Method and system for balancing bleed flows from gas turbine engines

• US 20060174628A1
• Filed: 02/09/2005
• Published: 08/10/2006
• Est. Priority Date: 02/09/2005
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Mikhail, Sami H.
• Granted Patent: US 7,536,865 B2
• Time in Patent Office: Days
• US Class Current: 60/772
• CPC Class Codes: B64D 13/00 Arrangements or adaptations of air-treatment apparatus for aircraft crew or passengers, or freight space , or structural parts of the aircraft treatment rooms with artificial climate for medical purposes A61G10/02; respiratory apparatus in general A62B; for vehicles in general B60H
• CPC Class Codes: F02C 3/13 having variable working fluid interconnections between turbines or compressors or stages of different rotors controlling flow ratio between different flows of multi-flow jet-propulsion plant, e.g. ducted fan F02K3/075
• CPC Class Codes: F02C 6/08 the gas being bled from the gas-turbine compressor
• CPC Class Codes: F02C 7/36 Power transmission arrangements between the different shafts of the gas turbine plant, or between the gas-turbine plant and the power user F02C3/107 - F02C3/13 and F02C7/32 take precedence; couplings for transmitting rotation F16D; gearing in general F16H
• CPC Class Codes: F02C 9/18 by bleeding, bypassing or acting on variable working fluid interconnections between turbines or compressors or their stages F02C3/113 takes precedence
• CPC Class Codes: F05D 2270/301 Pressure
• CPC Class Codes: F05D 2270/309 Rate of change of parameters
• CPC Class Codes: G05D 7/0658 the plurality of throttling means being arranged for the control of a single flow from a plurality of converging flows G05D7/0652 takes precedence; ratio control G05D11/13
• CPC Class Codes: Y02T 50/50 On board measures aiming to increase energy efficiency

Abstract

A bleed air balancing system includes a plurality of bleed air flow paths (12) each carrying bleed air from one of a plurality of gas turbine engines (10), each bleed air flow path (12) including a flow rate sensor (19), and a circuit (52, 200) outputting at least one flow rate setpoint based on flow rates measured by each of the flow rate sensors (19), wherein each of the plurality of bleed air flow paths (12) includes: a pressure regulating valve (16), a pressure sensor (18), and a controller (20) for controlling the position of the pressure regulating valve (16), the controller (20) including an output (26) connected to the pressure regulating valve (16), a pressure control loop (60) generating a pressure correction signal, and a flow control loop (62) generating a flow correction signal, wherein the controller (20) outputs a control signal (28) on the output (26) based on the pressure correction signal and the flow correction signal. A method of operating the system is also disclosed.

Claims

1. A method of balancing bleed air flows in a plurality of bleed air flow paths associated with a plurality of gas turbine engines comprising the steps of:

providing a pressure regulating valve in each of the plurality of bleed air flow paths;

measuring a flow rate in each of the bleed air flow paths;

determining a flow setpoint for each bleed air flow path based on the measured flow rate in the bleed air flow paths;

measuring a pressure in each of the bleed air flow paths;

providing a reference pressure; and

controlling a position of the pressure regulating valve in each bleed air flow path based on a flow difference between the measured flow rate in said each bleed air flow path and the flow setpoint and a pressure difference between the measured pressure in said each bleed air flow path and the reference pressure.

2. The method of claim 1 wherein said step of determining a flow setpoint comprises the step of determining an average of a predicted flow rate in each of the plurality of bleed air flow paths.

3. The method of claim 1 wherein said step of determining a flow setpoint comprises the step of measuring a temperature in each of the bleed air flow paths and determining a flow setpoint for each of the bleed air flow paths based on the measured temperature in said each of the bleed air flow paths.

4. The method of claim 1 wherein said step of controlling a position of the pressure regulating valve comprises the steps of, for each of the plurality of flow paths:

providing a controller for the pressure regulating valve;

providing the flow difference for the each bleed air flow path as a first input to the controller;

providing the pressure difference for the each bleed air flow path as a second input to the controller; and

providing a control signal output from the controller to the pressure regulating valve based on the first and second inputs.

5. The method of claim 4 wherein said step of providing a control signal output comprises the step of adding the pressure difference and the flow difference to a control bias.

6. The method of claim 1 wherein said step of controlling a position of the pressure regulating valve comprises the steps of:

determining a flow difference gain;

determining a pressure difference gain;

multiplying the pressure difference by the pressure difference gain; and

multiplying the flow difference by the flow difference gain.

7. The method of claim 6 including the additional step of varying the flow difference gain and the pressure difference gain based on measured operating conditions of the plurality of engines.

8. The method of claim 6 wherein the flow difference gain comprises a proportional gain and an integral gain and the pressure difference gain comprises a proportional gain and an integral gain, and including the additional steps of varying the proportional gains and integral gains based on measured operating conditions of the engines.

9. The method of claim 6 including the additional step of setting the flow difference gain to a first flow difference gain value and the pressure difference gain to a first pressure difference gain value and including the additional step of reducing the first flow difference gain value when the pressure difference falls below a predetermined value.

10. The method of claim 8 including the additional step of reducing the integral gain of the flow difference gain to 0 when the pressure difference falls below a predetermined value.

11. The method of claim 8 including the additional step of reducing the proportional and integral gains of the flow difference gain and reducing the integral gain of the pressure difference gain to 0 when the pressure difference falls below a predetermined value.

12. The method of claim 1 wherein said step of controlling a position of the pressure regulating valve in each channel comprises the step of independently controlling a position of the pressure regulating valve in each channel.

13. A bleed air balancing system comprising:

a plurality of bleed air flow paths each carrying bleed air from one of a plurality of gas turbine engines and including a flow rate sensor;

a circuit outputting at least one flow rate setpoint based on flow rates measured by each of the flow rate sensors;

wherein each of the plurality of bleed air flow paths includes;

a pressure regulating valve;

a pressure sensor; and

a controller for controlling the position of the pressure regulating valve, said controller including an output connected to said pressure regulating valve, a pressure control loop generating a pressure correction signal, and a flow control loop generating a flow correction signal;

wherein said controller outputs a control signal on said output based on said pressure correction signal and said flow correction signal.

14. The system of claim 13 wherein said at least one flow rate setpoint comprises an average of a predicted flow rate in each of the plurality of bleed air flow paths.

15. The system of claim 13 wherein said pressure control loop has a variable pressure gain and said flow control loop has a variable flow gain.

16. The system of claim 15 wherein said variable pressure gain comprises a variable integral gain and a variable proportional gain and said variable flow gain has a variable integral gain and a variable proportional gain.

17. The system of claim 15 wherein said variable pressure gain has a first value under a first set of operating conditions and a second value under a second set of operating conditions.

18. The system of claim 16 wherein said variable pressure integral gain takes on a first value and said variable pressure proportional gain takes on a second value under a first set of operating conditions and wherein said variable pressure integral gain takes on a third value and said variable pressure proportional gain takes on a fourth value under a second set of operating conditions.

19. The system of claim 13 including:

a temperature sensor in each of said plurality of bleed air flow paths; and

a circuit connected to each of said temperature sensors for adjusting said at least one flow rate setpoint based on measured temperatures in said bleed air flow paths.

20. A method of balancing bleed air flows in a plurality of bleed air flow paths associated with a plurality of gas turbine engines comprising the steps of:

providing a pressure regulating valve in each of the plurality of bleed air flow paths;

measuring a flow rate in each of the bleed air flow paths;

measuring a temperature in each of the bleed air flow paths;

determining a flow setpoint for each of the bleed air flow paths based on the measured temperature and measured flow rate in each of the bleed air flow paths;

providing a reference pressure;

for each of the bleed air flow paths;

measuring a pressure in said each bleed air flow path;

determining a pressure difference between the reference pressure and the measured pressure in the flow path;

determining a flow difference between the flow set point for said bleed air flow path and the measured flow rate;

weighting the pressure difference by a first amount;

weighting the flow difference by a second amount; and

controlling a position of the pressure regulating valve based on said weighted pressure difference and said weighted flow difference.