Index of Contents ƒ Introduction

Life Cycle Analysis Of Tunnel Equipment - Basis For Safe Operation

ƒ Basics ƒ Useful life period ƒ Life cycles of a few selected systems ƒ Summary & Recommendation

Road Tunnel Operations Management and Safety

ƒ Questions

Seminar Chongqing, 18 - 20 October 2006

Urs Welte Dipl. El.Ing. ETH Switzerland 2

Introduction

Life Cycle & Useful Life Period

Frequency

ƒ The importance of the technical equipment in tunnels (technical maintenance vs. total maintenance)

Early breakdowns

ƒ Existing tools for an optimal Asset Management

Life cycle

Age-related breakdowns

Useful life period

ƒ Exploration of the optimal useful life period ƒ Problem: The optimal useful life period of EM-Systems depends on the application area

Minimal acceptable value

ƒ Life cycle:

Time

max possible useful life period

ƒ Useful life period: time in which the system can be used reasonably Introduction

3

Basics

4

Impacts on Life Cycles

Impacts on Life Cycles

ƒ Maintenance

ƒ Refurbishment, Renovation due to external reasons

ƒ Aim: to improve the useful life period with a minimum of money & manpower, or minimize the risk of a break down Reasons for a total renovation Notes

ƒ Different maintenance strategies: ƒ High reliability, small error probability ƒ Longest possible useful life period

Pavement, sealing,…

New safety / environment requirements

Ventilation, escape route

Most of the equipment has reached its end of the life cycle

ƒ Ideal conservation of value

Basics

Structural renovation of the tunnel

5

Conclusions

Basics

6

Useful Life Period in Practice

ƒ In a systems life cycle, the replacement is influenced by: ƒ Life cycle curve of the system ƒ Total tunnel refurbishment ƒ New requirements ƒ Superior reasons (lack of maintenance,…)

Basics

7

Useful Life Period

8

Example 1

Example 2

Region 1

Region 2

35

25

number of systems

number of systems

29

30 25 20 15

17

15

15

11

10 5

3

5

20

15

11

11 8

10 5 5

1

0 1

0 1

20

20

5

9

13

17

21

25

29

5

9

13

33

17

21

25

29

33

useful life period [years]

useful life period [years]

Useful Life Period

9

Example 3

Useful Life Period

10

Example 4 Region 3

25

Region 4 23

number of systems

number of systems

17 14

15

27

30

20 20 15

10 5

25 20 15 7

10

5

5

7 3

1

1

0 1

1 0

6

11

16

21

26

31

36

41

46

useful life period [years]

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35

useful life period [years]

Useful Life Period

11

Useful Life Period

12

Example 5

Average

Standard SN 531 197/2

useful life period in average 25

useful life period

16 14 12 10 8 6 4 2 0

20 15 10 5

e er ag Av

4

3

on eg i

Po

R

1

2

on eg i

40

R

35

on

30

on

25

eg i

20

useful life period

eg i

15

R

10

R

5

we dar rS d ta tio n

0 St an

number of systems

30

Useful Life Period

13

Life Cycles of a Few Selected Systems

Useful Life Period

14

Illumination

ƒ Illumination ƒ Control and communication systems ƒ Energy cabling systems ƒ Fibre optic cabling systems

Life Cycles of a Few Selected Systems

15

Life Cycles of a Few Selected Systems

16

Illumination System

Illumination System Life Cycle

ƒ The illumination is part of a system including:

ƒ Mainly used components:

ƒ Control system

thermal influences

ƒ Fluorescent lamp

ƒ Luminaire

mechanical influences

ƒ High pressure sodium lamp

ƒ Lamp ƒ Electronic ballast

electronic influences electrical influences environmental influences

Life Cycles of a Few Selected Systems

17

Illumination System Life Cycle

Life Cycles of a Few Selected Systems

18

Life Cycle vs. Switching Periods

ƒ Useful life period ends if: ƒ The luminous flux is lower than 70-80% of the original luminous flux

useful life period

Life Cycles of a Few Selected Systems

19

Life Cycles of a Few Selected Systems

20

How to Define Replacement Cycle

Conclusion ƒ The optimal life period can be defined by: ƒ Supplier data & special "tunnel effect"

Criteria

Comment

Operating hours

Best practice

Luminance measuring

Difficult due to changing conditions

Life Cycles of a Few Selected Systems

21

Data vs. Actual Experience

Life Cycles of a Few Selected Systems

Life Cycles of a Few Selected Systems

22

Control & Communication Systems

23

Life Cycles of a Few Selected Systems

24

Control Systems are Used for:

Bath Tub Curve of Control Systems

ƒ Traffic

ƒ Typical life cycle of control systems

ƒ Technical systems

Failure rate

ƒ Alarms

Elimination of design failures

End of the useful life period

-

Unavailable maintenance Unavailable spare parts New requirements New technologies Software revision New applications

Guarantee

Acceptance

Commissioning

Site accpetance test

ƒ Messages

Specification

Maintenance

- Cleaning - Replacement - Software Update, Upgrades

Time

Life Cycles of a Few Selected Systems

25

Life Cycles of a Few Selected Systems

Theoretical Life Cycle Data is Basing on:

Typical Elements of Control Systems

ƒ Room temperature: 20-25°C

ƒ Active components without moving parts and

ƒ Humidity:

26

hot spots

40-60%

ƒ No vibrations

ƒ Active components with moving parts (PC, Server,…)

Life Cycles of a Few Selected Systems

27

Life Cycles of a Few Selected Systems

28

Typical Elements of Control Systems

Example: PC

ƒ Joining elements (sockets, plugs,…)

Disks

ƒ Passive components like communication

Fan for the chip

networks (fibre glass,…)

Power supply unit Fan for the casing

ƒ Software

Life Cycles of a Few Selected Systems

29

Life Cycles

Life Cycles of a Few Selected Systems

30

Measures for Better Life Cycles: PC

Without Hot Spots

PC-Board

Applications

Software-Version

14

Industrial-PC w ithout fan

12

System software

MTBF (years)

10 Chips

HD

On chip

Fan

8 6 4

Desktop-PC w ith fan

Industial-PC w ith fan

Laptop w ith fan

2

Casing

0 0

Life Cycles of a Few Selected Systems

5

10

15 years

31

Life Cycles of a Few Selected Systems

32

Measures for Better Life Cycles: Temperature

Temperature = Most Important Stress Factor

ƒ T ” 0.7 Tmax (28°C –rule)

Arrhenius ƒ Higher temperatures Æ faster chemical reactions

ƒ T+10°

Failure rate

r 0.7

33

ts ta E k Ts Ta

Aging Factor

exp

Reaction rate at room temperature Reaction rate at a higher temperature Activation Energy Boltzmann-term Room temperature High temperature

E § 1 1 ·

¨  ¸ k © Ts Ta ¹

Factor of the accelerated aging

dq dt

A exp

§ E · ¨ ¸ © kT ¹

Svante Arrhenius 1859-1927

Life Cycles of a Few Selected Systems

q r A E k T

Chemical reaction Reaction rate Absolute Material term Activation Energy [eV] Boltzmann-term 8.6*10^-5 eV/K Absolute temperature

34

Energy Cabling Systems ƒ Operational life cycle: 30-40 years ƒ Main reason for damages: short circuit Æ damages to other systems

10

ƒ Aging is influenced by high operating voltages & high temperatures

1.1 eV 8

double reaction rate

Temperature

1.0

Life Cycles of a Few Selected Systems

ts ta

Æ

(Arrhenius) 0.8 eV 0.5 eV

6

4

2

0

0

2

4

6

8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 Delta T over 22°C

Life Cycles of a Few Selected Systems

35

Life Cycles of a Few Selected Systems

36

Preventive Actions to Avoid Early Breakdowns ƒ Overload protection ƒ No damages at the cable jacket

Electrical stress

Heat

Humidity

Condition

Mechanical stress

Risk Factors (Cables PE, XPE)

ƒ Overvoltage protection ƒ Periodic isolation tests

Forced aging

Usual material aging

Limit of damage

Time

Life Cycles of a Few Selected Systems

37

Conclusion

Life Cycles of a Few Selected Systems

38

Fibre Optic Cabling Systems ƒ The useful life period is affected by:

Insulation stability

Incident with influence on the aging process (shortterme overvoltage,…)

ƒ Intrinsic factors: surface conditions, micro cracks ƒ Extrinsic factors: bending, torsion, temperature, humidity, gases ƒ Optical factors: short term optical overstress

t1

t2

Operating time t

Diagnostic for the verification of the early aging

Life Cycles of a Few Selected Systems

39

Life Cycles of a Few Selected Systems

40

Static Stress

Preventive Measures for Long Life Cycles ƒ No variations in temperature (cable conduit) ƒ No humidity (cable conduit) ƒ Good mechanical support ƒ Bending rules

ƒ Reduction in stress & protection from environmental effects Æ

Life Cycles of a Few Selected Systems

41

longer life cycle

Life Cycles of a Few Selected Systems

42

Summary & Recommendations ƒ Extrinsic factors have a high influence on a systems life cycle ƒ Empirical evaluation and observation necessary ?

ƒ Analysis and diagnostics on a case-to-case basis

Summary & Recommendations

43

?

Questions?

?

44