Tesla's Ambient Heat Engine Theory - Right or Wrong ?

[Tom Booth]

Tesla was talking in principle. He was a bit vague as to exactly how all this is to be accomplished. For example he states: "Conceive, for the sake of illustration, [a cylindrical] enclosure T, as illustrated in diagram b, such that energy could not be transferred across it except through a channel or path O, and that, by some means or other, in this enclosure a medium were maintained which would have little energy, and that on the outer side of the same there would be the ordinary ambient medium with much energy.  Under these assumptions the energy would flow through the path O, as indicated by the arrow, and might then be converted on its passage into some other form of energy."

"By some means or other" is not very specific, but IMO Tesla is clearly talking about a heat engine here. A Stirling Engine fits the bill. "little energy" (cold) on one side "the ordinary ambient medium with much energy" relatively hot on the other side. "the energy would flow through the path O, as indicated by the arrow, and might then be converted on its passage into some other form of energy" This describes exactly the function of a Stirling type Heat Engine.

[Tom Booth]

Another attempt at a concept drawing:

[Tom Booth]

If there is any chance of something of this sort working at all, it would, of course, require some sort of auxiliary starting mechanism to run the compressor until a temperature differential is established.

Also, it should be noted that in this illustration ALL the heat and cold generated in the air-cycle system is used to run the Stirling engine - which in turn, will take over running the compressor. Power output (if any) would come from the re-expanding of the air through the turbine which would turn an electrical generator.

The job of the whole air-cycle system is mainly to produce COLD. Extreme Cold. The colder the better. That low grade ambient heat is turned into high grade heat in the process is almost incidental.

I think this is in harmony with the principles Tesla outlined, though I'm not sure it is exactly what he had in mind. In a way it is a reversal of what he described in that he talks about removing the excess heat from the "cold hole". Here the heat is removed by flushing out the "cold Hole" with the cold air expanded through the turbine.

As I said, Tesla was talking in the abstract. This is my own idea how it could be done, based on what I know about air-cycle heat-pumps, Stirling engines, compressed air... etc.

It may seem that it is counterproductive to cool the compressed air before it is expanded through the turbine. The idea there is to cool the expanding air as much as possible. That expanding the air through a turbine reduces the temperature dramatically (much more than throttling alone) because energy is being removed, is almost incidental. The main purpose of expanding the air through a turbine is to cool it. not power production, but as power production is a necessary byproduct of an air-cycle cooling system, it is there for the taking.

The idea here is simply to have something working. A "Self-Acting" engine. To start with... with some power output at least.

if that much can be accomplished, then it can be modified to maximize power output later.

But IMO, even if we just end up with something that sits and runs on a coffee table as a conversation piece that would be a marvel.

[memoryman]

Tom, a very interesting topic. At the moment i am dealing with some serious personal matter, and have little time to spend on posting. Find a video wit Daniel Sheehan on 'challenges to the second law of thermodynamics'; give me you thoughts on that.

[Tom Booth]

Tom, a very interesting topic. At the moment i am dealing with some serious personal matter, and have little time to spend on posting. Find a video wit Daniel Sheehan on 'challenges to the second law of thermodynamics'; give me you thoughts on that.

Certainly Tesla was well aware of the second law and was going head to head with it in his discussion regarding his "Self Acting Engine". He wrote:

I read some statements from Carnot and Lord Kelvin (then Sir William Thomson) which meant virtually that it is impossible for an inanimate mechanism or self-acting machine to cool a portion of the medium below the temperature of the surrounding, and operate by the heat abstracted.  These statements interested me intensely...

He then goes on to describe various possible loopholes so-to-speak in this second law. Primarily this idea of creating an artificial heat sink for the ambient heat to flow into so that energy could be extracted from that flow. Perhaps there was some flaw in his logic but I am not aware that his idea has ever been tested in any practical way, by building some such engine as he proposed. Personally I think he was right and I think it would be worth the investment to build such a device and see what happens.

Beyond that I've been round and round about the second law on various forums. To me it seems quite like an article of faith for some and quite slippery when it comes to definitions. Just for example, If a Heat Pump has a COP > 1 is that because the second law doesn't apply because it is an "open system" or what ? What constitutes an "open system" anyway ?

The little "Drinking Bird" appears to violate the second law. But we can get around that by redefining what is or isn't an open system.

In my mind the bird is simply a heat engine extracting energy from the ambient air and using some of that energy to drive it's own simple refrigeration system. My argument is simply that a drop of water on a toy birds felt beak is not much of a "cold hole" and that the same principle could be used to drive a larger more practical heat engine with a more effective cooling system and from which some real usable energy could be derived, violation of the second law or not.