Thermal buffer: avoid surface evaporation of hot water with oil or other blocking product?

[Christophe]

No I'm not sure but what is the problem if there is wax in contact with the exchangers? Which is solid or liquid?

The potential problem, with solid wax which would have deposited on an exchanger which is "cold" by nature, is that you will reduce (physically, by reducing the passage sections) the natural convection flows of the water in your buffer between the tubes and fins of your exchanger, and therefore create a "more or less cold bubble" around it.

This would be especially valid in the case of dynamic heat exchangers with double flow, type with plate (internal fouling)... but in the case of a semi static exchanger as it is the case here the reduced surface of exchange would be frankly very very very small...

I remind you that I intend to put 3 to 4 mm of wax on the surface approximately...

[sicetaitsimple]

You asked the question "No I'm not sure but what is the problem if there is wax in contact with the exchangers? Which is solid or liquid?"

I tried to answer it in the case of solid wax, and I did not speak of a reduced exchange surface, but of a reduction in convection flow rates. Do what you want with my answer.
But personally, during my few professional experiences, I have never seen an exchanger whatever it is better or as much exchange when it was dirty as when it was clean .....

[Christophe]

You know I had understood that it was a possible fouling problem but you don't understand what in 3 to 4 mm?



And Seb answered the question: liquid wax exchanges heat better than water...the solid probably not...to be checked.

In any case, the possibly "dirty" surface will be small!

[sicetaitsimple]

In any case, the possibly "dirty" surface will be small!

Reread with your finger...I didn't talk about clogged exchange surfaces, but about reducing the convection flow rates of the water in your buffer circulating "through" your submerged exchangers.
But if "SEB answered the question", I don't see why you insist. Problem fixed....

[Christophe]

I understood eh (fouling reduces convection) but how does an anti-evaporation cover reduce convection movements UNDER the cover?

On the contrary, it increases the temperature of the body of water near the surface...where the heat exchanges are...

You saw the video ? With wax there is less surface convection but it still exists: so it still exists under the cover...

[Christophe]

But if "SEB answered the question", I don't see why you insist. Problem fixed....

Response that AD 44 had obviously not read...but who is insisting on this? You or me ?

[SebastianL]

The thermal conductivity of liquid paraffin is low (0.152 W/mK)
The thermal conductivity of solid paraffin is low (0.2 W/mK)
The thermal conductivity of liquid water is lower (0.6 W/mK)

The convection will be slowed down a little because the temperature delta will be lower, however this "acceleration" of convection is a pure loss and the useful convection is produced by the Water - exchanger temperature delta.

I don't see the point of putting > 1mm of wax. The thinner it is, the more it is able to take on a domed shape to absorb the volume of water that descends and the volume of vapor created by the descent of the roof.

[Obamot]

[•••] the function of these "drainers" was more of a "vacuum breaker" function
Well, if it drains well, that's the main thing...

[•••] but I just didn't know the term vacuum breakage...more air vacuums (aspirair?) than vacuum breakage!

In some cases, it goes from one to the other, and there is a name that sums it up:
"ballbuster" I am fine too.

[sicetaitsimple]

The thermal conductivity of liquid paraffin is low (0.152 W/mK)
The thermal conductivity of solid paraffin is low (0.2 W/mK)
The thermal conductivity of liquid water is lower (0.6 W/mK)

Christophe 3 posts above: "And Seb answered the question: liquid wax exchanges heat better than water."
Who to trust?

[Christophe]

Well, I must have misunderstood his first answer? Don't want to look for it, it's not a big deal...given the low volume of wax...