inter seasonal storage solar thermal

Solar thermal energy in all its forms: solar heating, hot water, choosing a solar collector, solar concentration, ovens and solar cookers, solar energy storage by heat buffer, solar pool, air conditioning and solar cold ..
Aid, counseling, fixtures and examples of achievements ...
User avatar
AXEAU
I understand econologic
I understand econologic
posts: 197
Registration: 06/10/09, 09:04
Location: DROME
x 7




by AXEAU » 10/12/15, 21:21

Hello Lilian, I can not advise you too much for your storage, I made one by pebble tunnels under a workshop 60 m2 and the result is mixed but there are still details to settle. I used polycarbo. 4 mm for the sensor and I am aware that cells have cracked. So for the long term it is compulsory tempered glass. The concrete in the sensor I do not believe, it is too long to heat up it will not go much in storage. In my opinion the cheapest will be tablecloths polyet. to heat the pools in your insulating box.
Not easy to follow these two, interesting in theory but not seen concrete ...

jlg
0 x
User avatar
Obamot
Econologue expert
Econologue expert
posts: 28795
Registration: 22/08/09, 22:38
Location: regio genevesis
x 5583




by Obamot » 10/12/15, 21:31

Hey hey, hi AXEAU, who "those two there"? The biggest" loulou "here is still lilian07 Image

lilian07 wrote:really nice music ... and the rest ....

... oh well? Love you music >>> you play an instrument? What is the coolest song in those posted (to your taste)?
Last edited by Obamot the 10 / 12 / 15, 22: 00, 1 edited once.
0 x
lilian07
I posted 500 messages!
I posted 500 messages!
posts: 534
Registration: 15/11/15, 13:36
Location: Use
x 56




by lilian07 » 10/12/15, 21:58

Good evening Axeau ... interesting your experience .... I thought well HDPE swimming pool for the sensor but I can not get used to it I feel that it is fragile ... there is someone who made concrete storage sensor and its results look good:
[Url] http://basile.chez-alice.fr/capteur.htm
This type of sensor has much more concrete than mine (20cm) what I wanted to avoid, I want to limit myself to 2 / 3 cm so I do not think there really storage (20 liters of concrete / m² it's 50.000 J / ° with a winter sunshine at 500W it's a buffer of 100 seconds / ° ... I think it's minimal, it will cause a small phase shift of power towards the end of the day but that does not seem prejudicial ....)
Polycarbonate is a product that I find remarkable I have a good experience (anti UV MAKROLON is very strong and does not yellow at least in 17 years ...) I have a swimming pool completely made of polycarbonate of this type 6mm and it's solid ....
On the other hand I join you certainly less good than a window .... in any case I went through a trial of realization this winter of a concrete panel. I was more afraid of the limit of resistance of the concrete due to the small thickness, risk of cracking ....

Regarding 2 loulous ... it's true that they are funny sometimes .... they are passionate experts each in their field and I find them really exciting elsewhere but sometimes I'm not too much ....

They really contributed in their own way to move the project forward and that's what counts I believe ... whatever the way ....

I read the article about the pebble tunnel and I must say that this is precisely what made me believe in inter seasonal storage ... and then let's face it is the miracle of this century if the we could put the calories in the bottle ...

Can you tell me more about your TAG results ... it's important I think maybe for my project .... [/ url]
0 x
lilian07
I posted 500 messages!
I posted 500 messages!
posts: 534
Registration: 15/11/15, 13:36
Location: Use
x 56




by lilian07 » 10/12/15, 22:00

...Is that so ? Do you like music >>> do you play an instrument? What's the coolest song in those posted (to your liking)?

no I do not play an instrument but I appreciate the music in general, rather commercial as the last you told me ...

0 x
User avatar
Obamot
Econologue expert
Econologue expert
posts: 28795
Registration: 22/08/09, 22:38
Location: regio genevesis
x 5583




by Obamot » 10/12/15, 22:15

There are some who know the music so well that, as a bistro theorist, they hang over the construction technicians. Image

Too strong ! : Mrgreen:
Last edited by Obamot the 10 / 12 / 15, 22: 52, 1 edited once.
0 x
User avatar
AXEAU
I understand econologic
I understand econologic
posts: 197
Registration: 06/10/09, 09:04
Location: DROME
x 7




by AXEAU » 10/12/15, 22:51

I needed a workshop and took the opportunity to experiment. I do not really need to heat this room.
There are 4 tunnels connected in loop of tickelman. Between the 2 eme and the 3 on the input side I placed 1 probe at - 70 cms. 1 other than - 180 cms. On the same side, I have another one outside the excavations at - 300 cms. Incoming air could reach 86 ° to 300 m3 / h. for three months I have observed an increase in t ° of stock and a slight fall despite this contribution. I suspect the water infiltrations but I probed at the ends and I did not see anything. I stopped ventilating late seven to go live in the house next door. I think there are more calories in stock in the stock, I'll check.

jlgImagethe 4 January t 6 ° ext
jlg
0 x
dedeleco
Econologue expert
Econologue expert
posts: 9211
Registration: 16/01/10, 01:19
x 10




by dedeleco » 11/12/15, 00:42

"storage becomes less preponderant .." it all depends on the solar heat surface area captured in winter !!

delta penetration length:

https://fr.wikipedia.org/w/index.php?ti ... =100041470
delta = racincarrée (DxT / Pi)
Day night is period T = 86400seconds and
T / P = 27502s

whereas with a T = year T / Pi = 10,0382millions of seconds is 365 times less so that to store everything decreases in size by racincarrée (365) = 19 times smaller

On the other hand Axeau has a personal realization with reactions corresponding to his system of pebbles and air, but does not store long enough, because as for the earth, you need a large volume of pebbles, more than 1000m3 in a ball from summer to winter, and the pebbles benefit much less from the diffusion effect at the root of time. .

It is good to calculate simply and clearly verifiable by all to avoid predictable errors.

The time constant of the concrete according to its thickness is calculated and is measured also:
concrete capacity 2,4x0,88 = 2,112milleKJ / m3 ° C
and therefore 1cm 100 times less on 1m2 stores with DT = 36 ° C
2,1mille / 100x36 = 760KJoules

So because of 1kW of solar power max it takes 760seconds is 12,7 minutes to heat this cm of concrete !!
In summer with an 50% yield it is 500W and therefore 25 minutes.

In winter with 100W real it takes 10 times longer is 2hours7 minutes

It's a bit long in winter if the sun is short-lived.

20cm of concrete is obviously too thick 4h in summer and 20h in winter approximately.

In addition, the alternative diffusion length delta for the diffusivity of the concrete. of 0,54mm ^ 2 / s. for T = 1h = 3600s gives
with delta = racincarrée (DxT / Pi) = connected (0,54x3600 / Pi) = 24,8mm
which shows that in a few minutes we will heat only the surface of the delta concrete.
In a day rac24 times more 122mm so that the concrete 20cm is heated only over a little more than half of its thickness.

So a thin veil of concrete (or something else, glue, clay) a few mm, less than cm is a maximum, if you want a quick response time of a few minutes!

Finally, HDPE end hose can not be bent sharply in zigzag (otherwise it bends and closes), and the solution in round loops is easier.

As shown AXEAU low air flow or water (heat capacity XNUMxtimes more than the air by m3219), T can climb very high.
In winter less but everything depends on the thermal insulation of the panels.

It is very important to encrypt before realizing, to save time and reduce errors.
Even after scaled down to measure and check on a short time.

"concrete storage sensor and its results look good" is different, because here we do not need to store in the sensorbut with circulating water, it is stored underground in a much larger volume, and is much better preserved for long periods of time with diffusion as the square root of time, which does not exist long in a concrete wall.

We can manage to store from summer to winter walking at dlsc.ca from 2007 but if we do not respect the specific physical laws respected by dlsc.ca, we can not achieve it, very visible in some varied achievements !!

See it 5 years ago:
https://www.econologie.com/forums/post185931.html#185931

https://www.econologie.com/forums/post185949.html#185949

https://www.econologie.com/forums/post242882.html#242882
0 x
Thiazolinones neuro toxic to avoid them being everywhere, madness, killing at least ppm, bacteria and your neurons, which multiplies Alzheimer !!
The bees disappear pesticide, Roundup, and are killing us slowly. http://www.pollinis.org/petitions/petit ... noides.php
lilian07
I posted 500 messages!
I posted 500 messages!
posts: 534
Registration: 15/11/15, 13:36
Location: Use
x 56




by lilian07 » 11/12/15, 10:51

Given the calculations ... I understand that the solution of the solar concrete sensor works poorly ... 2h phase shift in winter is not suitable because I must reduce losses at this level to maximize the storage in earth ....
The radius of curvature of PE is 7,8 on its diameter so with a pitch of 10 cm it goes ....
Damage to concrete is a solid material cheap and very resistant .... and we can make a solar parking with ....
As I have more than one string to my bow I look in parallel the possibility of using insulated steel flat radiators in a box .... for now I can get the radiator steel m2 10 euros .....
The manufacturing is slightly faster and the overall cost is similar: 20 euros / m² ....
Another track, the use of steel tray cover in the bottom but I stumble on the way to use cheap pipes that carries the transfer of steel tray to the pipe (I see that the copper pipe overpriced).

I understand Obamot with the calculations of Bistrot .... if I had a little more time I could reread my copy ...
0 x
User avatar
Obamot
Econologue expert
Econologue expert
posts: 28795
Registration: 22/08/09, 22:38
Location: regio genevesis
x 5583




by Obamot » 11/12/15, 13:40

Why are eXergie calculations so "fins", precisely because we have to fight against monsters like thermodynamics.

... which must be an ally and not fight against, in short, it is the accumulation of mini-winnings here and there that will make all the difference of the overall system in the end.

So every time someone claims to use such and such a material or technique "for the sake of economy" it means that he loses the chance of real gain in the end. Like not using HDPE when there is nothing better value for money.

(And the list would be too long and everything has already been said.) Too bad to say and so little time, redouble useless ...
0 x
Christophe68
I learn econologic
I learn econologic
posts: 29
Registration: 27/06/15, 12:55
Location: Alsace




by Christophe68 » 11/12/15, 14:07

lilian07 wrote: I do not think that a calculation can get us out of the impasse (if there are expert masters it is now that we must show up or be silent forever ...)


I do not share this opinion at all!
Calculations are the foundation of all technological achievements. They are essentials to the project and determine its feasibility or not.
If your PAC works, it's good that a pro has calculated his shot. There are installers who think that calculations are not important. In general it ends badly, with an unusable installation, dissatisfied customers, lawsuits, and discredit of the profession.
I find it unfortunate that you do not perceive the importance.

lilian07 wrote:Effect to be obtained: given the building site, 100% objective of solar autonomy at term, consumption of the hamlet (4 apartments of about 100 m2) annual consumption of heating (attention CAP electrical consumption say COP = 3 on average PAC water / water):
20169 Kwh / year 7989 (HC) 12180 (HP)


Ok, so I'll be able to calculate your needs, it would have been wise to start there.
When in doubt, not knowing the actual COP of your PAC, I will take the worst assumption in our project (and more realistic, considering that installation in the correct air) that it has a COP of 4.
Which brings us back to a need of 80MW / h per year.
To cover this need, a calculation based on the thermal capacity of the earth, with the previously discussed conditions, leads us to the conclusion that it takes a 20m cylinder of diameter for 20m of height!
An approximate calculation (of which I spare you the details) of the earth heat dissipation, taking the most unfavorable case, the clay (according to the principle that when there is a missing data, we take the most unfavorable) gives us an annual loss of more than 300MW (sided) after 5 years.
The heat dissipation in this unfavorable hypothesis shows that the project is not feasible.
The losses being greater than the accumulated heat capacity, the earth will cool itself before the end of the winters, without it being necessary to draw anything from it.
The critical dimension is not reached here (which I estimate at the sided near 35m).
In the hypothesis that the clay is replaced by an insulating earth, one would find oneself above the critical dimension (which remains to be refined). But in this case, it will tighten drilling, which will result in a surplus of work that will make the operation unattractive.
In conclusion, the success or failure of the realization will depend on the nature of the soil, but it is in any case a very big job and we are far from having discovered the panacea.

This conclusion confirms the one I had already achieved some time ago on the other forum (see my first post on the thread).
Inter-season storage works well on a large scale with water.

Replacing your borehole system with a pond could work, but it will require an administrative authorization that I doubt you could get.

I still put a diagram for info.
Image

The top is covered with expanded polystyrene, (placed directly on the water) surmounted by a slab of mortar set with pipes, which serves both as ballast for weather resistance, while ensuring the function of cheap solar collector .
It's very close to Lilian's scheme.

With this configuration we have a surplus of thermal energy, with 400m² of solar collectors, and 2000m3 of water as buffer (80MW / h exploitable), able to cover in the faith the totality of the annual needs and probably the losses (which remains to determine precisely).

By curiosity, if Lilian could estimate the working time for the excavation of the basin?
0 x

 


  • Similar topics
    Replies
    views
    Last message

Back to "Solar thermal: solar collectors CESI, heating, hot water, stoves and solar cookers"

Who is online ?

Users browsing this forum : No registered users and 65 guests