Stirlingengineforum.com

Fool wrote: ↑Sun Jun 02, 2024 2:56 pm.
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Tesla, wrote his article during a time when the second law, and Entropy were being hotly debated and still unknown to most. He probably spent the rest of his life trying to figure out that his ambient cold hole scheme can't work. He was unsuccessful in building one. Entropy and the second law weren't completed until after Tesla died, and his and many others failures, have led to the laws acceptance by mainstream science. That and the additional study's that students perform even today.

...

Funny thing is, Tesla was 100% correct in stating that heat is a form of energy that can be converted. Kelvin and company were 100% wrong in stating that heat was ALL "rejected".

And yet, today our educational systems, largely financed and controlled by oil interests are still pushing Carnot limit.

And every forum I visit on the internet has at least one "fool" ready to pounce on anyone who might float an idea contrary to the all powerful, unbreakable universal so-called 2nd Law.

You seem like a smart, well educated guy Mr. "Fool". Why do you waste your time going around harassing deluded "perpetual motion" nuts ?

There are paid shills for just about anything and everything.

I can remember being lectured on the impossibility of "perpetual motion" in grade school. "There is no such thing as free refrigeration".

Actually, there are quite a few methods for obtaining "free refrigeration".

I think it is relentless discouragement from people like yourself, Mr "fool" that keeps 99.9% of all potential inventors from ever trying to invent anything, no less try to bring it to market.

I agree.
Maybe that's the underlying problem that causes the lack of innovation these days. I can't even count the times somebody told me I can't possibly achieve a certain thing. It often stopped me in my tracks, but recently it just motivates me. And I've proven some wrong. Not anything as big as the second law, but it's what makes me stubborn now. I won't stop just because someone tells me it can't work. What do they know? Have they tried exactly this?
I'm not aiming this at fool, but people in general like to cut down the head that sticks out. It makes them feel better about themselves for not even trying.

Rules and laws are there to be broken, adjusted, amended, reformed or tossed out and replaced by new ones.

Personally, I don't see why combining a Stirling engine with a heat pump should be so "impossible"

The only reason that my comments here could irritate someone is if an ignorant statement were proven wrong by a scientific fact. I am not here to dissuade anyone of their loved pursuits. Quite the contrary. Encouraging learning by doing, is the main goal of adding science. Science directs exploration into reliable areas.

I was never flustered growing up by someone telling me that I couldn't do something. It made me want to do it more. Of course it was about stuff I knew I could do. That is why I was the only child of four that had a car in highschool. Began fixing it in 8th grade. Cost $75 for parts lots of big parts, stared out as a wrecked totaled. People told me I couldn't do it, I still have it. BFHTD, but fun.

There is a big difference between an ignorant person saying something can't be done and a scientific principle, law, fact or data. The can-not-fly crowd were all religious ignoramuses, the might-be-able crowd varied from ignoramuses to budding scientists, such as the Wright Brothers. The same is true of round earth, heliocentrism, supersonic flight, periscopes, etc... budding science was on the correct side.

Be very cautious of what you vocally poo poo, as to wether you or they are on the side of science or ignorance. I'm trying to inject needed science into this forum, as is Matt.

I would love to explore materials. If the Stirling Brothers had 316 SS in 1800 there would be a lot more Stirling Engines today. It is not a cheap material, but a good one. I think ceramics is the next possibility to look into. Phillips has the corner on theory. Newer better materials are being developed every day. Chemistry is wickedly complex and ripe for experimentation. Tim Tinker has encouraging prospects into ceramics/refractories.

If I had time I would be playing with those, and TK motors. I would also play with coolers, specifically cryocoolers. Producing liquid gases and fractionally distilling them could pay well. I weld, separated gases are good.

I don't have any interest in running an engine on a cooler. I do like the idea of running one on wood. I burn a lot, both to heat the house, and to clean up in big fire piles. I just imagine putting branches into a shredder, and into a fluidized bed power plant.

Fool wrote: ↑Tue Jun 04, 2024 12:05 pm ...
There is a big difference between an ignorant person saying something can't be done and a scientific principle, law, fact or data. The can-not-fly crowd were all religious ignoramuses, ...

Funny you should say that when it was Kelvin who most vigorously promoted the Carnot theory.

He also said:

"I can state flatly that heavier than air flying machines are impossible."

— Lord Kelvin, 1895

The thing I think I'm pointing at is the blindness our brains create to other things when it is shown a certain direction or when it has preconceived ideas. There's probably a word for that, but my English isn't proficient enough for that.
Our brains are wired to find information to substitute what we already believe. Whether that's right or wrong (if there even are such things).
So scientists could be blinded and outright reject things because they don't fit into their beliefs (yes, science is just another belief system).
Maybe this is me just making a case for me and my thinking, but I've studied enough zen to understand that a clear mind without attachments sees most.
I'm not saying I'm right, I have no clue. I could be stupid or genius. But I do feel like my beginners mind in this area might give an edge.
I'm not trying to dismiss science but rather trying to test it for myself.

Back to the topic at hand haha.

Jack wrote: ↑Tue Jun 04, 2024 4:55 pm The thing I think I'm pointing at is the blindness our brains create to other things when it is shown a certain direction or when it has preconceived ideas. There's probably a word for that, but my English isn't proficient enough for that.
Our brains are wired to find information to substitute what we already believe. Whether that's right or wrong (if there even are such things).
So scientists could be blinded and outright reject things because they don't fit into their beliefs (yes, science is just another belief system).
Maybe this is me just making a case for me and my thinking, but I've studied enough zen to understand that a clear mind without attachments sees most.
I'm not saying I'm right, I have no clue. I could be stupid or genius. But I do feel like my beginners mind in this area might give an edge.
I'm not trying to dismiss science but rather trying to test it for myself.

Back to the topic at hand haha.

I'm not trying to dismiss science either. I just don't see anything scientific about the "Carnot efficiency limit" at all. It was not based on any kind of science whatsoever.

I guess I'll just have to leave you with your choices. Plenty of mathematical proofs for me that are easy enough to follow.

Fool wrote: ↑Wed Jun 05, 2024 12:49 am I guess I'll just have to leave you with your choices. Plenty of mathematical proofs for me that are easy enough to follow.

Like what? Aside from your own made up self referential "derivations" that just end up right where they started; with the unproven Carnot limit temperature difference supposition.

Perhaps it's relevant here, there is a video of the sunpulse 500 claiming a cop of 5 when being used as a heat pump for refrigeration.

Thats about the best designed ltd engine out there.

https://youtu.be/CxnoNl85P3Y?si=DPuQfPgH0LUq7OnM

VincentG wrote: ↑Wed Jun 05, 2024 9:44 am Perhaps it's relevant here, there is a video of the sunpulse 500 claiming a cop of 5 when being used as a heat pump for refrigeration.

Thats about the best designed ltd engine out there.

https://youtu.be/CxnoNl85P3Y

Interesting.

I never imagined a Sun Pulse Stirling being used as a cooler. I wonder what kind of temperatures they are getting and if they are just dumping heat in the pond.

This article/review states:

"when cooling 25 ° C to the freezing point, the power factor of 5"

"If the power of a 500 Watt panel drives the Coolpulse by an electric motor during the day, 2.5KW cooling capacity (up to 15KWh of cooling energy per day), which can provide cooling around the clock in conjunction with a cold store.“

A 25°C ∆T of cooling seems pretty substantial for an unpressurized engine using air.

https://oneplanetthriving.com/2016/11/s ... als-notes/

It also says:

Cooling the cold side: simultaneous water pumping and cooling by integrated pump

I could be wrong, but my assumption is that water cooling is also used in "cool pulse" refrigeration mode

It might make a rather huge difference if you don't happen to have a cold running stream in your back yard for some "free" cooling.

I received the eBay Tesla turbine.

I'm not impressed.

Turning it by hand it I can actually feel the bearings grinding. It has a lot of resistance and takes considerable psi to get it to start.

Quite a bit of sideways play in the rotor.

Once it gets going at highish speed, (just blowing air through it with my shop vac) it seems better, I haven't had a chance to put real compressed air to it yet.

No idea why it turns so rough by hand.

Anyway, I just sent for some dental drill heads I found on eBay. Very tiny air turbines but can rotate at fairly low pressure and can reach as high as 400,000 RPM.

Not Tesla type turbines, but might work for a small air cycle refrigeration system. At $10 and free shipping I guess it's worth a try. Not sure why so cheap. Might not include bearings or something. Those dental drills normally have some high speed ceramic bearings and cost hundreds of dollars even used so I'm not really sure what I'll be getting for $10.

Tom Booth wrote: ↑Thu Jun 13, 2024 9:00 pm I received the eBay Tesla turbine.

I'm not impressed.

Turning it by hand it I can actually feel the bearings grinding. It has a lot of resistance and takes considerable psi to get it to start.

Quite a bit of sideways play in the rotor.

Once it gets going at highish speed, (just blowing air through it with my shop vac) it seems better, I haven't had a chance to put real compressed air to it yet.

No idea why it turns so rough by hand.

Anyway, I just sent for some dental drill heads I found on eBay. Very tiny air turbines but can rotate at fairly low pressure and can reach as high as 400,000 RPM.

Not Tesla type turbines, but might work for a small air cycle refrigeration system. At $10 and free shipping I guess it's worth a try. Not sure why so cheap. Might not include bearings or something. Those dental drills normally have some high speed ceramic bearings and cost hundreds of dollars even used so I'm not really sure what I'll be getting for $10.

Compress_20240613_235947_7868.jpg

How much is the spacing between the discs? The play turbines usually have way too much space between them. Then they need a huge amount of air to start spinning.

Jack wrote: ↑Fri Jun 14, 2024 7:36 am [...
How much is the spacing between the discs? The play turbines usually have way too much space between them. Then they need a huge amount of air to start spinning.

I haven't had it apart and can't see through the aluminum so I don't know. It might be in the specifications on one of the eBay pages selling these.

All I know at this point is you could turn blue trying to blow into it to get it to spin. It's like blowing into a bottle as if closed off.

It turns over by turning the shaft with your fingers fairly easily, but doesn't turn smooth, like the bearings are dirty or rough or binding, or maybe something fairly big inside the router housing, like aluminum chips or filings.

Anyway, air does not go through easily at all, so I wouldn't think the disks are spaced too far apart.

It kind of feels like the bearings are greased up with thick grease making the rotor hard to turn.

If you spin it by hand it is kind of hard to turn and makes an audible noise similar to turning a stepper motor and only makes a few turns and stops.

Fresh out of the packaging it looks like it was hastily put together in a very dusty dirty environment, covered with smears of glue (locktite ?) dust and fingerprints.

Probably no better inside.