identifying faults in the variable geometry system of …

LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS

Identifying Faults In The Variable Geometry System Of A Gas Turbine Compressor 00-33:1/ 23

IDENTIFYING FAULTS IN THE VARIABLE GEOMETRY SYSTEM

OF A GAS TURBINE COMPRESSOR

A. Tsalavoutas, K. Mathioudakis,

A.Stamatis , M.K. Smith

Laboratory of Thermal Turbomachines National Technical University of Athens



Identifying Faults in the Variable Geometry System of a Gas Turbine Compressor

• Variable guide vane (VGV) system and related malfunctions

• A test program for VGV fault effects

• VGV faults impact on engine performance

• Analysis of fault effects with adaptive modelling

• Effect on EGT profiles

• Discussion-Conclusions



Variable Guide Vane (VGV) System



Variable Guide Vane (VGV) System Controlling Mechanism on Compressor Casing

Schematic of a linkage of a variable geometry vane



Schematic Representation Of Individual Vane Mistuning



A Test Program for VGV Fault Effects

Test Engine: TORNADO



Engine Layout And Measured Quantities

Implanted fault cases

Ø Different magnitude (severity: size, number of vanes)

Ø Different locations



Implanting Vane Mistuning



VGV Fault Effects On Engine Performance

( a )

- 8

-6

-4

-2

0L o a d W C D P C D T W f T E T

5 d e g . 1 0 d e g . 1 5 d e g .

(b )

-8

-6

-4

-2

0

5 d e g . 1 0 d e g . 1 5 d e g .

( c )

- 8

-6

-4

-2

0

v a n e 1 0 d e g . tw o v a n e s 1 0 d e g .

( d )

- 8

- 6

- 4

- 2

0

o n e I G V 1 0 d e g .

a) Stage-1, one-vane faults, b) Stage-1, three vane faults, c) Stage-4 faults and d) IGV faults



Setting-Up An Adaptive Model For Fault Diagnosis

Compressor:

refcc qqf ,1 /= refpcpcf ,2 /ηη= Burner:

refBPLBPLf /3 = refbbf ,4 /ηη= Turbine:

refTT qqf ,5 /= refisTTisf ,,6 /ηη=



Modification Factors Percentage Deviations ( a )

- 2

- 1 . 5

- 1

- 0 . 5

0

0 . 5

1

1 . 5

2

f 1 f 2 f 4 f 5 f 6

5 d e g r e e s 1 0 d e g r e e s 1 5 d e g r e e s ( b )

- 2

- 1 . 5

- 1

- 0 . 5

0

0 . 5

1

1 . 5

2

f 1 f 2 f 4 f 5 f 6

5 d e g r e e s 1 0 d e g r e e s 1 5 d e g r e e s

( c )

-2

-1 . 5

-1

-0 . 5

0

0 . 5

1

1 . 5

2

f 1 f 2 f 4 f 5 f 6

v a n e 1 0 d e g r e e s tw o v a n e s 1 0 d e g r e e s

( d )

- 2

- 1 . 5

- 1

- 0 . 5

0

0 . 5

1

1 . 5

2

f 1 f 2 f 4 f 5 f 6

o n e I G V 1 0 d e g re e s

a) Stage-1, one-vane faults, b) Stage-1, three vane faults, c) Stage-4 faults and d)IGV faults



Compressor Diagnostic Plane

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

-2 -1.5 -1 -0.5 0 0.5 1 1.5 2

f1

f2

St-1, 1 vane 5 deg

St-1,1 vane 10 deg

St-1, 1 vane 15 deg

St-1, 3 vanes 5 deg

St-1, 3 vanes 10 deg


St-4, one vane 10 deg


IGV , 1 vane 10 deg

Healthy Engine A rea



Turbine Diagnostic Plane

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

-2 -1.5 -1 -0.5 0 0.5 1 1.5 2

f5

f6

St-1, 1 vane 5 deg

St-1,1 vane 10 deg

St-1, 1 vane 15 deg

St-1, 3 vanes 5 deg



St-4, one vane 10 deg


IGV, 1 vane 10 deg

Healthy Engine A rea



Exhaust Temperature Distributions

T - T = dT refi,ii

dT1

dT|dT| dT = dT

avs

ii

ri

N

Td = dT

i

N

=1iav

∑

,



Temperature Pattern At Core Turbine Outlet For Two Cases

T

840

860

880

900

920

940

960

980

1000

1020

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16Thermocouple

Tem

pera

ture

(Kel

vin)

Faulty Healthy



Reduced Temperature Deviations

Three vanes of stage-1 mistuned

-10

-5

0

5

10

15

20

25

30

35

40

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Thermocouplde

dTi

5 degrees 10 degrees15 degrees Healthy Limits




One vane of first stage mistuned

-10

-5

0

5

10

15

20

25

30

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Thermocouplde

dTi

5 degrees 10 degrees15 degrees Healthy Limits




Different cases of mistuned vanes

-10

-5

0

5

10

15

20

25

30

35

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Thermocouplde

dTi

One IGV 10 degrees Stage 4 vanes 10 degreesStage 4, two vanes 10 degrees Healthy Limits



Reduced Temperature Deviations For Burner Faults (Tsalavoutas Et Al, 1996)



Comparison Of Reduced Temperature Patterns

Burner Faults

VGV faults

-10

-5

0

5

10

15

20

25

30

35

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Thermocouplde

dTi

One IGV 10 degrees Stage 4 vanes 10 degreesStage 4, two vanes 10 degrees Healthy Limits



Temperature Spread for the Examined Cases

0.74

0.76

0.78

0.8

0.82

0.84

0.86

0.88

0.9

0.92

0.94

5 10 15 5 10 15 10 10 10

Spr

ead

/ Spr

ead,

ref

Stage-1, one Stage-1, three vanes

One IGV Stage-4



Diagnostic Observations

Particular features of VGV faults

Ø Mainly f1 reduction

Ø Effect on EGT profile Ø Mis-rigging no effect on EGT

-6

-5

-4

-3

-2

-1

0

1

f1 f2 f4 f5 f6

IGV +6 Degrees misrigging

VGV faults also produce acoustic signatures



Conclusions

• Individual VGV faults have an effect on performance

• Adaptive modelling provides component oriented (localized) information

• EGT patterns are influenced by individual VGV faults (distinguishable on reduced temperature patterns)

identifying faults in the variable geometry system of …

Documents