adaptive control or estimation of values
• CPC Class Codes: F24F 11/63 Electronic processing
• CPC Class Codes: F24F 11/72 for controlling the supply of treated air, e.g. its pressure
• 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: Y10T 137/0379 By fluid pressure
• CPC Class Codes: Y10T 137/7722 Line condition change responsive valves

Abstract

In at least one illustrative embodiment, a fluid flow control apparatus may comprise a fluid network including a plurality of parallel branches, each parallel branch of the plurality of parallel branches being fluidly coupled between an inlet and an outlet of the fluid network. Each parallel branch of the plurality of parallel branches may comprise a pressure-independent flow control device configured to limit fluid flow through the respective parallel branch to a reference flow amount irrespective of a pressure at the inlet of the fluid network.

Claims

1. A fluid flow control apparatus comprising:

a fluid network including a plurality of parallel branches, each parallel branch of the plurality of parallel branches being fluidly coupled between an inlet and an outlet of the fluid network;

wherein each parallel branch of the plurality of parallel branches comprises a pressure-independent flow control device configured to limit fluid flow through the respective parallel branch to a reference flow amount irrespective of a pressure at the inlet of the fluid network.

2. The fluid flow control apparatus of claim 1, further comprising a controller operatively coupled to the pressure-independent flow control devices of the plurality of parallel branches, the controller being configured to:

select a set of parallel branches from among the plurality of parallel branches; and

control the pressure-independent flow control devices to (i) block fluid flow through each of the plurality of parallel branches that are not in the selected set of parallel branches and (ii) limit fluid flow through each of the plurality of parallel branches that are in the selected set of parallel branches to the respective reference flow amount.

3. The fluid flow control apparatus of claim 2, wherein the controller is configured to select the set of parallel branches such that a sum of the reference flow amounts of the selected set of parallel branches approximates a flow amount setpoint.

4. The fluid flow control apparatus of claim 1, wherein the fluid network further includes an additional parallel branch fluidly coupled between the inlet and the outlet of the fluid network, the additional parallel branch comprising a pressure-independent flow control device configured to limit fluid flow through the additional parallel branch to a variable flow amount irrespective of the pressure at the inlet of the fluid network.

5. The fluid flow control apparatus of claim 4, further comprising a controller operatively coupled to the pressure-independent flow control devices of the plurality of parallel branches and to the pressure-independent flow control device of the additional parallel branch, the controller being configured to:

select a set of parallel branches from among the plurality of parallel branches;

select the variable flow amount of the additional parallel branch; and

control the pressure-independent flow control devices to (i) block fluid flow through each of the plurality of parallel branches that are not in the selected set of parallel branches, (ii) limit fluid flow through each of the plurality of parallel branches that are in the selected set of parallel branches to the respective reference flow amount, and (iii) limit fluid flow through the additional parallel branch to the variable flow amount.

6. The fluid flow control apparatus of claim 5 wherein the controller is configured to:

select the set of parallel branches such that a sum of the reference flow amounts of the selected set of parallel branches is less than a flow amount setpoint; and

select the variable flow amount of the additional parallel branch to be a difference between the flow amount setpoint and the sum of the reference flow amounts of the selected set of parallel branches.

7. The fluid flow control apparatus of claim 6, wherein the variable flow amount is smaller than the reference flow amounts of the plurality of parallel branches.

8. The fluid flow control apparatus of claim 6, further comprising a flow meter fluidly coupled in series with the fluid network, the flow meter being configured to measure a total flow amount through the fluid network and to provide the total flow amount to the controller for comparison to the flow amount setpoint.

9. The fluid flow control apparatus of claim 1, wherein the reference flow amounts of the plurality of parallel branches are equal.

10. The fluid flow control apparatus of claim 1, wherein the reference flow amounts of the plurality of parallel branches are configured in a geometric sequence.

11. The fluid flow apparatus of claim 10, wherein a common ratio of the geometric sequence is two.

12. The fluid flow control apparatus of claim 1, wherein the pressure-independent flow control devices of the plurality of parallel branches each comprise a controlled value and a pilot-operated pressure regulator configured to maintain a fixed pressure differential across the controlled valve.

13. A chiller system comprising:

a chiller configured to remove heat from a cooling fluid;

a pump fluidly coupled to the chiller and configured to circulate the cooling fluid between the chiller and a heat exchanger; and

a fluid network including a plurality of parallel branches fluidly coupled between the pump and the heat exchanger, wherein each parallel branch of the plurality of parallel branches comprises a pressure-independent flow control device configured to limit fluid flow through the respective parallel branch to a reference flow amount irrespective of a pressure at an inlet of the fluid network.

14. The chiller system of claim 13, wherein the pump is configured to circulate the cooling fluid between the chiller and the heat exchanger by creating the pressure at the inlet of the fluid network.

15. The chiller system of claim 13, further comprising a controller operatively coupled to the pressure-independent flow control devices of the plurality of parallel branches, the controller being configured to:

select a set of parallel branches from among the plurality of parallel branches; and

control the pressure-independent flow control devices to (i) block fluid flow through each of the plurality of parallel branches that are not in the selected set of parallel branches and (ii) limit fluid flow through each of the plurality of parallel branches that are in the selected set of parallel branches to the respective reference flow amount.

16. A method of controlling fluid flow comprising:

selecting a set of parallel branches from among a plurality of parallel branches of a fluid network, each of the plurality of parallel branches being fluidly coupled between an inlet and an outlet of the fluid network and comprising a pressure-independent flow control device;

blocking fluid flow through each of the plurality of parallel branches that are not in the selected set of parallel branches; and

limiting fluid flow through each of the plurality of parallel branches that are in the selected set of parallel branches, using the respective pressure-independent flow control device, to a reference flow amount irrespective of a pressure at the inlet of the fluid network.

17. The method of claim 16, wherein blocking fluid flow comprises entirely closing a controlled valve of each of the pressure-independent flow control devices of the plurality of parallel branches that are not in the selected set of parallel branches.

18. The method of claim 16, wherein selecting a set of parallel branches comprises selecting the set of parallel branches such that a sum of the reference flow amounts of the selected set of parallel branches approximates a flow amount setpoint.

19. The method of claim 16, further comprising limiting fluid flow through an additional parallel branch, using a pressure-independent flow control device of the additional parallel branch, to a variable flow amount irrespective of a pressure at the inlet of the fluid network, wherein the additional parallel branch is fluidly coupled between the inlet and the outlet of the fluid network.

20. The method of claim 19, wherein:

selecting a set of parallel branches comprises selecting the set of parallel branches such that a sum of the reference flow amounts of the selected set of parallel branches is less than a flow amount setpoint; and

limiting the variable flow of the additional parallel branch comprises selecting the variable flow amount to be a difference between the flow amount setpoint and the sum of the reference flow amounts of the selected set of parallel branches.