Stirling Generator + + Rocket Stove

[xboxman4]

http://www.tegmart.com/thermoelectric-modules/22-watt-teg-power-module-by-tegpro/

More interesting and cheaper than industrial stirling for a longer service life: you take 10 modules (total 220w) for approximately $ 600.

no longer on life: many reviews for this type of product gives a high degree of breakdown and high temperature is fragile.

See video of Barnabas

https://www.youtube.com/watch?v=_-4__gCwIHk

Chinese peltier modules yes! Here it is a US box which provides thermopiles for NASA satellites. Their technical data sheet announces a lifespan equivalent to more than 50 years in normal use.

[fabio.gel]

More interesting and cheaper than industrial stirling for a longer service life: you take 10 modules (total 220w) for approximately $ 600.

It's true, it's a good idea but I try to stay in the eco philosophy .... nology
600 $ = 540 € for me designer study for 20 years on Catia, Creo, Soliworks, Freecad software employed for 3 years by the largest company in France (Pôle emploi )
it's out of budget ...

[Gaston]

More interesting and cheaper than industrial stirling for a longer service life: you take 10 modules (total 220w) for approximately $ 600.

The documentation of these modules indicates that they produce 22W of electricity (3A at around 8V) with a hot source at 300 ° C and a cold source at 30 ° C for a thermal power of around 400W.
If the module is maintained under these ideal conditions, the efficiency reaches 6,5%, but it degrades (very) quickly as soon as one departs from the conditions of temperature or drawn electrical power.

In short, the use of these modules requires an investment in controlling their operating environment much more expensive than the cost of the modules.

[Petrus]

I received the Peltiers modules and I started to do some experiments:

The assembly is made up of 4 TEC1-12706 modules connected in series and sandwiched between two 3mm aluminum plates. I glued a thermocouple in the center of the hot plate and another on the cold to measure the difference and avoid exceeding the maximum temperature of the modules (138 ° C). I used tealight candles and an alcohol burner when the candles became insufficient, the fan is powered by an external power supply for the experiments, here are the data collected:

Tchaud = 53 ° C, Delta = 20 °
- no-load voltage: 3,2V
-current in short circuit: 170mA

Tchaud = 88 ° C, Delta = 40 °
- no-load voltage: 6,3V
-current in short circuit: 340mA

Tchaud = 122 ° C, Delta = 60 °
- no-load voltage: 9,9V
-current in short circuit: 530mA

And here is the assembly with the motor and a temporary fan:

The engine starts from a temperature delta of 7 ° C.
It works, but given the heat around the stove, the temperature difference is limited. At the moment it is 19,6 ° C for a temperature of the hot part of 109 ° C.

[Gaston]

This type of assembly works (and is even marketed).

But other than making it blow the hot air out of the stove top (which is good for heating the room), you can't really use it to "generate electricity".

From your measurements, we see that for a delta of 20 °, the electric power supplied is less than 0,5W, for 40 ° less than 2W and for 60 ° less than 5W.
All this using 4 modules with a "power" of 60W each.

You also noticed the difficulty of using ambient air as a cold source.
Ideally, there should be liquid cooling with a remote radiator, but I don't think the modules produce enough to power a pump ...

PS
This document (in English) has just tested the same type of module.
He concludes that the maximum power is 1,2W per module for a temperature difference of 68 ° C (maybe we can do better with one face at 120 ° and another at 0 °?) And that the maximum efficiency (on a suitable load) is 2,2%

[Petrus]

In fact, it's worse than that. No-load voltage and short-circuit current measurements correspond to operating points where the module does not provide any power, they are used to define a theoretical model of the generator composed of a voltage source with a resistance in series.
The voltage source corresponds to the no-load voltage and the resistance is calculated by the formula R = U / I therefore for a delta of 20 ° C
U = 3,2V and R = 18,8 ohms

To recover the most power from this generator, the equivalent resistance of the load must be equal to the resistance of the generator. The voltage across the generator is then 2x lower than the no-load voltage: 1,6V in our example. The power is calculated by the formula P = U ^ 2 / R.
The maximum extractable power is therefore 0,136W and not 0,544W (Uvide x Icc).

I made another measurement with the maximum temperature difference that I can reach with the alcohol burner at maximum and the fan turning fully:
Delta = 66 ° C
- no-load voltage: 11,42V
-current in short circuit: 570mA

This makes a max extractable power of 1,63W. The fan powered by an external power supply consumes 2,5W.

Regarding the stove fan, I will improve it by putting a modified PC fan in front of the heatsink, as in the test setup. Since a PC fan cannot start with such a low voltage, I will replace the brushless motor inside with a small DC motor.

[izentrop]

Hello,
The most suitable use for the Peltier module is the electric cooler, which can be cold 4 to 6 ° in a small volume with little bulk.
Less efficient than its compressor counterpart, it is also found in beer pumps , in the small fridges of hotel rooms and retirement homes for their silence

[dede2002]

There are some who are ready to market this in Africa.

http://www.lemonde.fr/afrique/article/2 ... _3212.html

It seems more complicated, more expensive and more dangerous than a mini solar panel, and I already imagine people who will light a fire just to charge their phone ..., while wood is becoming scarce.

[chatelot16]

pelletier module to make electricity in africa ??? it's wacky ... make a wood fire to make electric hobbies! I see this kind of peletier module only useful for supplying the electronic gadgets of a wood-fired boiler: the main function is to heat when there is electricity to turn the pumps and the fans ... in the event of a power outage, the pelletier modules can rotate the pump and fan at reduced power to provide minimum service better than complete failure

for africa there is no hesitation it is the best photovoltaic panels ... selling heating with cogeneration in africa is worse than selling fridges to the eskimos because with the heating they will need it !

[Christophe]

for africa there is no hesitation it is the best photovoltaic panels ... selling heating with cogeneration in africa is worse than selling fridges to the eskimos because with the heating they will need it !

It stands!