Heat to Kinetic Energy

Oman

Right. I'm doing this project and really was wondering is there any possible way to turn heat energy into kinetic or electric energy.
its heat from the sun, btw. i was thinking of simply a black metal plate that is connected to the device and the heat transfers into the device but cant figure out how to turn the heat into electricity, if thats possible.

Is there something you can buy that will convert it or should I try something else for my project
Any help appreciated

Thomas_S_Hunterson

Well the standard method for power generating (only practical on huge scales) is to use heat to boil water and drive turbines. This would be extremely inefficient on a small scale.

Thermocouples would be worth looking into, they're probably the most direct and efficient way.wiki-link although to generate anything but a miniscule amount of power will be difficult.

Oman

well what I'm doing is very small scale. I'm trying to use heat to power a fan, not sure on the size but probably only small.
Does that thermocouples actually generate electricity because it looks like it just reads temperature but if it generates electricity it'd be great, if it does is it the hotter it is the more energy because thats what im looking for

Thomas_S_Hunterson

It generates a small current based on the ddifference in temperature between the ends of the thermocouple (one end needs to be kept cold).

If you wanted to power a fan, you'd probably need to rig up quite a few.

/edit: The thermocouple itself is just a couple of different conductors in parallel. It can be used to measure temperature because the voltage increases as the difference in temperature between the two ends increases.

Oman

thanks a million. Do you have any idea of the price and if they're easy enough to get adn also should i be going for type K

Michael Collins

Can you not just use a photovoltaic cell (solar panel)?

CSU

Michael Collins wrote: »

Can you not just use a photovoltaic cell (solar panel)?

that would be too easy;)

Oman

CSU wrote: »

that would be too easy;)

exactly,

Of course i thought of a solar panel but i want the fan to be on constantly but it wont work if its cold and gets faster the hotter it gets, know what i mean

CSU

xb

Michael Collins

Oman wrote: »

exactly,

Of course i thought of a solar panel but i want the fan to be on constantly but it wont work if its cold and gets faster the hotter it gets, know what i mean

OK, so how about power it off a rechargeable battery that you charge up from the solar cell? This way the battery will keep the speed (fairly) constant while allowing it to work in periods of low-light / darkness.

Motors take a reasonable amount of power, I'm not sure you could get the required power from themocouples or other methods. Besides, the rules of thermodynamics say you can't take energy in the form of heat from a location without a net input of energy on your part!

CSU

is it an extractor fan or something? if so try go with a 12v fan.

Oman

its just a normal small fan, the type people use to cool themselves down, im starting to think i'll have to go down the solar panel route or try something else

CSU

...you must be taking the piss?

Oman

CSU wrote: »

...you must be taking the piss?

i wish i was

CSU

...you must be if you've planned to run a ruddy fan off the sun, this is Ireland:P

seriously, what is the point or exact application here?

...and if you tell me it's a hand-held personal type fan you wanna power from the sun (with battery backup for dark hours) i'll wet myslef:(

bogwalrus

Oman wrote: »

exactly,

Of course i thought of a solar panel but i want the fan to be on constantly but it wont work if its cold and gets faster the hotter it gets, know what i mean

could you not get a capacitor and transistor set up to get a steady current flow from the photovalic cell? surely you can get a steady current to come from the solar cell even when its hot/cold. The capacitor will only ever let out a certain current so it builds up heat when hot and stores when cold.

or something like that.

EvilMonkey

Sounds like a Stirling engine.
Heres a Youtube video of one.

Fringe

I remember seeing a post before with something that used light from the sun to heat the air which would go up this chimney moving turbines while doing so. Can't remember where it was...

Oman

thanks for all the feedback, its only a small farty fan, id say. it doesn't have to be very practacal, just to show it can be done, the stirling engine looks good, i'll have to read more on it adn fringe youve got me thinking

GlennHalpin

http://youtu.be/vzE8d5AXImo[/URL]
Working on an event at the moment, one of the themes of the event is sustainability.
Obviously what can be seen in the above video is a bit out there. What I am wondering is.. how possible is it to create a dance floor that using the momentum or heat created by dancers, kinetic energy could be created and used to charge peoples phones???
I have Zero engineering background so please put it in layman terms... can it be done at a reasonable price and is there a company in Ireland that could manage it?

bogwalrus

Creating a convection current would be easiest. Remember those candle lanterns that move those thin aluminium fans?using solar cells to heat a point that then creates a Nice current to move a small fan.

bogwalrus

Or maybe focus the sun using a magnifying glass to heat something up to create a flame that moves something.

muppeteer

http://sustainablerotterdam.blogspot.com/2008/09/club-watt-worlds-first-sustainable.htmlHave a look here for piezoelectric solutions. Not sure how practical or cheap they are though.

krd

Something I've been thinking about.

I did a search to see if I could find if anyone's done it, but didn't find anything.

Would it be possible, to create a nano circuit, that would take ambient thermal radiation, and convert it straight into current?

I'm thinking of something that doesn't violate any thermodynamic law - just pulls ambient energy out of the air, and converts it directly to electricity. And the current flows to wherever.

Years ago, I saw there was research being done on chlorophyll.. The way the molecule stacks up, traps sunlight and converts it to electricity. I don't know if that is actually happening - I think I saw this on television news.