Isolated cold hole

Discussion on Stirling or "hot air" engines (all types)
Post Reply
Fool
Posts: 1240
Joined: Sun Jul 16, 2023 9:14 am

Re: Isolated cold hole

Post by Fool »

.

Tic tac toe! LOL

TS?

Tommy, it is not a lie to point out that heat needs a temperature difference to transfer. Your unacceptable vituperation commands that you are full of yourself, nothing more. Grow up.

.
Last edited by Fool on Sat Nov 02, 2024 4:36 pm, edited 1 time in total.
Fool
Posts: 1240
Joined: Sun Jul 16, 2023 9:14 am

Re: Isolated cold hole

Post by Fool »

.

VincentG, Stirling Engines of higher design have fairly good regenerators. As soon as the gas goes through the regenerator it is at Th. It won't pickup heat until the expansion stroke. Then it must become colder than the hot plate, or the expansion be very slow, like 'a week'.

Depending on how fast that expansion is will determine that temperature drop. Instead of 80 to 40, that temperature will likely be 70 inside of hot plate, and 60 for the gas Tmax, if that.

Engines block the heat. Even Tom found that out cause the ice melted more slowly with an engine on top, than for an open top.

As I've been saying all along, 'Carnot is an optimist'. As Senft says, "Real engines are rarely half as efficient."

.
Tom Booth
Posts: 4711
Joined: Tue Nov 07, 2006 2:03 am
Location: Fort Plain New York USA
Contact:

Re: Isolated cold hole

Post by Tom Booth »

Fool wrote: Sat Nov 02, 2024 4:35 pm .

VincentG, Stirling Engines of higher design have fairly good regenerators. As soon as the gas goes through the regenerator it is at Th. It won't pickup heat until the expansion stroke. Then it must become colder than the hot plate, or the expansion be very slow, like 'a week'.

Depending on how fast that expansion is will determine that temperature drop. Instead of 80 to 40, that temperature will likely be 70 inside of hot plate, and 60 for the gas Tmax, if that.

Engines block the heat. Even Tom found that out cause the ice melted more slowly with an engine on top, than for an open top.

As I've been saying all along, 'Carnot is an optimist'. As Senft says, "Real engines are rarely half as efficient."

.
Don't try to use me to support your disgusting filthy lies you SOB.

The engine does not "block" heat preventing it from reaching the ice, it CONVERTS heat to WORK which prevents heat from reaching the ice.

Typically, during engine operation, in a cycle the temperature fluctuation on the hot side is considerably greater than on the cold side, indicating the heat "disappearing" from the hot side is not transferring to the cold side.
Tom Booth
Posts: 4711
Joined: Tue Nov 07, 2006 2:03 am
Location: Fort Plain New York USA
Contact:

Re: Isolated cold hole

Post by Tom Booth »

Fool wrote: Sat Nov 02, 2024 4:20 pm ....
Tommy, it is not a lie to point out that heat needs a temperature difference to transfer. ...
Thanks, it's good to hear you finally admit that.
Fool
Posts: 1240
Joined: Sun Jul 16, 2023 9:14 am

Re: Isolated cold hole

Post by Fool »

.

You have no idea, why your last statements are all completely wrong. My lies are clean lies. You are the vulgar person on this site.

Isn't conversion to work, one way of not letting heat through.

Fluctuating temperatures on the Th hot side. Hmmmm is there something wrong with your heater? Hot plate? Measuring tools? Give it a rest. You are out classed here by everyone. Especially by Carnot, and Kelvin.

Explain to me how a tiny little engine, with intermittent gas-insulator cycles (displacer), can conduct heat through faster than direct continual contact hot to cold?

.
Tom Booth
Posts: 4711
Joined: Tue Nov 07, 2006 2:03 am
Location: Fort Plain New York USA
Contact:

Re: Isolated cold hole

Post by Tom Booth »

Fool wrote: Sat Nov 02, 2024 6:22 pm .

You have no idea, why your last statements are all completely wrong. My lies are clean lies. You are the vulgar person on this site.

Isn't conversion to work, one way of not letting heat through.
I must say, you're a master at lying and twisting things.

You were saying the engine "blocking' heat would prevent much of a temperature reduction. That the gas heats up to Th "as soon as it passes through the regenerator", so can't absorb heat; that the gas would have to expand for a week to cool and other idiotic nonsense.

You constantly try to pass yourself off as some Stirling engine expert but you're nothing but a lying troll, or much worse.



Fluctuating temperatures on the Th hot side. Hmmmm is there something wrong with your heater? Hot plate? Measuring tools? Give it a rest. You are out classed here by everyone. Especially by Carnot, and Kelvin.
Well, let's see.

This looks kind of like independent confirmation:
Temperature_vs_angle.png
Temperature_vs_angle.png (5.1 KiB) Viewed 970 times
We are all familiar with those readings by now I think.

The temperature fluctuation of the working fluid on the hot side is more than 100° on the cold side looks like maybe 50°. Half the heat "disappearing" each cycle.
Explain to me how a tiny little engine, with intermittent gas-insulator cycles (displacer), can conduct heat through faster than direct continual contact hot to cold?

.
Don't know what you're talking about. Just trying to change the topic?

Anyway what is your obsession with viciously dissing VincentG's theorizing, speculations or ideas.

You are full of threats and fear mongering. Keep considering Tesla's "cold hole' in any way shape or form, or anything even close, and according to "fool" you will be sued for wire fraud. Beware! Remember what happened to Pons and Fleischmann. Oh the dire consequences!

You're nauseating.

Get lost troll.
Fool
Posts: 1240
Joined: Sun Jul 16, 2023 9:14 am

Re: Isolated cold hole

Post by Fool »

.
Tom Booth wrote:The temperature fluctuation of the working fluid on the hot side is more than 100° on the cold side looks like maybe 50°. Half the heat "disappearing" each cycle.
Half the heat disappearing! I guess that means that half is being absorbed by the cold side. Oh you forgot that your comment proves Carnot. So you are also trying to say, at the same time, the engine is 50% efficient, right. My bet is if the areas were added up properly it would depict somewhat less. But I can work with 50%. Let us just compare your numbers to Carnot's. Anyone here know how to do that?

Th 800 K
Tc 350 K

Now what was that formula???

Oh yeah!:

n=(Th-Tc)/Th=(800-350)/800 wow! That is like 450/800 or 45/80 or a little more than 50%. How could Carnot be predicting a maximum that is higher than actual if it is so obsolete? In fact the Carnot limit is approximately 45/80=0.5625 or 56%.

Hmmm. So now that Cannot has been verified experimentally, or do you prefer empirically, how can we tell if the engine is blocking heat from temperature data. Well, without all the other information on the engine it is impossible to tell Qh and Qc and for that matter Qcz. It could be a tiny little engine the size of my pinky finger, or a great big LTS 14' John Ericsson Engine used for shipping. So absolute Q's can't be determined.

But relative Q's can be estimated from some assumptions. (I know it makes an ass/donkey out of you and Mptions.). Use the cooler in VincentG question and the same heat exchanger areas for the two engine plates, hot and cold. That seems fair.

Taking the provided 40 F Tcex (Temperature cold side of heat exchanger.) and room temperature 80 F, we have direct room air to metal contact, probably electric fan forced convection. Qcex (Heat Q going into cold cooler heat exchanger.) say 80 on outside of cooler wall 40 on the inside.

The mathematics for conduction is described in the following link to site:

https://www.engineeringtoolbox.com/cond ... d_428.html

It is on the order of:

Q = (k / s)•A•∆T

Where k is conductance, 1/R-value. Watts/m K.
s is thickness of conductor or wall.
A surface area
∆T of course outside wall temperature - inside wall temperature.

We are looking at what difference ∆T makes so all the rest, out of fairness, stays the same. k,s,A all stay the same. Only ∆T changes.

80-40 F ∆T for Qcex = 40•A•k/s sets the coolers heat intake normally from the room without the engine.

Now what is the ∆T for the hot side of the Engine?

Room air temperature again 80 F (I'd rather have it 68 F or lower and keep it there.)

Hot plate, as stated by VincentG, 80 F. Not sure how heat is going to go from the 80 F room air to An 80 F hot plate. But, that is the restraint imposed on us by the threads opening.

The heat must now flow into the gas inside the engine. Using the data Tom has provided, that process is caused by a temperature difference. Tom's data, 800 to 700 for a 100 ∆T out of Th-Tc 800-400 or about 0.25

Converting that to 80 F and 40 F we get 10 F. So Qh into the engine is 10•A•k/s

Comparing the two:

Cooler by itself:
Qcex = 40•A•k/s

Max heat into engine:
Qc = 10•A•k/s

Already there is a reduction/blockage factor of 4. Four times less heat max can get into the gas in the engine for the same type and size of heat exchanger.

It gets worse, as can clearly be seen by Tom's data. The gas is only absorbing the heat at that rate during the maximum temperature difference. Most of the time the temperature difference is less, and some of the time it is negative. So what do we do?. We must have a larger engine and hot plate. A lot larger engine and hot plate.

I could go on with the cold side and the expected efficiencies for a 80 F to 40 LTD engine. But I think the above is plenty for a brief introduction to why a Stirling Engine blocks heat transfer. And why Tom's ice melts more slowly.

I agree with Tom, it is nauseating technical drivel, but, VincentG asked 'why'. It is much easier to say the second law prevents it. It is more difficult to prove, over and over again, how the second law holds, for each and every person's brainstorm. It is why several websites are moderated to ban over unity talk. In the end the person brainstorming the over unity scheme won't buy it anyway. So the end has accomplished nothing. It would be acceptable for those over unity people to learn how to spot logical and natural flaws in their own schemes. I suppose, that is asking too much.

Trying to beat the Carnot limit is striving for over unity. If you don't know why, and just happen to verifiably beat Carnot, please contact me, near Seattle, and I'll work with you for that over unity machine. Do not bother if you only think you can. Bring a working model. In this thread, and VincentG case, it could be just a small refrigerator unit that he's modified. Get it running. Get the data. Double check with more and different data. Follow any suggested recommendations for more data. Then bring the device, rent a laboratory here for us to work.

Looking forward to seeing one of more of you, LOL. But really...

This is taking up too much of my valuable time and effort. From now on, my correspondence here will be brief and cryptic. Why? I feel zero effort on your parts to learn this stuff, and a very combative nature that requires an excessive amount of defense and explanatory effort. This stuff is easy and obvious to learn. Even calculus.

In other words, this entire thread is constructed and run on the guise that Carnot can be beaten without a single device have measured work output data. Tom is so caustic he won't even accept the observable fact that contained gasses always have a pressure. Simple observable natural phenomena. Not even that.

.
Tom Booth
Posts: 4711
Joined: Tue Nov 07, 2006 2:03 am
Location: Fort Plain New York USA
Contact:

Re: Isolated cold hole

Post by Tom Booth »

Fool wrote: Sun Nov 03, 2024 6:43 am .
Tom Booth wrote:The temperature fluctuation of the working fluid on the hot side is more than 100° on the cold side looks like maybe 50°. Half the heat "disappearing" each cycle.
Half the heat disappearing! I guess that means that half is being absorbed by the cold side. ....
Not necessarily. I'm being conservative based on the temperature ∆ fluctuations alone.

A good portion of the cold side working fluid temperature ∆ is likely from static "heat of compression" rather than heat transfer.

By "static" meaning the temperature increase from compression is canceled by expansion cooling without any "heat" actually entering or leaving the engine.
Tom Booth
Posts: 4711
Joined: Tue Nov 07, 2006 2:03 am
Location: Fort Plain New York USA
Contact:

Re: Isolated cold hole

Post by Tom Booth »

Tom Booth wrote: Sun Nov 03, 2024 9:29 am ...
A good portion of the cold side working fluid temperature ∆ is likely from static "heat of compression" rather than heat transfer.

By "static" meaning the temperature increase from compression is canceled by expansion cooling without any "heat" actually entering or leaving the engine.
That underlined should be, "without any "heat" actually entering or leaving the cold side of the engine"

To make this clear, look at the area above and below the cold side heat exchanger line (straight blue line).

The curve is about equally divided, above the line 1/2 cycle and below 1/2 cycle.

On the hot side the area BELOW the straight red line, between that straight line and the curve is relatively enormous by comparison.

The ∆T over time on the hot side is huge, indicating a lot of heat flow INTO the engine. Remove the "hysteresis' factor, and it is still huge.

The cold side curve is much more shallow. Remove the hysteresis factor from the cold side and it would likely appear steady state.
Fool
Posts: 1240
Joined: Sun Jul 16, 2023 9:14 am

Re: Isolated cold hole

Post by Fool »

.

The gas temperature in the cold side has a maximum of 40 K above Tc for about 185 degrees rotation.

It has a low of about 25 K below Tc for about 175 degrees of rotation.

That makes it obvious that more heat is being rejected to the cold plate than being absorbed from the cold plate. Over all some is being rejected.

It is hard to tell how much it is from just temperature readings. Thanks for addressing just the science.

.
Tom Booth
Posts: 4711
Joined: Tue Nov 07, 2006 2:03 am
Location: Fort Plain New York USA
Contact:

Re: Isolated cold hole

Post by Tom Booth »

Fool wrote: Sun Nov 03, 2024 12:32 pm .

The gas temperature in the cold side has a maximum of 40 K above Tc for about 185 degrees rotation.

It has a low of about 25 K below Tc for about 175 degrees of rotation.

That makes it obvious that more heat is being rejected to the cold plate than being absorbed from the cold plate. Over all some is being rejected.

It is hard to tell how much it is from just temperature readings. Thanks for addressing just the science.
"That makes it obvious that more heat is being rejected to the cold plate than being absorbed from the cold plate"

Not obvious if you take into account the angle of rotation, position of the pistons, location of the hot and cold has.

The cold gas is hottest at 160° rotation. Presumably an Alpha engine. Hard to say with certainty where 0° or 160° was considered to be by the author of that graph but let's just say for arguments sake 0° is at 12 o'clock putting 160° at 6 o'clock
heat_location.jpg
heat_location.jpg (233.18 KiB) Viewed 807 times
alpha-stirling-engine-animations.gif
alpha-stirling-engine-animations.gif (116.04 KiB) Viewed 808 times
In that position there is very little working fluid in the cold side cylinder. I've pointed this out many times before in regard to LTD type engines especially.

In a Stirling engine, when the temperature is elevated enough to make heat rejection to the cold side thermally possible, the working fluid is moved to the hot side, making heat rejection physically impossible. Maybe not 100% but certainly the percentage of the working fluid that is in a condition (temperature and location) to be both thermally AND physically capable of transferring heat needs to be taken into consideration.

IMO the length of time for meeting BOTH of those conditions is vanishingly small to entirely non-existent BY DESIGN.

A Stirling engine is designed to retain and/or move heat to the hot side where it can be converted to work (used for expansion/work output) and PREVENT heat from reaching the cold side where it would go to waste.

This makes perfect sense from an energy perspective.

The Carnot theory runs completely contrary to common sense and contrary to the observable facts of how a Stirling engine actually operates.

Sure, it made sense IF it were actually true that heat is a fluid that powers an engine by "running through" from the hot to the cold side like water running through a turbine, but as it turns out, that is not true at all.

The fact that heat is not a fluid, but simply another form of energy that needs to be converted to be useful changes the entire rationale for heat engine design.

Efficiency does not depend on how quickly you can get the heat to run through from the hot to the cold side by means of a "steeper" temperature gradient and more effective cooling.

Efficiency in a Stirling engine depends on retaining as much heat as possible, not letting ANY transfer through the engine from the hot to the cold side AT ALL. If it tries, it needs to be forced back over to the hot side. Any heat that passes through is wasted energy and lowers efficiency. That should be obvious, but the Carnot theory has so infected thinking about how heat engines operate today, not only is it not obvious, it is outright denied by fanatical, self appointed 2nd Law enforcers like crackpot "fool" here.

Tesla tried to make all this clear back in 1900 but the lunatic Carnot 2nd Law fanatics were already running rampant with their lunacy and nobody listened. Today they are still running rampant and hardly anyone is listening, but the few independent thinkers that do are persecuted, attacked, ridiculed, censored and silenced. Lives ruined, life's work lost, human progress halted.

The so-called "Carnot efficiency Limit" theory is a scourge that needs to be rooted out.
VincentG
Posts: 1056
Joined: Tue Feb 21, 2023 3:05 pm

Re: Isolated cold hole

Post by VincentG »

I could go on with the cold side and the expected efficiencies for a 80 F to 40 LTD engine. But I think the above is plenty for a brief introduction to why a Stirling Engine blocks heat transfer. And why Tom's ice melts more slowly.
Again we are stuck associating energy flow with temperature-based efficiency. Lets say it's 40F outside and 80F inside and you replace your double pane window with two plates of aluminum with an air gap in-between. The efficiency of heat transfer may be low, but that doesn't stop large quantities of energy from passing through. A displacer just allows the energy naturally passing through the gas itself to be converted to a useful form. The power piston can accelerate this with a heat pumping effect.

The engine blocking the cold plate can only serve to keep the cold plate closer to Tc and while it will slow heat transfer rate as compared to no engine, the specific power(read cooling power) of the main heat pump is not tied to it's efficiency. This is the same thing as saying a more efficient Atkinson's cycle engine must have more displacement to reach the same power level as a smaller, less efficient, Otto.

Also there was discussion on one of the physics forums where a few highly educated posters agreed that of course Tom's engine melts the ice more slowly as it is converting some of the heat to work and preventing it from reaching the ice.
Tom Booth
Posts: 4711
Joined: Tue Nov 07, 2006 2:03 am
Location: Fort Plain New York USA
Contact:

Re: Isolated cold hole

Post by Tom Booth »

Fool wrote: Sun Nov 03, 2024 6:43 am ...

This is taking up too much of my valuable time and effort. From now on, my correspondence here will be brief ...
Promise?
Fool
Posts: 1240
Joined: Sun Jul 16, 2023 9:14 am

Re: Isolated cold hole

Post by Fool »

.

Not a good thing.

.
Tom Booth
Posts: 4711
Joined: Tue Nov 07, 2006 2:03 am
Location: Fort Plain New York USA
Contact:

Re: Isolated cold hole

Post by Tom Booth »

Just BTW; a 30° or 40°F temperature at the evaporator of a heat pump is, IMO not realistic for this application.

A cold weather heat pump using conventional refrigerant can extract heat from outdoor winter air down to -20°F (20 below zero) so obviously to take in heat the actual evaporator can be much colder than 40°F.

I think -40° might actually be more realistic.

Evaporator temperatures of -70° or -80°F are not impossible for heat pump systems designed for the far north.

Refrigerants generally have low boiling points at atmospheric pressure and under vacuum in a vapor/compression system the boiling point is further reduced.

The boiling point of the very common refrigerant R-134a for example is -15°F under atmospheric pressure. Under vacuum conditions in a refrigeration system, of course, the boiling point is much lower.

Also, as the evaporator can be located inside a hermetically sealed engine containing a "dry" inert gas, problems with condensation/frost on the evaporator (reducing efficiency) can be avoided. (No frost blocking evaporator/no defrost cycle required)
Post Reply