Modulated cooling flow scheduling for both SFC improvement and stall margin increase

Patent metadata

Field	Value
Publication number	US-9482236-B2
Application number	US-201314039841-A
Country	US
Kind code	B2
Filing date	Sep 27, 2013
Priority date	Mar 13, 2013
Publication date	Nov 1, 2016
Grant date	Nov 1, 2016

Abstract

A turbine engine includes a compressor, and high and low pressure turbines. The configuration includes a mid-compression station which can be, in the case of a single compressor in the middle of that compressor, or at the exit of the first compressor in the case of two compressors. Also, there is an exit pressure station at the exit of the compression system. A first gas flow line is interposed between the mid-compression station of the compressor and the low pressure turbine, and a second gas flow line is interposed between the exit pressure station of the compression system and the high pressure turbine. A first valve is coupled to the first gas flow line and modulates a low pressure flow rate of coolant in the first gas flow line, and a second valve is coupled to the second gas flow line and modulates a high pressure flow rate of coolant in the second coolant flow line. A controller is configured to operate the first and second valves based on an operating condition of the turbine engine so as to improve the specific fuel consumption while ensuring acceptable stall margin.

First claim

What is claimed is:

1. A turbine engine comprising:
a compressor having a mid-compression station and an exit pressure station;
a low pressure turbine and a high pressure turbine;
a first gas flow line interposed between the exit pressure station of the compressor and the high pressure turbine;
a second gas flow line interposed between the mid compression station of the compressor and the low pressure turbine;
a first valve coupled to the first gas flow line and configured to modulate a first flow rate of coolant in the first gas flow line;
a second valve coupled to the second gas flow line and configured to modulate a second flow rate of coolant in a second coolant flow line;
a controller configured to operate the first and second valves based on an operating condition of the turbine engine; and
a computer programmed to instruct the controller to modulate the first and second valves based on the operating condition, wherein the computer is programmed to instruct the controller to modulate the second valve to a full open position based on the operating condition that comprises one of an acceleration and a bodie.

2. The turbine engine as claimed in claim 1 , wherein the computer is programmed to instruct the controller to modulate the first and second valves to full open positions based on the operating condition that comprises at least one of:
a) comparing a corrected speed of the compressor to a first given threshold (C 1 ) above which speed the compressor is destabilized;
b) comparing a power level angle rate to a second given threshold (C 2 ) above which speed of the compressor can be destabilized; and
c) comparing the corrected speed to a third given threshold (C 3 ) below which speed the compressor can be destabilized.

3. The turbine engine as claimed in claim 2 , wherein the computer is programmed to instruct the controller to modulate the first and second valves both to a partially closed position if all three of operating conditions a), b), and c) do not indicate that the compressor is destabilized.

4. The turbine engine as claimed in claim 1 , wherein the computer is programmed to instruct the controller to modulate the first valve to a full open position based on the operating condition that comprises determining a presence of large high pressure compressor aft clearances.

5. The turbine engine as claimed in claim 1 , wherein the computer is programmed to instruct the controller to modulate the first and second valves to full open positions based on the operating condition that comprises one of an acceleration and a bodie, and further comprises determining a presence of large high pressure compressor aft clearances.

6. The turbine engine as claimed in claim 1 , wherein the computer is programmed to instruct the controller to modulate the first and second valves to full open positions based on the operating condition that comprises determining whether a corrected compressor speed of a high pressure compressor is below a given threshold thereof.

7. A method of operating a turbine engine comprising:
modulating first and second valves of the turbine engine based on an operating condition of the turbine engine, wherein:
the first valve is coupled to a first coolant line that is interposed between an exit pressure station of a compressor and a high pressure turbine, and the first valve is configured to control a first coolant rate in the first coolant line; and
the second valve is coupled to a second coolant line and is interposed between a mid-compression pressure station of the compressor and a low pressure turbine, and the second valve is configured to control a second coolant rate in the second coolant line;

the method further comprising:
determining a stall margin based on the operating condition of the turbine engine; and
operating the first and second valves based on the determination.

8. The method as claimed in claim 7 , further comprising:
determining the operating condition as one of:
a) comparing a speed of a compressor of the turbine engine to a first given threshold above which speed the compressor can be destabilized;
b) comparing a power level angle rate to a second given threshold above which speed the compressor can be destabilized;
c) comparing the compressor speed to a third given threshold below which speed the compressor can be destabilized; and
modulating both the first and second valves to a full open condition if one of steps a), b), and c) indicates that the compressor can be destabilized.

9. The method as claimed in claim 8 , further comprising:
modulating both the first and second valves to respective partially closed positions if all three operating conditions of a), b), and c) do not indicate that the compressor can be destabilized.

10. The method as claimed in claim 7 , comprising modulating the first valve to a full open position based on the operating condition that comprises determining a presence of large high pressure compressor aft clearances.

11. The method as claimed in claim 7 , comprising modulating the first and second valves to full open positions based on the operating condition that comprises one of an acceleration and a bodie, and further comprises determining a presence of large high pressure compressor aft clearances.

12. The method as claimed in claim 7 , comprising modulating the second valve to a full open position based on the operating condition that comprises one of an acceleration and a bodie.

13. The method as claimed in claim 7 , comprising modulating the second valve to a full open position based on the operating condition where the compressor is subjected to inlet total pressure distortion.

14. The method as claimed in claim 7 , comprising modulating the first and second valves to full open positions based on the operating condition that comprises determining whether a corrected compressor speed is below a given threshold thereof.

15. A non-transitory computer-readable medium tangibly embodying computer-executable instructions comprising:
instructions for modulating a rate of coolant flow between a compressor and a turbine within a gas turbine engine, via first and second valves, based on an operating condition of the turbine engine, wherein:
the first valve is within a first coolant flow line that is configured to flow coolant between an exit section of a compressor and a high pressure turbine, and the first valve is configured to control a first coolant flow rate in the first coolant flow line; and
the second valve is within a second coolant flow line that is configured to flow coolant between a mid-pressure section of the compressor and a low pressure turbine, and the second valve is configured to control a second coolant flow rate in the second coolant flow line;
wherein the instructions further comprise steps to determine the operating condition based on at least one of:
a) a comparison of a compressor speed of the compressor to a first given threshold above which speed the compressor can be destabilized;
b) a comparison of a power level angle rate to a second given threshold above which speed the compressor can be destabilized; and
c) a comparison of the compressor speed to a third given threshold below which speed the compressor can be destabilized; and

the instructions further comprise modulating both of the first and second valves to full open conditions if one of the determined operating conditions indicates that the compressor can be destabilized.

16. The computer-readable medium as claimed in claim 15 , wherein the instructions further include modulating the first and second va

Assignees

• Rolls Royce Corp

Inventors

• Khalid Syed Jalaluddin
• Gritton Mark J

Classifications

• Y02T50/671

  Cross-Sectional Technologies · mapped topic

• F02C9/18

  by bleeding, bypassing or acting on variable working fluid interconnections between turbines or compressors or their stages {(F02C3/113 takes precedence)} · CPC title

• F05D2270/101

  Compressor surge or stall · CPC title

• F04D27/0246 Primary

  by varying geometry within the pumps, e.g. by adjusting vanes · CPC title

• Y02T50/60

  Efficient propulsion technologies, e.g. for aircraft · CPC title