1. Phase Change Materials used for thermal
control of systems - Applications, technology,
developments
Nicolas Nutal
TTC conference: Smart Materials for Smart Products
30th January 2013

2. Slideshow organisation
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What’s a Phase Change Material (PCM)?
Applications of PCM
Conclusions
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Phase Change Materials used for thermal control of systems - Applications, technology, developments

3. Slideshow organisation
©CRM Group - All rights reserved for all countries. Cannot be disclosed, used, or reproduced without prior written specific
authorization of CRM Group - CONFIDENTIAL - Privileged Information - CRM Group proprietary information.
What’s a Phase Change Material (PCM)?
Applications of PCM
Conclusions
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Phase Change Materials used for thermal control of systems - Applications, technology, developments

4. Definition (1/3)
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Thermal energy storage?
What’s a Phase Change Material (PCM)?
Liquid state
Specific
Solid state
heat
Gazeous state
Solid/liquid
Latent heat Solid/solid
Liquid/gazeous
Solid/gazeous
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Phase Change Materials used for thermal control of systems - Applications, technology, developments

5. Definition (2/3)
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Storage mechanism
What’s a Phase Change Material (PCM)?
Solid state Phase change Liquid state
(constant temperature)
Temperature
Melting
(heat storage)
Solidification
(heat release)
Energy content
Specific heat Latent heat Specific heat
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Phase Change Materials used for thermal control of systems - Applications, technology, developments

6. Definition (3/3)
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PCM are compounds that store/release large amounts of heat
What’s a Phase Change Material (PCM)?
while undergoing a phase change at a constant temperature
Water
Melting temperature : ~0˚C => latent heat : 333kJ/kg
Heating water from 1 to 80˚C => specific heat : 332kJ/kg
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Phase Change Materials used for thermal control of systems - Applications, technology, developments

7. What’s a Phase Change Material (PCM)?
Latent heat density [kJ/L]
Paraffin
Paraffin : CH3(CH2)nCH3
Ex : n-hexadecane, n-eicosane…
Organic PCM compounds (1/3)
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8. What’s a Phase Change Material (PCM)?
Latent heat density [kJ/L]
Fatty acids
Fatty acids : CH3(CH2)nCOOH
Ex : Caprylic acid, Capric acid…
Organic PCM compounds (2/3)
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9. What’s a Phase Change Material (PCM)?
Latent heat density [kJ/L]
Paraffines
Sugar
alcohols
Ex : Xylitol, Galactitol…
Organic PCM compounds (3/3)
Sugar alcohol : HOCH2(CH(OH))nCH2OH
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10. Inorganic PCM compounds (1/2)
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Hydrated salt (dehydration) :
What’s a Phase Change Material (PCM)?
Ex : CaCl2.6H2O, LiNO3.2H2O
Salt hydrates
AB·nH2O AB·mH2O +(n-m)H2O
AB·nH2O AB + nH2O
Latent heat density [kJ/L]
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Phase Change Materials used for thermal control of systems - Applications, technology, developments

11. What’s a Phase Change Material (PCM)?
Latent heat density [kJ/L]
Pure salts
Nitrates
Ex : KNO3, KOH, NaCl…
Hydroxides
Chlorides
Inorganic PCM compounds (2/2)
Carbonates
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Fluorides
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12. Eutectic PCM compounds
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Eutectics : mixtures of two or more constituents, which solidify
What’s a Phase Change Material (PCM)?
simultaneously out of the liquid at a minimum freezing point
Ex :
Salt and water : NaCl + H2O (22.4/77.6) (-21°C)
Salt and hydrated salt : CaCl2 + MgCl2.6H2O (50/50) (25°C)
Salts : KNO3 + NaNO3 (54/46) (222°C)
Organics : Miristic acid + Capric acid (34/66) (24°C)
Metals : CuZnSi (74/19/7) (765°C)
Huge number of mixtures => wide temperature and energy storage ranges
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Phase Change Materials used for thermal control of systems - Applications, technology, developments

13. Typical PCM problems (1/4)
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But…
What’s a Phase Change Material (PCM)?
Phase separation (hydrated salts (ex: CaCl2.6H2O))
Expected behaviour (quick transformation) Real behaviour (slow transformation)
CaCl2
CaCl2.6H2O
+ 6 H2O
(solid)
(solution)
CaCl2 poor (solution) CaCl2.4H2O (solid)
⇒ Macroscopic separation => no reversibility => limited effectiveness
Solutions : Gelling additive (prevent separation), increase PCM viscosity,
mixing, other composition (more water)…
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Phase Change Materials used for thermal control of systems - Applications, technology, developments

14. Typical PCM problems (2/4)
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But…
What’s a Phase Change Material (PCM)?
Sub-cooling
Ideal behaviour
Real
⇒ Temperature not constant, lower temperature required to regenerate PCM
Solutions : Nucleators (compounds which have the similar melting
temperatures and crystal structures) or cold-finger
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Phase Change Materials used for thermal control of systems - Applications, technology, developments

15. Typical PCM problems (3/4)
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But…
What’s a Phase Change Material (PCM)?
Poor thermal conductivity
⇒ Heat transfer problems + low transformation rate
Solution : Adding metallic fins or foams
Compatibility with other materials
⇒ Corrosion of metals (inorganic PCM), loss of stability of plastics (organic
PCM)...
Solutions : Adequate containment after compatibility tests
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Phase Change Materials used for thermal control of systems - Applications, technology, developments

16. Typical PCM problems (4/4)
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But…
What’s a Phase Change Material (PCM)?
Leakage and volume change
⇒ Containment destruction
Solutions :
Macro-encapsulation Micro-encapsulation
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Phase Change Materials used for thermal control of systems - Applications, technology, developments

17. Slideshow organisation
©CRM Group - All rights reserved for all countries. Cannot be disclosed, used, or reproduced without prior written specific
authorization of CRM Group - CONFIDENTIAL - Privileged Information - CRM Group proprietary information.
What’s a Phase Change Material (PCM)?
Applications of PCM (at CRM)
Thermal comfort in buildings
Satellite
Satellites launcher
Wood stove
Others...
Conclusions
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Phase Change Materials used for thermal control of systems - Applications, technology, developments

18. Thermal comfort - Low inertia buildings (1/3)
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Frame :
Context : In low thermal inertia buildings, daily walls temperature
Applications of PCM's
fluctuations are high
⇒ Thermal comfort is poor
⇒ Heating/cooling devices are used to compensate (€€€)
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Phase Change Materials used for thermal control of systems - Applications, technology, developments

19. Thermal comfort - Low inertia buildings (2/3)
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Objective : develop metallic structures with PCM to increase
thermal inertia (thermal comfort) in low thermal inertia buildings
Test configuration :
Applications of PCM's
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Phase Change Materials used for thermal control of systems - Applications, technology, developments

20. Thermal comfort - Low inertia buildings (3/3)
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Detailed analysis of a specific configuration (~200kg of PCM) :
Applications of PCM's
PCM allows to
increase thermal
comfort ☺
More comfortable temperatures reached in PCM building
Temperature fluctuations inside the PCM building (~6˚C) are lower than
in the ref building (~13˚C)
Estimated return : 5 to 9 years
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Phase Change Materials used for thermal control of systems - Applications, technology, developments

21. Satellite (1/3)
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Frame :
Context : Small satellites (<100kg) need constant temperature
Applications of PCM's
(electronic parts) but have low thermal inertia (low weight)
⇒ When electronic is on/off, satellite’s temperature fluctuate
⇒ Radiators and resistances are used to compensate : Heavy
systems (€€€)
⇒ Objective : develop a PCM heat storage device to increase
thermal inertia but with limited weight increase
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Phase Change Materials used for thermal control of systems - Applications, technology, developments

22. Applications of PCM's Satellite (2/3)
Heat storage device
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PCM selected : n-octadecane (~28˚C), volume : 210ml
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23. Satellite (3/3)
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Heating/cooling cycles
With PCM
Without PCM
Applications of PCM's
PCM allows to increase thermal inertia ☺
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Phase Change Materials used for thermal control of systems - Applications, technology, developments

24. Launcher
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Frame :
Context : VEB is the brain of the launcher, has low thermal
Applications of PCM's
inertia and needs almost constant temperature (electronic parts)
⇒ Thermal control is passive => extra mass (+€€€) (1)
⇒ Due to the temperature increase, it is not feasible to place
satellites in different orbits (2)
⇒ Objective : develop a PCM heat storage device to solve both
problems by increasing thermal inertia with limited weight
increase
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Phase Change Materials used for thermal control of systems - Applications, technology, developments

25. Wood stove
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Frame :
Objective : develop modules with PCM to store heat in high
temperature range and to improve efficiency of wood stoves
Applications of PCM's
Tf: 579.5oC heating
Tf: 569.7oC cooling
Hf: 711.4 kJ/kg
Metallic alloy (Al75-Si25).
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Phase Change Materials used for thermal control of systems - Applications, technology, developments

26. Other applications at CRM
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Heat losses in steel industry :
Steel making converter (1600˚C), High temperature slags (1200-
1600˚C), Coke (1050˚C)…
Applications of PCM's
Only 17% of heat losses is recovered
=> much work to do!
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Phase Change Materials used for thermal control of systems - Applications, technology, developments

27. A lot more applications...
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Solar thermal power plants
Clothing
Trucks
Applications of PCM's
Blood transfer
PCM cup
Pocket heaters
Medical pouches
....
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Phase Change Materials used for thermal control of systems - Applications, technology, developments

28. Slideshow organisation
©CRM Group - All rights reserved for all countries. Cannot be disclosed, used, or reproduced without prior written specific
authorization of CRM Group - CONFIDENTIAL - Privileged Information - CRM Group proprietary information.
What’s a Phase Change Material (PCM)?
Applications of PCM
Conclusions
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Phase Change Materials used for thermal control of systems - Applications, technology, developments

29. What’s to be remembered?
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PCM are a cheap, dense and easy way to store energy/heat
PCM compounds are divided in a few families, each of them has
its particular applications
Almost all the problems met with PCM (low thermal conductivity,
Conclusions
high volume change...) can be solved with simple solutions
With a few developments, PCM can find a lot of applications,
from the buildings, through industries and even to space!
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Phase Change Materials used for thermal control of systems - Applications, technology, developments

30. Special thanks to :
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authorization of CRM Group - CONFIDENTIAL - Privileged Information - CRM Group proprietary information.
- Jean-Paul Collette (Walopt)
- Romain Peyrou-Lauga (ESA)
- Boris Defays (ARCADIS)
- Mary-Hélène Delvaux (CORI)
- Jean Lagneau (CRIBC)
- Anthony Massin (Bodart et Gonay)
- Jean Crahay, Maïwenn Larnicol and Yves Hardy (CRM Group)
Thank you for your attention!
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Phase Change Materials used for thermal control of systems - Applications, technology, developments