Stirlingengineforum.com

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Grow up. Learn more.

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Fool wrote: ↑Thu Nov 14, 2024 1:50 am .

Grow up. Learn more.

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I'm learning every day. I'm always exploring new territory and new concepts, theories and ideas.

I have an open curious mind.

I started studying wave mechanics in my father's library, quantum physics and string theory in high school. Hell, I was doing experiments with my brothers in my father's lab when I was five. I grew up with science and learning. Expanding horizons is fun

You're still living in 1820 trying to defend the obsolete Carnot model.

The so-called "Carnot efficiency limit" is antiquated baseless nonsense with zero experimental validation, zero sound mathematical "proof", zero logic. It's theoretical basis is water-wheel foolishness.

You need to grow up and grow a brain

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If you are so well educated. How come you think gasses can contract in a vacuum? By all comments you've made, 'gas molecules have attractive and repulsive forces in ballance' you still think that gasses in a vacuum contract when cooled. Where did you learn that erroneous memory?

Gasses always push, even when cooled, or compressed. Any reduction in volume has to come from a greater force on the outside. A simple scientific fact that you deny.

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The Carnot Theorem has never been exceeded in any cyclic process, as shown by proper measurements. Usually by no closer than 50%. It is an optimistic prediction always exceeding overall efficiency.

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Fool wrote: ↑Fri Nov 15, 2024 8:05 am .

The Carnot Theorem has never been exceeded in any cyclic process, as shown by proper measurements. Usually by no closer than 50%. It is an optimistic prediction always exceeding overall efficiency.

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I agree that this is true. As often stated;

It would be impossible to exceed the "Carnot Limit" because that would mean that the engine converted "ALL the heat" all the way down to Absolute Zero.

That is one way of looking at "efficiency".

But in the real world we measure efficiency according to energy supplied starting at about 300°K or ambient earth atmosphere temperature, here where we actually live.

We haven't colonized the dark sde of the moon yet, and even that is not absolute zero.

So if I have an LTD Stirling engine that runs on a cup of coffee I heated up by taking 300°K ambient temperature water and bringing it to a boil at 373°K the maximum "Carnot Efficiency" when I've used up all the heat I added to boil the water will be about 19.5% because

Converting all the heat supplied to boil the water only bring the temperature back down to 300°K which is only 19.5% of the way down to absolute zero

But some confused academics abysmally poor at simple mathematics and completely lacking in common sense got all confused by this. You Mr. "fool" being one of them, or having been "educated" by one or more of them, can't keep things straight in your head, or have some reason for intentionally perpetuating confusion on the subject.

Now, if my LTD engine converts ALL the heat supplied to boil water lowering the temperature from 373°K back down to 300°K) then uses the work output to move and convert additional heat bringing the temperature a little closer to absolute zero, by 2 degrees, then the "Carnot Efficiency" will be a little greater: 20.1% insteady of 19.5%

But that engine with "no load" will still only be spinning its own wheels for a "Net" or practical efficiency of zero.

So we are looking at three different measures of efficiency.

1) "Carnot efficiency" is how much heat we used on the absolute temperature scale.

2) Then there is the thermal efficiency based on the amount of heat actually supplied in Joules starting at 300°K (or ambient). and utilized back down to ambient.

3) On top of that you have practical efficiency, or how much of my house can I unplug from the grid if I use this engine to generate electricity.

That's three different measures of "efficiency".

I'm only concerned with #2 how much of the heat I supply does the engine convert, not including the existing ambient thermal energy at 300°K.

You have that confused with the other two which are of no particular interest to me.

You (along with many other academics with no common sense), are a confused lunatic who can't think straight, is bad at math and can't differentiate the meaning of the same word used in different contexts.

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Tom Booth wrote:It would be impossible to exceed the "Carnot Limit" because that would mean that the engine converted "ALL the heat" all the way down to Absolute Zero.

Carnot won't ever be beaten, even going all the way to zero Kelvin. At the best, it can only be equaled. It is an equation that gives a goal of the efficiency a perfect engine would have.

It is like the equation for a perfect circle. The best one could do would be equivalent to that circle equation. Unlike Carnot, a drawn circle comes way closer to perfection. The circle equation doesn't account for the roughness of paper, sloppiness of pivot point, flexing of compass or bluntness and wear of pencil point.

Carnot doesn't account for, friction, thermal leakage, non ideal cycles, etc, but all those things effect a real engine. Real engines aren't typically even as close as 50%. Way worse than a compass to a perfect circle.

Carnot isn't about zero Kelvin. Zero Kelvin doesn't even show up in the equation. n=(Th-Tc)/Th=W/Qh

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Tom Booth wrote:But in the real world we measure efficiency according to energy supplied starting at about 300°K or ambient earth atmosphere temperature, here where we actually live.

No. We determined efficiency by measuring the fuel burned and the electrical power output by the system. Or other similar ways. Dynamometer, indicator diagram, volt amp meters. Etc. heating of water, melting of ice, etc ...

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Tom Booth wrote:So we are looking at three different measures of efficiency.

1) "Carnot efficiency" is how much heat we used on the absolute temperature scale.

2) Then there is the thermal efficiency based on the amount of heat actually supplied in Joules starting at 300°K (or ambient). and utilized back down to ambient.

3) On top of that you have practical efficiency, or how much of my house can I unplug from the grid if I use this engine to generate electricity.

That's three different measures of "efficiency".

Wow! You forgot to put in any mathematics, or tools to do any measuring. Those related wishes are nothing more than wild ass comments, incomprehensible, mishmash of gobblely goop. Yes there are many different ratios that could be called efficiency. It is easy to keep them straight, unless someone doesn't listen well.

1) Carnot efficiency, n=(Th-Tc)/Th=W/Qh. Sure you can measure Th and Tc, and compare it to measured Work and measured fuel, or supply energy. But it seems to have no room to enter zero Kelvin. It is not how much energy we use. It is a ratio of how much work the piston does, to how much energy enters the working gas, for a full cycle. It is a maximum for a perfect engine.

3) You seem to be hinting about a ratio of engine-generator output power, to your house power. Why? That has nothing to do with engine efficiency or Carnot.

Tom Booth wrote:I'm only concerned with #2

Wow! Humor! You are only concerned about number two. Did you hear that, Matt, Vincent, Jack, and anyone? Toms only concerned about number two. No number one or number three, butt number two. Number one is good. Number two is worse than number one, and number three a combination of one and two and is worse yet. I know it's crap, but let us look at number two, hopefully no one will step in it.

This may help:

https://m.youtube.com/watch?v=kXH3HDE9Czo

2) "the thermal efficiency based on the amount of heat actually supplied in Joules starting at 300°K (or ambient). and utilized back down to ambient."

How is that different from Carnot? Carnot is from ambient Tc to heat added Th. Or Work out, divided by, Heat from ambient to Th and back to ambient. Hmmm I guess it has to have Work out measured unlike number two, which avoids that necessary data.

Utilized equals work? Hmmmm. It could be utilized just to heat up breakfast. Gobblely goop. Number two.

Think about how many Joules the few tablespoons of air in a LTD engine could absorb going full temperature swing, from 300 K to 600K, then realize it's not even going that far. 350 to 450 K? Less than 500 RPMs. Now reduce Th down to 400 K. And 200 RPMs. Now realize, all that heat is going in and out of the regenerator, not even being supplied by the hot plate. Instead Qh goes in only during the power stroke. It is dependent on the adiabatic cooling effect of the tiny little piston. What is that compression ratio 0.1(a guess). Maybe someone with an engine can measure it a little more accurately and tell us. How much temperature drop for 0.1 change in volume?

Anyway, most people will get my drift here.

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I'm only interested in #2 as it relates to Tesla's proposed "cold hole" engine in terms of, is it even possible at all, like the drinking Bird. Not if it is practical or if it has useable power output.

You still seem incapable of differentiating different types or methods of construing "efficiency" or just want to perpetuate confusion, or more likely just don't have a brain or enough common sense to see the distinction.

No, most people do not "get your drift". Your a confused idiot talking nonsense.

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Dream on Tommy.

When you understand simple gas properties, lake gasses always pushing. We'll discuss more complex principles. Like the cube root of 27, and more.

Most people don't get anything about science, which is a pity. But people here, that know anything about science, can observe the fact that gasses always push, and Tom denies that, and has a foul mouth, at times.

As far a efficiencies go. You still don't understand ratios. They are simple fractions.

Which fraction is bigger, 1/3 or 1/5? Not a trick question. Googling it is cheating.

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Fool wrote: ↑Sat Nov 16, 2024 12:26 pm .

Dream on Tommy.

When you understand simple gas properties, lake gasses always pushing. ...

Your obsessed with "gasses always push".

If you knew anything about the topics related to "real gas behavior" beyond calling them "buzzwords" you might get past 1820's physics theories.

Real gases have forces of attraction. Two or more gas molecules being drawn together by mutual attraction is not "always pushing".

You seem incapable of reading all the.numerous references or watching any of the videos already posted so believe whatever you like.

If you are so sure of yourself why follow me around like a paparazzi critiquing every word ? Go find something useful to do with your life.

Fool wrote: ↑Sat Nov 16, 2024 3:51 am .

Tom Booth wrote:It would be impossible to exceed the "Carnot Limit" because that would mean that the engine converted "ALL the heat" all the way down to Absolute Zero.

Carnot won't ever be beaten, even going all the way to zero Kelvin. At the best, it can only be equaled. It is an equation that gives a goal of the efficiency a perfect engine would have.

Hmmm, my approach is never say never, just highly unlikely.

Fool - your math is all based on modern yadda-yadda-yadda=0 scheme which has dominated western thinking since the medieval period with rise of literacy. Many years ago, I solved an impossible mechanical issue via yadda-yadda-yadda=1 whereupon I became more suspicious of math. Current 0 scheme (base 10) may be rock solid for modern financial stuff, but often lacking when stepping outside the box.

Beating Carnot is not like over-unity and beating Carnot on the low end appears far easier than the high end (numerical leverage). I don't sit around scheming how to beat Carnot, but I refuse to rule out the possibility. Once you rule this out then you could easily overlook the solution like King Midas..

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True. Beating Carnot, something no one has ever done, only opens the theoretical door to over unity. Again violating the second law can only be done if the first law is breakable.

Carnot = (Th-Tc)/Th = (400-300)/400 = 0.25 engine max.
Carnot = Th/(Th-Tc) = 400/(400-300) = 4 heat pump max.

An Efficiency of 26% times a COP of 400% equals a combined machine total of 104%, or over unity.

Or in 'real numbers, not those ridiculous percentages:

n=0.26 times COP of 4 equals over one, or exactly 1.04 that is more than unity.

n•COP= no more than 1 <<< first law
0.26•4=1.04 over unity, greater than one. If Carnot is beat in either direction or both.

Learn how to run the numbers, and why they are correct.


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I figured you are too afraid to answer the following:

Which fraction is bigger, 1/3 or 1/5? Not a trick question.

Good luck.

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https://m.youtube.com/watch?v=eoVUdwOgjiA

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