PROBLEMS OF LIFETIME ASSESSMENTPROBLEMS OF LIFETIME ASSESSMENT OF WATER-STEAM CIRCUIT ELEMENTSOF WATER-STEAM CIRCUIT ELEMENTS

OF POWER UNITSOF POWER UNITS

I. M. DMYTRAKH and V. V. PANASYUK  

Karpenko Physico-Mechanical Institute, National Academy of Sciences of Ukraine,

Lviv, UKRAINE

1st Hungarian - Ukrainian Joint Conference“Safety, Reliability and Risk of Engineering Plants and Components”

Bay Zoltan Institute for Logistics and Production SystemsMiskolc, HUNGARY, 11- 12 April 2006

ABSTRACT

The analysis and synthesis of the modern scientific and engineering approaches for life assessment of the structural elements of basic heat and mechanical equipment for heat power plants are presented. Basic concepts and methods for strength and durability assessment of materials and structural elements are stated grounding on the fracture mechanics approaches. The examples of calculations of residual life of the basic structural elements are given with take into account of the actual data of metal properties and operating conditions of equipment.

 

CONTENTS

1. GENERAL CHARACTERISATION OF IN-SERVICE DAMAGES AND FAILURES OF BASIC EQUIPMENT OF HEAT POWER PLANTS

2. FRACTURE MECHANICS APPROACHES

3. ENGINEERING APPLICATIONS FOR SERVICEABILITY ASSESSMENTS OF POWER ENGINEERING PIPELINES

1. GENERAL CHARACTERISATION OF IN-SERVICE DAMAGES AND FAILURES OF BASIC EQUIPMENT

OF HEAT POWER PLANTS

1. Water-wall tubes of high-pressure steam boilers

2. Super heater tubes of sub- and supercritical pressure boilers

3. Water economizers

4. Non-heated boiler’s elements

5. Feeding pipelines of supercritical pressure power generating units

1. WATER-WALL TUBES OF HIGH-PRESSURE STEAM BOILERS

2. SUPERHEATER TUBES OF SUB- AND SUPERCRITICAL

PRESSURE BOILERS 3. WATER ECONOMIZERS

5. FEEDING PIPELINES OF SUPERCRITICAL PRESSURE POWER GENERATING UNITS

4. NON-HEATED BOILER’S ELEMENTS

2. FRACTURE MECHANICS APPROACHES

MATERIAL

STRESS STATE

CORROSIONFRACTURE

ENVIRONMENT

Fig. 2.1. Factors that define corrosion fracture

Fig. 2.2. Stages of corrosion fracture

Surface film breakdown Surface film breakdown

Corrosion pits developmentCorrosion pits development

Pit-crack transitionPit-crack transition

Crack growth to critical size Crack growth to critical size

Catastrophic fracture Catastrophic fracture

2.1. ASSESSMENT OF CORROSION PITS DEVELOPMENT

12

34

56

78

910

1520

2528

0,49

1,03

1,2

0,001

0,01

0,1

1

i, mA/cm 2

c, m

, %

STAGE I dc0 τ;σ;iFc appitpit

c

c aa

dc N;σ;iFa eff*pitcrack

effσ

STAGE IІ

SVETEki

Fig. 2.3Fig. 2.4

(2.1)

(2.2)

2. 2. SURFACE FATIGUE CRACK NUCLEATION AS RESULT OF CORROSION DEFORMATION INTERACTIONS

2.2.1. EXPERIMENTAL BACKGROUND

00 100 200 300

0

100

200

300

400

s

12

pH=3,0

I c(

)

12Kh1МF

max

I, n

А

, МPаFig. 2.5 Fig. 2.6

N

III III

(2.3)

2.2.2. EXPERIMENTAL PROCEDURE

4 0 5

50

1 0

12 16

9

4

3

P

1

13 1514

8

76

5

2

11

10

17

Fig. 2. 7. Testing equipment.

a)

b)

c)

102

103

10410

1

102

103

s, M

Pa

N, cycles

I II III

Fig. 2.8. Correlation between parameter s and level of corrosion fatigue

damaging of cyclic deformed surface (08Kh18N12T steel; pH=6.5).

2.2.4. ASSESSMENT OF SURFACE CORROSION FATIGUE CRACK NUCLEATION

s

s

neMM z

Fig. 2.13

(2.4)

2.3. CORROSION FATIGUE CRACK GROWTH

2.3.1. MODEL OF THE CORROSION CRACK

)S(B);τ(A);σ(P;CΦdNda mnji(2.5)

Where da/dN - corrosion fatigue crack growth rate; Pj() - parameters, that characterise stress-strain

state of materials and are function of the external applied load ; An() - parameters, that determine in

time physicochemical processes that occur between deformed material and environment; Bm(S) -

parameters, that characterise the material surface state S which is created during fracture processes; Ci

are constants that characterise given system “material - environment”; i, j, m, n = 1, 2, 3…

.E;pH;K;CΦdNda ttIi0 (2.6)

Fig. 2.9. Model presentation of a material prefracture zone at corrosion crack

Where pH t and Et - hydrogen

exponent of environment and electrode potential in the crack tip; KI - stress

intensity factor.

P

P

s

s

E

pH

s

s

E

pHtpH

tE

IK

2.3.2. EXPERIMENTAL METHODOLOGY

1

2

34

5

6

initial cracknotch

L

a w

d

t

60.

ha

Fig. 2. 10. Technique for electrochemical measurements in corrosion crack: a) - Scheme of the minielectrodes installation: 1- specimen; 2- crack; 3- crack propagation front; 4- crack propagation plane; 5- mini electrodes; 6 – driver. b) - Specimen geometry. c) - Minielectrodes: 1 – teflon tube; 2-antimony indicator; 3-ions conductor; 4-isolator

d<0.3mmd<0.3mm d<0.3mm

D=1.0mm D=1.0mm D=1.0mm

a b c

1 1 1

2

3

4 4 4

d<0.3mmd<0.3mm d<0.3mm

D=1.0mm D=1.0mm D=1.0mm

a b c

1 1 1

2

3

4 4 4

a)

c)

b)

Fig. 2.11. General view (a) and principal scheme of testing system (b): 1- specimen; 2- corrosion cell; 3- heater; 4-temperature gauge; 5- temperature control unit; 6- load mechanism; 7- load registration; 8-minielectrodes; 9- mini electrodes motion mechanism; 10- step motor; 11-operating unit; 12- registration unit; 13-PC; 14-keyboard; 15- monitor; 16- printer.

F

pH

E

PC

14

13

11

15

1612

105

7

1

2

3

4

6

9

8

a) b)

2.3.3. ELECTROCHEMICAL CONDITIONS IN THE CORROSION CRACKS

axmexpax1pHxpH 1n

01

axmexpax1ExE 2n

02

Fig. 2.12. Dependencies of pH(x) and E(x).

Fig. 2.13. Distribution of pH values in the corrosion crack cavity for cracks of different length (40Kh13steel - reactor water of boron regulation; pH=8.0).

x0

pHt

Et

pH(x)

E(x)

0 < x < a

pHts

E ts

pH0E 0

a

x0

pHt

Et

pH(x)

E(x)

0 < x < a

pHts

E ts

pH0E 0

a

x0

pHt

Et

pH(x)

E(x)

0 < x < a

pHts

E ts

pH0E 0

a

x0

pHt

Et

pH(x)

E(x)

0 < x < a

pHts

E ts

pH0E 0

a0 0.2 0.60.4 0.8 x / a

1

2

3

4

5

6

7

pH(x)

8 - a = 3.40mm

-a = 5.80mm

-a= 13.8mm

(2.7)

(2.8)

2.3.4. METHOD FOR FORECASTING OF THE THRESHOLD STRESS INTENSITY FACTOR UNDER STRESS CORROSION CRACKING

AND CORROSION FATIGUE

Sm

1

0bSt

StSISCC TTpHbaEAK

Cm

1

0bCt

CtCth NNpHbaEωAKΔ

Where A and m are the constants “material-environment” system; a and b are a thermodynamic constants, that define an electrochemical conditions of electrolytic hydrogen forming from corrosion environment; is a frequency of cyclic loading; T0 and N0 are respectively time and number of

cycles loading, that correspond to the beginning of hydrogen formation in the crack tip; Tb and Nb are the base of tests in hours and in cycles of loading,

respectively. Subscripts s and c specify static or cyclic loading conditions, respectively.

(2.9)

(2.10)

Fig. 2.14. Comparison the cyclic crack growth resistance diagrams for pressure vessels metal those have been built according to ASME data (curves 1 and 2) and Bamford’s data (curves 3 and 4) and also on the base of proposed method (curve 5). Note that different curves represent different test conditions: 1 - dry air; 2 - humid air; 3 - corrosive environment, load ratio R<0.5; 4 - corrosive environment, load ratio R>0.5; 5 - corrosive environment, load ratio R=0.7.

2.3.5. METHOD FOR DETERMINING OF BASIC CHARACTERISTICS OF CORROSION CRACK GROWTH RESISTANCE

110100

1

2

3

4

5

1

2

3

4

5

310

410

510

210

mMPa,KΔI

da/dN,mm/cycle

da/dN,mm/cycle

da/dN,mm/cycle

da/dN,mm/cycle

110100

1

2

3

4

5

1

2

3

4

5

310

410

510

210

mMPa,KΔI

da/dN,mm/cycle

da/dN,mm/cycle

da/dN,mm/cycle

da/dN,mm/cycle

.constE.;constpH tt (2.11)

3. ENGINEERING APPLICATIONS FOR SERVICEABILITY ASSESSMENTS OF POWER ENGINEERING PIPELINES

 

Fig 3.1. Typical distribution and view of crack-like defects in the pipeline wall.

d

S

 

3.1. SUBJECT OF STUDIES 

D =219

S=42

50

50

50

a)

b)

c)

a) b)

 

Fig 3.2. Element of pipe (a) and schematic cutting plan (b).

3.2. DETERMINING OF PERIOD FOR SURFACE CORROSION FATIGUE CRACK NUCLEATION

(3.1)

pH12Kh1MF steel 08Kh18N12T steel

а, mm а, mm

1 5 10 1 5 10

рН=3,0 32565 45285 52272 217541 255481 274469

рН=6,5 49777 69925 81093 134573 160021 173304

рН=9,0 34464 46270 54051 184605 213375 227405

Table 3.1

104

105

104

105

08Kh18N12Т 55443

32

32

45

21

11

1 а=1 mm2 а=2 mm3 а=5 mm4 а=10 mm5 а=20 mm

Nex, cycles

Nca

l, cy

cles pH3,0

pH6,5 pH9,0

105

106

105

106

12Kh1МF

1 а=1 mm2 а=2 mm3 а=5 mm4 а=10 mm5 а=20 mm

5432

34

54

2

3

5

21

1

1

Nex, cycles

Nca

l, cy

cles pH3,0

pH6,5 pH9,0

Fig. 3.3. Experimental and predicted according to formula (7.1) values of number cycles of loading N for corrosion fatigue surface crack of different length.

3.3. ASSESSMENT OF ADMISSIBLE CORROSION FATIGUE CRACK DEPTH

The assessment of admissible crack depth in pipelines walls has been done on the base of corrosion fatigue crack growth rate, i.e:

(3.2)

where is the maximum crack growth rate that may be admitted in the wall of pipelines during planned time of exploitation

dNdl

Table 3.2. Operating aqueous environments and their chemical composition

Number of environment

Environment Chemical composition

1 Boron regulation 1 %-solution H3BO3+KOH (pH8)

2 Boron regulation with chloride admixtures

1 %-solution H3BO3+KOH (pH8) + +5 mg/kg Cl– (10,5 mg/kg KCl)

3 Boron regulation with nitride admixtures

1 %-solution H3BO3+KOH (pH8)+ +10 mg/kg

3NO (16,3 mg/kg KNO3)

4 Ammoniac Distilled water+NH3 (pH9) 5 Hydrazine-ammoniac (I) H2O+NH3 (pH9)+100 g/kg N2H4 6 Hydrazine-ammoniac (II) H2O+NH3 (pH9)+100 mg/kg N2H4

7 Ammoniac with chloride admixtures

H2O+NH3 (pH9)+ +10 mg/kg Cl–(16,5 mg/kg NaCl)

8 Ammoniac with admixtures of hydrochloric acid

H2O+NH3 (pH9)+ + 10 mg/kg Cl– (HCl); pH3,95

9 Ammoniac with admixtures acetic acid

H2O+NH3 (pH9)+ +10–5 mole/l CH3CH2COOH; pH5,9

10 10010

-9

10-8

10-7

10-6

08Kh18N12T

dl/d

N, m

/cyc

le

KI , МPа(m)1/2

1 2 3

10 10010

-9

10-8

10-7

10-6

12Kh1MF

dl/d

N, m

/cyc

le

KI , МPа(m)1/2

4 5 6 7 8 9

Fig 3.4. Corrosion fatigue crack growth rate diagrams of steels 08Kh18N12Т and 12Kh1МF in operating environments of different composition. The numbers of

points correspond to numbers of environments in Table 3.2.

Table 3.3. Coefficients in Paris equation for tested conditions

Steel Number of

environment C n R2

1 2.10-17 7,61 0,8162 2 6.10-19 8,95 0,9339 08Kh18N12Т 3 4.10-12 3,48 0,8306 4 2.10-16 7,13 0,9181 5 3.10-16 7,15 0,9289 6 1.10-14 5,79 0,9199 7 7.10-21 10,26 0,9528 8 2.10-14 5,50 0,8978

12Kh1МF

9 3.10-31 21,39 0,8051

Table 3.4. Admissible crack depth in the wall of pipelines versus number cycles of loading of the heat plant power units

Admissible depth of crack l , mm Shape of

crack Steel

Number of environment 500

cycles 1000 cycles

2000 cycles

3000 cycles

5000 cycles

1 7,2 7,1 7,0 6,9 6,8 2 7,1 7,0 6,9 6,8 6,8 08Kh18N12Т 3 7,9 7,6 7,3 7,1 7,0 4 7,1 7,0 6,8 6,7 6,6 5 7,0 6,9 6,7 6,7 6,6 6 7,2 7,0 6,9 6,8 6,6 7 7,1 7,0 6,9 6,9 6,8 8 7,2 7,1 6,9 6,8 6,7

201al

12Kh1МF

9 6,2 6,2 5,9 5,8 5,8 1 7,8 7,6 7,5 7,4 7,2 2 7,6 7,5 7,4 7,3 7,2 08Kh18N12Т 3 8,6 8,2 7,8 7,7 7,4 4 7,7 7,5 7,3 7,2 7,1 5 7,5 7,4 7,2 7,1 7,0 6 7,8 7,6 7,4 7,2 7,1 7 7,6 7,5 7,4 7,4 7,2 8 7,8 7,6 7,4 7,3 7,1

31al

12Kh1МF

9 6,6 6,6 6,4 6,3 6,3

Fig 3.5. Assessment of admissible crack-like defect depth on operation time of pipe-line made from steel 08Kh18N12Т (a, b) and steel 12Kh1МF (c, d): a, c – a/b=1/10; b, d – a/b=2/3. Numbers of points correspond to numbers of environments in Table 4.1.

0 100 200 300 4006

7

8

9a)

l * , m

m

103, hours

1 2 3

0 100 200 300 4005

6

7

8c)

l * ,

mm

103, hours

4 5 6 7 8 9

0 100 200 300 400

6

7

8

9

b)

103, hours

l * , m

m

1 2 3

0 100 200 300 4005

6

7

8

d)

103, hours

l * , m

m

4 5 6 7 8 9

3.4. ASSESSMENT OF METAL PROPERTIES DEGRADATION UNDER LONG TERM EXPLOITATION

Table 3.5. Statistic data on exploitation regimes of power plant units.

Power Plant Exploitation

term, thousand hours

Number of unit start

Number cycles of loading

Vyhlehirska Power Plants (V)

120-150

170-350

850-17500

Ladyghynska Power Plants (L)

135-145

360-455

1800-2275

C Mn Si Cr Ni Cu S P As Fe 0,12 1,2 0,7 0,3 0,3 0,3 <0,04 <0,03 <0,08 Bal.

Ultimate stress MPa480σU Yield stress MPa250σY

Table 3.6. Chemical composition of steel 16HS (in weight %).

“ M a t e r i a l - e n v i r o n m e n t ” s y s t e m

n

C

N e w m e t a l - n o m i n a l e n v i r o n m e n t

1 1 . 2 1 8 7 1 1 0 1 6.

N e w m e t a l - o r g a n i c a d d i t i o n s

1 0 . 5 5 3 0 2 1 0 1 5.

M e t a l V - n o m i n a l e n v i r o n m e n t

1 4 . 0 7 1 6 6 1 0 1 8.

M e t a l V - o r g a n i c a d d i t i o n s

1 0 . 6 6 3 2 4 1 0 1 5.

M e t a l L - n o m i n a l e n v i r o n m e n t

3 2 . 8 7 1 6 6 1 0 3 3.

M e t a l L - o r g a n i c a d d i t i o n s 1 8 . 3 6 4 3 6 1 0 2 2.

Table 3.7. Corrosion fatigue crack growth resistance of feeding pipelines metal (16HSsteel).

da/dN,mm/cycle

R Hz 0 7 10. ; . R Hz 0 7 10. ; .

K MPa m, K MPa m,

10

10-6

10-5

10-4

129876 10

10-6

10-5

10-4

10-3

129876

(a) (b)

1

2

3

1

2

3

dl /dN,mm/cycle

R Hz 0 7 10. ; . R Hz 0 7 10. ; .

K MPa m, K MPa m,

10

10-6

10-5

10-4

129876 10

10-6

10-5

10-4

10-3

129876

(a) (b)

1

2

3

1

2

3

da/dN,mm/cycle

R Hz 0 7 10. ; .R Hz 0 7 10. ; . R Hz 0 7 10. ; .R Hz 0 7 10. ; .

K MPa m, K MPa m, K MPa m, K MPa m,

10

10-6

10-5

10-4

129876 10

10-6

10-5

10-4

10-3

129876

(a) (b)

1

2

3

1

2

3

10

10-6

10-5

10-4

129876 10

10-6

10-5

10-4

10-3

129876

(a) (b)

1

2

3

1

2

3

dl /dN,mm/cycle

R Hz 0 7 10. ; .R Hz 0 7 10. ; . R Hz 0 7 10. ; .R Hz 0 7 10. ; .

K MPa m, K MPa m, K MPa m, K MPa m,

10

10-6

10-5

10-4

129876 10

10-6

10-5

10-4

10-3

129876

(a) (b)

1

2

3

1

2

3

10

10-6

10-5

10-4

129876 10

10-6

10-5

10-4

10-3

129876

(a) (b)

1

2

3

1

2

3

Fig 3.6. Comparison of the corrosion fatigue crack growth resistance diagrams of new metal (1) and used pipe-line metals from Vyhlehirska Power Plant (2) and Ladyghynska Power Plant (3) for operating environments of different composition: (a) - environment of nominal composition; (b) - with organic additions.

Fig. 3.7. Dependencies of admissible rack-like defects depth on the planned service life for new metal (1) and used pipeline metals from Vyhlehirska Power Plant (2) and Ladyghynska Power Plant (3). Environment: (a) and (c) - nominal composition; (b) and (d) - with organic additions. Type of crack-like defect: (a) and (b) - furrow-type; (c) and (d) - ulcer-type. 0 1 0 0 2 0 0 3 0 0 4 0 0

3

4

5

6

7(d )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(a )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(b )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 03

4

5

6

(c )

3

2

1

a m m ,

a m m ,

h o u rs1 0,T 3 h o u rs1 0,T 3

0 1 0 0 2 0 0 3 0 0 4 0 0

3

4

5

6

7(d )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(a )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(b )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 03

4

5

6

(c )

3

2

1

h o u rs1 0,T 3 h o u rs1 0,T 3

0 1 0 0 2 0 0 3 0 0 4 0 0

3

4

5

6

7(d )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(a )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(b )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 03

4

5

6

(c )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

3

4

5

6

7(d )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(a )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(b )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 03

4

5

6

(c )

3

2

1

h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3

0 1 0 0 2 0 0 3 0 0 4 0 0

3

4

5

6

7(d )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(a )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(b )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 03

4

5

6

(c )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

3

4

5

6

7(d )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(a )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(b )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 03

4

5

6

(c )

3

2

1

h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3

0 1 0 0 2 0 0 3 0 0 4 0 0

3

4

5

6

7(d )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(a )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(b )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 03

4

5

6

(c )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

3

4

5

6

7(d )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(a )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(b )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 03

4

5

6

(c )

3

2

1

h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3

0 1 0 0 2 0 0 3 0 0 4 0 0

3

4

5

6

7(d )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(a )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(b )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 03

4

5

6

(c )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

3

4

5

6

7(d )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(a )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(b )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 03

4

5

6

(c )

3

2

1

h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3

0 1 0 0 2 0 0 3 0 0 4 0 0

3

4

5

6

7(d )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(a )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(b )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 03

4

5

6

(c )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

3

4

5

6

7(d )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(a )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(b )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 03

4

5

6

(c )

3

2

1

h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3

0 1 0 0 2 0 0 3 0 0 4 0 0

3

4

5

6

7(d )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(a )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(b )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 03

4

5

6

(c )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

3

4

5

6

7(d )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(a )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(b )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 03

4

5

6

(c )

3

2

1

h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3

0 1 0 0 2 0 0 3 0 0 4 0 0

3

4

5

6

7(d )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(a )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(b )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 03

4

5

6

(c )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

3

4

5

6

7(d )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(a )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(b )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 03

4

5

6

(c )

3

2

1

h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3

0 1 0 0 2 0 0 3 0 0 4 0 0

3

4

5

6

7(d )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(a )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(b )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 03

4

5

6

(c )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

3

4

5

6

7(d )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(a )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(b )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 03

4

5

6

(c )

3

2

1

h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3

0 1 0 0 2 0 0 3 0 0 4 0 0

3

4

5

6

7(d )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(a )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(b )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 03

4

5

6

(c )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

3

4

5

6

7(d )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(a )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(b )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 03

4

5

6

(c )

3

2

1

h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3

0 1 0 0 2 0 0 3 0 0 4 0 0

3

4

5

6

7(d )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(a )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

mm,l

mm,l

0 1 0 0 2 0 0 3 0 0 4 0 0

3

4

5

6

7(d )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(a )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(b )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 03

4

5

6

(c )

3

2

1

a m m ,

a m m ,

0 1 0 0 2 0 0 3 0 0 4 0 0

3

4

5

6

7(d )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(a )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(b )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 03

4

5

6

(c )

3

2

1

a m m ,a m m ,

a m m ,a m m ,

h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3

0 1 0 0 2 0 0 3 0 0 4 0 0

3

4

5

6

7(d )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(a )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(b )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 03

4

5

6

(c )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

3

4

5

6

7(d )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(a )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(b )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 03

4

5

6

(c )

3

2

1

h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3

0 1 0 0 2 0 0 3 0 0 4 0 0

3

4

5

6

7(d )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(a )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(b )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 03

4

5

6

(c )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

3

4

5

6

7(d )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(a )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(b )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 03

4

5

6

(c )

3

2

1

h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3

0 1 0 0 2 0 0 3 0 0 4 0 0

3

4

5

6

7(d )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(a )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(b )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 03

4

5

6

(c )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

3

4

5

6

7(d )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(a )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(b )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 03

4

5

6

(c )

3

2

1

h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3

0 1 0 0 2 0 0 3 0 0 4 0 0

3

4

5

6

7(d )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(a )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(b )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 03

4

5

6

(c )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

3

4

5

6

7(d )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(a )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(b )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 03

4

5

6

(c )

3

2

1

h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3

0 1 0 0 2 0 0 3 0 0 4 0 0

3

4

5

6

7(d )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(a )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(b )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 03

4

5

6

(c )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

3

4

5

6

7(d )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(a )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(b )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 03

4

5

6

(c )

3

2

1

h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3

0 1 0 0 2 0 0 3 0 0 4 0 0

3

4

5

6

7(d )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(a )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(b )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 03

4

5

6

(c )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

3

4

5

6

7(d )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(a )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(b )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 03

4

5

6

(c )

3

2

1

h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3

0 1 0 0 2 0 0 3 0 0 4 0 0

3

4

5

6

7(d )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(a )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(b )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 03

4

5

6

(c )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

3

4

5

6

7(d )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(a )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(b )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 03

4

5

6

(c )

3

2

1

h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3*h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3

0 1 0 0 2 0 0 3 0 0 4 0 0

3

4

5

6

7(d )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(a )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(b )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 03

4

5

6

(c )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

3

4

5

6

7(d )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(a )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(b )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 03

4

5

6

(c )

3

2

1

h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3

0 1 0 0 2 0 0 3 0 0 4 0 0

3

4

5

6

7(d )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(a )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(b )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 03

4

5

6

(c )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

3

4

5

6

7(d )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(a )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(b )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 03

4

5

6

(c )

3

2

1

h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3

0 1 0 0 2 0 0 3 0 0 4 0 0

3

4

5

6

7(d )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(a )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(b )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 03

4

5

6

(c )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

3

4

5

6

7(d )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(a )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(b )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 03

4

5

6

(c )

3

2

1

h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3 h o u rs1 0,T 3

0 1 0 0 2 0 0 3 0 0 4 0 0

3

4

5

6

7(d )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

2

3

4

5(a )

3

2

1

0 1 0 0 2 0 0 3 0 0 4 0 0

mm,l

mm,l

EXPERT SYSTEM

FOR ASSESSMENT OF RELIABILITY AND DURABILITYFOR ASSESSMENT OF RELIABILITY AND DURABILITY OF STRUCTURAL COMPONENTS OF HEAT POWER PLANTSOF STRUCTURAL COMPONENTS OF HEAT POWER PLANTS

CONCLUTIONS

1. Analysis of the characteristic types of in-service damages and failures of 1. Analysis of the characteristic types of in-service damages and failures of basic equipment of heat power plants (water-wall tubes of high pressure steam-basic equipment of heat power plants (water-wall tubes of high pressure steam-boilers, super heater tubes of sub- and supercritical pressure boilers, water boilers, super heater tubes of sub- and supercritical pressure boilers, water economizers, non-heated boiler’s elements and feeding pipelines of economizers, non-heated boiler’s elements and feeding pipelines of supercritical pressure power generating units) has showed on predominantly supercritical pressure power generating units) has showed on predominantly cracks nucleation and growth processes as result of as result of long time of cracks nucleation and growth processes as result of as result of long time of exploitation or as result of different reflections of operating regimes of exploitation or as result of different reflections of operating regimes of equipment.equipment.  2. Fracture mechanics approaches are preferable as basic concept for expert 2. Fracture mechanics approaches are preferable as basic concept for expert assessments of technical state and reliability of heat-and-power engineering assessments of technical state and reliability of heat-and-power engineering equipment.equipment.  3. Service life extension of such equipment is to be carried out on the base of 3. Service life extension of such equipment is to be carried out on the base of diagnostics of its actual state and diagnostics of its actual state and residual life of the basic structural elements residual life of the basic structural elements should be evaluated with takes into account of the actual data of metal should be evaluated with takes into account of the actual data of metal properties and operating conditions of equipment.properties and operating conditions of equipment.