Isolated cold hole

Discussion on Stirling or "hot air" engines (all types)
VincentG
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Re: Isolated cold hole

Post by VincentG »

Still, if you calculate the joules going in to heat the box with the engine not powering an external generator outside the box and get a 20° temperature rise inside the box.

Then run the experiment again with the heat engine running a generator that powers a heater outside the box and get the same 20° temperature rise inside the box while also generating additional heat outside the box, then you would have a "spontaneous" generation of heat from nothing.
I believe the work will come from the kinetic energy of the gas at elevated temperature. Normally the kinetic energy is wasted, as pressure only increases linear to temperature, while molecular energy does not, as evident by the emission of visible light above a certain temperature, and phase changes.

A miniature oxygen acetylene torch can cut though steel but could never heat your house through direct thermal transfer.

A fuel oil flame can heat your house but could never cut through steel.

A much lower temperature than either is actually required to heat your house.

The much higher temperature of the oxygen torch is representative of a much higher state of energy that required more work/energy to obtain. To only use the caloric heat(measured in calories or joules), would be a gross waste of energy. A much better use of the high temperature would be to force it to flow through a gas which allows that kinetic energy to be converted to work, while then allowing the total caloric heat to pass through with minimal losses.

I think Tom has been for years observing the conversion of nonlinear kinetic energy, not the linear scale of "heat" as we normally experience it. It stands to reason then that an external combustion engine cannot and never will measure high in "efficiency", and that the regenerator only serves to strangle these engines, which should be designed to allow energy to pass through, and not be recycled internally.

The ECE should then IMO have two forms. One is a low-tech design meant to scavenge low grade heat as it equalizes to ambient, the other is a high-tech design meant to convert very high temperature to high pressure. The latter is something that could benefit from someone like Elon Musk and SpaceX with their extreme temperature alloys and high-performance insulation tiles.
Tom Booth
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Re: Isolated cold hole

Post by Tom Booth »

VincentG wrote: Tue Nov 12, 2024 11:16 am
Still, if you calculate the joules going in to heat the box with the engine not powering an external generator outside the box and get a 20° temperature rise inside the box.

Then run the experiment again with the heat engine running a generator that powers a heater outside the box and get the same 20° temperature rise inside the box while also generating additional heat outside the box, then you would have a "spontaneous" generation of heat from nothing.
I believe the work will come from the kinetic energy of the gas at elevated temperature. Normally the kinetic energy is wasted, as pressure only increases linear to temperature, while molecular energy does not, as evident by the emission of visible light above a certain temperature, and phase changes.

A miniature oxygen acetylene torch can cut though steel but could never heat your house through direct thermal transfer.

A fuel oil flame can heat your house but could never cut through steel.

A much lower temperature than either is actually required to heat your house.

The much higher temperature of the oxygen torch is representative of a much higher state of energy that required more work/energy to obtain. To only use the caloric heat(measured in calories or joules), would be a gross waste of energy. A much better use of the high temperature would be to force it to flow through a gas which allows that kinetic energy to be converted to work, while then allowing the total caloric heat to pass through with minimal losses.

I think Tom has been for years observing the conversion of nonlinear kinetic energy, not the linear scale of "heat" as we normally experience it. It stands to reason then that an external combustion engine cannot and never will measure high in "efficiency", and that the regenerator only serves to strangle these engines, which should be designed to allow energy to pass through, and not be recycled internally.

The ECE should then IMO have two forms. One is a low-tech design meant to scavenge low grade heat as it equalizes to ambient, the other is a high-tech design meant to convert very high temperature to high pressure. The latter is something that could benefit from someone like Elon Musk and SpaceX with their extreme temperature alloys and high-performance insulation tiles.
You have me pretty thoroughly confused.

A "Joule" is a very specific and well defined unit of energy.

You're throwing around terms and concepts that appear to be "made up"? And have not been defined again, so I am having difficulty following whatever it's you're saying

Just for example: "I think Tom has been for years observing the conversion of nonlinear kinetic energy, not the linear scale of "heat" as we normally experience it".

How do you define "nonlinear kinetic energy"?

OK you say: "Normally the kinetic energy is wasted, as pressure only increases linear to temperature, while molecular energy does not, as evident by the emission of visible light above a certain temperature, and phase changes."

So, for example, you can boil a pot of water, putting energy into it but the temperature remains at 0°C ???

Assuming no phase change, for a gas, temperature is considered a direct measure of the kinetic energy or "internal energy" of the gas.

At any rate, if you heat the engine inside the box with 100 joules, and end up with 100 joules still in the box and additional heat generated by a resistance heating element outside the box, I think we still have a problem with conservation of energy .
VincentG
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Re: Isolated cold hole

Post by VincentG »

Simply put, you can boil water with a yellow flame or a blue flame but the overall energy going into the water is the same. Putting combustion efficiency aside, the blue flame is less efficient because the high temperature is wasted, as the end goal is only the temperature of boiling water.

I'm just speculating that energy as measured in a given quantity is not directly converted to work at all, but instead the temperature as measured in molecular speed/internal energy is converted to work.
At any rate, if you heat the engine inside the box with 100 joules, and end up with 100 joules still in the box and additional heat generated by a resistance heating element outside the box, I think we still have a problem with conservation of energy .
If the 100 joules is delivered by a sufficiently high temperature as compared to the ambient box, than yes it could be considered a problem. I would argue it is not, as the end result would leave two states of energy that are not able to return back to their higher temperature starting state without external work input(heat pump).
Tom Booth
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Re: Isolated cold hole

Post by Tom Booth »

Fool wrote: Tue Nov 12, 2024 10:19 am
Tom Booth wrote: Mon Nov 11, 2024 5:37 pm
Fool wrote: Mon Nov 11, 2024 5:14 pm .

I have. You don't understand. You don't even try.
I can in fact put a scientific test/experiment together in a properly equipped lab and document the process properly.
I said prove it.

Do any experiment, video record it and post the results.

I don't think you can tie your own shoelace.
I would be happy to do so and get right on it, as soon as I'm provided a properly equipped laboratory and a salary ...
In other words, no you can't.
Fool
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Re: Isolated cold hole

Post by Fool »

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In other words, 'you need to pay me to do your pointless pursuits'.

Vincent both the yellow flame and blue flame are converted to boiling equally efficiently. 100%. What you are loosing is the ability to convert more energy to work. The blue flame to boiling has the possibility of being converted to more work than the yellow flame.

The question then becomes, 'what are you going to use the heat for?', and how much will it cost? The blue flame may have a more efficient conversion of fuel energy to work, but, the yellow flame may give a cheaper ride.


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Tom Booth
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Re: Isolated cold hole

Post by Tom Booth »

VincentG wrote: Tue Nov 12, 2024 1:47 pm Simply put, you can boil water with a yellow flame or a blue flame but the overall energy going into the water is the same. Putting combustion efficiency aside, the blue flame is less efficient because the high temperature is wasted, as the end goal is only the temperature of boiling water.

I'm just speculating that energy as measured in a given quantity is not directly converted to work at all, but instead the temperature as measured in molecular speed/internal energy is converted to work.
At any rate, if you heat the engine inside the box with 100 joules, and end up with 100 joules still in the box and additional heat generated by a resistance heating element outside the box, I think we still have a problem with conservation of energy .
If the 100 joules is delivered by a sufficiently high temperature as compared to the ambient box, than yes it could be considered a problem. I would argue it is not, as the end result would leave two states of energy that are not able to return back to their higher temperature starting state without external work input(heat pump).
Well, I still don't think I get it.

Looking forward to seeing your larger epoxy chamber engine finished though, and the results of any experiments you end up doing.

As far as theories about heat go, I don't really have any. Or conservation or energy, "overunity", perpetual motion, whatever.

All I know is none of my engines stop running regardless of how well the "cold side" is insulated. I cannot "feel" or measure any heat coming through, if all the avenues for direct heat conduction are removed, even when the hot bottom plate is impossible to touch (scorching hot from boiling water) for hours on end.

This is interesting, but unfortunately open to some question as the "dummy" engine on the left is not actually an engine.
stirling2.png
stirling2.png (172 KiB) Viewed 1014 times
https://concord.org/blog/an-infrared-in ... ng-engine/

However, you've seen my own thermal camera images and videos showing a similar, apparently cold top above an otherwise hot engine.

I should redo that concord experiment but using two real Stirling engines, one running and the other not. The displacer and air space are both good insulators and no real telling what he is using for the dummy engine there, what material, solid, hollow, tin, aluminium?

Anyway, my expectations for your experiment is that the box does not get hot at all, if you can ensure in some way that the heat cannot enter the box other than through the working fluid of the running engine. All friction points that could generate heat from the work output are outside the box and some load powered by a generator is outside the box.

Something like this:
Compress_20241112_193431_1110.jpg
Compress_20241112_193431_1110.jpg (14.09 KiB) Viewed 1014 times
Tom Booth
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Re: Isolated cold hole

Post by Tom Booth »

Fool wrote: Tue Nov 12, 2024 5:22 pm .

In other words, 'you need to pay me to do your pointless pursuits'.
...
Not my pointless pursuits, I said any experiment at all. Take your pick.

Let's see you tie your shoelace without your mommy helping for example.
Fool
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Re: Isolated cold hole

Post by Fool »

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Your pursuit, right now is to get me to do professional work without compensation. Good luck with that.

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VincentG
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Re: Isolated cold hole

Post by VincentG »

Vincent both the yellow flame and blue flame are converted to boiling equally efficiently. 100%. What you are loosing is the ability to convert more energy to work. The blue flame to boiling has the possibility of being converted to more work than the yellow flame.

The question then becomes, 'what are you going to use the heat for?', and how much will it cost? The blue flame may have a more efficient conversion of fuel energy to work, but, the yellow flame may give a cheaper ride.
You are correct that the BTU output of the flame gets converted equally and the hotter flame has faster heat transfer too. Modern LP water heaters take full advantage of this using many very fine water tubes and end up with a low exhaust temperature and high rated efficiency. Modern fuel oil heaters can have close to the same efficiency with a much lower flame temperature. The extra efficiency of the LP heaters is mainly due to their ability to use finer heat exchangers due to cleaner combustion. The much higher flame temperature is in large part wasted.
Anyway, my expectations for your experiment is that the box does not get hot at all, if you can ensure in some way that the heat cannot enter the box other than through the working fluid of the running engine. All friction points that could generate heat from the work output are outside the box and some load powered by a generator is outside the box.
For the sake of simplicity, I was going to put the whole thing in the box, but keeping the hot end outside the box could be arranged. IMO, any friction will be negligible, so the mechanism can be inside the box. It would be great to find any other tests like this that have been done in the past.
Jack
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Re: Isolated cold hole

Post by Jack »

VincentG wrote: Tue Nov 12, 2024 11:16 am
I believe the work will come from the kinetic energy of the gas at elevated temperature. Normally the kinetic energy is wasted, as pressure only increases linear to temperature, while molecular energy does not, as evident by the emission of visible light above a certain temperature, and phase changes.
I haven't read the whole thread here, just loosely following. But here you touch on something that I've been thinking about and basing my own project around. This might go a little off topic.

My reasoning was that if heat going into a fluid changes the kinetic energy of the molecules, then why aren't we focusing on that?
Pressure is a second order effect. Kinetic energy has to be equalized into pressure.
So in my mind any piston engine is going lack efficiency just because of it using pressure to push the piston. A lot of the kinetic energy in the molecules is wasted by bouncing into the walls and ceiling of the cylinder and wherever else. Heat loss..
If we were to point all the molecules into one direction and let them bounce off a turbine, that would already improve a lot.
And if we use a turbine that doesn't rely on the molecules bouncing off it (because that's one bounce and only half its energy transferred after that the molecules is off playing somewhere else) but in stead relies on the molecules wanting to adhere to it we'd be even further along.

Just my .02
Fool
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Re: Isolated cold hole

Post by Fool »

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I think it boils down to what moves the piston. To resist that motion requires a force. There is a force from inside pushing out that needs a push from the outside pushing in. As long as they are the same, the piston doesn't move. Forces on the piston are caused by pressure.

For an engine to run, the pressure inside must be greater than the outside during the expansion stroke.

If the pressure outside doesn't change, we can ignore it. Work from the outside will cancel each other over the two equal strokes. P∆V and P(-∆V). Equal and opposite.

So the only way to get power out is to change the pressure inside.

We change the pressure inside so it is higher during expansion, and lower during compression.

The power out at higher pressure during expansion is saved and used to power the compression. It takes less power to compress at a lower pressure, saving some of the forward work to have an output.

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Fool
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Re: Isolated cold hole

Post by Fool »

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Tom Booth
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Re: Isolated cold hole

Post by Tom Booth »

Fool wrote: Tue Nov 12, 2024 6:36 pm .

Your pursuit, right now is to get me to do professional work without compensation. Good luck with that.

.
My pursuit right now is building a form to be there when this one goes completely under, as seems inevitable.

I have no interest in your so-called "professional work".

Infact, I'll make you an offer: How much money would it take to get you to go away?
Tom Booth
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Re: Isolated cold hole

Post by Tom Booth »

VincentG wrote: Tue Nov 12, 2024 7:35 pm
. All friction points that could generate heat from the work output are outside the box...
... IMO, any friction will be negligible, so the mechanism can be inside the box...
I don't think it's negligible. It would be where all the heat is going almost 100%

All the heat is converted to mechanical work, then the mechanical work produces friction and the work is converted back into heat.

If the engine and heat source are both inside the insulated box, where else is the energy supposed to go?
VincentG
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Re: Isolated cold hole

Post by VincentG »

I don't think it's negligible. It would be where all the heat is going almost 100%

All the heat is converted to mechanical work, then the mechanical work produces friction and the work is converted back into heat.

If the engine and heat source are both inside the insulated box, where else is the energy supposed to go?
Top
If the heat from friction is significant enough to largely influence results than this is certainly a waste of time. Power output and overall throughput of heat should be much greater than the friction of ball bearings and a glass syringe.

The heat source would be insulated so that it mostly escapes through the engine. The box needs to be large enough to allow a 5 minute or so run time before the rise in "ambient" temperature slows the engine down much. The temperature rise inside the box can then be measured for all different conditions like engine off, no load, full load, etc. The heat source should be an electric element for consistent measurements. The electrical or mechanical power developed can be transferred outside the box.

Many configurations will work, this is just what seems best to me.
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