Plasma-Sprayed Coatings for Solar Receivers

Transcription

1 Plasma-Sprayed Coatings for Solar Receivers International Thermal Spray Conference 28 Orlando Aurélie Quet, Alice Ravaux, Alexander Füssel 2, Steffen Kunze 2, Fritz Zaversky 3, Marcelino Sánchez 3, Martin Knoch 4 CEA DAM Le Ripault, 3726 Monts, France 2 Fraunhofer-Institute for Ceramic Technologies and Systems IKTS, 277 Dresden, Germany 3 National RenewableEnergyCenter (CENER), Solar Thermal EnergyDepartment, 362 Sarriguren, Spain 4 FCT Ingenieurkeramik GmbH, Frankenblick, Germany

2 Introduction: concentrated solarpower and CAPTure project OUTLINE Coating development Silicides Borides Oxides Optical properties As-sprayed coatings Ageing Conclusion

3 SOLAR ENERGY Abundant amount of solar energy incident on planet earth Thermodynamic cycles Dispatchablepower by means of thermal energy storage and/or hybridization Radiation-to-heat conversion Photovoltaïc Solar-to-electric conversion Thermal 29 OCTOBRE 28 PAGE 3

4 CONCENTRATED SOLAR POWER AN ANCESTRAL PRINCIPLE Myth of Archimedes burning mirrors 29 OCTOBRE 28 PAGE 4

5 Solar Receiver CONCENTRATED SOLAR POWER FOUR CSP TECHNOLOGIES COMMERCIALLY AVAILABLE Linear concentration Central concentration Moving Parabolic trough Dish Stirling Fixed 29 OCTOBRE 28 Fresnel reflector Power tower PAGE 5

6 CAPTURE H22 PROJECT CONTEXT Tower technology Crescent Gemasolar Ivanpah Dunes Andalousie California Nevada Solar Bright Torresol Reserve Source Receiver: 565 C, molten water salts Objectives : increase plant efficiencies reduce levelized cost of electricity (LCOE) CAPTure: 3 partners Coordinator: CENER (Spain) Plataforma Ethan Solar Miller/Getty de Torresol Almeria Solar / Energy Reserve Images CIEMAT PAGE 6

7 CAPTURE H22 PROJECT WORK PACKAGES - Modular multi-tower decoupled solar combined cycle concept 2 Solar 2 -Récepteur receiver 3 Regenerative heatexchanger system 4 -Gasturbine 5 -Heliostats 6 -Prototype 8 -Dissemination 7 -Risks OCTOBER 29, Exploitation - Management PAGE 7

8 CAPTURE H22 PROJECT SOLAR RECEIVER Receiver:juxtaposition of several cups Function: absorption solar radiation to heat air flow o Operating temperature > C Receiver specifications o Overall thermal efficiency > 8 % lower black body radiation losses Optical coating working at high temperature PAGE 8

9 Introduction OUTLINE Coating development Silicides Borides Oxides Optical properties As-sprayed coatings Ageing Conclusion

10 OPTICAL COATINGS SiC: Emissive absorber Objective: Selective absorber Selectivity = high solar absorption, low emittance in IR spectrum Reflectance,9,8,7,6,5,4,3,2, Sunlight spectrum Black body at C, Wavelength (µm) Emissive absorber Absorption =,9 Emissivity =,9 Min efficiency Selective absorber Absorption >,85 Emissivity <,6 To reducethermal lossesby black body radiance Challenge: maintainopticalpropertiesat temperatures> C in air PAGE

11 SELECTIVE COATINGS Schematic design of selective solar absorber coatings Assess coaengs by plasma spraying Intrinsic seleceve coaengs Materials: borides, silicides, oxides Process: IPS(to avoid particles oxidation during spraying process), APS, SPPS (to produce thin protective layer) PAGE

12 [ ] ) ( ), ( ) ( ) ( = λ λ λ λ θ λ θ α d A d R A Solar absorption α [ ] ), ( ), ( ), ( ) ( = λ λ λ λ θ λ θ ε d T E d R T E Emissivity ε at T (operating temperature) With A the solar spectrum radiance, R the measured reflectance, E the blackbody emittance at T Measure: total hemispherical reflectance = R Opaque materials : A = -R 2 spectrophotometers: Cary 5 UV-visible (,25-2,5 µm) Bruker IFS66 IR (,8-5,8 µm) OPTICAL PROPERTIES PAGE 2

13 SILICIDES As-sprayed MoSi 2 α,77 ε( C),76 Hemispherical reflectance,9,8,7,6,5,4,3,2, Solar spectrum Blackbody at C MoSi2 Spectre solaire Corps noir à C,2 2 2 Wavelength (µm) Bad cutting wavelength PAGE 3

14 SILICIDES MoSi 2 + annealing 4 C Hemispherical reflectance MoSi MoSi2 2 -TT 4 C - tth 4 C,9,8,7,6,5,4,3,2,,2 2 2 Wavelength(µm) MoSi2 2 -no - sans TT tth Solar Spectre spectrum solaire Corps Blackbody noir à at C As-sprayed Annealing 4 C α,8 ε( C),75 α ε α,85 ε( C),75 Improved selectivity with an higher absorption PAGE 4

15 BORIDES As-sprayed ZrB 2 α,75 ε( C),5 Hemispherical reflectance,9,8,7,6,5,4,3,2, ZrB2 Solar Spectre spectrum solaire Corps Blackbody noir à at C,2 2 2 Wavelength (µm) Better selectivity But low resistance to oxidation during annealing PAGE 5

16 BORIDES Composite ZrB 2 / SiO 2 APS ZrB 2 α,75 ε( C),5 α ε Hemispherical reflectance ZrB2 + SiO2 ZrB2 Solar Spectre spectrum solaire Blackbody Corps noir at à C,9,8,7,6,5,4,3,2,,2 2 2 Wavelength(µm) ZrB 2 + SiO 2 APS α,85 ε( C),7 PAGE 6

17 BORIDES Composite ZrB 2 / SiO 2 APS + ageing oxidation,9,8 Solar Spectre spectrum solaire 4 C,7 Blackbody Corps noir à at C,6 SiO 2 diffusion SiO 2 layer Hemispherical reflectance,5,4,3,2, ZrB2 + SiO2 ZrB2 + SiO2 + + tth TT 5 C 3H ZrB2,2 Wavelength(µm) 2 2 ZrB 2 α,75 α ε ZrB 2 + SiO 2 APS α,85 α ε ZrB 2 + SiO 2 APS + TT α,8 ε( C),5 ε( C),7 ε( C),8 Partial protection against oxidation but loss of selectivity PAGE 7

18 BORIDES ZrB 2 ZrB 2 + SiO 2 SPPS SiO 2 Hemispherical reflectance Blackbody Rayonnement at C du corps noir à C,9 ZrB2,8 ZrB2 + Ludox SiO2,7,6,5,4,3,2, O-H,2 2 2 Wavelength (µm) Solar Spectre spectrum solaire ZrB 2 α,75 ε( C),5 α ε ZrB 2 + SiO 2 α,85 ε( C),75 PAGE 8

19 BORIDES ZrB 2 + SiO 2 SPPS + ageing ZrB 2 SiO 2 Hemispherical reflectance Solar Spectre spectrum solaire,9 Blackbody Rayonnement at du C corps noir à C ZrB2,8 ZrB2 + + Ludox SiO2,7 ZrB2 + ludox SiO2 + tth + TT 4 C 4 C,6,5,4,3,2,,2 Wavelength (µm) 2 2 ZrB 2 α,75 α ε ZrB 2 + SiO 2 α,85 α ε ZrB 2 + SiO 2 + annealing α,93 ε( C),5 ε( C),75 ε( C),87 Good protection against oxidation but loss of selectivity PAGE 9

20 OXIDES LaSrMnO 3 (LSM) Cr 2 O 3 Good resistance to oxidation + Promising selective trend Cr 2 O 3 after ageing α,9 ε( C),7 LSM after ageing α,9 ε( C),8 PAGE 2

21 CONCLUSION AND OUTLOOKS For Now MoSi 2 : bad cutting wavelength but improvement with annealing ZrB 2 : promising selectivity at room temperature but very sensible to oxidation Protection with a plasma-sprayed silica layer: good protection against oxidation but also increasing of emissivity Cr 2 O 3 : promising selectivity and resistance to oxidation Outlooks Decrease the thickness of the silica protective layer by using another coating process (PVD, sol-gel ) to preserve the transparency Decrease operating temperature, below C PAGE 2

22 Thank you! This project has received funding from the European Union s Horizon 22 research and innovation programme under grant agreement No DIRECTION DES APPLICATIONS MILITAIRES DÉPARTEMENT DES MATÉRIAUX SERVICE DÉVELOPPEMENT ET INDUSTRIALISATION info@capture-solar-energy.eu