Carnot efficiency does not apply to Stirling engines

[Tom Booth]

It is generally claimed that the Carnot efficiency limit formula applies to any and all engines that have ever been built or will ever be built. This "limit" on the maximum efficiency of any power producing engine is said to be a "Law"; a physical natural law of the universe. No way around, up, over, under... just can't be done.

Tesla in his 1900 article in century magazine suggested otherwise. 

You could say Tesla was an early debunker of the Second Law of Thermodynamics.

I was never educated in thermodynamics, however, I've been an engine mechanic most of my life, begining in high school. At 17 I already had my own lawnmower repair shop in my parents garage.

I've worked professionally in repair shops for years with a quota to diagnose and repair five engines per day. Meet the customer, get a description of the symptoms, make a diagnosis, give the customer an estimate and fix whatever was actually wrong.

Well, what is wrong with Stirling engines? Why are we not using them?

Well, after retiring from the gasoline powered small engine repair business, I spent many years Studying these "Stirling" engines and doing experiments just trying to figure out how a Stirling engine actually works, because in reality there is at least, I'd say, about half a dozen different types of "Stirling" heat engine and different theories going around about how they work. Does anyone really know?

Getting down to the nitty gritty:

Here is the output from an online "Carnot efficiency" calculator using figures that approximate my actual experimental conditions:

   

Room temperature about 69°F a cup of near boiling water at lets say 200° F  yields a "Carnot efficiency" of just under 20%. Why? Who knows? Supposedly that is how far the "caloric" falls. The temperature "drops" from 200°F down to 69°F at most, which on the absolute temperature scale or Kelvin temperature scale is just 20% of the way down to absolute zero.

As I've been led to understand, this result means that at least 80% of the heat going in through the bottom of the engine and entering into the "working fluid' continues on through, going up and out the top of the engine to be dissipated as "waste heat". IMO there seems to be a flaw in that logic. To get the engine running we just heated it up 20% on the Kelvin scale. What does the other 80% got to do with anything?

Now remember, Tesla in his article wrote specifically:

But let us reflect a moment. 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. ... heat is transformed in passing from hot to cold. 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.

"Established science" says that in my experiment 80% (or likely much more) of the heat goes THROUGH the engine BY NATURAL LAW. Only 20% AT BEST can be converted to mechanical energy: the calculator says so. The other 80% must (MUST!!!) according to the 2nd "LAW" of thermodynamics, pass through the engine and be "rejected" as "waste heat" to the "cold reservoir".

This is problematic, because it does not appear to hold up experimentally.

The following video shows a "solar powered" Stirling engine I found for sale on eBay running on a cup of hot water.

The top of the engine is clear acrylic to let sunlight in which light hits the black disk ("displacer") inside, so the air inside heats up like a greenhouse. In other words the heat is trapped inside the engine.

The "waste heat" is supposed to be let out through the metal bottom. A good conductor. So that is how it is supposed to work. Sunlight in the top. Heat gets trapped inside. Maybe up to about 20% of that heat gets converted to mechanical motion to run the engine and the 80% "waste heat" is let out through the metal  bottom. 

That is how it is SUPPOSED TO operate.

Well, to test Carnot vs Tesla I thought, what if we were to run this engine upside down from the way it was intended.

We could heat the metal plate on the bottom to let heat INTO the engine, but then the "greenhouse effect" would trap the heat inside.

Unlike the metal bottom, Acrylic is an insulator: a very very poor conductor of heat. So if there is 80% "waste heat" building up inside the engine every cycle that absolutely needs to be "rejected" out the top, where is that heat going to go? It can't go anywhere right? So the "flow" of heat "through" the engine will stop and the engine will stall. It really shouldn't be able to run at all, not even one cycle. The heat needs to flow all the way THROUGH for the engine to operate, (according to the 2nd Law.

But, if Tesla was correct, and the heat is all converted so that: "no heat at all would arrive at the low level, since all of it would be converted into other forms of energy" 

Then no problem. The engine keeps running because there is no "waste heat" to build up and overheat the engine as all of it has been converted to mechanical motion.

Can we all agree that this is a valid experiment? A way of testing who was right or which theory is correct, Tesla or the Second Law of thermodynamics?

Well, let's see what happens anyway..

[Jim Mac]

Hi Tom. I don't know much about heat engines, but what you see is most likely the reason most of us are here. 

We all seem to have our preferred area of focus, but we all seem to be after the same goal.

 As for myself, I believe wholeheartedly the second law of thermodynamics is either incorrect or incomplete. 

There is a member who pops his head in here and there named Tommy Reed.  He has made some Sterling engines.

[Tom Booth]

I have corresponded with Peter Lindemann on occasion, over the years, through online forums, some direct email communication and over the phone. I have to say, though, I maintain this friendship "at arms length" to some degree, primarily because the people and organization Peter has been associated with seems to be overly interested in turning a profit from books and lecture tours and the like, and would, I think, seek to patent and gain exclusive rights and control over anything they came across that actually worked.

Personally, I am the polar opposite, which is one of the main reasons I am here. I was very pleased to see there is a strict "open source" policy here.

Quite often my "experiments" are recorded and uploaded to my YouTube channel within minutes. There have been times when an experiment took days and the videos were uploaded in segments as the experiment continued, before the conclusion was known. I'm not trying to push any outcome over another or hide or fail to disclose my results, and I'm certainly not getting paid of monetizing my videos.

I have been criticized for trying to start a crowdfund to help finance my research, but the only donors were my two daughters. GoFundMe suggested that as a way to get the ball rolling. It didn't work.

Anyway, with that in mind, I don't believe Peter Lindemann is "in it for the money". What I will say though is I will not purchase any material from Emedia Press. I was about to once, to purchase a book Peter recommended, but during checkout it was necessary to agree to terms which essentially amounted to a non-disclosure agreement.

The problem there is that my research and Peters overlap, and overlap to such a degree as to run parallel to a great extent. Therefore, to agree to such terms I would be agreeing to not disclose my own research findings that might parallel or overlap with Peters.

Peter has assured me the agreement is unenforceable, however, a review of DMCA takedown requests in Peter Lindemann name, or associated with Emedia Press material tells a somewhat different story.

There has been rather aggressive action taken to protect Emedia Press assets. So, I'm in a bit of a pickle. I consider Peter a good friend and respected researcher and writer in the same "field" of research but I do not trust Emedia Press not to file some kind of legal action if I were to read any of his books.

With all that out of the way, there are a number of interviews and so forth freely available that have been uploaded to youtube that cover this subject of heat engines and the 2nd Law.

This one is on bitchute:

https://www.bitchute.com/video/k2pdMhmmbtQA


And also on YouTube:

---

....I believe wholeheartedly the second law of thermodynamics is either incorrect or incomplete. 

There is a member who pops his head in here and there named Tommy Reed.  He has made some Sterling engines.

I had no opinion about the second law. Generally I don't have a problem with it.

The "Carnot Efficiency Limit" however, especially the way it is being interpreted and currently taught seems completely outlandish to me, having no experimental basis whatsoever, and the so-called "equation" is not really anything but a thermometer reading. A difference in temperature.

Like the ratio calculated above, approximately 80% and 20% is just the distance you go up the thermometer reading. Temperature has what exactly to do with the quantity of heat in joules going into or coming out of the engine?

If anyone can somehow make some kind of sense out of that, it still doesn't wash. It doesn't hold up to experiment.

[ovun987]

Tom, really enjoying your posting here. I like your style and line of thinking. Very excited to learn more from your experiments and discoveries. Thank you for posting.

[Tom Booth]

Tom, really enjoying your posting here. I like your style and line of thinking. Very excited to learn more from your experiments and discoveries. Thank you for posting.

Thanks, it's nice to feel welcome somewhere (for a change). I've been going toe to toe with people on the various science, physics and other forums for years. The reception is not so great, often quite hostile. (I've been banned from most if not all the major Science and Physics forums) BTW, for anyone interested in it, I have always used my real name "Tom Booth" on all those forums, so a Google search (with my name in quotes along with "Stirling" "Tesla", "Self-Acting engine" will turn up many additional past discussions on various forums.

Anyway, here is an example of what I'm talking about:



I ran this experiment running one of my Stirling engines on near boiling hot water for several hours 

I used a double walled vacuum insulated cup to hold the hot water so as to retain heat, but also changed the hot water with fresh hot water at least 5 times during the course of the experiment. Later in other similar experiments I used a boiler to maintain a constant temperature.

Now, I've been told that infrared thermometers or cameras of this sort are "unreliable", but I've repeated these experiments many times in many different ways using various thermal measuring instruments with much the same result.

Here the thermal imagery clearly SEEMS to indicate that the top of this engine stays near to the temperature of the ambient surroundings. Needless to say, it also remained cool to the touch.

How it "felt" is subjective I know, but human sensation is just one "measure" among many others used, but perhaps the most convincing in some ways.

What is perhaps somewhat remarkable in this case is that, aside from the area near the power piston, which got warm, presumably due to friction from the piston sliding up and down in the cylinder, the rest of the exposed top side of the engine became, (after hours and hours of operating with boiling hot water below as a heat source), slightly colder than the ambient surroundings, according to the instrument readings.

Now, again, I've been told that these infrared cameras are supposedly unreliable due to emissivity and reflectivity and/or just generally "cheap" and unreliable, (I think it only cost me about  $200 or so, a substantial outlay for my budget). So dismissed offhand,  Nevertheless, even allowing for some "margin of error", how can it be imagined that the MAJORITY of the heat (at least 80% according to "Carnot efficiency limit" calculations) entering the engine is passing through to the cold side?

Heat does not flow from cold to hot, yet the readings show that the top of the engine is a degree or two below ambient.

That would suggest heat is being absorbed by the engine, taking in heat rather than "rejecting" heat, not only on the heated side, but also on the "cold" side to some degree.

I have developed a theoretical model to explain this. Needless to say it paints a very different picture of how these engines actually operate.

Not by heat "flowing through" like water.

[Tom Booth]

I do like to get as much input as possible from science professionals.

Doing a "vanity search" on old posts I've made over the years, I came across a science forum thread I had started way back in 2012. The discussion topic "Electricity from ambient heat"  was started by someone else and I came in late. The thread ended by being locked by a moderator.

Out of curiosity I tried logging in, and remarkably, I was not banned, or the ban expired after all these years, not sure.

Anyway, as I said, I like any input I can get from anyone more knowledgeable on a subject than myself so I went ahead and opened another topic there asking a simple question that I could never find a satisfactory answer to.

https://www.sciforums.com/threads/origin...th.166462/

On this page for example:

https://galileo.phys.virginia.edu/classe...Engine.htm

It states:

Efficiency  =  (TH−TC)/TH.
 
This was an amazing result, because it was exactly correct, despite being based on a complete misunderstanding of the nature of heat!

In all my research over the years, though, I have not been able to discover where exactly this formula originated or how it was determined to be "exactly correct" although based upon the obsolete Caloric theory

[Jim Mac]

I had no opinion about the second law. Generally I don't have a problem with it.

The "Carnot Efficiency Limit" however, especially the way it is being interpreted and currently taught seems completely outlandish to me, having no experimental basis whatsoever, and the so-called "equation" is not really anything but a thermometer reading. A difference in temperature.

Hi Tom,

Do you think breaking the Carnot Limit is also a violation of the 2nd law of thermodynamics?

"if a heat engine could exceed the Carnot limit, it would imply an efficiency of greater than 100% in extreme cases, effectively creating more energy than it consumes, which directly contradicts the conservation of energy."

I have no arguments to your views. I do believe efficiency of a machine can well exceed 100%.  And I hope you can nail this coffin shut for the world to see.

[Tom Booth]

Hi Tom,

Do you think breaking the Carnot Limit is also a violation of the 2nd law of thermodynamics?

... I hope you can nail this coffin shut for the world to see.

I'll tell you how things went when I took a 2 year course in small engine repair in high school. (Mid 70's)

Initially we were given no theory or instruction:

Each student was provided with an engine and a set of tools and told to take the engine in front of them on the workbench apart and put it back together again.

For the next few days the instructor mostly sat at his desk reading his newspaper.

After that we were told to bring in an engine from home, a neighbors engine, lawnmower, chain saw, generator, weed eater, whatever. There was no shortage of small engines that needed repair.

Mostly we had to all figure it out on our own with minimal interference or guidance.

In other words, to me your question is kind of like asking me if proving the Wizard of Oz was not a real wizard, would that prove that the land of Oz itself is not real?

I never heard of any "2nd Law" or 'Carnot Limit". before I (mostly) retired from internal combustion engine repair and became interested in Stirling external combustion engines, about 15 years ago, and then, I had zero interest in academic THEORY about how ANY engine operates.

As far as I'm concerned, thermodynamics is all poppycock. Some pipedream. Who in the world ever dreamt up all that  nonsense?

The whole field of thermodynamics is a muddle of contradictions and impossible fantasies.

All I know is, after retiring and studying Stirling engines for a while, I designed a combined Stirling engine and air-cycle refrigeration system for an acquaintance.

I didn't know at the time that he was a military contractor. He told me he wanted a design for a solar powered Stirling engine, It sounded like a good opportunity and maybe a lot of fun and a good income.

So after researching and designing I came up with what I thought was a perfectly good design for a Solar powered Stirling engine.

He got back to me saying he was told by someone, that my design "violated the second law of thermodynamics".

He seemed to be completely unwilling to discuss it any further. To this day, if I bring up the topic he'll change the subjects or say he's gotta go and hang up the phone.

So, after that I just took to the internet.

In my opinion, thermodynamics is more a conviction than a science. There is no talking any kind of common sense or logic with these people. The "Carnot Limit" is an article or faith.

What in the world is a "Carnot engine"?

If I can't put it on my workbench, tear it down and put it back together and get it running, it's not worth time talking about or even thinking about. It's complete and utter nonsense.

A heat engine is like a water wheel? Heat falls down like a water fall? Childish juvenile idiocy.

What I think people need to do is completely forget or ignore all that madness and stupidity and just take a fresh look at how heat REALLY behaves and how a heat engine really works.

IMO the whole field of thermodynamics, as far as how heat engines operate and what their limitations might, or might not be,  has no correspondence with reality whatsoever.

[Jack]

Hey Tom, I followed you in here. I'm still on the fence about all this and still want to discuss both "sides" equally. Can't do that on the Stirling engine forum, bit of a one sided story now.
And fool's little victory post doesn't sit right with me.

Anyway, hope you don't mind. I'm here to participate in the discussion and want to try and find out things for myself. With every respect to your opinions and findings. Because intuitively your story adds up better than the official story.

[chief colbacict]

Do you think breaking the Carnot Limit is also a violation of the 2nd law of thermodynamics?

In the special case of two reservoirs, Tн and Tх, we take heat Q from the heater, do work A and transfer (Q-A) to the refrigerator. Clausius inequality:
Q/Tн - (Q-A)/Tх ≤ 0 , we transfer, rewrite: A/Q ≤ 1 - Tх/Tн = (Tн - Tх)/Tн