dealing with extreme heat in aerospace and solar energy
TRANSCRIPT
“Dealing with extreme heat in aerospace and solar energy applications”
Prof Jose L. EndrinoSurface Engineering & Nanotechnology Institute
School of Aerospace, Transport, and Manufacturing
Acknowledgements!
• D. Rickerby (Rolls-Royce)• I. Heras (Abengoa)• J R Nicholls, T. Roberts, D. Bhattacharyya (SENTi), C. Sansom (PEI)
Overview of SENTi
Design of thermal barrier coatings in gas
turbines
High temperature resistant solar selective
coatings
Outline
Manufacturing theme
• Surface Engineering and Nanotechnology Institute• Precision Engineering Institute • Through-life Engineering Services Institute • Enhanced Composites and Structures Centre • Integrated Vehicle Health Management Centre • Welding Engineering and Laser Processing Centre • Sustainable Manufacturing Systems Centre • Manufacturing Informatics Centre
High speed rail
Energy
efficiency
Bulk recycling
CO2 mitigation
Concrete
Water
purification
Materials for sustainable development
Tools and mechanical parts
Optical lenses
Selective coatingsTurbine blades
Automotive & Domestic items
Medical prosthesis
Decorative tilesFood packagingData storage
World of Surface Engineering Solutions
Catalysis
Surface Engineering &
Nanotechnology Institute
Aqueous
Corrosion
Tribology &
Mechanical
Testing
Ceramics
High
Temperature
Oxidation
Energy
Harvesting
Environment
SensorsFunctional
Nanomaterials
Coatings Facilities
EB-PVD
Resistive heated evaporators
Multi/single-target PVD
CVD and gas phase CVD
Controlled atmosphere plasma spraying
Sol-gel deposition
Electroplating
Coating Systems for bond coats
• Traditional β-Ni(Pt)Al Coatings by CVD (diffusion – time @
temperature)
• β-Ni(Pt)Al by Ionic Liquids (exothermic reaction synthesis)
Corrosion Testing Facilities
High Pressure Fatigue Rig (HPFR)
Environmental Fatigue Rig (EFR)
Environmental, Thermal Cycling Rig (ITP)
Accelerated Furnace Cyclic Testing (AFCT)
Environmental Centrifugal Erosion Rig
High Pressure, Hot, Tribo-corrosion Rig
Vertical and horizontal furnaces
Overview of SENTi
Design of thermal barrier coatings in gas
turbines
High temperature resistant solar selective
coatings
Outline
Gas turbine applications
CeramicThermal Barrier Coating
Metallic Bond Coat
Metallic
Lowering the Thermal Transport
Reducing phonon transport. Modification of PYSZ by the addition of ternary
and quaternary compounds.
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
Ref
eren
ce
Nic
kel O
xide
Erb
ia
Ytter
bia
Neo
dymia
Gad
olinia
Th
erm
al C
on
du
cti
vit
y [
W/m
K ] Version 1… 25% reduction in k over
Zirconia - 8wt% Yttria reference
Lowering the Thermal Transport
Can one Layer within a Column? *
* Challenge by David Rickerby, (1998),
Head of Surface Engineering at Rolls-Royce plc.
Periodic change in the Structural Density
and the introduction of Atomic Defects
should decrease apparent thermal
conductivity.
Lowering the Thermal Transport
Influence of Ion bombardment on the thermal
conductivity of layered EB-PVD TBCs
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
EB-PVD TBC PAPVD
Layered TBC
ver.1
PAPVD
Layered TBC
ver.2
Plasma
Sprayed TBC
Th
erm
al
Co
nd
ucti
vit
y
[ W
/mK
]
0.30 mA/cm2
0.15 mA/cm2
Lowering the Thermal Transport
Sequential Evaporation permits layered structures to be produced.
Reducing radiation transport by reducing the mean free path for photon
scattering + reduction of phonon conduction by introducing perpendicular
interface changes.
Layered white and pink TBC
A coating with dual functionality
• Consists of YSZ doped with rare earth
ions or another non reactive dopant,
eg: YSZ:Eu, YSZ:Dy, YSZ:Sm etc.
• Sensor TBCs can be constructed to
measure:
Temperature
Heat flux
Phase stability
Erosion loss
Corrosion attack
Sensor TBCs with a doped surface layer,
illuminated with UV light.
Embedding Self-Diagnostic Sensors
Thermal protection and sensing capability
Southside ThermalSciences (STS) Limited
Overview of SENTi
Design of thermal barrier coatings in gas
turbines
High temperature resistant solar selective
coatings
Outline
Central Receiver CSP
• Increase CSP efficiency byincreasing the receptor’sworking temperature
Solucar Plant (Abengoa)
Increase CSP efficiency by ML design
1000 10000
0
200
400
600
800
1000
1200
1400
1600
1800
2000
Flu
x(W
/m2m
)
Wavelength (nm)
Refle
ctance
1.00
0.50
0.00
G (λ): Solar irradianceA.M.1.5 (ISO 9845-1)
B (λ, 650ºC): Blackbodyradiation
Ideal Solar Selective Absorber
• 180 layers – 5 groups of 12
stacks of tri-layers (L/2 H L/2) –
Al2O3-7YSZ on aluminised N75
coupon
•Total thickness 46µm
•Dark layers are Al2O3; light layers
7YZ chosen for their different
refractive indices
•Designed to filter from short
wavelength IR to visible
radiation7YSZ-
Solar TBCs
Increase CSP efficiency by ML design
Conclusions
thermal conductivity of coatings can be decreased through the appropriate doping (or ion bombardment) aiming for maximum anharmonicity (vacancies, interstitials) - Phonon transport
Optimization of optical properties (colouring) is common to gas turbine TBCs and SSC – Radiative transport apparent thermal conductivity
Multilayer designs are effective in applications dealing with high heat (protection + functionality) – radiative and phonon transport
