Store thermal energy with palm oil? Natural Phase Change Material (PCM)

[Christophe]

It is not false
In any case, thank you for this Thesis: it looks like the bible of thermal storage ...

It will take me a good week to study it in detail!

[curieux80000]

Good luck then I wait for your conclusions and your opinion on the subject ... for my part I think that using palm oil creates too many limits ^^

[Christophe]

In high temperature yes, palm oil is not suitable ... but this subject has never concerned high temperatures!

If you want to store energy at high temperature: you must take advantage of the latent heat of evaporation or melting of the material in question.
This is the basic principle of the storage of phase change materials, most of which use the melting phase (easier to "manage" because the difference in volumes is much smaller).

But the ideal would be, physically speaking, to take advantage of the latent heat of fusion and evaporation in the desired range of use. That would be the top then!

Example with water:

1 gram of water passing from 99 to 100 ° C contains 540 times more energy than the same gram that goes from 98 to 99 ° C ...
1 gram of water that goes from -1 ° C to 0 ° C contains about 80 times more energy than the same gram that goes from 0 ° C to 1 ° C ...

Thus the water passes from 101 ° C to -1 ° C, releases 620 times more energy than the same quantity of water passes from 99 ° to 0 ° C ... and 87% of this energy is linked to its condensation...

So it's all about finding phase change materials that are compatible with the intended use!

And palm oil (melting point between 35 and 45 ° C) is quite a buffer for low temperature domestic heating!

[curieux80000]

I do not doubt what you advance, I might have created another subject, but as I came across this one ... me what I'm looking for it is precisely for the HIGH temperature x)

[Christophe]

In this case: molten salts ... this is what is used in concentration plants in Spain (and elsewhere)

[izentrop]

Hello,
I flew over this very interesting document.
What is sought is a thermal energy transfer oil to replace the current mineral oil used.
This requires an oil with the lowest possible vapor pressure and a flash point above 231 °, while having a lower cost.
We see page 67 that rapeseed oil is very suitable and page 69 the comparison with other oils.

[Christophe]

Ah it therefore concerns more heat transfer fluids, rather than storage materials by thermal buffering ...

These 2 properties are obviously linked but there are differences: a heat transfer fluid that changes phase implies a more complicated fluid transfer ... and the solid phase is obviously not usable (pump a solid is a little complicated. ..lol)

Steam heating networks (for example in New York ... that's why a lot of manholes smoke in movies or series ...) do they use water in its liquid form? Otherwise is what water condenses during the cycle (ideally it should be for the reason that I explained above ... otherwise not much interest to go through the vapor phase ...)?

[curieux80000]

At the risk of being mistaken for a fool ... can you explain to me what the flash point is? is it related to the evaporation temperature?
Moreover, the oil at high temperature is a curious product and me information, the oils are often used without parabolic cylindro solar plants, I would be curious to know what measures are taken to avoid incidents ...

Christophe a big part of the document is devoted to the storage of energy, I think you always have the means to find your happiness

[Christophe]

The flashpoint (also called fire point) concerns fuels only: it is the temperature from which the air, charged with vapors of this fuel, can ignite in the presence of an ignition source (flame or spark) ...

It is therefore logically lower than the temperature of boiling / evaporation (except exception kind bizarre fuels ???)

This is what makes the danger of gasoline compared to fuel in case of accident. The dieselisation of marine engines has saved many lives (there is no worse than the fire at sea ...) and made shipping much more secure

ps: ok should I dive seriously ...

[curieux80000]

So the plants currently using oil with temperatures around 400 ° C see more, are time bombs? ^^