Heat transfer firebrick and air?

[clasou]

Re, you can take pictures of your installation, see if we are talking about the same thing.
Ah yes it is sure that in cheap philosophy, thick copper bars, it will help.
Hello return on investment.
How can you say take a good stove, it makes business bad.
Because at no time do you care to know the current consumption, insulation the current means of heating, when a bed is built in it and you will see that when you talk about soot, you have to review your subject.
As said nlc, the worst is that when it annoys you you hide the answers, besides I wonder if you would not be an experimental robot, because to see the turn of your answers, I have the impression of having the answers of online translators, that is to say without any humanity.
a + claude

[dedeleco]

Clasou, barely legible given his spelling, refusing to understand the thermal bases, will have surprises, like the other with his magnets, to get tired for nothing !!!!

In fact copper is not mandatory, aluminum, iron, but in central heating or sanitary for water we put a lot more !!!!

but it's less dangerous than telling your kids that

AIDS as such cannot be transmitted

https://www.econologie.com/forums/post227389.html#227389

as a rejection and negation of realities.

Apart from being asphyxiated by invisible and odorless CO if leaks between the bricks !!

110
110
110

[clasou]

I'm waiting foto your accomplishments with impatience.
a + claude

[dedeleco]

My thermal mass is my not young houses, of a lot of tons of concrete blocks and plasterboard, with inertia of more than a day !!

[Woodcutter]

[plasmanu]

Dedicated your thermal mass you get it by brainstorming.
Or by heating your fingers on the keyboard?
Try the human heat: 100w since you are several it can heat a lot

[chatelot16]

the misunderstanding begins from the first message

brick heat capacity 840 d / kg / ° C

forgetting the / ° C we find all kinds of comparable material

the advantage of the refractory brick is that it can be raised very high: why not 800 ° C: and to go back down to 20 ° C it is 720 ° C apart so 720 x 840 = 604800 XNUMX J / kg of brick

materials with the same heat capacity but only able to rise to 80 ° C will store much less

a material that is too good a conductor of heat like metal will store a lot, but will quickly restore the stored heat unless it is wrapped in insulation

brick is poor conductor of heat: the interior part of the hearth will go up to 800 ° C or 1000 ° C and store a lot, but the middle of brick will heat less ... and the outside face even less ... the calculation of the total stored heat will therefore be more complicated

for an exact calculation you can try to follow the link of dedeleco, but you did not leave the hostel

for a pifometric calculation you can say that half the thickness of the brick rises at high temperature and that the outside half remains cold and does not store anything

the problem is rather to choose the right thickness of brick: too thin it stores little ... too thick it is a bad conductor: the interior temperature rises high, but the heat comes out too slowly: you should not increase that thickness, but also the surface

and that is why some prefer to store heat in a water tank: the hot water tank is isolated: the heat does not come out when we want to store it ... and it comes out quickly when we circulate it. water where it is needed

edit error 40J / kg / ° C instead of 840J / kg / ° C

[dedeleco]

I had set the values ​​of diffusion length as a function of time, and if we want to store like this, it must be used with large bricks, or breeze blocks, heated on all their faces, of thickness double the length of diffusion !!
https://www.econologie.com/forums/post228505.html#228505

The quantity stored is proportional to the mass multiplied by the difference of T: delta T.

The storage time is linked to the exchange surfaces multiplied by the deltaT and inversely to the square of the diffusion thickness to reach the center of the mass (or of each brick) and the same to slowly destock to the air outside the brick, which requires less surface area and a greater thickness of the external covering, to keep it long.

We "leave the hostel" using the diffusion time as the square of the thickness, which gives the essential without complicated calculations !!
http://fr.wikipedia.org/wiki/Conduction_thermique
http://fr.wikipedia.org/wiki/Diffusivit%C3%A9_thermique

too thin it stores little ... too thick it's bad conductor

is to modify at the end is quick to store and lose, and the quantity stored is proportional to the total mass of bricks of all thicknesses.
and thick is long in time to store and destock but also good conductor over long time.

The water tank is simpler to understand, in appearance, but identical, in fact and unable to rise above 100 ° C and piping and complications of water (copper).
The circulation of hot gases is also simple to carry out.

If we want to quickly store the heat of a rapid fire and return it slowly, we must juggle with these principles, that is to say, quantities stored, surfaces and thicknesses of brick layers, with time as the square of thicknesses.

4 tight bricks to cross takes 4x4 = 16 times longer to exit by diffusion !!

So we go from 1h to 16h

and 5 tight bricks takes 5x5 = 25 times longer to come out.


For this same reason, a large chicken (or roast or turkey) takes a while to cook in its center, proportional to the square of its thickness, just until the heat reaches its center. without changing the cooking power as much.
Otherwise, we will burn it on its surface, keeping it cold and raw in its center.

I hope this concrete image is clearer.
But it's the same for bricks and a mass stove.

.