Proell Effect

Discussion on Stirling or "hot air" engines (all types)
VincentG
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Re: Proell Effect

Post by VincentG »

Fool wrote: Sun Dec 01, 2024 11:53 am .

The gas is just responding to pressure and temperature differences. The gas doesn't respond to the volume. Volume change just dictates pressures and temperatures. There is a response to moving walls, as they bounce off.

The gas knows nothing of load, except for the pistons response to the load, slowing or accelerating.

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Can I get that on the record? Doesn’t that suggest that this effect is real and profound?
Fool
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Re: Proell Effect

Post by Fool »

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I suppose. How is it much different from adiabatic bounce?

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matt brown
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Re: Proell Effect

Post by matt brown »

I finally read thru Rauen's white paper. I was transfixed on first 2 pgs for some time, but curious as to his conclusions.

Rauen paper.png
Rauen paper.png (100.04 KiB) Viewed 3034 times
I found this tidbit amusing and couldn't agree more. However, his penchant for relating Proell effect via constant volume regen is a tad disturbing, since it's far easier to elude during an expansion process with regen (how I fell into this rabbit hole). Rauen's ambient vent test vs isolated expansion leads me to conclude he was chasing an ambient engine early on.



Essex vs 2 Stirlings.png
Essex vs 2 Stirlings.png (16.18 KiB) Viewed 3034 times
This graphic (cartoon - lol) says it all via comparing these 3 similar expansion processes (frames 3-4). Despite T given, Qin can only be surmised, but clearly something is awry due to this inconsistent PV work. Over the years, I've seen this irregularity pop up, but always dismissed it as a variation due to RA-GA modeling. However, while modeling cold vs hot PP, this anomaly popped up in clear sight.

Fool - this graphic may appear as sleight of hand or cherry picking, yet I thought you would quickly confirm PVT values and also conclude "Houston, we have a problem." How did you dismiss these Q vs W variations akin AB, AC, BC ???

Rauen is fuzzy on regen details (scattered thruout text), but I'd sum this up as 3 regen potentials:

(1) under size matrix - temperature differential tends to disappear during displacer cycles

(2) ideal size matrix - Proell effect when based on conventional gas dynamics

(3) over size matrix - temperature differential tends to maintain during displacer cycles
matt brown
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Re: Proell Effect

Post by matt brown »

Fool wrote: Sun Dec 01, 2024 2:10 pm
I suppose. How is it much different from adiabatic bounce?
C'mon Fool, adiabatic bounce involves...work

If this simple "event" warps conventional PVT concepts than it's worth exploring. Yes, the original event may be fruitless, but it could lead to other fruitful events.

This reminds me of my favorite quote: "I never let my schoolin' interfere with my education." - Mark Twain

Vincent - do you recall commenting that after PP expansion, when displacer moves gas from hot to cold space prior 'cold stroke', that same anomaly should occur ??? (somewhere in my anomaly thread) That was genius and what enticed me to cross verify my anomaly via Cv regen while trying to quantify effect during expansion. Once I verified Cv regen, I found Rauen confirmation, but nothing relating to typical expansion process. Kinda funny in retrospect, thanks for the help !!!
VincentG
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Re: Proell Effect

Post by VincentG »

Vincent - do you recall commenting that after PP expansion, when displacer moves gas from hot to cold space prior 'cold stroke', that same anomaly should occur ??? (somewhere in my anomaly thread) That was genius and what enticed me to cross verify my anomaly via Cv regen while trying to quantify effect during expansion. Once I verified Cv regen, I found Rauen confirmation, but nothing relating to typical expansion process. Kinda funny in retrospect, thanks for the help !!!
Yes I remember and I later found in semi-static testing that the pressure drop was rapid enough to fog out the cylinder. Enough evidence for me to stay encouraged.

Glad to help in any way and thanks to you as well, if not for your persistent interest and efforts in graphical analysis I wouldn't have near the interest at this point(almost 2 years into this obsessio...hobby).
matt brown wrote: Sun Dec 01, 2024 6:50 pm
Fool wrote: Sun Dec 01, 2024 2:10 pm
I suppose. How is it much different from adiabatic bounce?
C'mon Fool, adiabatic bounce involves...work

If this simple "event" warps conventional PVT concepts than it's worth exploring. Yes, the original event may be fruitless, but it could lead to other fruitful events.
Yea, C'mon Fool, doesn't this get your curiosity going just a bit?
Fool
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Re: Proell Effect

Post by Fool »

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Adiabatic bounce has no net work or heat change. It ends up zero zero.

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Tom Booth
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Re: Proell Effect

Post by Tom Booth »

Fool wrote: Sun Dec 01, 2024 9:22 pm .

Adiabatic bounce has no net work or heat change. It ends up zero zero.

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Except when you introduce a displacer that shifts the air from side to side or top to bottom in sync with the temperature variations. Or a regenerator that similarly accumulates the heat generated on one side, or both acting in concert.

As usual, you have a blind spot when it comes to any heat transfer process not based on your limited comprehension of the 1820's Carnot waterfall theory of heat.
matt brown
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Re: Proell Effect

Post by matt brown »

Tom Booth wrote: Mon Dec 02, 2024 1:24 am
Except when you introduce a displacer that shifts the air from side to side or top to bottom in sync with the temperature variations. Or a regenerator that similarly accumulates the heat generated on one side, or both acting in concert.
It's "both acting in concert" that makes this possible.
Tom Booth wrote: Mon Dec 02, 2024 1:24 am As usual, you have a blind spot when it comes to any heat transfer process not based on your limited comprehension of the 1820's Carnot waterfall theory of heat.
Now Fool is in denial - lol

I'm working on a simple graphic to show how to game this, but clueless (for now) as to any design. It's an amusing idea similar a mini cold hole that you can manipulate on the thermal scale. If it consumes heat, it's not "perpetual motion".
Tom Booth
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Re: Proell Effect

Post by Tom Booth »

matt brown wrote: Mon Dec 02, 2024 2:38 am
It's "both acting in concert" that makes this possible.
I guess, but really that is always the case.

With just a displacer, the hot and cold side surfaces of the displacer and chamber walls act as regenerator.

A regenerator just increases the available surface area making it more effective. At the sacrifice though of introducing additional dead air space that tends to reduce the effect.

I think a displacer and chamber with some type of corrugated surfaces that fit together would serve to increase surface area without increasing dead air space.
Tom Booth
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Re: Proell Effect

Post by Tom Booth »

That was also the basic idea of my earlier sliding regenerator in a fire piston engine.

I was attempting there to illustrate the capture and accumulation of this "Proell Effect", but had no particular name for it at the time other than "heat of compression" and "expansion cooling".
sliding_regenerator.jpg
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There should be some mechanism to time the movement of the sliding regenerator so that it slides over to the cold side during expansion and over to the hot side during compression, but I was lazy.

I imagine though, some sideways "walking beam" type mechanism attached to the flywheel/crank would do.

I was trying to illustrate there the "heat pump" effect, where the cold regenerator would be progressively refrigerated (colder than ambient) and the hot side regenerator would become hotter than the heat source, though the "extra" heat would be continuously converted to mechanical rotation of the engine.

That was all just to make clear or more understandable my observations of how a Stirling engine ACTUALLY already works, without modification.

The real point being heat is not "flowing" between the hot and cold regions.

The cold side or cold regenerator is not a "heat sink", as conventional theory would have us imagine or believe.
Fool
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Re: Proell Effect

Post by Fool »

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I would call that a sliding temperature sink engine. As the piston rises up over the hot heat plate the gas tends to heat up. At max volume, the gas will have a higher temperature than the cold plate. Now compress the gas towards the cold plate. It gets hotter. If hot gas hits the cold plate, the plate will tend to get hotter. If insulated, the cold plate will tend to get hotter, ultimately reaching the Temperature of the hot plate. Maybe it will need external cooling after all.
Tom Booth wrote:Except when you introduce a displacer that shifts the air from side to side or top to bottom in sync with the temperature variations. Or a regenerator that similarly accumulates the heat generated on one side, or both acting in concert.
Yes, when you include adiabatic bounce and and a displacer, you have a new device, historically called a Stirling Heat Pump.

Hooked to a Stirling Engine it could be a Stirling powered refrigerator. But that will have three temperatures, and some other requirements.
Matt Brown wrote:Now Fool is in denial - lol
De Nile flows between to points that are further apart than any other river on de Earth.

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Fool
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Re: Proell Effect

Post by Fool »

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"Yes, when you include adiabatic bounce and and a displacer, you have a new device, historically called a Stirling Heat Pump. "

Oh yeah, forgot to mention that it won't be adiabatic nor bouncing any more. It will be driven, and all heat from the cold space will need to go through it, plus the work input is completely converted to heat. All that heat must come out on the hot side. Plus an unavoidable loss of Enthalpy and gain in Entropy too boot.

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Tom Booth
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Re: Proell Effect

Post by Tom Booth »

Fool wrote: Mon Dec 02, 2024 5:58 am .

I would call that a sliding temperature sink engine.
Do you?

An expert on my recent invention already?
As the piston rises up over the hot heat plate the gas tends to heat up. At max volume, the gas will have a higher temperature than the cold plate.
Sorry, but you've got it wrong. As previously stated, during expansion the sliding regenerator having effectively trapped heat of compression in the hot side regenerator, moves the cold side regenerator into position under the piston.

Expanding gas cools as it expands and with the trapped heat in the regenerator slid off and out of the picture the expansion cooling is uninhibited. The cooling effect is further amplified by mechanical expansion due to the momentum of the flywheel extending the expansion past the natural limit. The result is a refrigerating effect that cools the cold side regenerator further.
Now compress the gas towards the cold plate. It gets hotter. If hot gas hits the cold plate, the plate will tend to get hotter.
Wrong again. That doesn't happen either First of all the gas is not hot it is very cold and the pressure drops accordingly. The gas "contracts".

Eventually the gas will begin to increase in temperature as compression by atmospheric pressure and flywheel momentum continues, but at that point the sliding regenerator moves back over to position the hot side under the piston. The cold regenerator is again out of the picture, uninfluenced by the increasing heat. So no hot gas hits the cold plate and the cold plate does not "tend to get hotter" at all.
If insulated, the cold plate will tend to get hotter, ultimately reaching the Temperature of the hot plate.
Both hot and cold regenerators are thermally isolated from each other and from the outside environment, except where the hot regenerator is able to receive "make up" heat to compensate for heat that has been converted to mechanical motion or external work output through the crank.

Keeping the cold regenerator in a cold insulated side pocket when the hot regenerator is in use allows the cold regenerator to become colder and colder, dropping below ambient. The effect when the cold regenerator is in position is similar to having ice (below ambient temperature) on the cold side of a Stirling engine to increase the ∆T, but through internal "self cooling" (Proell effect) rather than an external "sink".
Maybe it will need external cooling after all.
Not at all.
Tom Booth wrote:Except when you introduce a displacer that shifts the air from side to side or top to bottom in sync with the temperature variations. Or a regenerator that similarly accumulates the heat generated on one side, or both acting in concert.
Yes, when you include adiabatic bounce and and a displacer, you have a new device, historically called a Stirling Heat Pump.
What I've been describing is the behavior of an ordinary, typical Stirling engine, except that the function of the ordinary displacer is here illustrated by the "sliding regenerator" to make the function of the ordinary Stirling engine displacer more readily apparent. That function is to dynamically maintain the separation between the sequence of hot and cold generation through time (cycle).
Hooked to a Stirling Engine it could be a Stirling powered refrigerator. But that will have three temperatures, and some other requirements.
Fantasy stemming from your misunderstanding and lack of reading comprehension and general stupidity and ignorance.
Fool
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Re: Proell Effect

Post by Fool »

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Tom, your device as you describe, compresses the gas into the hot plate. It then switches to the cold plate and expands.

The problem with that is the cold gas is spread out over the entire cylinder and is away from the cold plate. The only time the entire gas is next to the cold plate is when it is compressed and hot. Maybe if you had three plates, hot, insulated, cold, then waved the cold one through the cold expanded gas.

Your description will produce zero power. It will require power input, just like a heat pump. And any generated heat differential will be trapped inside the machine. I assume you know that.

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Fool
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Re: Proell Effect

Post by Fool »

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The Proell Effect comes about by mass flow from one temperature to a different, with associated pressure change. At constant volume. Quit adding a piston.

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