Is Carnot efficiency valid?

[Tom Booth]

1 hour ago, Ghideon said:

That seems reasonable. But under the insulation the temperature will be rather stable once the Stirling engine has run for a while? Temperature will likely vary depending on the load and added heat (and more) but if the effect you propose is there the temperature should read below ambient if the insulation is good enough. Initially it is good enough tho show experimentally, beyond doubt and in a repeatable fashion, that effect you predict exits; exact numbers can be found in later experiments?

Well, it is already widely accepted fact that a Stirling engine acts as a heat pump when turned over manually, in the same way and in the same direction that it normally runs as an engine.

There are many, many, many different heat engines or "hot air" engines out there that are lumped together as "Stirling". To name a few, the LTD (Stirling) engine is of rather recent origin as is the Ringbom (Stirling) the "thermoacoustic" (Stirling), Free Piston, free displacer, "Rice"-thermoacoustic (literally the rice people eat) is absolutely astonishing, Laminar flow, Thermal lag, "metronome", fluidine etc etc aside from the broad categories or designations alph, beta, gamma, so making broad generalizations about what "will" happen or what is "predicted" is misleading at best.

Most of the engines I purchased for experimenting with were immediately modified. Metal heat conducting bolts replaced with non-heat conducting nylon bolts. The timing/advance angle manually set to the "best" position in my own estimation based on the resulting performance and so forth.

In the case of the ice freezing (apparently) I don't know exactly how I set the timing.

My plan was to put some grinding compound on the piston/power cylinder and let it run on ice until it ran more freely to break in the new epoxy piston.

I had to adjust the timing several times to a position where the engine would run, the piston intentionally gummed up with grinding paste. I don't know exactly what I set the advance to as I did not intend that to be a controlled experiment, I was just attempting to break in the new epoxy piston in preparation for using it in a future experiment.

I'm quite sure the "conditions" are fairly easily reproducible (for someone who has some idea what they are doing), but these things take time and money. I just sent away for that upside down engine for $60 for example.

My point is, I don't actually know what caused the ice to re-freeze. (Four times in 45 minutes). But it sure didn't seem like a lot of heat was being pumped through the engine.

The ice came straight out of the freezer so was probably well below 0°C.

Possibly there was enough cold in the ice to cause it to refreeze when covered or re-covered over after beginning to melt on the surface. But like I say, the engine was room temperature. Just weird that the ice should keep re-freezing IMO if the engine is passing heat through to the ice AT ALL while running.

Personally, I think your idea of putting the cold sides of two engines back to back is brilliant and virtually fool proof.

If some ice is used to get the engines going, well, it either melts eventually or it doesn't. If it melts, that can't really be attributed to insulation leakage if the only thing on the other side of the engine is another identical engine.

Honestly I've been scratching my head over the problem for years already and you come up with a solution almost instantly.

It is, theoretically, like having two refrigerator/freezers back to back or front to front chilling the same freezer compartment. How could it not get cold if the freezers are actually functional. Better really. Conventional freezers still require insulation. This could be arranged in a way that doesn't.

You are a genius.

 

[swansont]

3 hours ago, Tom Booth said:

Probably none. That's the point. It's an anomaly that appears to run contrary to "known science".

Mechanical devices getting stuck violate NO principles of known science.

 

 

[sethoflagos]

3 hours ago, Ghideon said:

Recommendation: don't focus too much on ice based experiments unless you have some way to properly control the temperature of the ice. There seem to be many sources of errors which allows for different interpretations and varying outcomes. 

A good and important point @Ghideon

An ice block fresh out of the freezer should be oto -18 ^oC (0 ^oF) throughout. Even it has been left a while, the surface may well be at freezing point, but the bulk of the inside may be considerably colder. 

When it is placed under the cold plate of a Stirling engine, it is effectively insulated from ambient air while it continues to lose heat to the inside of the block.

It is entirely consistent for the engine to appear to run well, rejecting a certain amount of heat to the ice interface, while that interface freezes and cools further due to a greater heat loss to the core.

The cold reservoir is in this case the core of the ice block and the distribution of its temperature is unknown.

[Tom Booth]

3 hours ago, Ghideon said:

Recommendation: don't focus too much on ice based experiments unless you have some way to properly control the temperature of the ice. There seem to be many sources of errors which allows for different interpretations and varying outcomes.

 

If this were under government contract or grant or something  maybe we could milk it for all it's worth I suppose, but with nearly zero budget at my disposal, ice will probably have to do for now.

BTW you might be interested to know that I just posted your idea to the Stirling Engine forum as THE solution.

https://stirlingengineforum.com/viewtopic.php?f=1&t=478&p=18490#p18490

Hope you have no objections, and hopefully not against forum rules.

I think it may be the longest running (still active) thread on the forum. (Since 2010).

42 minutes ago, swansont said:

Mechanical devices getting stuck violate NO principles of known science.

 

 

The mechanical part did not get stuck. The engine continued running.

The engine running "on ice" (ambient heat) "stuck" to the ice which re-froze. Ice that had already begun to melt. It required considerable force to break the engine free.

I'd break the engine loose, watch the ice get wet and slippery, starting to melt, put the now WARM engine back on the ice and the ice would freeze again. The engine would eventually get frozen solid to the ice so it could not be lifted off. That took about ten minutes.

You can dismiss that with your flippant comment as if it's nothing, but I was there, I had to pry the engine loose from the ice over and over. There was no mechanical failure with the engine. It kept running the entire time.

Edited February 1, 2023 by Tom Booth

[swansont]

28 minutes ago, Tom Booth said:

The mechanical part did not get stuck. The engine continued running.

So you’re coming up with a new definition of stuck? “For example, I say my engine got "stuck", apparently frozen.”  But it wasn’t a mechanical part? How does a non-mechanical part get stuck? To be stuck, doesn’t it need to be something that normally moves? 

You definitely need to post pictures, with circles and arrows on them, because your descriptions are lacking sufficient detail.

[Tom Booth]

41 minutes ago, sethoflagos said:

A good and important point @Ghideon

An ice block fresh out of the freezer should be oto -18 ^oC (0 ^oF) throughout. Even it has been left a while, the surface may well be at freezing point, but the bulk of the inside may be considerably colder. 

When it is placed under the cold plate of a Stirling engine, it is effectively insulated from ambient air while it continues to lose heat to the inside of the block.

It is entirely consistent for the engine to appear to run well, rejecting a certain amount of heat to the ice interface, while that interface freezes and cools further due to a greater heat loss to the core.

The cold reservoir is in this case the core of the ice block and the distribution of its temperature is unknown.

Good explanation. 

I more or less think that is probably what happened, but, in my mind, according to the Carnot theory, I figured the engine should melt the ice nearly as quickly as the ambient air itself. That 80% minimum pass through of "waste heat"

Also I had run the same engine in the same way, on the same ice in the same container type, everything the same possibly a dozen times already and nothing like that happened before.

The only thing different was the extra work the engine was doing, and possibly the timing might have been a little different.

As a reasonable alternative explanation though, I agree, maybe that's all it was.

1 minute ago, swansont said:

So you’re coming up with a new definition of stuck? “For example, I say my engine got "stuck", apparently frozen.”  But it wasn’t a mechanical part? How does a non-mechanical part get stuck? To be stuck, doesn’t it need to be something that normally moves? 

 

The engine was on a double wall vacuum insulated cup full of ice (the cup was from Walmart a cheap makeshift Dewar) 

The engine, started out at ambient temperature, about 80°F

I had the cup of ice in the freezer. Took it out of the freezer and set the engine on top. I was not in any particular hurry about this. By the time I started the engine the ice had already started melting and was slippery and the engine kept sliding off the wet ice.

I decided to use my usual experimental setup with the cup wrapped in insulation, styrofoam and blanket around the whole setup just to prevent the engine from sliding off the slippery wet ice.

Once I had the engine stable on the ice and able to run after adjusting the timing, I just let it run for a while.

Normally with that setup, I can very easily just lift the engine up off of the cup of ice.

This time when I went to check on the progress to see if the piston was more free to move or not with the honing job, when I went to lift the engine, I couldn't. It had become stuck to the ice. It was stuck to the ice. Could not be moved. The bottom of the engine was frozen solid and stuck to the ice.

Like if you touch cold metal with a wet finger and your finger gets stuck to the cold metal.

Cambridge dictionary for "stuck"

Quote

unable to move from a particular position or place

The engine could not be lifted from it's position on the ice, it was stuck to the ice.

This is why I think a video can be valuable, no lengthy explanation required, no confusion about the meaning of words.

[swansont]

1 hour ago, Tom Booth said:

The engine could not be lifted from it's position on the ice, it was stuck to the ice.

This is why I think a video can be valuable, no lengthy explanation required, no confusion about the meaning of words.

And you can post video as long as the discussion can proceed without having to view it. IOW, as long as the lengthy explanation is there.

[sethoflagos]

1 hour ago, Tom Booth said:

Good explanation. 

I more or less think that is probably what happened, but, in my mind, according to the Carnot theory, I figured the engine should melt the ice nearly as quickly as the ambient air itself. That 80% minimum pass through of "waste heat"

The only load on the machine is frictional losses, which should be very small and most of those are retained within the system. If waste heat is actually 4 times the work output (it will be a little more), simply ask yourself what 4*0 is equal to.

It might be helpful to know what these no-load losses are:

If you are able to secure a cotton bobbin squarely and centrally on the flywheel and a small weight to the free end of the cotton you can time how long it takes for the weight to drop through say 3 feet. Try and find a weight that's large enough to turn the machine, but small enough to take at least 10 seconds to cover the distance (for timing accuracy). Repeat until your results are consistent and you have at least 10 timings. Then post the timings here along with the distance of travel, size of weight used and the diameter of the bobbin would be interesting as well.

[Tom Booth]

1 hour ago, swansont said:

And you can post video as long as the discussion can proceed without having to view it. IOW, as long as the lengthy explanation is there.

Sounds reasonable. In this case some explanation is necessary because it is just a short 2 minute or so segment of a rather lengthy occurrence. The video only shows me prying the engine loose from the ice one time, but this re-freezing of the ice kept happening over and over every time I placed the engine back onto the ice and started it running again. I'd come back ten or fifteen minutes later and it would be stuck again.

After it happened two or three times I got my camera and took the following video, just on the chance it happened again. It did. And then again when I was uploading the video. After that I just let it run and went to bed because I was tired and it was late and I wanted to see what would happen.

When I woke up the engine had stopped and the ice had melted. I couldn't use the engine after that because it had been ground down too much. It apparently ran until it lost compression and then stopped.

So I couldn't determine if it stopped because the ice melted and it lost power, or did it stop because of loosing compression due to the grinding compound.

All I knew for sure is it was ruined, had lost compression, the seal around the piston leaked too much air. and it could no longer be started.

 

I wouldn't have thought much about it, or I would say, the significance of it seemed greater when I saw an additional video where it appears that a similar low temperature Stirling got stuck to a block of ice in open air, that is, no insulation around anything.

He stated in the video that the engine runs faster and faster as it gets colder and colder, then he picks up the engine and the ice comes up with it apparently stuck like mine was. A rather large heavy block of ice.

In the beginning of the video the engine is constantly sliding to the side almost falling off the wet block of ice but then gradually the engine becomes stable and doesn't slide around any more  gets stuck to the ice like mine did is how it looked to me.

If that is enough explanation I can post that video also?

https://youtu.be/L6Jmdve1JK8?list=PLpx2INw8sRqqVTK-hBBerAnBsnwr82var

I know, an alternative explanation is that the wet melting ice stuck on the bottom of the engine like a wet suction cup. But after experiencing the same sort of thing I would have to say it was actually frozen.

At first the engine is sliding around and he has to keep repositioning it on the ice.

Well maybe the room he was in was very cold, below freezing. I don't know, but I know what it looks like. Like my engine, his stopped sliding around and got stuck when the engine ran for a few minutes and the bottom of the engine got cold. 

The engines had to be at least reducing the amount of heat reaching the ice for it to have a chance to re-freeze itself from within.

That is what those flow charts show right?

Some heat converted to work so less heat reaches the ice.

But would just a little less heat allow the ice to refreeze like that?

Seems like it would take a whole lot less heat IMO like less than no heat, like maybe putting the ice back in the ice box for a while.

Maybe the guy was using dry ice?

I don't think the engine would slide around like that on dry ice.

1 hour ago, sethoflagos said:

The only load on the machine is frictional losses, which should be very small and most of those are retained within the system. If waste heat is actually 4 times the work output (it will be a little more), simply ask yourself what 4*0 is equal to.

It might be helpful to know what these no-load losses are:

If you are able to secure a cotton bobbin squarely and centrally on the flywheel and a small weight to the free end of the cotton you can time how long it takes for the weight to drop through say 3 feet. Try and find a weight that's large enough to turn the machine, but small enough to take at least 10 seconds to cover the distance (for timing accuracy). Repeat until your results are consistent and you have at least 10 timings. Then post the timings here along with the distance of travel, size of weight used and the diameter of the bobbin would be interesting as well.

I would assume a weight that was an even metric weight like 10 grams might be helpful?

The only problem is that directly under the center of the flywheel is the engine. Maybe turn it upside down.

Are you interested in the piston being extremely tight and gummed up with grinding compound paste or just an ordinary off the shelf engine. Or both or what, and why? Just out of curiosity.

Calculating frictional loses, no load work involved in just turning the engine. Something like that?

Here is a screenshot from the video at the moment he picks up the engine and the block of ice comes up with it.

 

Edited February 2, 2023 by Tom Booth

[studiot]

9 hours ago, Tom Booth said:

The engine could not be lifted from it's position on the ice, it was stuck to the ice.

This is why I think a video can be valuable, no lengthy explanation required, no confusion about the meaning of words.

Like everybody here I too thought your use of the word 'stuck' meant that the engine had stopped running, from the context.

So thank you for putting that right, stuck to the ice is perfectly acceptable, but the general misunderstanding shows the value of respectful discussion.

I agree that a video can be a valuable addition, especially if it is short enough, to confirm the salient points.

But these salient points should always be listed in writing.

Photos and diagrams are also important, but as swansont says should be properly annotated to focus attention on the salient points. I use PaintShopPro for this.

Likewise it is helpful if the video can be annotated with a voiceover and the demonstrator pointing out the salient points with finger or pointer.

 

Please note this thread is allegedly about Carnot, not Stirling.

I do not wish to make a formal off topic complaint which might lead to its closure but I would like to reiterate that I think you still have not understood the true meaning of a hot source or a cold sink (since you seem to wish to use those terms).

I have offered you a formal definition and a block diagram in order to help as proper understanding stands at the very beginning of any analysis. In particular what heat gains and losses occur and where, how and why they occur.

This understanding is also essential to sensible and efficient experimentation technique..

It is so important that perhaps discussing this one subject merits a thread of its own.  What do you think ?

 

 

[sethoflagos]

8 hours ago, Tom Booth said:

I would assume a weight that was an even metric weight like 10 grams might be helpful?

Any small known weight sufficient to turn the engine but not too fast.

8 hours ago, Tom Booth said:

The only problem is that directly under the center of the flywheel is the engine. Maybe turn it upside down.

That should work.

8 hours ago, Tom Booth said:

Are you interested in the piston being extremely tight and gummed up with grinding compound paste or just an ordinary off the shelf engine. Or both or what, and why? Just out of curiosity.

It must be an operable engine. We have no interest in performance data for ruined engines.

8 hours ago, Tom Booth said:

Calculating frictional loses, no load work involved in just turning the engine. Something like that?

Something like that.

If you can perform a second experiment experiment with the displacer linkage disconnected (if this is possible without breaking the engine) then that would be useful too.

[Tom Booth]

1 hour ago, studiot said:

Please note this thread is allegedly about Carnot, not Stirling.

I do not wish to make a formal off topic complaint which might lead to its closure but I would like to reiterate that I think you still have not understood the true meaning of a hot source or a cold sink (since you seem to wish to use those terms).

I have offered you a formal definition and a block diagram in order to help as proper understanding stands at the very beginning of any analysis. In particular what heat gains and losses occur and where, how and why they occur.

This understanding is also essential to sensible and efficient experimentation technique..

It is so important that perhaps discussing this one subject merits a thread of its own.  What do you think ?

 

 

Well, there is a guy named Karl Popper, as you probably already know. Falsifiability is mentioned in the rules here under this "speculations" heading.

Arguably, an actual Carnot engine does not meet that criteria of falsifiability, would you agree?

Quick definition via Google: https://www.simplypsychology.org/Karl-Popper.html#:~:text=The Falsification Principle%2C proposed by,by observing a black swan.

Quote

The Falsification Principle, proposed by Karl Popper, is a way of demarcating science from non-science. It suggests that for a theory to be considered scientific it must be able to be tested and conceivably proven false.

Does anyone have a genuine Carnot engine we can test to prove empirically by experiment that it is actually, ... well, ANYTHING?

How about our perfect hot and cold reservoirs? Is there anything about them we could actually run some kind of experiment on? Use to run any kind of engine?

How about the various thermodynamic processes? Isothermal, Adiabatic etc.

Can we test an engine that sports true Isothermal expansion?

Don't get me started on "Entropy".

Allegedly, all these things constitute "established science", so I'm told.

Established when? Where? How? By whom? 

What procedure was used?

Measurements? Actual Data?

I see one thing at least that can be tested in all this; the presence or absence of waste heat leaving a real engine which the Carnot efficiency limit equation suggests is the reciprocal of the work output.

We cannot test the heat input, output, work or whatever of a Carnot engine for any sort of comparison whatsoever, but there is the Axiom, the formula from which it is possible to calculate the maximum efficiency and therefore the minimum reciprocal of efficiency, the waste heat.

Can we measure the waste heat output of some real engine?

Personally, I don't see why not.

Certainly the simple actual presence or absence of any waste heat could be determined if not the actual percentages with exactitude.

As I understand it, there absolutely cannot be < 0 (less than zero).

To disprove the Carnot efficiency equation however, (as currently interpreted) we actually only need to find < 80% of the heat input at the output.

I've basically been told that my measurement of what seems like very near ZERO heat output from my Stirling engine simply means that the heat input is zero. 4 X 0 = 0 so we can all go home satisfied.

Is that really reasonable? Is that argument sufficient? Everybody's happy with that?

Do we need a new thread to define source and sink?

Personally I think everybody has those concepts under their belt, but if you feel they, or something related needs clarification, I have no objections. Agreement regarding terminology is certainly a necessity as a basis for communication.

Edited February 2, 2023 by Tom Booth

[studiot]

5 minutes ago, Tom Booth said:

Everybody's happy with that?

Sigh.

You went to the bother of quoting my post.

And got me all excited.

Thinks : "Perhaps he has bothered to read it."

But No.

Another gargantuan post containing everything but an answer to a simple question.

Thank you for wasting my time yet again.

I am now formally reporting this nonsensical saga.

 

[Tom Booth]

48 minutes ago, sethoflagos said:

Any small known weight sufficient to turn the engine but not too fast.

That should work.

It must be an operable engine. We have no interest in performance data for ruined engines.

Something like that.

If you can perform a second experiment experiment with the displacer linkage disconnected (if this is possible without breaking the engine) then that would be useful too.

OK,

The only possible bone I have to pick is that the conditions I observed where an apparent refrigeration effect took place was with the engine laboring under what I would consider a fairly substantial load. The engine was not ruined until after some extended run time. I think any other substantial load that does not bring the engine to a complete stop would be suitable and cause no harm to the engine. A sime brake of some kind on the flywheel for example, commonly used to test engines. I think that additional data would be important.

Any particular preference as far as the type of engine? Off the shelf, or my own "customized" version generally used for experiments?

14 minutes ago, studiot said:

Sigh.

You went to the bother of quoting my post.

And got me all excited.

Thinks : "Perhaps he has bothered to read it."

But No.

Another gargantuan post containing everything but an answer to a simple question.

Thank you for wasting my time yet again.

I am now formally reporting this nonsensical saga.

 

Wow.

What question exactly did I miss?

Edited February 2, 2023 by Tom Booth

[sethoflagos]

2 minutes ago, Tom Booth said:

Any particular preference as far as the type of engine? Off the shelf, or my own "customized" version generally used for experiments?

Off the shelf for sure. Then we have repeatability by other experimenters.

[Tom Booth]

I posted my response just a few minutes ago. Studiot.

11 minutes ago, sethoflagos said:

Off the shelf for sure. Then we have repeatability by other experimenters.

A certain load or drag on a flywheel is not repeatable?

I think both measurements are VERY significant and easily repeatable. Load and no load.

The question relates to work output being correlated with waste heat output. The reciprocal relationship could be plotted on a graph. See how waste heat output correlates with work output etc. Vital information.

Edited February 2, 2023 by Tom Booth
To address response to Studiot changed "work output" to "waste heat" for clarification

[exchemist]

38 minutes ago, Tom Booth said:

Well, there is a guy named Karl Popper, as you probably already know. Falsifiability is mentioned in the rules here under this "speculations" heading.

Arguably, an actual Carnot engine does not meet that criteria of falsifiability, would you agree?

Quick definition via Google: https://www.simplypsychology.org/Karl-Popper.html#:~:text=The Falsification Principle%2C proposed by,by observing a black swan.

Does anyone have a genuine Carnot engine we can test to prove empirically by experiment that it is actually, ... well, ANYTHING?

How about our perfect hot and cold reservoirs? Is there anything about them we could actually run some kind of experiment on? Use to run any kind of engine?

How about the various thermodynamic processes? Isothermal, Adiabatic etc.

Can we test an engine that sports true Isothermal expansion?

Don't get me started on "Entropy".

Allegedly, all these things constitute "established science", so I'm told.

Established when? Where? How? By whom? 

What procedure was used?

Measurements? Actual Data?

I see one thing at least that can be tested in all this; the presence or absence of waste heat leaving a real engine which the Carnot efficiency limit equation suggests is the reciprocal of the work output.

We cannot test the heat input, output, work or whatever of a Carnot engine for any sort of comparison whatsoever, but there is the Axiom, the formula from which it is possible to calculate the maximum efficiency and therefore the minimum reciprocal of efficiency, the waste heat.

Can we measure the waste heat output of some real engine?

Personally, I don't see why not.

Certainly the simple actual presence or absence of any waste heat could be determined if not the actual percentages with exactitude.

As I understand it, there absolutely cannot be < 0 (less than zero).

To disprove the Carnot efficiency equation however, (as currently interpreted) we actually only need to find < 80% of the heat input at the output.

I've basically been told that my measurement of what seems like very near ZERO heat output from my Stirling engine simply means that the heat input is zero. 4 X 0 = 0 so we can all go home satisfied.

Is that really reasonable? Is that argument sufficient? Everybody's happy with that?

Do we need a new thread to define source and sink?

Personally I think everybody has those concepts under their belt, but if you feel they, or something related needs clarification, I have no objections. Agreement regarding terminology is certainly a necessity as a basis for communication.

Don't be ridiculous. This is a total ranting rhetorical muddle as usual and contains a stupid straw man. There is no such thing as a "Carnot engine". You have made that up.

There is a Carnot cycle, which, as several people have told you several times, is a theoretical optimum heat engine cycle whose thermal efficiency, according to the theory of thermodynamics, no real engine can exceed.  

The theory of the Carnot cycle would thus obviously be falsified if someone were to produce a heat engine exceeding Carnot cycle efficiency. So it is - obviously-  a falsifiable theory, in Popper's terms. 

 

Edited February 2, 2023 by exchemist

[studiot]

23 minutes ago, Tom Booth said:

Wow.

What question exactly did I miss?

 

Might that be the line at the end, the only line in the post with a question mark at the end.

The rest of the post was , of course, useful information.

9 minutes ago, exchemist said:

Don't be ridiculous. This is a total ranting rhetorical muddle as usual and contains a stupid straw man. There is no such thing as a "Carnot engine". You have made that up.

There is a Carnot cycle, which, as several people have told you several times, is a theoretical optimum heat engine cycle whose thermal efficiency, according to the theory of thermodynamics, no real engine can exceed.  

The theory of the Carnot cycle would thus obviously be falsified if someone were to produce a heat engine exceeding Carnot cycle efficiency. So it is - obviously-  a falsifiable theory, in Popper's terms. 

 

Thank you +1

[Tom Booth]

4 minutes ago, exchemist said:

Don't be ridiculous. This is a total ranting rhetorical muddle as usual and contains a stupid straw man. There is no such thing as a "Carnot engine". You have made that up.

There is a Carnot cycle, which, as several people have told you several times, is a theoretical optimum heat engine cycle whose thermal efficiency, according to the theory of thermodynamics, no real engine can exceed.  

The theory of the Carnot cycle would thus obviously be falsified if someone were to produce a heat engine exceeding Carnot cycle efficiency. So it is - obviously-  a falsifiable theory, in Popper's terms. 

 

The "Carnot efficiency" relates to the environment, not the engine. So it is not even theoretically possible to build or "produce an engine" that exceeds the result of calculations unrated to the performance of the engine.

Well, with a possible exception.

If the engine is also capable of changing the surrounding environment.

2 minutes ago, studiot said:

 

Might that be the line at the end, the only line in the post with a question mark at the end.

I think I did answer that. Your usual rabid impatience resulted in us cross posting. I was still reading through your post and editing, apparently. It happens.

[Ghideon]

13 hours ago, sethoflagos said:

An ice block fresh out of the freezer should be oto -18 ^oC (0 ^oF) throughout. Even it has been left a while, the surface may well be at freezing point, but the bulk of the inside may be considerably colder. 

When it is placed under the cold plate of a Stirling engine, it is effectively insulated from ambient air while it continues to lose heat to the inside of the block.

It is entirely consistent for the engine to appear to run well, rejecting a certain amount of heat to the ice interface, while that interface freezes and cools further due to a greater heat loss to the core.

The cold reservoir is in this case the core of the ice block and the distribution of its temperature is unknown

Thanks for your comments! I guess proportions are also a concern; a really large piece of ice on a low power engine allows for other factors to have significant impact? Also freezers are maybe not built to precision, hysteresis may allow for the ice to have different temperatures. A few degrees may make a difference when a small engine melts the ice.

[Tom Booth]

13 minutes ago, studiot said:

 

Might that be the line at the end, the only line in the post with a question mark at the end.

The rest of the post was , of course, useful information.

Thank you +1

[Ghideon]

12 hours ago, Tom Booth said:

Hope you have no objections,

Sharing is ok with me but note that my question was a rethorical. Elaborating may take the thread off topic but I’ll clarify if you wish. 

[exchemist]

15 minutes ago, Tom Booth said:

The "Carnot efficiency" relates to the environment, not the engine. So it is not even theoretically possible to build or "produce an engine" that exceeds the result of calculations unrated to the performance of the engine.

Well, with a possible exception.

If the engine is also capable of changing the surrounding environment.

 

That's ballocks. It is an ideal theoretical engine cycle, with constant temperature heat input and output. The environment has nothing to do with it.    

[Tom Booth]

2 minutes ago, Ghideon said:

Sharing is ok with me but note that my question was a rethorical. Elaborating may take the thread off topic but I’ll clarify if you wish. 

Well OK. Rhetorical.

So you thought I would say "Oh no, that can't work!!!" or some such response?

Hey, my theory is perfectly falsifiable by your method. I'm very grateful for the suggestion. If there is a way to DISPROVE it, conclusively, then I can put all this behind me and get on with the rest of my life.

I have no desire to continue wasting time and money on nonsense.

 

[Ghideon]

1 minute ago, Tom Booth said:

Well OK. Rhetorical.

So you thought I would say "Oh no, that can't work!!!" or some such response?

Hey, my theory is perfectly falsifiable by your method. I'm very grateful for the suggestion. If there is a way to DISPROVE it, conclusively, then I can put all this behind me and get on with the rest of my life.

I have no desire to continue wasting time and money on nonsense.

 

The logical consequence of your idea seems to be that you are just one simple component short of creating a major breakthrouh in physics. But I do not believe in such machinery therefore my question was rethorical. But I would be happy to be proven wrong.