Stirlingengineforum.com

I agree Tom as even automotive air conditioners routinely ice over on the low pressure lines and can go quite a bit below freezing even in a hot engine bay, but absolute temperatures are not crucial for this proposed cycle.

The second law says that not all heat can be converted to work and that some heat is converted to work. That means some of the ambient heat in the room can be converted to work, and if the cold side was a block of ice no one would argue this.

Carnot says that heat must be rejected to the cold side to complete the engine cycle. That means the engine is actively pumping heat into the evaporator using part of the power it produced from ambient heat in the first place.

Fool argues cooling would take more time, but time for cooling is just like horsepower, and horsepower is not related to efficiency.

If an air conditioner consumes 1000 watts and a series heat engine can offset 999 watts, that is not over-unity!

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https://inspectapedia.com/aircond/Air_C ... atures.php

That web page has more information than is needed for just AC operations, or heat pumps operating in reverse like an AC, or cooler. But it has buried in it the following, (Bolding mine.] :

Air Conditioner Suction Line Pressure and Temperature - Typical Data and What It Means
Determining proper suction "pressure" (we're measuring low pressure on the "low side" of the cooling system) is critical for proper refrigeration equipment operation assessment.

Typical Suction Side or Low Side Pressure & Temperature
Normally suction line pressure on air conditioning equipment is about

45 degF with a suction pressure of 42 psi for Freon 12
45 degF and about 76 psi for Freon 22

These low side suction line temperature and pressure measurements will vary as a function of refrigerant, ambient temperature and other factors.

The data points for the new refrigerants will be a bit different, but this example makes clear that the air conditioning system pressure measurement numbers (both suction vacuum and compressor outlet side pressures and temperatures) will be different for each refrigerant.

In normal air conditioner or heat pump or other refrigeration equipment operation we see positive pressure on both the HIGH side (high pressures) and on the LOW side (low pressures) of an HVACR system. The low side is also referred to as the vacuum line or suction line as it's the compressor input side.

Only during system installation or servicing would we actually pull a true vacuum on the system as part of evacuating it prior to installing a refrigerant charge. IN that case too it's "pressure" but negative pressure or vacuum.

Thanks to reader Charles for clarifying by comment that the suction line is under low pressure in HVACR systems during normal operation, 14 Aug 2015.

The bolding emphasizes that 45 F is the typical AC evaporator target temperature for any gas. And pressure is always higher than the ambient 15 psi. No vacuum during AC operation. Of course, if you've ever recharged your own AC system, as I have, you'd have seen and know that.

The reason AC units don't go below 32 degrees is because the warm moist muggy inside air moisture would stick to it in the form of frost/ice. That would block the air from flowing through the little holes between the fins.

VincentG, two aluminum plates with an air gap between them, assuming dead air space, would be an effective insulation. It would only let a large amount of heat through if it were really large, or spent a long time doing it.

A displacer doesn't produce any work. It just forces convection in the gas across the hot plate while insulating the cold plate. Then it forces that same air across the cold plate while insulating the hot plate. Ideally half the time for each, using dwell.

The regenerator picks up all the heat in the gas before it contacts the cold plate. It then returns that heat before it hits the hot plate. That effectively turns a displacer chamber, with no power piston, into just an insulator.

To get work out and heat into a displacer chamber a power piston is added that expands the gas when the displacer is insulating the cold plate. During the return stroke, the piston puts work back into gas in the form of compression, when the displacer is insulating the hot plate. That return work is less than the forward expansion stroke, because of the temperature difference of the strokes. Ideally, so it's easy to understand and calculate with simple mathematics.

Real engines are measured with dynos, and indicator diagrams. And graphically integrated. Now with computers.

Without those tools, their processes can't be discussed colloquially or with hand waving. However, if it doesn't work ideally, it will only be worse for real engines. That is the whole purpose of "ideally", to see the best case scenario for almost nature. Nature is always worse.

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VincentG wrote:If an air conditioner consumes 1000 watts and a series heat engine can offset 999 watts, that is not over-unity!

What you just said is that a combination of an engine and cooler moves 999 watts from cold to hot using 1000 watts for a COP of less than 1. Is that better than a heat pump alone with a COP of 3 moving 3000 watts of heat from cold to hot using 1000 watts???

Or do you mean that a heat pump and engine combination can consume 1 Watt and move 3000 Watts of heat from cold to hot for a COP of 3000???

Certainly moving 3000 Watts of heat to the hot side, an engine using that heat, could then produce 30 watts from any engine that is 1% efficient or better and power your combination with one Watt producing an over unity of 29 Watts.

Yes, breaking the second law, enabled the first law to be broken.

Second law bashers are, by default, over unity quacks.

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VincentG wrote: ↑Mon Nov 04, 2024 7:19 pm I agree Tom as even automotive air conditioners routinely ice over on the low pressure lines and can go quite a bit below freezing even in a hot engine bay, but absolute temperatures are not crucial for this proposed cycle.

The second law says that not all heat can be converted to work and that some heat is converted to work. That means some of the ambient heat in the room can be converted to work, and if the cold side was a block of ice no one would argue this.

Carnot says that heat must be rejected to the cold side to complete the engine cycle. That means the engine is actively pumping heat into the evaporator using part of the power it produced from ambient heat in the first place.

Fool argues cooling would take more time, but time for cooling is just like horsepower, and horsepower is not related to efficiency.

If an air conditioner consumes 1000 watts and a series heat engine can offset 999 watts, that is not over-unity!

Well, personally, I would not call any utilization of solar energy in the form of ambient heat "over-unity", even down to near absolute zero. It would just be utilization of a recognized energy source.

The second law, regardless of what form it may take today or what the current justification for it may be, originated from Caloric theory.

A "fluid seeks its own level, so naturally "heat" viewed as something similar to a fluid, could not be made to "flow down" below it's own level (ambient). In other words, you can't siphon a lake by emptying it into ITSELF. That makes perfect sense in that context (if heat is a fluid).

But is that true of energy generally? Kinetic energy? Is "energy" a "fluid"?

If I throw a bowling ball down a lane into another bowling ball, how much energy put into the first ball can be transfered to the second? It's just Newtons laws of motion.

If "heat" is just a form of motion why should it not follow the same rules as everything else? If air molecules are just little "bowling balls" set into motion by the heat or the sun, then it should be possible to harvest that motion, and, infact it is harvestable, in many different ways. Wind power, water power (hydroelectric), even coal, oil, natural gas... Wood,.. all just transformations of solar energy.

It just takes a clever bit of engineering, not a violation of conservation of energy or "over-unity" more energy out than in. The "energy in" is heat from the sun that has already heated the earth and it's atmosphere up from... Maybe not quite absolute zero, but what temperature would the earth and it's atmosphere be without the heat from the sun keeping it warm?

Utilizing a known energy source is not "over-unity". But in 1820 heat was not considered an intrinsic energy source. A fluid flowing down is not a self contained energy source or form of motion. It is a manifestation of gravity.

Water flows down due to the "pull" of gravity, not its own kinetic energy or latent internal force or motion.

What makes air molecules "vibrate" more vigorously? No gravity or anything like gravity, as far as I know, just getting knocked around by photons from sunlight.

The jiggling air molecules are the carriers of their own motion, not being "pulled down" by anything. Their motion IS intrinsic, not a consequence of an outside force, not even the sun.

The sun already did the job of transferring energy to the air particles. Proof: the heat in the atmosphere lingers after sunset. Take away gravity and water would stop flowing down immediately.

Regardless. As formulated and as applied to heat engines, utilizing heat down to a temperature lower than the coldest object available, on a continual basis would "violate the 2nd Law", for the same reason you can't empty a bucket of water by pouring it out into itself. You can't siphon water up hill or even on a level plane, it has to run DOWN.

But, as stated, heat in hot air is not compelled to "run down" through a heat engine to a "cold reservoir" by some analog of "gravity" or outside force. The motion of air particles is self contained, and once set in motion by bombardment by photons from the sun, is independent from outside forces, or is it?

I don't know.

I have my doubts about all this, but theoretically, why not a heat engine that can utilize heat in the atmosphere down to a temperature below ambient temperature?

It doesn't violate conservation of energy, it doesn't violate Newtons laws of motion.

Well, it DOES, apparently violate "the 2nd Law", but for reasons that seem invalid now that the actual nature of "heat" is better understood.

The energy in the air particles is not flowing "down" or flowing towards anything, is not dependent on "gravity" or any equivalent "outside force" the motion of the particles is self contained, independent, and so, can be, or should be able to be, transfered in some clever way, and converted to some useful form, like any other form of energy. Right?

Yes? No?

I don't know.

But so far, my little kitchen table experiments seem to indicate that the "Carnot Limit", for whatever reason, does not apply to Stirling engines.

I can run a Stirling engine all day long and none of the heat going in appears to be coming out as "heat", just as other forms of energy. Mostly mechanical motion, along with a little noise. (Very little. Stirling engines run very quiet). A little friction of no consequence. A little vibration maybe. Some air resistance,... but "HEAT", no. That all, apparently "disappears" or, rather, is "transformed" or converted.

https://youtube.com/playlist?list=PLpx2 ... vDf0h9ZXRJ

Now I'm very skeptical.

Skeptical of the whole Tesla "cold hole" theory. Skeptical that a heat engine could operate a heat pump to supply its own "fuel" FREE from the atmosphere...


But really, all our fuel comes "free' from the sun, including wood heat, coal, oil and natural gas, and also wind and flowing water, and, of course, direct solar, thermal and photovoltaic, all forms of direct or "STORED" solar energy. So why not the solar energy stored in the atmosphere?

The declaration of some 1800's philosophers who were mistaken about the ultimate nature of "heat" seems like a pretty flimsy and baseless reason to entirely dismiss the possibility.

"It would violate the 2nd Law of thermodynamics!!!!"

So what?

Carnot was wrong. Kelvin was wrong.

Tesla was correct.

Heat is not "a fluid".

So, IMO, such experiments as you propose here are well worth trying and should by all means be encouraged, not discouraged.

People like "Fool" should be ignored. He's just rehashing obsolete 1800's depreciated caloric theory.

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Tom Booth wrote:But is that true of energy generally? Kinetic energy? Is "energy" a "fluid"?

Can you empty a sun by conducting its own heat into itself?

Can you freeze a glass of room temperature water by conducting its own heat into itself?

All attempts to do so, are attempts at over unity.

Work is just a temporary diversion of some heat into another form, destined to become heat again.

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"fool" is also doing what he's always accusing me of doing.

Cherry picking.

His source, (aside from being out of date (2007) both refrigerants discussed were phased out years ago), ... is misleading.

The refrigerant, in a typical air conditioning system intended to remove summer heat from a building, with unlimited volumes of hot air blowing across the evaporator, may enter the condenser at 40° or 50° and absorb heat rapidly as it boils with little or no reduction in temperature, but it IS absorbing heat as it changes phase and if the heat available is restricted in some way, as in a freezer insulated ice box, the temperature will quickly fall below freezing and in a winter heat pump application with northern temperatures below freezing outside the refrigerant in the evaporator will continue to boil and boil getting colder and colder and colder, theoretically all the way down to its freezing point. As previously stated, evaporator temperatures down to -75°F or so for heat pump systems designed for cold weather climates is not impossible.

In this application, in theory at least, the Stirling engine would be removing heat by converting it to work, so in that way would be restricting the heat flow to the evaporator with the result that the refrigerant temperature would fall, and fall and continue falling all the way down to the refrigerants boiling point and further.

How cold depends on the refrigerant used and the design and intended use of the system.

A typical air conditioner will work just fine with a refrigerant that never goes below 40 or 50° F. That is plenty cold for living space cooling. There is no benefit in going colder.

A Stirling engine, on the other hand would benefit from going much much colder and that is well within the realm of possibility while still maintaining a reasonable heat pump COP.

Hard to know if fool is just ignorant or being intentionally misleading but the accumulating evidence indicates the latter IMO. He lies and lies unashamedly over and over with no apology or remorse. His intentions here appear to be deliberately malicious and destructive.

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Last I checked, when the temperature outside is 100F and the AC unit.cooler inside is supposed to be no lower than 40, if it goes lower, down to the boiling point of the gas, it must work harder. Thanks for providing the engine blocks the heat and the AC must work harder to cool the same building. AKA, less efficient.

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Fool wrote: ↑Tue Nov 05, 2024 1:23 am .

Tom Booth wrote:But is that true of energy generally? Kinetic energy? Is "energy" a "fluid"?

Can you empty a sun by conducting its own heat into itself?

Does a heat pump "conduct" heat? No.

Can you freeze a glass of room temperature water by conducting its own heat into itself?

Does a Stirling engine "conduct" heat? No.

All attempts to do so, are attempts at over unity.

Work is just a temporary diversion of some heat into another form, destined to become heat again.

And so for all other forms of energy. Light, electricity, motion, etc.

So what?

A heat pump moves the heat away FOR the Stirling engine to increase the temperature difference. ("For" rather than from, the Stirling is not supplying heat or "conducting" heat to the heat pump, it is converting heat)

The Stirling engine converts the heat in the room to a source of useable energy so the heat does not reach the heat pump.

The role of the heat pump is just to deepen the ∆T so that the Stirling engine can convert heat more rapidly. The greater temperature difference gives the working fluid in the Stirling engine more "room" for expansion and cooling when heat is added intermittently rather than providing cold as a place to conduct heat to more rapidly as formerly believed.

As a result, the heat pump would likely only need to run occasionally while the Stirling engine performs the bulk of the heat "removal" by converting the heat to another form of energy, like electricity, and the electricity can be used for producing heat again somewhere else, like in the kitchen for cooking.

So what if the work turns back into heat? That heat can be made useful as well for heating hot water, to blow dry hair, make some toast and scrambled eggs, perk some coffee, power an internet wifi router, drive tools and other appliances or whatever.

Fool is full of subtle and carefully crafted misdirection, discouraging half truths and outright lies. It's hard to believe his defacement of these threads and this forum generally is out of good will.

The heat pump doesn't need to work harder when the Stirling engine is doing most of the heat removal. It hardly has to do any work at all.

That a Stirling engine operates by "conducting heat" through itself is the disproven, obsolete 1820's Caloric theory. A fact fool can't seem to recognize or deliberately ignores and denies.

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Last I checked. Cooling off the cold heat exchanger to a lower temperature took more effort than cooling it off to a higher temperature.

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Fool wrote: ↑Tue Nov 05, 2024 7:48 am .

Last I checked. Cooling off the cold heat exchanger to a lower temperature took more effort than cooling it off to a higher temperature.

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Perhaps true. It's a trade off, but the Stirling engine benefits from the colder temperature, and it would be doing the majority of the heat removal.

The Stirling engine would benefit, probably much more than the heat pump would suffer.

At any rate, the heat pump could very likely go much colder than 40°F without degrading performance (COP) at all.

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I don't think the building would be cooled.

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Fool wrote: ↑Tue Nov 05, 2024 1:00 pm .

I don't think the building would be cooled.

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Must be rather depressing living in a world where nothing will ever work.

... LOL..

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AC systems, running on classical theory, run just fine. Your theory hasn't built anything useful. Go build something.

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Fool wrote: ↑Tue Nov 05, 2024 1:28 pm .

AC systems, running on classical theory, run just fine. Your theory hasn't built anything useful. Go build something.

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Actually, not true.

"Ideal gas" does not phase change. If it had to depend on "classical theory", phase changing vapor compression systems would not exist at all.

What has AI got to say?

Question: "do "ideal gases" condense into liquid?"

Search Labs | AI Overview

No, an ideal gas cannot condense into a liquid because, by definition, an ideal gas has no intermolecular forces, meaning its particles cannot attract each other enough to form a liquid phase; therefore, an ideal gas can only exist as a gas and cannot undergo a phase change to become a liquid.

Key points about ideal gases and condensation:
No intermolecular forces:
The key concept is that an ideal gas is a theoretical model where particles have no attractive forces between them, which is necessary for condensation to occur.

Phase transition limitation:
Since ideal gases lack intermolecular interactions, they cannot undergo a phase transition like condensation to become a liquid.

Real gases vs. ideal gases:
Real gases, which exist in the real world, can condense into liquids because they do have intermolecular forces, unlike ideal gases.

LOL...

Fool is such a loser.

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Steam engines, and condensing into a liquid was known and part of classical theory long before ideal gas law theory.

You have not discovered anything that wasn't known already and likely long ago. Classical theory is not just ideal gas law.

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