peter heller department qualification german aerospace center...

R&D on predicting component and material failure

Peter Heller

Department Qualification

German Aerospace Center DLR

CSP Today Sevilla 2014

www.DLR.de • Chart 1 > Institute of Solar Research > Department Qualification> 2014 CSP Today Seville, 13.11.2014

R&D on predicting component and material failure

Motivation

-Material and component failures are leading to

-Higher investment cost (financing, bancability, guarantees)

-Higher maintenance cost (personnel, spare parts)

-Less revenues from operation (down-times, performance loss)

-Performance test in laboratory

-Durability and lifetime prediction

Needs

www.DLR.de • Chart 2 > Institute of Solar Research > Department Qualification> 2014 CSP Today Seville, 13.11.2014

Components of major interest

- Mirrors

- Receivers

- Ball Joints

www.DLR.de • Chart 3 > Institute of Solar Research > Department Qualification> 2014 CSP Today Seville, 13.11.2014

Methodology Mirrors

Commercial mirrors

Field operation

„accelerated“

degradation

mechanism

„natural“

degradation

mechanism

Guideline for durability testing of reflectors

Accelerated

aging testing

Indoor storage

-www.DLR.de • Chart 4

> Institute of Solar Research > Department Qualification> 2014 CSP Today Seville, 13.11.2014

Ageing of aluminium mirrors

• Definition accelerated test methods and deduction of correlations to outdoor weathering sites

Gerichtete

ReflexionsverlusteΔρS + ΔρK

Gerichtete

ReflexionsverlusteΔρS + ΔρK

Direct reflectance exposed samples without protection layer in Almeria

Adaptation of production process by manufacturer for increased life expectancy

• Modeling of reflectance prediction by measurement of corrosion induced reflectance loss

Correlation salt spray test Golden, USA

Provision of methods for estimation of life expectancy of new materials

6 months outdoor weathering

560 h Salt spray test ISO 9227

Outdoor weathering time [months]

Sa

lt s

pra

y t

estin

g [h

ou

rs]

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Ageing of Reflectors

• Reflector Laboratory (OPAC) with CIEMAT

• Independent test laboratory for industry services

• Outdoor weathering in Spain / North Africa

• Optical Characterization and microscopy

• Standardized aging tests

ISO 9227: Salt spray test

IEC 62108: Damp heat test

ISO 11507: UV light and moisture exposure

DIN 50018: Kesternich Test

ISO 61215: Temperature Cycle Test

ISO 6270-2CH: Humidity test

IEC 62108: Humidity frost test

MIL-STD 810G: Sand abrasion

ISO 11998: Wet scrub resistance

ISO 92114: Abrasion optical coatings

Outdoor weathering

Salt spray test ISO 9227

UV light and moisture ISO11507 [Atlas]

www.DLR.de • Chart 6 > Institute of Solar Research > Department Qualification> 2014 CSP Today Seville, 13.11.2014

Tested mirror samples

3 protection lacquers 2 protection lacquers 2 protection lacquers,

without copper layer

Sample code: A1, A2, A3, C1 Sample code: B1 Sample code: C2

Type A: Commercial products (outdoor proven)

Type B: Prototype product (no outdoor data available)

Type C: Commercial product (degradation observed in Tabernas, Spain / Newcastle, Australia)

-www.DLR.de • Chart 7 > Institute of Solar Research > Department Qualification> 2014 CSP Today Seville, 13.11.2014

Outdoor degradation of sample C2 in

Newcastle, Australia

Pitting corrosion up to 29 mm in diameter

-www.DLR.de • Chart 8 > Institute of Solar Research > Department Qualification> 2014 CSP Today Seville, 13.11.2014

Outdoor degradation of sample C2 in Newcastle, Australia

Intact layer structure

Glass

Prime Coat

Top Coat

Silver layer

Glass

Cross section of local corrosion spot

-www.DLR.de • Chart 9 > Institute of Solar Research > Department Qualification> 2014 CSP Today Seville, 13.11.2014

Outdoor degradation of sample C2 in Newcastle, Australia

Chloride and Sulfur

and Silicon found in

delamination gap

-www.DLR.de • Chart 10 > Institute of Solar Research > Department Qualification> 2014 CSP Today Seville, 13.11.2014

Sulfur and Iron found in pinhole

Area 1

Area 2

Outdoor degradation of sample C2 in Newcastle, Australia

Pinhole in paint

2

1

Fe

S

-www.DLR.de • Chart 11 > Institute of Solar Research > Department Qualification> 2014 CSP Today Seville, 13.11.2014

• Area 1 has an increased amount of NaCl

at interface

• NaCl still observed outside corrosion front

Area 1

NaCl

Area 2

Low NaCl

Corrosion

Edge

Undamaged

Ag Reflector

Outdoor degradation of sample C2 in Newcastle, Australia

1 2 Cl

Cl

-www.DLR.de • Chart 12 > Institute of Solar Research > Department Qualification> 2014 CSP Today Seville, 13.11.2014

Glass 4 mm

Silver

Prime Coat

Top coat

Delamination in Glass – silver interface

Outdoor degradation of sample C2 in Newcastle, Australia

pinhole

Silver

chloride

Silicon, Chloride

and Sulfur

containing filling

material

-www.DLR.de • Chart 13 > Institute of Solar Research > Department Qualification> 2014 CSP Today Seville, 13.11.2014

Methodology

Commercial mirror samples

Field operation

„accelerated“

degradation

mechanism

„natural“

degradation

mechanism

Guideline for durability testing of reflectors

Accelerated

aging testing

Indoor storage

-www.DLR.de • Chart 14 > Institute of Solar Research > Department Qualification> 2014 CSP Today Seville, 13.11.2014

-Chart 15

Accelerated aging

No differences

visible after 480 h

-www.DLR.de • Chart 16 > Institute of Solar Research > Department Qualification> 2014 CSP Today Seville, 13.11.2014

• Heating with heating rods

• Overheating test: performed with at 478 °C for

1000 h

• Thermal cycling test: 200°C to 478°C for

100 cycles

→ Necessity to limit heat up speed at T > 400 °C

k: reactions per time

A: constant (prefactor)

EA: activation energy

R: universal gas constant

T: temperature in K

Overheating And Thermal Cycling Test Bench

Arrhenius equation

𝑘 = 𝐴 ∙ 𝑒−𝐸𝐴𝑅∙𝑇

www.DLR.de • Chart 18 > Institute of Solar Research > Department Qualification> 2014 CSP Today Seville, 13.11.2014

Bellow Fatigue Test Bench

• heating with internal heating rods

• absorber 200 °C/ 400 °C

• move glass relative to absorber

• failure detection: increase in

heating power

• test

o until failure

o until 20 000 cycles reached

www.DLR.de • Chart 19 > Institute of Solar Research > Department Qualification> 2014 CSP Today Seville, 13.11.2014

Accelerated aging / lifetime testing of REPAs

under power plant operation conditions:

• heat transfer fluid thermal oil

@ 300-450°C, 25bar

• external forces simulating receiver expansion

• rotational collector movement drive

• adjustable focal length

• monitoring of forces, torques and operation conditions during testing

Objectives

• REPA component qualification

• Investigation of failure mechanisms

• Development of standard REPA test procedures

Joint construction and operation by DLR and Ciemat at PSA

(Spring/Summer 2015)

Joint Test Facility for

Rotation and Expansion Performing Assemblies

www.DLR.de • Chart 20 > Institute of Solar Research > Department Qualification> 2014 CSP Today Seville, 13.11.2014

Acellerated Ageing of Parabolic Trough Receiver

Overheating Test

• Acellerated ageing of absorber coating

• Absorber temp. up to 600°C

• 1000 h overheating time correlates to

aging over 25 years

Bellow Fatigue Test

• Testing of bellow durability

• Absorber mean temperature 200 °C

• Absorber temperature at bellow 400 °C

• 10 000 cycles (1 per sec) correlates to 25

years of receiver operation

www.DLR.de • Chart 21 > Institute of Solar Research > Department Qualification> 2014 CSP Today Seville, 13.11.2014

a) Airborne camera vehicle during a test

flight at KONTAS test facility (PSA)

d) Slope deviation measured by QFly for KONTAS

collector

[mrad]

c) Photogrammetric determination of

camera and collector position

Qualification of Concentrators

Field Measurement: Qfly (optical and thermal)

b) IR Temperature measurement of receivers

www.DLR.de • Chart 22 > Institute of Solar Research > Department Qualification> 2014 CSP Today Seville, 13.11.2014

Conclusion

• Further field data necessary to

• Understand failure mechanisms

• develop lifetime models

• develop accelerated ageing methods

• develop quality and testing standards

• Prestine samples to be stored for comparison

• First guidelines for testing standards under development (mirrors,

receivers, heliostats)

• Long term R&D to develop methodology for durability tests

• Test and qualification laboratories available

www.DLR.de • Chart 23 > Institute of Solar Research > Department Qualification> 2014 CSP Today Seville, 13.11.2014