Efficient, powerful Heat Engine

https://youtu.be/R_QB5amihko


https://youtu.be/lFhUkzHRbWo

A primary goal of this project is to improve the  Stirling heat engine for power production.

A related purpose is to test out Nikola Tesla's insights on how  heat engines might utilize ambient heat so as to be "Self Acting".

Stirling engines use heat itself, derived from any source,  including wood, coal or concentrated sunlight as fuel, even the warmth from the hand, or with some source of cold, like a wet piece of paper, the surrounding heat in the air 

Check out this YouTube video for example:

https://www.youtube.com/embed/ARD3ctp80ac

In spite of it's versitiliry, in the course of research,  I've encountered several design problems that tend to keep the usefulness of the Stirling engine rather limited.

Having worked with engines of all kinds most of my life, I see many ways these Stirling heat engines could be improved. My goal is to build a better, more efficient, stronger, more powerful heat engine.

Here are some of the ways I believe the Stirling Engine could be improved:

TIMING

Unlike a car engine a Stirling Engine has no adjustable timing mechanism. The timing in a car or truck engine is critical and is almost always being self-adjusted to maximize power and torque under varying conditions, Timing also needs to be adjusted for different qualities of fuel.

HEAT as an energy source for the Stirling can also have different qualities, from a warmth that is barely perceptible to extremely hot. Heat can be made available in different quantities and at different rates. A standard Stirling engine has no ability to compensate for such changes. In other words, a Stirling Engine is almost always "out of time", Like a car engine that is in really bad need of a tune-up.

DWELL

Another weakness of most Stirling engines is that they are also lacking what some Stirling engine enthusiasts call "dwell" .  This term is ordinarily applied to gasoline engine ignition systems. A Stirling engine however, has no "ignition", no spark plugs but as in a car engine "dwell", ultimately has to do with how and when heat is delivered to the power cylinder to expand the air inside and drive the piston.

In a gas engine the heat is delivered quite suddenly and  with explosive force. A fuel air mixture is ignited by a spark and there is a literal explosion. In a conventional Stirling engine, the heat is delivered gradually. In fact, heating and cooling overlap, so the engine is working against itself.

There are various ways the DWELL in a Stirling engine CAN be made to more closely resemble the explosive ignition of a gasoline engine . This would be by more effectively controlling the movement of the displacer with a cam or other independent mechanism.

The above are two ways (Timing and Dwell) in which these engines could be markedly improved. There are some additional ways that the Stirling Engine could be made more efficient, powerful, compact and competitive. Really, there has been little effort put into improving the Stirling since its invention in 1816.


More Ways A Stirling Engine Could be Improved

Heat Generation and Recycling

Both types of engine Stirling and gasoline, ultimately run on a hot expanding gas pushing a piston but a gas engine wastes a lot of heat. A  Stirling engine however operates directly on heat itself and not on any heat producing fuel, therefore it is possible to recirculate or reclaim unused "waste heat" from a Stirling but doing so requires an understanding of heat pumps and heat exchangers. Nicola Tesla had much to say on this topic of combining a heat engine with a heat pump or refrigeration system 

According to Nikola Tesla, by combining a refrigeration system with a heat engine it should be possible to capture heat directly from the ambient air, concentrate and direct that heat in such a way as to make the engine or machine "Self Acting", that is, he believed that such a machine could actually draw its own "fuel" (heat) from the surrounding air and run itself. A kind of apparent "perpetual motion machine".

There has been much speculation about this possibility as heat pump and heat engine efficiencies continue to improve but I don't know of anyone who has ever actually tried this. Not since Tesla anyway.

Tesla, in his recently published "Lost Letters" revealed to a friend that he had succeeded in developing such a machine! Whatever happened to this prototype engine is unknown.

"In this letter, a part of the Nikola Tesla Collection, at Columbia University Library, Tesla claimed he had already developed such a generator and to have revealed the underlying physical laws."

Here is the letter:

http://www.bibliotecapleyades.net/tesla/esp_tesla_27.htm

And here is Tesla's Article where he describes the underlying principles:

http://www.tfcbooks.com/tesla/1900-06-00.htm

Many are skeptical that Tesla's idea could be realized in full as it is  considered a violation of the second law of thermodynamics and therefore "impossible" but I do think it is an idea worth experimenting with. Otherwise I would have to conclude that Tesla was a fool and a liar, at any rate, Tesla's writings on the subject afford many clues and insights into how the general efficiency of an ordinary heat engine might at least be improved.

Non-Heat Conducting Materials

One more way a Stirling Engine could be improved is by building it from materials that were not available in the 1800's.

A Heat Engine has to be able to control the flow of heat through the AIR in the engines sealed air chamber, not through the chamber walls, but Traditionally Stirling Engines have been made out of metals like Cast Iron which rapidly conducts heat OUT of the engine.

Why is this important? You want the heat to travel through the trapped air so that it expands. This is what transforms the heat into mechanical power. The heat enters into the trapped air, the air expands from the heat and the expanding air drives the piston. Metals conduct heat readily. Unfortunately that is not what one wants. Making a stirling engine out of metal is like making a water wheel out of window screen. Most of the heat is lost or simply passes right through without producing any power. A non- heat conducting ceramic engine could retain and therefore better utilize the available heat.

The Stirling Engine, though showing great promise as a potential source of clean renewable energy has largely been a big failure in the marketplace, hardly rising above the level of a forgotten curiosity or table top conversation piece. I would very much like to change all that and build a Stirling type heat engine that is efficient powerful practical and competitive in the marketplace.

Really with global warming and the problems associated with dwindling energy resources this is something the world desperately needs.

Typically this type of R&D would and should be conducted by a big company with millions of dollars at it's disposal, but as far as I know, none are doing that and I think certainly no one has ever put Tesla's idea to the test, if infact anyone since Tesla himself ever understood his idea.

I may not need ten thousand dollars to implement some of these ideas and demonstrate an improved heat engine. Anyone who has watched a few videos on YouTube about Stirling Engines can see that these engines are rather simple and some models can be built from little more than tin cans and coat hangers. I would however, like to take this as far as possible which will certainly require something more than just a tin can Engine.

My goal is to demonstrate that with the right design and a few modifications and also by taking some wisdom from the HVAC and other departments (like cryogenics and gas liquifaction methods which Tesla mentioned) a really practical heat engine may be realizable.