Questions tagged [thermoelectricity]
168 questions
9
votes
1 answer
Cause of negative Thomson's effect?
Why do metals like iron, cobalt, and nickel show a negative Thomson's effect? What is the reason for other metals like copper and zinc to show a positive Thomson's effect? Is there any reasonable idea explaining this other than experimental…
user63923
3
votes
3 answers
Why does a thermoelectric generator need both p and n elements?
A thermoelectric (peltier) generator turns heat flow into DC electrical power. Here is a typical schematic:
(image from here). Notice that there are two thermoelectric materials required: p-type (red) and n-type (yellow).
Why can't you make a…
Steve Byrnes
- 16,612
2
votes
0 answers
Calculating Peltier efficiency
This is half Skeptics SE , half here.
Please help me proving this Kickstarter is baloney. Besides the stupid marketing claims what we have here is a neck band shaped portable device of 180x177x45mm total size which utilizes Peltier cooling operated…
chx
- 153
- 6
2
votes
0 answers
Why the Seebeck coefficient of platinum/palladium/tungsten changes sign when temperature rises from 0 K?
From Wiki and this paper: Cusack, N.; Kendall, P. (1958). "The Absolute Scale of Thermoelectric Power at High Temperature". Proceedings of the Physical Society. 72 (5): 898. What mechanism is related to this phenomenon? Is it phonon drag or spin or…
Wenjie Zhang
- 356
2
votes
2 answers
Relation between Seebeck coefficient and electrical resistivity?
I was wondering if there is a mathematical relation between the Seebeck coefficient of a material and its electrical resistivity (or conductance). For me it makes sense intuitively since (as far as I understand) the Seebeck coefficient and the…
Lukeception
- 23
2
votes
2 answers
Coupling of two different metals
I have read about thermoelectric effects such as the Seebeck effect, the Peltier effect, and the Thomson effects. I understand that if there is a temperature difference between two ends of a metal, then in the hot junction end electrons will move…
user101134
- 701
2
votes
2 answers
Using Thermoelectric generator to power another Peltier cooler
i have a feeling that this isnt possible but wanted to double check.
Could you use a Peltier plate on a heat source to generate electricity and then use that electricity to power a Peltier plate as a cooling device?
I want to use the heat given off…
David Murray
- 23
1
vote
1 answer
Does Peltier element become a weaker thermo-insulator when taking off power?
Imagine we have two bodies (environments) with different temperatures connected to each other through Peltier element. Say, one body has temprature $T_l$, the other $T_h$. For the sake of experiment, heat exchanges only through Peltier element,…
user129516
- 13
1
vote
1 answer
The opposite of thermionic emission
"Thermionic emission is the liberation of electrons from an electrode by virtue of its temperature (releasing of energy supplied by heat). This occurs because the thermal energy given to the charge carrier overcomes the work function of the…
noodles
- 59
1
vote
0 answers
Joule heater physics
Why does a joule heater element heat up from the middle outwards to the ends?
In the picture below, the kanthal mesh heating element is shown heating up from the middle outwards. I'm looking for an explanation of why that is.
The image is a screen…
Buk
- 11
1
vote
0 answers
Current from Internal Energy?
Internal energy in a conductor includes the collective vibration of the constituent particles including electrons and nuclei.
If I place a heated conductor in a magnetic field, the charges will experience some sort of confining force such that the…
Joeseph123
- 749
1
vote
0 answers
What are the efficiency limits of the Peltier effect?
I understand that thermoelectric coolers are perhaps a quarter as efficient as heat pumps. Why? What is the source of this efficiency limit? What would have to change for thermoelectric coolers to be more efficient?
Stephen Collings
- 429
1
vote
0 answers
Good thermocouples for cooling and/or power generating
I can't figure out if a good thermocouple for thermoelectrical cooling is a good thermocouple for generating power with the Seebeck Effect.
Maxime
- 11
1
vote
1 answer
How is voltage generated due to difference in temperature in a thermocouple?
How is voltage generated due to difference in temperature between the two junctions of a thermocouple? What happens to the electrons at the junctions of the two materials and how do they behave when they are immersed in hot and cold medium?
Tea is life
- 2,726
0
votes
1 answer
Does the volume of water going over a hydroelectric dam matter?
How does the volume of water going over a hydroelectric dam affect electricity production? Could the flux of the generators not be modulated to different amounts of electricity with the same flow of water? If so, what would the minimum flow be?
Derek Seabrooke
- 784