An Alpha type design could potentially work, I think, though some modification from the typical Alpha, as usually depicted would be necessary.
For example, as depicted in many animations of the alpha Stirling engine, nearly all of the working fluid is driven out of the hot chamber while compression is underway.
Rather than the working fluid being driven INTO the confined heating space, as in a Beta it is driven out, also the piston offset in an Alpha is such that a high compression is not really achievable.
Another interesting observation I've made recently is that Stirling's original, somewhat complicated looking linkage had the piston AND displacer reaching TDC simultaneously, which allowed the Beta style engine to achieve the highest possible compression. There was no 90° advance on the displacer.
Modified "Hot" Beta engine
Re: Modified "Hot" Beta engine
Read that chapter on the 5hp engine and wow nothing about that thing was easy or simple to make.
Re: Modified "Hot" Beta engine
Yes, I agree, and according to that forum post, never got anywhere near five hp either, but also, apparently, was not the engine developed previously by Sunpower.
Re: Modified "Hot" Beta engine
You've said that over and over again. Let me ask the following question, please.Tom Booth wrote:This is actually a rather conservative view. What is rather radical IMO is the idea that "heat" is in some way different or special and for some unknown reason. behaves differently than all other forms of energy.
If you put 100 Joules of work into a machine and it moves 300 Joules of heat into a hot plate, a COP of 3, (Plus a cooling of 2, that no one mentions.), how is that not different than putting 100 Joules push/work into a weight and having it move 100 Joules potential energy up a hill, a COP of 1.0? It's the same push either way, different amount of stored energy. Heat transfer is different. We are stuck with it.
Above is a description of an empirically tested and testable heat pump machine. They can be purchased.
Furthermore if one expected, from that same machine, to get more than 100 Joules of work out from an input of 300 Joules of heat in, working at the same temperatures, one would also expect to get unlimited over-unity free-energy from the connection of two of those identical machines.
I can only comment that you should expect to get less work out, probably a lot less, friction you know.
Instead of a hill, think of a valley. A car starts rolling into a valley, zipps past the bottom and goes up the other side it stops at the same height as the starting height. If you are good and can backup a vehicle as well as Burt Reynolds in the movie Hooper, the car will roll down the hill zip past the bottom and back up to the starting point. (If there is zero friction and zero drag.) How much energy is gained? Zero. This is analogous to adiabatic bounce or an air spring.
I can only comment that the car won't go as high, by a long shot, friction you know.
I'm not a fan of Bill Nye. He failed to explain that principle in his poorly built over hyped demonstrations. I'm surprised he got even one comment. More than it deserved but still telling. Omitting that point makes his demo misleading at best. Please look other places, as well, to learn your science, like from a real scientist. It rolled further because it was going through the bottom of the energy valley where zero forces were acting on stored kinetic energy. It had mass and velocity.
Re: Modified "Hot" Beta engine
Here are links to power producing Stirlings:
https://m.youtube.com/@ShanePomeroy/videos
https://m.youtube.com/channel/UCEkpABav ... TkQ/videos
Furthermore page 69 of Ivo Kolin's Book, The Evolution Of The Heat Engine, has a 1.0 hp beta engine by Lehmann. 13.78" bore and 6.85" stroke.
Plus others in that book and many other cycles.
Those engines are huge compared with the power of they produce. Many are not pressurized.
The size of fire needed for Shane's engine is huge when compared to the size fire I need to keep my place warm. In other words, we can't get many watts out of a wood stove while heating a cabin.
Here is a link to smaller engines:
https://www.youtube.com/@tkmotors991/videos
They've all been posted here before.
I don't see any reason that one of these traditional engines can't be built and experimented with insulating the cold side. At least one would have an engine that could deliver a known amount of power. Even a copy of the original James and Robert double acting engine got 40 hp. It was huge, but not that huge. Maybe a similar modern material one could be build with two propane, oxygen, or stainless steel beer keg bottles for displaces and power cylinder.
https://m.youtube.com/@ShanePomeroy/videos
https://m.youtube.com/channel/UCEkpABav ... TkQ/videos
Furthermore page 69 of Ivo Kolin's Book, The Evolution Of The Heat Engine, has a 1.0 hp beta engine by Lehmann. 13.78" bore and 6.85" stroke.
Plus others in that book and many other cycles.
Those engines are huge compared with the power of they produce. Many are not pressurized.
The size of fire needed for Shane's engine is huge when compared to the size fire I need to keep my place warm. In other words, we can't get many watts out of a wood stove while heating a cabin.
Here is a link to smaller engines:
https://www.youtube.com/@tkmotors991/videos
They've all been posted here before.
I don't see any reason that one of these traditional engines can't be built and experimented with insulating the cold side. At least one would have an engine that could deliver a known amount of power. Even a copy of the original James and Robert double acting engine got 40 hp. It was huge, but not that huge. Maybe a similar modern material one could be build with two propane, oxygen, or stainless steel beer keg bottles for displaces and power cylinder.
Re: Modified "Hot" Beta engine
I basically agree with these points, and I'm not trying to claim, and I'm quite sure Bill Nye is not trying to claim any "over unity".Fool wrote: ↑Wed Dec 27, 2023 9:21 am ...
Instead of a hill, think of a valley. A car starts rolling into a valley, zipps past the bottom and goes up the other side it stops at the same height as the starting height. If you are good and can backup a vehicle as well as Burt Reynolds in the movie Hooper, the car will roll down the hill zip past the bottom and back up to the starting point. (If there is zero friction and zero drag.) How much energy is gained? Zero. This is analogous to adiabatic bounce or an air spring.
(...)
it was going through the bottom of the energy valley where zero forces were acting on stored kinetic energy. It had mass and velocity.
But pistons in engines also have mass and velocity which for some reason is often overlooked when talking about heat engines.
Re: Modified "Hot" Beta engine
Let's use your valley illustration.
Suppose we have this car going down the hill into the valley and up to the top of the next hill, oscillating back and forth. First up one hill, down, then back up the other etc. etc. with "perfect" frictionless bearings on the wheels and no air resistance.
We could give the car a little extra push when it gets to the top of one hill and then it could go up and over the other hill.
But, suppose we take a little "work" out. Maybe have someone in the valley throw a light object into the car as it passes by. The car will carry that object up the hill and someone could take it out at the top of the hill
When the car returns it will then need another push.
Each push represents heat added at TDC and every object carried up the hill represents "work" output, or the load on the engine.
As long as these two energies are balanced and enough "extra" heat is supplied to also compensate for friction and other loses, this oscillation between two hills through the valley could continue.
The push at the top of the one hill has to match the work required to carry whatever object is tossed into the car up the other hill...
If you watch the Bill Nye video, from 3:00 when he leaves the bottle on the table, and before leaving the room, the bottle with the rubber band and coins keeps rolling a little one way, then back the other, then the other way again, then back etc. etc. a little less each time, but this oscillation continues until they leave the room.
There are no "free energy" claims being proposed here.
But I do think that maybe you are being rather loose with the concepts of energy utilization vs. energy transportation. As in a heat pump with a COP of 3 moving heat, so it gets cooler in one place from where heat is being taken and hotter in the place to which it is being carried... and heat transformation, as in a heat engine doing shaft "work" as a result of some load on the engine.
These are at least two different things; heat transport and heat conversion.
Heat conversion to "work" is kind of like using heat to melt ice. If the ice is 0°C or 32°F "transporting" heat into the ice does not result in any increase in temperature. In effect the heat "disappears" and the ice melts, but the melted ice is still 32°F
Putting heat into a heat engine has the same effect.
You keep putting heat in but it "disappears", but instead of melting ice the heat is transformed into "work" but it (the "heat" as thermal energy) still "disappears".
If the heat input is balanced by the work output then there is no "waste heat" to be removed.
That this is "impossible", to have work output balanced by heat input and that 100% heat utilization cannot be achieved without going down to absolute zero is completely ludicrous.
Suppose we have this car going down the hill into the valley and up to the top of the next hill, oscillating back and forth. First up one hill, down, then back up the other etc. etc. with "perfect" frictionless bearings on the wheels and no air resistance.
We could give the car a little extra push when it gets to the top of one hill and then it could go up and over the other hill.
But, suppose we take a little "work" out. Maybe have someone in the valley throw a light object into the car as it passes by. The car will carry that object up the hill and someone could take it out at the top of the hill
When the car returns it will then need another push.
Each push represents heat added at TDC and every object carried up the hill represents "work" output, or the load on the engine.
As long as these two energies are balanced and enough "extra" heat is supplied to also compensate for friction and other loses, this oscillation between two hills through the valley could continue.
The push at the top of the one hill has to match the work required to carry whatever object is tossed into the car up the other hill...
If you watch the Bill Nye video, from 3:00 when he leaves the bottle on the table, and before leaving the room, the bottle with the rubber band and coins keeps rolling a little one way, then back the other, then the other way again, then back etc. etc. a little less each time, but this oscillation continues until they leave the room.
There are no "free energy" claims being proposed here.
But I do think that maybe you are being rather loose with the concepts of energy utilization vs. energy transportation. As in a heat pump with a COP of 3 moving heat, so it gets cooler in one place from where heat is being taken and hotter in the place to which it is being carried... and heat transformation, as in a heat engine doing shaft "work" as a result of some load on the engine.
These are at least two different things; heat transport and heat conversion.
Heat conversion to "work" is kind of like using heat to melt ice. If the ice is 0°C or 32°F "transporting" heat into the ice does not result in any increase in temperature. In effect the heat "disappears" and the ice melts, but the melted ice is still 32°F
Putting heat into a heat engine has the same effect.
You keep putting heat in but it "disappears", but instead of melting ice the heat is transformed into "work" but it (the "heat" as thermal energy) still "disappears".
If the heat input is balanced by the work output then there is no "waste heat" to be removed.
That this is "impossible", to have work output balanced by heat input and that 100% heat utilization cannot be achieved without going down to absolute zero is completely ludicrous.
Re: Modified "Hot" Beta engine
If a hot air or Stirling engine is actually an oscillator, and a heat pump, then it is (the piston that is) bouncing between two energy sources.
The piston is bouncing between the pressure created at one end by the addition of heat, AND atmospheric pressure at the other end.
In the middle between these two extremes is "the valley" which is the mass, momentum and velocity of the piston between the "bounces" at each extremity.
The Stirling engine "heat pump" runs on heat, like a vuilleumier cycle, then transforms that heat into "work".
This is radically different from the Carnot concept that heat is for some unknown reason hell bent on making a beeline for "cold" and that a heat engine derives energy from this "fall" of heat as the heat heads towards absolute zero.
That is like saying if you roll a ball down one hill it cannot keep going all the way up the next hill unless your "valley" is all the way down at the center of the earth.
The distance to the center of the earth has little if anything to do with how far up the next hill the ball can roll.
The piston is bouncing between the pressure created at one end by the addition of heat, AND atmospheric pressure at the other end.
In the middle between these two extremes is "the valley" which is the mass, momentum and velocity of the piston between the "bounces" at each extremity.
The Stirling engine "heat pump" runs on heat, like a vuilleumier cycle, then transforms that heat into "work".
This is radically different from the Carnot concept that heat is for some unknown reason hell bent on making a beeline for "cold" and that a heat engine derives energy from this "fall" of heat as the heat heads towards absolute zero.
That is like saying if you roll a ball down one hill it cannot keep going all the way up the next hill unless your "valley" is all the way down at the center of the earth.
The distance to the center of the earth has little if anything to do with how far up the next hill the ball can roll.
Re: Modified "Hot" Beta engine
I'm sorry. It was not my intention to imply Bill Nye was an over unity promoter. I think he would agree with the second law. That would, by definition, eject him from the over unity crowd.
If one is a denier of the second law, then by definition, that would imply that a "tricky" combination of machines would produce over unity. The second law prevents over unity. Breaking the second law allows over unity. The first law is why it is impossible to break the second law.
Yes. Many people ignore the fact that the piston has mass. People ignore that the air has mass. They ignore the pressure on the outside, when convenient to do so, as well as the pressure on the inside. They also ignore the work and direction when convenient. It's easy to forget, too. They also forget that, to get heat two different temperature surfaces need to be in contact.
Heat begins to flow immediately. The hother the faster. The more surface area the faster. The longer the path the slower. It also depends on the R value, lower R equals faster.
Work always requires motion, a stroke, a passage of time.
I try to think what would happen in a vacuum, or space. I also think of a double sided piston in a cylinder with both ends closed and equal pressures both sides. That tends to remind me of those effects. The piston, or just air, bouncing back and forth if shaken.
If one is a denier of the second law, then by definition, that would imply that a "tricky" combination of machines would produce over unity. The second law prevents over unity. Breaking the second law allows over unity. The first law is why it is impossible to break the second law.
Yes. Many people ignore the fact that the piston has mass. People ignore that the air has mass. They ignore the pressure on the outside, when convenient to do so, as well as the pressure on the inside. They also ignore the work and direction when convenient. It's easy to forget, too. They also forget that, to get heat two different temperature surfaces need to be in contact.
Heat begins to flow immediately. The hother the faster. The more surface area the faster. The longer the path the slower. It also depends on the R value, lower R equals faster.
Work always requires motion, a stroke, a passage of time.
I try to think what would happen in a vacuum, or space. I also think of a double sided piston in a cylinder with both ends closed and equal pressures both sides. That tends to remind me of those effects. The piston, or just air, bouncing back and forth if shaken.
Re: Modified "Hot" Beta engine
I don't think I agree with all that.Fool wrote: ↑Wed Dec 27, 2023 11:33 pm ...
If one is a denier of the second law, then by definition, that would imply that a "tricky" combination of machines would produce over unity. The second law prevents over unity. Breaking the second law allows over unity. The first law is why it is impossible to break the second law.
...
Generally speaking, as I've pointed out before, I very often see the second law equated with, or used interchangeably with or in conjunction with the "Carnot limit" mathematical "efficiency equation":
Maximum efficiency = 1−Tc/Th
The "first law" thermal efficiency equation is:
Qh=Ql+W
Which I don't have a problem with. It does not imply that work can exceed the heat input, but neither does it suggest that the work output in Joules cannot match the heat input in Joules.
The first law does not forbid the existence of an engine more efficient than the Carnot limit, not at all.
So this statement is not true: "The first law is why it is impossible to break the second law."
100% efficiency is not forbidden by the first law, and 100% efficiency is not "over unity".
The Carnot limit however, (as apparently universally interpreted) might say, for example, that a heat engine operating between the two temperatures of 300k and 400k is 25% efficient.
So the first law suggests if you put in 1000 joules of heat you can get out 1000 joules of work, if Ql is equal to zero. That does not mean absolute zero mind you. It just means zero joules of heat at the exhaust. If the exhaust is 300k and the ambient sink is 300k then there is no "heat". That is not absolute zero.
The Carnot limit however calculated that if you put in 1000 joules of heat you can only get out a poultry 250 joules of work.
So, you could violate the Carnot limit aka the second law by a mile and never come anywhere near violating the first.
Re: Modified "Hot" Beta engine
Why is a heat pump able to move more thermal energy than the energy required to operate it?
I guess that maybe this is due to the kinetic motion of gas. Compression is kind of like hurding cattle.
That is, if you compress a gas with a piston you have, say, 200 billion hot gas molecules 200 billion cold molecules and another 200 billion warm or some such combination.
But as the piston closes in reducing the volume, how many gas molecules are actually colliding with the face of the piston at any one time?
So if the piston moves the width of one molecule it is resisted by only a very small fraction of the molecules actually impacting the piston. The remainder 99% or whatever molecules are essentially cooperating. Heading in some other direction rather than hitting the piston.
The hot molecules are only being moved or corraled into a smaller pen, no heat is being created.
Incidentally, where the hot molecules are being moved away from gets colder.
Is that "over unity"?
A heat pump is just a compressor.
A piston in an engine during the compression stroke is also a compressor.
I guess that maybe this is due to the kinetic motion of gas. Compression is kind of like hurding cattle.
That is, if you compress a gas with a piston you have, say, 200 billion hot gas molecules 200 billion cold molecules and another 200 billion warm or some such combination.
But as the piston closes in reducing the volume, how many gas molecules are actually colliding with the face of the piston at any one time?
So if the piston moves the width of one molecule it is resisted by only a very small fraction of the molecules actually impacting the piston. The remainder 99% or whatever molecules are essentially cooperating. Heading in some other direction rather than hitting the piston.
The hot molecules are only being moved or corraled into a smaller pen, no heat is being created.
Incidentally, where the hot molecules are being moved away from gets colder.
Is that "over unity"?
A heat pump is just a compressor.
A piston in an engine during the compression stroke is also a compressor.
Re: Modified "Hot" Beta engine
I don't know that the rounding up of hot molecules is the real reason, just a guess.
Another possibility is molecular attraction and repulsion.
Colder gas molecules that are far apart tend to have attractive forces dominating, while gas molecules that are hot and close together repel each other.
So while the gas is expanded and cold, it seems there is an advantage and it can be compressed more easily, but when fully compressed then the repulsive forces dominate.
So, I think that maybe that could be why the compression ratio and acting very quickly is important.
If the gas is expanded and attracting, take advantage of that moment and compress it quickly before the repulsive forces kick in, then when compressed and wanting to expand, take advantage of that moment as well and boost the expansion to the max by a sudden blast of additional heat, to kick the repulsive forces into hyperdrive to get an explosive expansion.
If that is not the case, then I don't really see why there could be any gain from a higher compression ratio. But IC engines did not really take off except when rapid high compression was used.
Logically, the work needed to compress the gas is lost. I mean, if you lift a weight and let it down there is no gain. But if you compress a gas quickly, then expand it quickly your engine will run... Better?
So this "adiabatic bounce" takes action at the extremities of full expansion and full compression where there is the greatest "leverage" so to speak.
At full expansion there is an advantage to rapid compression because at that moment the gas is "cooperative" and "willing" to move the way you try to send it.
Then at full compression you say, OK you're free to go, and the gas again cooperates as you encourage it to expand while giving it an extra kick in the ass.
Another possibility is molecular attraction and repulsion.
Colder gas molecules that are far apart tend to have attractive forces dominating, while gas molecules that are hot and close together repel each other.
So while the gas is expanded and cold, it seems there is an advantage and it can be compressed more easily, but when fully compressed then the repulsive forces dominate.
So, I think that maybe that could be why the compression ratio and acting very quickly is important.
If the gas is expanded and attracting, take advantage of that moment and compress it quickly before the repulsive forces kick in, then when compressed and wanting to expand, take advantage of that moment as well and boost the expansion to the max by a sudden blast of additional heat, to kick the repulsive forces into hyperdrive to get an explosive expansion.
If that is not the case, then I don't really see why there could be any gain from a higher compression ratio. But IC engines did not really take off except when rapid high compression was used.
Logically, the work needed to compress the gas is lost. I mean, if you lift a weight and let it down there is no gain. But if you compress a gas quickly, then expand it quickly your engine will run... Better?
So this "adiabatic bounce" takes action at the extremities of full expansion and full compression where there is the greatest "leverage" so to speak.
At full expansion there is an advantage to rapid compression because at that moment the gas is "cooperative" and "willing" to move the way you try to send it.
Then at full compression you say, OK you're free to go, and the gas again cooperates as you encourage it to expand while giving it an extra kick in the ass.
Re: Modified "Hot" Beta engine
Right or wrong, I view it kind of like a game of tennis.
You have heat input to the engine on one side and atmospheric pressure on the other, being the two forces playing against each other batting the "ball" (piston) back and forth.
Neither player can do anything while the ball is in flight. All they can do is wait until the ball is in their court and then hit it hard at that precise instant.
Between the two extremities what can you do?
Actually, maybe it is kind of like the ball is in a tether of sorts as well. Like a long rubber band.
Instead of tennis, maybe more kinda like tetherball.
https://youtu.be/H3SyFsavKhI?si=jjF5Mt3DJtPDTgD3
The main point being, there is no point really in trying to "chase" the ball around. It's moving too fast anyway. The only time you can really give it a good boost is when it is changing direction anyway, at TDC and BDC.
Because you are dealing with something that is elastic or "bouncy", much of the force or energy is conserved or put back with each hit in the other direction.
Maybe it is my IC mechanic background. I've spent years and years just repairing engines, a lot of that involved setting the timing. There is just this one precise instant where everything happens at once, full compression and ignition.
I've repaired hundreds of lawn mowers where the trimming was out by just a hair because of hitting a rock and the flywheel turned on the shaft like 1/64th of an inch, making just a dent in the side of the flywheel key.
https://youtu.be/x8whgnLsTq8?si=LTWY12q9wEOrFg1i
Now, maybe Stirling engines are different?
Maybe the timing is not so significant in a Stirling engine or external combustion engine?
Maybe you can follow the piston, in effect chasing it down the cylinder with more heat?
Maybe, but I don't think so.
You have heat input to the engine on one side and atmospheric pressure on the other, being the two forces playing against each other batting the "ball" (piston) back and forth.
Neither player can do anything while the ball is in flight. All they can do is wait until the ball is in their court and then hit it hard at that precise instant.
Between the two extremities what can you do?
Actually, maybe it is kind of like the ball is in a tether of sorts as well. Like a long rubber band.
Instead of tennis, maybe more kinda like tetherball.
https://youtu.be/H3SyFsavKhI?si=jjF5Mt3DJtPDTgD3
The main point being, there is no point really in trying to "chase" the ball around. It's moving too fast anyway. The only time you can really give it a good boost is when it is changing direction anyway, at TDC and BDC.
Because you are dealing with something that is elastic or "bouncy", much of the force or energy is conserved or put back with each hit in the other direction.
Maybe it is my IC mechanic background. I've spent years and years just repairing engines, a lot of that involved setting the timing. There is just this one precise instant where everything happens at once, full compression and ignition.
I've repaired hundreds of lawn mowers where the trimming was out by just a hair because of hitting a rock and the flywheel turned on the shaft like 1/64th of an inch, making just a dent in the side of the flywheel key.
https://youtu.be/x8whgnLsTq8?si=LTWY12q9wEOrFg1i
Now, maybe Stirling engines are different?
Maybe the timing is not so significant in a Stirling engine or external combustion engine?
Maybe you can follow the piston, in effect chasing it down the cylinder with more heat?
Maybe, but I don't think so.
Re: Modified "Hot" Beta engine
I mean, in principle, I think it is similar to firing a gun.
Can you do anything more after the hammer falls to speed up the bullet?
Can you do anything more after the hammer falls to speed up the bullet?
Re: Modified "Hot" Beta engine
When I think of high rapid compression, a diesel engine comes to mind (compression ratio about 20:1) a hand operated "fire piston" has a higher compression ratio than a diesel engine (about 25:1).
You can't get high compression like that easily with slow or gradual compression. A fire piston is also called a "slam rod" for obvious reasons I think.
Anyway, a Beta type Stirling, which seems to have been Robert Stirling's original patent design, looks like a way to achieve a much higher compression ratio than other types of "Stirling" engines.
Perhaps an opposed displacer and power piston design similar to an Essex engine could achieve high compression, but the displacer would have to be more a piston than a displacer. Basically an opposed Alpha?
You can't get high compression like that easily with slow or gradual compression. A fire piston is also called a "slam rod" for obvious reasons I think.
Anyway, a Beta type Stirling, which seems to have been Robert Stirling's original patent design, looks like a way to achieve a much higher compression ratio than other types of "Stirling" engines.
Perhaps an opposed displacer and power piston design similar to an Essex engine could achieve high compression, but the displacer would have to be more a piston than a displacer. Basically an opposed Alpha?