Heat recovery with salt!!

[Christophe]

Buy yourself some neurons...

[sicetaitsimple]

Buy yourself some neurons...

Very good answer! Well, you must have confused "phase change salts" with beef white, widely used in Belgium for fries and which actually melts at a fairly low temperature.

[fracass]

He talks about rewetting the salt, so it will be a chemical adsorption system rather, not pcm.
You have to see which salts heat up when moistened, naoh, koh, etc.
In summer you dry the brothel, in winter you slowly re-wet as needed.

Ps: can't stop the constant invectives, on one side as on the other, moreover, it makes reading the threads...disjointed.

[sicetaitsimple]

He talks about rewetting the salt, so it will be a chemical adsorption system rather, not pcm.
You have to see which salts heat up when moistened, naoh, koh, etc.

Well seen, it could be a thermochemical route.
Not sure that it is very prudent, nor authorized, to install this in your cellar...

[Obamot]

To heat a building, we are talking about a large volume of sodium, so we have to see the price of another type of "special" salt (if it exists and what its properties are), which would eventually be used to its exceptional endothermic (even eutectic) properties.

For sodium, these are well known and to be related to its change of state (solid => liquid => gaseous) its melting point is 97,8°C, it ignites spontaneously on contact with air from 140⁰C and boiling occurs at 883°C... Gift: in contact with water, it releases dihydrogen which can explode in the presence of air.

It's hot potato to temper a house

An alcoholate? What thermal properties would it have?? To try in the pool at 'Tophe

[Obamot]

PS: where then in the case quoted by Bellad, it would be necessary
a salt which possibly has a first endothermic phase, but in any case a state to be defined allowing progressive storage, followed by an exothermic phase which would release the heat 'on demand'?
Do not know.

[fracass]

As said above, thermochemical (rehydration of a compound like cuso4, naoh...) exothermic, or adsorption (solid/gas) like ammonia on silica gel or other. The difference with the pcm is that for a thermochemical storage the time lag can be practically infinite, whereas on a pcm it is necessary to keep the temperature

[reinoso]

PS: where then in the case quoted by Bellad, it would be necessary
a salt which possibly has a first endothermic phase, but in any case a state to be defined allowing progressive storage, followed by an exothermic phase which would release the heat 'on demand'?
Do not know.

if you consider a pool of salt water exposed to the sun with high concentrations of salt, the highest temperatures will be in
the bottom of the pond, thus limiting heat loss.
it is then sufficient to provide an exchanger at the bottom to recover the calories

[sicetaitsimple]

My God...

[sicetaitsimple]

For those who are interested and who have a little time, a thesis (229 pages) on the subject.
The substrate in question is the result of the insertion of magnesium sulphate (MgSO4) into a zeolite.
Well, from what I have read and understood, the results are not extraordinary...

https://theses.hal.science/tel-00665612/file/these.pdf