Thermoelectric generator - candle and cold water

[wizkycho]

Conrad:

I agree with you 100%.  No OU of course but I like the challenge of finding a way to use these where we are already paying for the hot, or the cold.  One example a buddy of mine used it for was against his cold window in the winter, and the heat from his house inside, that he paid for anyway....he could light a large led bulb via a jt circuit and it was free.  The reverse might be true in the hot summer with the ac on.

To me, this is the fun of it....trying to find out new and unique ways to apply this technology.  It is not easy as the hot and cold sides are very close together but...with some good thinking, I know folks will find some great ways to use these.

Bill

1. burning choped trees, oil, gas, coal, using freones, even OVERIDIOTIC nuclear power... is somewhat nice (except latest) and brought us where we are now, but it is not affordable anymore cause it does massive damage to ultra thin atmosfere layer.

_{from political aspect and a plot of it - it is just not civilized, THA MAN has to have unquestionable (money fearless) right on food, air, drinking water, living space, heat in winter, shade in summer ...as
long ...one becomes MEGALOMANIAC (in any way - money ,rule power , control over other THA MAN, OVERwelth ... etc.))
THA MAN allways knows the neccesity of those unquestionable things - by natural experience - by pure mother physics, by pure existance. (doesn't have to be induced by anyone).
because there IS meassure, there IS shape , there IS light ...
MEGALOMANIACS es OVERMONEY and OVERCONTROL have ultra hazy effect on THA MAN and MEGALOMANIACS must be dragged back to it's boundaries and real humanoid meassurements.
OVERUNITY is their CURE and WE GOT TO TAKE THE POWER BACK there is much at stake.
I am COMUNIST (updated on v2) and whole universe and everything (even everyone) in it is COMUNISTIC, because there IS meassure, there IS shape , there IS light, there are GODS rules everyone must follow.
Christianity and Communism are same thing. kapitalism is meere destruction and violence                          (this is ultra close to the truth)}

Keep up good research causemany todays devices sadly haven't been updated (exp. Refrigerators nad coolers - Magnet Gadolinium interaction ...)
although more efficient, durable and less harmfull technologies exists.
Maybe you could try to use gadolinium in cooling peltier.
... but as things looks today, (hope I'm wrong), preferably choose solving first "issue".

wiz

[wings]

now closed    but
using wayback machine:


http://web.archive.org/web/20060928004514/http://www.varmaraf.is/engl/prod.htm

http://solar-club.web.cern.ch/solar-club/solpv/autres/thermoPV.html

see also:


http://www.globalte.com/index.php?pageId=2&sId=31
http://www.azonano.com/article.aspx?ArticleID=1685

[conradelektro]

@wings:  thank you for the very interesting links.

May be someone knows this:

Many Peltier element specifications mention a maximum useful temperature difference of about 70° Centigrade.

Is this a limit for all Peltier elements? (A limit for the Seebeck effect?)

Many Peltier elements can operate at high temperatures, e.g. 200° or 1000" Centigrade. But at this high temperatures, does the limit of "70° temperature difference" still apply?

This would mean, if a Peltier element is operated at e.g. 200° Centigrade, it would not help (as far as efficiency is concerned) to keep the cold side at a lower temperature than 130° Centigrade?

Greetings, Conrad

[wings]

@wings:  thank you for the very interesting links.

May be someone knows this:

Many Peltier element specifications mention a maximum useful temperature difference of about 70° Centigrade.

Is this a limit for all Peltier elements? (A limit for the Seebeck effect?)

Many Peltier elements can operate at high temperatures, e.g. 200° or 1000" Centigrade. But at this high temperatures, does the limit of "70° temperature difference" still apply?

This would mean, if a Peltier element is operated at e.g. 200° Centigrade, it would not help (as far as efficiency is concerned) to keep the cold side at a lower temperature than 130° Centigrade?

Greetings, Conrad

I am not expert in this field but IMO the standard Peltier modules have 70° -75° maximum difference for cooling purpose (you apply current and the max temperature difference is 70°- 75°).
http://crystalltherm.com/thermomodules_s.html

The generator type have no reference to differential temperature.
http://crystalltherm.com/powergenerating.html

The maximum operating temperature 200° is related to the production process and in particular to the solder

http://crystalltherm.com/downloads/Products_Catalogue_2011.pdf
http://crystalltherm.com/downloads/New%20Modules%20Assembling%20Technology%20by%20Crystal%20Ltd.pdf


600°down to 50° - 678w
http://tes-ne.com/PDF/Panel%20E%20ACPACPO.pdf


the old style use direct gas flame
http://www.douglas-self.com/MUSEUM/POWER/thermoelectric/thermoelectric.htm

new from BMW and other
http://green.autoblog.com/2008/08/11/researchers-work-to-turn-cars-exhaust-into-power/
http://www.tellurex.com/products/tPOD1.php
http://tes-ne.com/English/01_home_e.html





 

[conradelektro]

@wings: again, nice links, I particularly like the lamp charger http://www.tellurex.com/products/tPOD1.php

I did some more experiments with my candle light based on a cold water container and two Peltier elements (see the photos).

I measured the Voltage and current draw under load when driving a Joule Thief which in turn lights a 1W 220 V LED bulb:

initially: 1,5Volt - 140 mA --> ~ 0,2 Watt

after 10 minutes: 1,3 Volt - 100 mA --> ~ 0,13 Watt

Why did the output drop? After some useless tinkering I stirred the cold water in the container with a spoon, and the output went up again to about 0,2 Watt. I could do this cycle several times.

I seems my contraption has a severe problem with heat dissipation from the two Peltier elements (cold side) into the water. When stirring the heat is transported away more efficiently, therefore more output.

I studied a bit the various manufacturer web sites (e.g. as provided by Wings, see http://www.customthermoelectric.com/TEG_install.html) and now I think one has to do the following:

- there has to be a certain pressure between the cooling/heating plate and the ceramic plates of the Peltier element in order to increase heat transfer

- some filler (thermal interface material) between ceramic plates and cooling/heating plate is necessary, again to increase heat transfer

I ordered some heat transfer paste (copper based) and have to come up with a design that allows to press the cooling / heating plate against the ceramic plates of the Peltier element. Have to look for a good heat isolation material.

People starting with experiments should take this into consideration.

(Of course, this was all known for a long time, but I did not know it. And therefore my contraption has such a poor output.)

Greetings, Conrad