Another compressed air idea

[Kludge]

Hello, I'm new here and I've got more ideas than I have time or money.

I really like the idea of the Savonius rotor for relative low speed muscular uses.  What I've got in mind is not power generation but has the potential to supplant power usage.

Here's the idea if anyone wants to play with it.

Hook a simple Savonius up to an air pump/compressor and run the output line underground or through water to cool it from the heat created by compression.  Then when the air is expelled through a nozzle it comes out cold.  This could be used to cool a tank of antifreeze which could then be pumped through a coil with a fan blowing over it to provide air conditioning.

The basic idea is not mine it is an adaptation from work done in the 1800's by a Dr. Gorrie who made ice this way.  His work was built on work by someone else who used the initial heat of compression to heat water.  Which is something else I'd like to play with.  Dr. Gorrie's device was hand cranked not wind powered though.

This idea has a real allure for me as I have a small winery in Oklahoma and during the summer months the airconditioner gets expensive.  What we don't have is a shortage of wind.  Also living on a bald hilltop won't hurt.

Does this sound doable?  I'd love to build this but can't afford hit or miss so any pointers or ideas would be more than welcome.

Thanks

Bill

[kitno455]

instead of compressing air, why not a phase change system instead? i think you will get more bang for your buck by converting existing air-conditioning or heat-pump equipment.

i mean- why do hotair->coldair->hotwater->coldwater->hotair->coldair?

you could use automotive style compressors, though they are not rated for the kind of continuous duty that residential/commercial units are.

another option is huge amounts of 4 inch pvc buried 6 feet down in a big loop, and just force air thru it. what comes out the other end is cool, dry air. gotta watch out for mold, though...

allan

[Kludge]

Actually it should be pretty simple.

Dr. Gorrie pumped the air into an output line which was cooled by a water bath so that when the air came out the final nozzle it was cold.  He bubbled it into a brine bath into which he put containers of pure water which then froze.  I'm just saying skip the brine and ice and use something that can be cycled through a radiator with a fan.  

I have thought about just having the output nozzle come through the wall but it would have to be a dry compressor so that no oil vapors come through.  The automotive a.c. compressor would have to output outside for this reason and cool some other medium which could then come inside.

Bill

[ffoegw]

I think it's a great idea!

No goofing around with or expense of gennies required.

You could also reverse it for the winter as follows:

Hook a simple Savonius up to an air pump/compressor and run the input line underground or through water to heat it from the cold created by decompression.  Then when the air is compressed into a heat exchanger it could be used to heat a forced air central heating system. Then decompressed and run back underground/water to heat up again.

I think it would be better as a heater because only a small part of the system would be compressed whereas to be used as a coolant the entire length underground would need to be compressed (and leakproof).

It would be fun just to build a small scale model to prove it to yourself and any potential investors.

If I see any old refrigerators being thrown out I think I might salvage some parts just in case I might try it.

Regards

Geoff

[sahlein]

How about something like a swamp cooler up on a tower containing a heat-exchanger and use the turbine to run a circulation pump for your "heat-exchange media".

Any of you ex-Army guys ever drink fairly cool water from a "Lister Bag" in the desert at Ft. Bliss in August???

A Lister Bag is just a cylindrical green canvas bag that sits in the sun and stays cool by the evaporation of water off the surface of the semi-porous bag.

Seems they held about 35 gallons or so.... Been a while....1968.  WOW!  Time DOES Fly!

If you could make something like the cooling towers at a Nuke power plant the updraft could help the evaporation and all the turbine would do is circulate the

"exchange media"... a little Ethylene Glycol type antifreeze should take out the mould in that part of the loop.

You might even be able to control the turbine/pump speed by throttling the coolant pipe flow.....

Now ya did it!.... Got me thinking again!

Thanks for kick-starting a back-burner project!!

Joe S.

[dinges]

Hmm, judging from your handle I think you picked the right name

Seriously. It might be an idea to try to calculate the amount of energy compressed air can hold. I.e. a vessel of, say, 100l at 10 bar means ??J of energy.

Don't know off-hand how to calculate this, perhaps others can help here.

My 'guess' is that the amount of energy that can be stored (and thus retrieved, minus some losses) is not very big.

Chemical storage of electrical energy, though perhaps not very efficient, surely allows a LOT of energy to be stored in a relatively small space.

Plus, the technology is relatively mature. (though battery-problems account for their share of RE problems)

And somehow I don't feel very comfortable around high-pressure vessels. Or rotating flywheels. But that may just be me, since I haven't been around them a lot.

(BTW, if you search on this board you should see similar discussions; at least I, as a relatively new member, remember them)

Succes,

Peter.

[dinges]

My assumptions... You are trying to build a heat-machine, not a way to store electrical energy.

Ignore previous post.

[tecker]

What is the optimum pressure on the high side ?

[hobot]

Made ice by hand crank unit, hmmm, googled good Dr. Gorrie.

History and a sad inventors ending

http://www.everything2.com/index.pl?node_id=1016979

http://www.enchantedlearning.com/inventors/indexr.shtml

More details on Gorrie's Fridge

http://www.phys.ufl.edu/~ihas/gorrie/fridge.htm

http://www.dejaelaine.com/gorrie.html

hobot

[Countryboy]

My advice..

Use the windmill to produce electricity to power the air conditioning...

That's probably going to be your simplest, cheapest solution in the short run.

If you are looking at the long haul, build a basement under the winery.  The ground stays about 55 degrees F year round.

Compressing and decompressing regular air doesn't give a great temperature change.  It remains a gas the whole time.  I think Boyle's Law deals with heat energy exchange with  changing pressure and volume.  Changing the state of the gas into a liquid or solid is where you will find the big energy transfer.  Compressing ammonia gas into ammonia liquid, for example, will take less energy per degree temperature difference.

I've always thought that rigging a DC motor to power a freezer or fridge's compressor, and then using a windmill or waterwheel to supply power to the fridge or freezer would be a good way of having off grid refrigeration.  

[wdyasq]

"The ground stays about 55 degrees F year round."

Maybe where you are.  The ground where I am stays a little over 70F and when I lived in Ohio it was about 57F.  In Northern Ontario it was 47F - IIRC. As these are the only places I have actually observed, they are the only ones I know reliable.

At this time the least expensive way to air-condition is probably grid power.  With tax credits and other 'artificial' accounting methods there may be some way to use wind or solar to an advantage.  

What won't work is spending a few thousand - or tens of thousands of dollars, to dig a large basement to find out the ground temperature is 68F and it takes 3 hours for the basement to cool after the door gets opened.

The new refrigerators and freezers have had a lot of research going into efficiency.  SunDanzer (I think) has a DC frig that is only a little more efficient than the most efficient 120V (here in "The States") refrigerators.  The cost difference will more than purchase the PV panels to make up the difference and buy an inverter.

That said I THINK there is a way to power a car type compressor with wind and get the 'cool' down a good sized tower without many problems.  It would not be inexpensive to try and would be frustrating to build the first few. One would need refrigeration experience, horizional wind turbine knowledge, good mathematical abilities, good reasoning skills, access to machine tools and abilities and probably need a good sense of humor just to attempt it.  

It is not practical to start a projects combining unproven designs.  Such things are prone to failure.  Unless one can clear the first hurtle there is no way one can finish the race.  Before one started a project using a VAWT, one should emulate one that is working as a start.

Good luck, do research, design with known parameters, use proven technology where it can be used and success is easier to achieve.

Ron

[nothing to lose]

Well if you make the ice that is a way to store the cold for later use. Like at night when cooler and you don't need as much airconditioning and the winds are high, make ice. Durring the day use the airconditioning system as needed and also the ice from the night before for even more cold air. Or use the ice to keep the sodas and wine cold for the employees durring break time and unplug the frig/cooler, save power too.

[SmoggyTurnip]

"Maybe where you are.  The ground where I am stays a little over 70F and when I lived in Ohio it was about 57F.  In Northern Ontario it was 47F - IIRC. As these are the only places I have actually observed, they are the only ones I know reliable."

The ground temperature stays at the mean anual air temperature.

.

[Kludge]

I did a little thinking on this and realized that I didn't need to build the mill to try out the concept.  All I needed to do is pump up my air compressor and let it cool off, then let the air out through a nozzle.  Of course this doesn't work for much cooling.  I don't know how Dr. Gorrie did it but I did find a cooling  element that generates cold and hot air at the same time.  What I found was the Hirsch vortex tube.  Unfortunately it might take more air pressure than I'm comfortable generating.

Thanks

Bill