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Author Topic: Tesla's Ambient Heat Engine Theory - Right or Wrong ?  (Read 95307 times)

memoryman

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Re: Tesla's Ambient Heat Engine Theory - Right or Wrong ?
« Reply #60 on: April 28, 2014, 03:42:26 AM »
Thank you for these posts.
I have been searching for a way to convert ambient heat to another form for years.
So far I have not done any experiments, but am encouraged by the replies.
Please keep the discussion going.

Tom Booth

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Re: Tesla's Ambient Heat Engine Theory - Right or Wrong ?
« Reply #61 on: April 17, 2015, 06:29:38 AM »
Hi, I have a campaign going to raise some funds to build a prototype engine based on the information provided here and on other forums. The idea being to test Tesla's idea in a practical way. There is no guarantee it will work, but I don't think we can really rule out the possibility until someone tries. I have recently been encouraged by coming across a little device called a fire piston which appears to be able to generate considerable heat by compressing a relatively small volume of air:

https://www.youtube.com/watch?v=Mvlm-BiCU2k

https://www.indiegogo.com/projects/exploring-cold-hole-technology/x/10539009

vasik041

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Re: Tesla's Ambient Heat Engine Theory - Right or Wrong ?
« Reply #62 on: April 17, 2015, 07:10:29 AM »
you can build something like this

MarkE

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Re: Tesla's Ambient Heat Engine Theory - Right or Wrong ?
« Reply #63 on: April 17, 2015, 11:02:59 AM »
Sorry guys, but you need a heat source and a lower temperature heat sink.  Otherwise that pesky Second Law will eat your lunch.  Now, that said, there are various heat sinks available at least for small scale power.  You can for instance exchange heat between the surface and depths of a pond.  And if you are really clever, there is always the sky window.  In space no one can see you freeze.

Tom Booth

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Re: Tesla's Ambient Heat Engine Theory - Right or Wrong ?
« Reply #64 on: April 17, 2015, 11:18:25 AM »
you can build something like this

Something like that, sort of. As drawn though, I don't understand how the device illustrated could work, for a couple reasons. There appears to be no compressor, without which it seems to me that pressure would simply equalize (or remain equal) within the loop and nothing would happen. More or less like a refrigerator that wasn't plugged in.

Also there is no indication of any means of power output. If energy (environmental heat) is going in, it would also have to come out in some form somewhere.

There would presumably, if things got moving somehow, be a build-up of heat in the pipes before the throttling device/turbine and a cooling in the condensation chamber but it does not appear that this temperature difference is being utilized.

Tesla's engine consisted, in part, of an air compressor and included some possibility of  liquefying air, apparently, it would seem then that his system was, or consisted of in part, an air-cycle refrigerator. This obviates the need for any kind of exotic gas or fluid such as Freon making the apparatus simpler and safer and easier to build I should think using air as a working fluid.

vasik041

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Re: Tesla's Ambient Heat Engine Theory - Right or Wrong ?
« Reply #65 on: April 17, 2015, 12:21:29 PM »
Quote
There appears to be no compressor
We have free "compressor" - gravity

Quote
Also there is no indication of any means of power output.
there is a "turbine" near reservoir top on right side

yes, picture is not perfect :)

pix

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Re: Tesla's Ambient Heat Engine Theory - Right or Wrong ?
« Reply #66 on: April 17, 2015, 02:16:59 PM »

What constitutes "the output of a heatpump" ?

Heat, right ?

But Tesla was not proposing running an engine on the output of a heat pump. Rather he was proposing running an engine on Ambient heat. Ambient heat does not have to be created or "pumped" it is just there.



Sorry, but every Heat Pump COP>1 is because it draws energy from AMBIENT Air.
Every low temperature boiling liquid, like commonly used refrigerants will exchange energy from surrounding air through evaporator coils.
If, for example at given compressor suction pressure refrigerant still boils at - 30 degC, it will exchange energy from surrounding air at -10 degC.
It is a matter of temperature difference of evaporating refrigerant and surrounding AMBIENT medium- air, ground or water.


Cheers,
Pix

pix

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Re: Tesla's Ambient Heat Engine Theory - Right or Wrong ?
« Reply #67 on: April 17, 2015, 02:20:11 PM »
you can build something like this
Nothing new under the Sun :-)
Every ORC system will do better. Let's take a look at his one, for example:
http://matteranenergy.us/animation.html


Cheers,
pix

Tom Booth

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Re: Tesla's Ambient Heat Engine Theory - Right or Wrong ?
« Reply #68 on: April 18, 2015, 06:40:38 AM »
We have free "compressor" - gravity
there is a "turbine" near reservoir top on right side

yes, picture is not perfect :)

OK, the question on my mind then is; if it were that simple, why hasn't it been done and in use long ago generating free power for everyone already?

The same question could be asked regarding my own, or Tesla's version of the idea, which is, as far as I can figure, a heat engine driving a heat-pump of some kind which delivers the "fuel" (heat) to run the heat engine, or rather, in actual fact, I believe that Tesla's idea was to use the heat-pump or refrigeration system to throw off excess heat from the heat-sink, the ambient heat being a given free for the taking.

He said: "Heat, though following certain general laws of mechanics, like a fluid, is not such; it is energy which may be converted into other forms of energy as it passes from a high to a low level...   If the process of heat transformation were absolutely perfect, no heat at all would arrive at the low level, since all of it would be converted into other forms of energy...  We would thus produce, by expending initially a certain amount of work to create a sink for the heat ... to flow in, a condition enabling us to get any amount of energy without further effort.  This would be an ideal way of obtaining motive power.  We do not know of any such absolutely perfect process of heat-conversion, and consequently some heat will generally reach the low level, ... necessitating continuous pumping out.  But evidently there will be less to pump out than flows in, or, in other words, less energy will be needed to maintain the initial condition than is developed by the fall, and this is to say that some energy will be gained from the medium.  What is not converted in flowing down can just be raised up with its own energy, and what is converted is clear gain. Thus the virtue of the principle I have discovered resides wholly in the conversion of the energy on the downward flow."

The whole idea being to create and maintain an artificial heat sink or "cold hole" for the sake of having a temperature differential to run a heat engine. As the heat being extracted from the "cold hole" can be easily reclaimed and used as Tesla claimed: "What is not converted in flowing down can just be raised up with its own energy"

This all seems relatively simple and straightforward to me. Yet since Tesla wrote his paper, scouring the internet for the past several years I haven't come across a single instance of anyone actually attempting to build any such device.

I suspect one of the main reasons is that it is perceived to be an impossibility in the mind of many and so there has been a reluctance to invest any time, money or effort in something that is clearly a violation of the second law of thermodynamics (in the opinion of many).

Quote
"The law that entropy always increases holds, I think, the supreme position among the laws of Nature. If someone points out to you that your pet theory of the universe is in disagreement with Maxwell's equations — then so much the worse for Maxwell's equations. If it is found to be contradicted by observation — well, these experimentalists do bungle things sometimes. But if your theory is found to be against the second law of thermodynamics I can give you no hope; there is nothing for it but to collapse in deepest humiliation."
Sir Arthur Stanley Eddington, The Nature of the Physical World (1915), chapter 4

I do tend to think though that Tesla had it slightly wrong.

Pumping the heat out of a "cold hole" and raising it back up and depositing it at a higher temperature is looking at it backwards. It is difficult and IMO unnecessary.

The heat pump rather should fist concentrate and use the heat from the atmosphere first, dump any excess, the cold is what's left over. It would be, IMO, easier to remove the excess heat while it is already at a higher than ambient temperature rather than attempt to remove it from the "cold hole" directly. Use the heat as much as possible dump the excess and then simply deposit the cold into the cold hole.

In that way you are removing the excess heat BEFORE it gets into the "cold hole" rather than after.

I don't think that the second law even applies where a physical substance, like air molecules, are moving through the system. Warm air being compressed to concentrate and remove/convert the heat therein to another form of energy, the cold spent air then being exhausted.

I think of it this way: Imagine a heat engine is a gasoline engine. Air molecules are like little cans of gasoline. The sun fills these little gas cans with fuel.

I see no problem with an engine running some kind of pump to deliver cans of fuel to itself and then discarding the empty cans. I don't think anyone would argue that such a thing is an impossibility.

DaS Energy

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Re: Tesla's Ambient Heat Engine Theory - Right or Wrong ?
« Reply #69 on: April 18, 2015, 07:07:01 AM »


First rule of inventing is forget what you have been taught for they are wrong. Do what your own eyes tell you and you will get it right.

With regard to the doomsayers, making a piston slide up and down a pipe is so simple, yet it took many a million of years before man did so!

vasik041

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Re: Tesla's Ambient Heat Engine Theory - Right or Wrong ?
« Reply #70 on: April 18, 2015, 08:21:36 AM »
May be this helps...

Tom Booth

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Re: Tesla's Ambient Heat Engine Theory - Right or Wrong ?
« Reply #71 on: April 18, 2015, 10:16:00 AM »
May be this helps...

Well... seems rather light on thermodynamic principles.

One thing I've found interesting lately are articles on various websites regarding compressed air and heat reclamation.

ex: "as much as 100% of the electrical energy used by an industrial air compressor is converted into heat"

http://us.kaeser.com/Products_and_Solutions/Rotary-screw-compressors/heat-recovery/default.asp

"In fact, 100% of the electrical energy used by an industrial air compressor is converted into heat"

http://kaesertalksshop.com/2013/09/18/turning-air-compressors-into-an-energy-source/

Figures vary slightly, usually a little more conservative, like 96% or 98% etc. but all these are conventional sources of information not "free energy" sites.

If that 100% heat can be reclaimed and utilized... There is still the compressed air... waiting to expand and do some work.

Doesn't this show up an obvious potential for "overunity"?

I think it is misleading though to say that the electricity is converted into heat. The heat is already in the air. Compressing the air so-to-say squeezes out the heat. The compressed air is then something like a compressed spring ready to re-expand once released from confinement. This re-expansion takes place at the expense of the air's own internal energy, the result being that the air thus released turns bone-chilling cold.

If 100% of the energy used to compress the air can be made available for use to compress more air, and the air being released can run a turbine or pneumatic engine of some kind (which results in additional cooling converting even more of the air's internal energy into mechanical/electrical energy) and the resulting cold can be utilized to deepen the "cold hole" or sink to make the heat engine/compressor even more efficient...

Further... the compressed air could be stored for a time and expanded through a simple solar collector (pipes painted black under glass) Not that I think that is even necessary, but while we are at it, why not?

What am I missing here that makes extracting solar heat/energy from the air impossible?

The problem with air-compressors is generally how to keep them cool. Cooling fins, water jackets, radiators, fans, anything to get rid of all that damn excess heat so the compressor pistons don't seize.

I don't think all that damn nuisance heat comes from the electricity used to run the compressor. That heat is solar energy being squeezed out of the air like water out of a wet sponge. The problem is that in a conventional compressor this heat is looked at as a problem. So also the cold produced from the expanding air which can form ice and clog up conventional air tools necessitating the addition of antifreeze to the air line.

Quote
"Water in the air is the cause of freezing at exhaust ports of (air) drills, pumps, etc., since the sudden expansion of the air on exhaust produces such a low temperature that ice is formed and the exhaust is clogged, oftentimes even in warm weather."

Compressed Air: A Reference Work on the Production, Transmission, and Application of Compressed Air; the Selection, Operation and Maintenance of Compressed-air Machinery; and the Design of Air Power Plants  - -Lucius Irving Wightman pg. 116

Both of these "problems", the super-heated compressed air and the sub-zero cold exhaust air from any kind of pneumatic engine running on the compressed air are no problem really if that extreme heat and cold are utilized to provide the necessary temperature differential to run a heat engine.

Compressed air can be used to produce extreme heat as well as extreme cold and without any need for any phase change.

memoryman

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Re: Tesla's Ambient Heat Engine Theory - Right or Wrong ?
« Reply #72 on: April 18, 2015, 02:53:09 PM »
very good discussion so far; however I found several wrong or incomplete statements in these posts.
For example, in the most recent one by Tom Booth: "Compressed air can be used to produce extreme heat" is backward; extreme heat can be produced by compressing air.
Will address them in a follow-up post.

Tom Booth

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Re: Tesla's Ambient Heat Engine Theory - Right or Wrong ?
« Reply #73 on: April 18, 2015, 08:54:56 PM »
very good discussion so far; however I found several wrong or incomplete statements in these posts.
For example, in the most recent one by Tom Booth: "Compressed air can be used to produce extreme heat" is backward; extreme heat can be produced by compressing air.
Will address them in a follow-up post.

I agree, in that I miss-stated. More properly IMO compressing air releases the heat already in the air. Again IMO the mechanical or electrical energy used to compress the air is not lost as heat. Air is elastic, like a spring. When you compress a spring it also releases heat but the energy used to do the compressing is stored as potential energy to be released when the spring is loosed from confinement, at which point the spring gets colder to some degree. In practice this release of heat from a compressed spring is not really noticeable as it is lost to the surroundings immediately. Air is much more elastic and the heat released is more noticeable but I think that the principle is the same.

IMO the heat released by compressing air is not, at least not all, due to the energy input being converted to heat. Some of that energy input, if not all of it, is stored as potential energy. The heat released by compression is, I think, MOSTLY the airs own INTERNAL energy. There is still MORE internal energy to be had when the air is allowed to re-expand, at which point it gets very cold - far below ambient. I think the fact that the air will of itself re-expand to its original volume when allowed to and that it gets very cold in the process is proof that it's own internal energy was lost during compression rather than the energy used to compress it being converted into heat.

I suppose heat is heat and making a distinction between the heat of compression, due to conversion of the energy input into heat and the air's own pre-existing internal heat (Atmospheric heat of the air having been heated up by the sun) is just a matter of how you look at it, But IMO it is more correct, or more in accordance with reality to say that the majority of the heat released by compressing air is SOLAR ENERGY that was stored in the air while the effort put into compressing the air is actually stored as potential energy as in any elastic substance or spring.

This heat recovery site claims that it is possible to reclaim up to 105% of the electrical input energy used to compress air:

http://www.atlascopco.com/useyourenergytwiceus/useenergytwice/useyourenergytwice/

Quote
The unique design of the cooling system of the ZR oil-free screw compressor with energy recovery allows to fully capture all this heat from the compressed air and oil system.
As a result, the total energy recovered as hot water amounts up to 80-105% of the electrical input energy, depending on the site conditions. (emphasis added)

They provide their own explanation for how this is possible.

But let us not forget that AFTER all this heat energy released during compression is recovered there is still the compressed air itself to be used as a power source to run pneumatic devices, air tools etc.

First of all, I'd have to say that it is impossible to reclaim 105% of the electrical input as heat. The additional 5% has to come from somewhere else, but there is also additional potential energy in the compressed air now stored in an air tank ready to do work. That is extra energy unaccounted for. It has to be coming from somewhere.

Or should we just suppose that 105% figure is some sort of misprint or exaggerated claim?

They claim: "Through the compression process, part of the energy is lost as radiation. Atlas Copco’s Energy Recovery unit is able to extract an amount of energy from compressed air that is equivalent to the amount of energy that the electric motor uses
The most common uses for the recovered energy include process heating, space heating and water heating. "

http://www.atlascopco.us/usus/service/k/stationarycompressors/050%20save-energy/3558502/

Quote
The testing process involved the real-time measurement of the electrical input power and the output power as hot water. It was proven that... 100% of the electrical input power could be recovered in the form of hot water.

http://www.atlascopco.com/microsites/images/use%20your%20energy%20twice_tcm758-1324420.pdf

Again, if 100% (or more) of the heat generated from compressing air is recoverable in actual practice under certain conditions, there is still the potential energy latent in the compressed air itself ready to do work. How is this accounted for?

is the claim that you can "use your energy twice" just poppycock?

An LTD type Stirling Engine can use very low grade heat. I really do believe that with the right design it could be demonstrated that a Stirling combined heat-engine/compressor could extract enough heat (and cold) from compressed air to run itself with additional power to spare.

Probably not without some precision engineering though. The testing I've been able to do with very crude tin-can devices shows some promise I think, but...

I suppose like most people, if I had the money to invest in such a project I wouldn't be interested in "Free Energy" in the first place.

"The best thing a man can do for his culture when he is rich is to endeavor to carry out those schemes which he entertained when he was poor" - Thoreau

memoryman

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Re: Tesla's Ambient Heat Engine Theory - Right or Wrong ?
« Reply #74 on: April 18, 2015, 10:54:28 PM »
Tom, compressing gas partially converts energy from the compression process to heat; similarly to friction losses. If the compressed gas is in a perfectly insulated container, than no (heat)energy is wasted or lost.