Qualifizierung von Flüssigsalz-Komponenten in der DLR-Anlage TESIS

Transcription

1 Qualifizierung von Flüssigsalz-Komponenten in der DLR-Anlage TESIS Dr. Thomas Bauer, Dr. Christian Odenthal, Dr. Alexander Bonk, Dr. Antje Seitz Deutsches Zentrum für Luft- und Raumfahrt (DLR) Institut für Technische Thermodynamik, Stuttgart/Köln Köln, DLR

2 Slide 2 > Thermal Energy Storage > Thomas Bauer Contents - Overview of high-temperature TES technology - Molten salt TES technology - Material qualification aspects - Qualification in the molten salt plant TESIS - Summary

3 Slide 3 > Thermal Energy Storage > Thomas Bauer Institute of Engineering Thermodynamics Prof. André Thess, Director Jörg Piskurek, Vice Director Computational Electrochemistry Prof. A. Latz Electrochemical Energy Technology Prof. A. Friedrich Energy System Integration Prof. A. Thess Prof. J. Kallo Thermal Process Technology Dr. A. Seitz Systems Analysis and Technology Assessment Dr. Ch. Schillings / C. Hoyer-Klick ~ 190 staff in Stuttgart, Köln, Hamburg, and Ulm ~ 20 Mio. EUR annual budget with 50% third party funding We are the scientific pathfinder for the energy storage industry

4 Slide 4 > Thermal Energy Storage > Thomas Bauer Locations and employees DLR: Approx employees across 33 institutes and facilities at 16 sites. Offices in Brussels, Paris, Tokyo and Washington. Thermal energy storage group: - Stuttgart - Cologne Juelich Cologne Bonn Bremen Trauen Braunschweig Lampoldshausen Stade Hamburg Goettingen Neustrelitz Berlin Stuttgart Augsburg Oberpfaffenhofen Weilheim

5 Slide 5 > Thermal Energy Storage > Thomas Bauer Department Thermal Process Technology Dr. Antje Seitz Thermal Power Plant Components Thermal Systems for Fluids Thermal Systems with Phase Change Thermochemical Systems Alternative Fuels Dr. Stefan Zunft Dr. Thomas Bauer Dr. Dan Bauer Dr. Marc Linder Dr. Uwe Dietrich Regenerator and solid media storage High temperature heat exchangers Molten salt storage Latent heat storage Thermochemical Storage Thermal Upgrade H2-Storage Regenerative power in liquid hydrocarbons Technoeconomic evaluation

6 Slide 6 > Thermal Energy Storage > Thomas Bauer Overview of high-temperature TES technology Commercial technologies - Sensible heat storage in solids - Regenerator (1 bar, 1200 C) - Sensible heat storage in liquids - Steam Accumulator (40 bar, 250 C) - Thermal oil (1 bar, 300 C) - Molten salt (1 bar, 550 C) Regenerator/Cowper Steam accumulator/ruth's, Source: PS10 Molten Salt, Source: Andasol 1

7 Slide 7 > Thermal Energy Storage > Thomas Bauer Installed global capacity for grid-connected storage Source: - CSP grid-connected molten salt storage power > 1500 MW el in CSP grid-connected molten salt storage capacity > 30 GWh th in 2015

8 Slide 8 > Thermal Energy Storage > Thomas Bauer Focus of the DLR group System aspects Material aspects Process technology (Upscaling) Components

9 Slide 9 > Thermal Energy Storage > Thomas Bauer Characteristics of molten salt - Liquid state over large temperature range (e.g., Solar Salt C) - Ability to dissolve a relatively large amount of compounds (corrosion may occur) - Low vapor pressure and high stability - Low viscosity - High heat capacity per unit volume - Several salts are inexpensive/available - Often nontoxic, nonflammable and no explosive phases Salt crystals at room temperature Nitrate salt in a glass beaker Model of molten Sodium Chloride (Source: Baudis 2001)

10 Slide 10 > Thermal Energy Storage > Thomas Bauer Classification of alkali nitrate/nitrite salt examples Ion No. System Classification Example System with Tm 2 Single salt NaNO C; KNO C 3 Binary system, common anion K,Na//NO C ( Solar Salt system) 3 Binary system, common cation Na//NO 2,NO C 4 Ternary additive, common anion Ca,K,Na//NO 3 ~130 C (HitecXL) 4 Ternary additive, common anion K,Li,Na//NO 3 ~120 C (LiNaK) 4 Ternary reciprocal K,Na//NO 2,NO C (Hitec) 5 Quaternary additive, com. anion Ca,K,Li,Na//NO C 5 Quaternary reciprocal Li,Na,K//NO 2,NO 3 80 C 6 Quinary reciprocal Ca,Li,Na,K//NO 2,NO 3 ~70 C (DLR) (examined systems at DLR)

11 Steel Slide 11 > Thermal Energy Storage > Thomas Bauer Ideal chemistry of molten nitrate salts N 2 O 2 Na + K + NO 3 - Cation Anion

12 Steel Slide 12 > Thermal Energy Storage > Thomas Bauer Chemistry of molten nitrate salts with side reactions NO NO 2 N 2 O 2 CO 2 H 2 O Na + K + NO 3 - OH - O 2- CrO 2- CO 2-4 NO Cation Anion Sources: Federsel, K., Wortmann, J., Ladenberger, M. (2015) Energy Procedia, 69, pp Nissen, D.A., Meeker, D.E. (1983), Inorganic Chemistry, 22, pp Bradshaw, R.W., Dawson, D.B., De La Rosa, W., et al. (2002) Report SAND Bauer, T., Pfleger, N., Laing, D., et al. (2013) Chapter 20 in "Molten Salt Chemistry: from Lab to Applications"

13 Slide 13 > Thermal Energy Storage > Thomas Bauer DLR Material research #1 - Development of alternative salt mixtures with - reduced melting temperature < 140 ºC - thermal stability up to 700 ºC - Investigation of the decomposition mechanisms of nitrates with parameters such as... - Temperature - Salt mixture type - Atmospheric conditions Nitrate salt test rig Chloride salt test rig Thermogravimetry evolved gas analysis for stability tests Phase diagram including HITEC salt mixture Halogen salt with (left) and without (right) decomposition during dehydration

14 Slide 14 > Thermal Energy Storage > Thomas Bauer DLR Material research #2 - Interactions of molten salts with - metals / corrosion - natural stone / filler materials - Thermal properties determination - Post-analysis of salt composition Metallic corrosion in molten salt flow Quartzite with and without molten salt UV-VIS Spectrometer for salt composition Ion chromatography for salt composition Rheometer for viscosity values DSC for heat capacity values

15 Commercial two-tank technology Direct storage system for solar tower systems (Storage medium = HTF) Indirect storage system for parabolic trough systems (Storage medium receiver HTF)

16 Slide 17 > Thermal Energy Storage > Thomas Bauer TESIS:store - storage test section Aim: - Demonstration of single-tank thermocline concept with filler Operating Parameters: - Operation temperature C with NaNO 2, NaNO 3, Ca(NO 3 ) 2, KNO 3, LiNO 3 salt mixtures - Storage capacity (ΔT=250K): 200 kwh/m³ with 20 m³ and 4 kg/s Research topics: - Heat / mass transfer, thermomechanics - Material compatibility - Operational aspects, scaling issues - System integration Potential - Previous examination at Sandia estimate % cost reduction

17 Slide 18 > Thermal Energy Storage > Thomas Bauer TESIS:store - storage test section

18 Slide 19 > Thermal Energy Storage > Thomas Bauer TESIS:com - component test-bench Aim: Test and qualification of molten salt components for research and industry (e.g. valves, receiver tubes, measurement & control) Examine operational molten salt aspects (e.g. freezing events) Operating Parameters: Temperature of C with NaNO 2,NaNO 3,Ca(NO 3 ) 2,KNO 3,LiNO 3 max. thermal gradient 50 K/s max. mass flow of 8 kg/s max. heating power 420 kw max. cooling power 420 kw

19 Slide 20 > Thermal Energy Storage > Thomas Bauer TESIS:com - component test-bench

20 Slide 21 > Thermal Energy Storage > Thomas Bauer Test facility for thermal energy storage in molten salt (TESIS)

21 Slide 22 > Thermal Energy Storage > Thomas Bauer Qualification aspects - Material - Molten salt quality - Metallic corrosion - Accuracy of thermal properties - Instrumentation - Reliability (e.g., thermal shock, leakage/seals, corrosion, freezing issues) - Accuracy (e.g. volume flow, temperature, level, pressure) - Storage systems - Boundary condition (with/without salt melting, auxiliary systems, heat exchanger, steam generator) - Thermal and hydraulic performance (losses, gradients)

22 Thank you for your attention! Institute of Engineering Thermodynamics (ITT), Köln