Electricity from ambient heat

Tom: 500 BTUs in a 75% efficient engine...that means we have 375 BTUs worth of electricity to play with...from which we take 125 BTUs worth of electricity to remove the 125 ACTUAL remaining BTUs from our heat source and are left over with 250 BTUs worth of electricity? Holy crap, no offense but you don't have a clue what you're talking about.

 

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There is no complex math in post 97.

In simple easy to follow logical steps the text there PROVES heat pumped out of the cold source is ALWAYS less than even the most perfect possible engine (a Carnot engine with zero friction) MUST deposit into the cold sink while producing the work, W, to drive the heat pump (any refrigerator removing heat from the cold sink and depositing it in the hotter supply - I.e. a closed cycle.)

Quote any line of the proof you do not understand and I will restate it in other terms etc. for you.

Again you need to realize that no amount of clever design or engineering will ever beat the efficiency of the ideal Carnot engine, operating between to temperature sources (Th and Tc). That Carnot efficiency E is limited to:
E = (Th -Tc) / Th. (temperatures in kelvin degrees)

 

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Thanks, I'm sure the math proves both your points, however, as I understand it, the math regarding Ideal gas law etc. is approximation. There is no such thing as an "Ideal" gas in reality is there. Every gas behaves a bit differently so to what does such a "Law" actually apply ? (Just for example).

Probably I don't know what I'm talking about but I know what my eyes tell me.

The drinking bird works. It is a heat engine that drives an evaporative cooler so as to provide itself with a heat sink. Can we agree about that ?

Why not a Stirling engine driving a swamp cooler ? Same principle, just a different type of heat engine driving a different type of evaporative cooler. Perhaps it would still only produce a millionth of a watt of un-usable excess energy but that isn't really the point. The question is, is such a thing even possible at all ? The math apparently says no. Yet the bird keeps churning out it's 1/1,000,000th of a watt.

Take two really smart guys, Tesla and Einstein. Einstein saw the drinking bird and couldn't figure out how it worked. I'd go with the guy who had an explanation.

Personally I don't see mathematics as the basis for science but rather observation. If the math says an airplane can't fly, well, if everybody believed that we'd still be traveling in hot air balloons.

You can observe the bird. Tesla had a theory that seems to apply to it or explain how it works, the next step would be experiment. Build an engine based on Tesla's theory and see if it works. If everybody believes the math or the 2nd "Law" as sacrosanct and irrefutable nobody will ever bother and we may miss out on one of the greatest discoveries or inventions in history.

 

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Your apparent paraphrasing of my statement does not seem to reflect what I actually stated. If that is what it is. I did not for example say "that means we have 375 BTU's worth of electricity to play with" If you are going to put my name in front of a string of apparent quotes at least quote me accurately even if you don't understand my point please.

To put it in different terms:

In a heat engine you have a heat source and a heat sink. Heat enters the engine, in a "Hot Air" heat engine, air in a chamber is expanded by the heat driving a piston which in turn drives, probably an electric generator, in this example anyway.

Ultimately the heat/energy is converted to electricity.

Lets say that 500 units of heat energy enter the engine, expand some air in a chamber and push a piston which turns a generator. On expansion the air gives up energy to push the piston and gets cold. The air contracts and the piston returns to its original position. Ideally that 500 units is ALL converted to electricity. The original heat/energy that entered the engine never makes it to the heat sink if the engine were 100% efficient.

Since real heat engines are not 100% efficient at converting the energy, some percentage of the original heat entering the engine will go to the heat sink at the other end of the chamber of air. That heat will have to be removed for the engine to continue to run.

In any event, whatever the actual efficiency of the engine there will ALWAYS be less heat that needs to be removed at the sink than that went in at the source. The exact numbers or units of whatever are not particularly relevant.

If 500x go in, 400x are converted to electricity then just 100x units end up at the sink.

If 500x go in and only 200x units of heat/energy are converted then 300x units of heat reach the heat sink.

If the engine were 100% efficient no heat at all would reach the sink and there would be no need to remove any heat whatsoever.

I'm not sure what it is you are objecting to or why exactly you say you think I don't know what I'm talking about.

Do you agree with the above ? that ALL the heat that enters a heat engine always reaches the sink ? That ALL the heat that goes into the engine passes through and goes to the heat sink regardless of efficiency ? That you would need a refrigerator that moves just as much heat out as goes in ?

Just curious.

 

"Ideal" means "this is as good as it gets". Not "this is the worst case, you can do better". The Carnot cycle is the best possible case achievable under ideal conditions. What ever you attempt to implement will not even achieve Billy T's limits. So your observation about the ideal case puts your proposed solution even farther from reach.

You are throwing around ideas from physics but you acknowledge you don't understand the math and science behind them. It's a common type or error. It's not your reliance on what you see, but your mistrust of the scientific explanations for what you do not see.

No, it doesn't drive the evaporation. The water will evaporate with or without the bird. It's just a second thermal well, nothing more.

No, it doesn't drive evaporation. That's a natural process. I doubt you can overcome the friction in a Stirling engine with mere evaporation like this. There are any number of more likely choices of hot/cold wells for a Stirling engine, such as solar and geothermal sources.

The bird isn't doing the work, the evaporation is doing work on the bird. If you mean "Can I harvest power from evaporation", then yes, that's how hydoelectric dams work.

Tesla spoke of decomposing water into gases, which goes even further than simple evaporation. I'm not aware of Einstein's analysis but I'm skeptical that he missed the fact that it worked on evaporation. In any case, you've misunderstood Tesla. Learn what vapor pressure is, and you'll be on the road to discovering the source of your error.

Indeed an airplane made out of lead won't fly. Math will not only predict this but it will reveal a huge complex of interactions that help engineers determine how to determine lift, thrust, drag and all the other details of making a working airplane. But your logic is faulty, since math doesn't predict all airplanes won't fly, just the flawed ones. It guides engineers to design the ones that will. And math is not the basis for science. Nature is. Math is the concise language that describes what it is that nature is consistently doing, which we call laws. To pretend they are not laws is to contradict the way nature operates without cause. It's entirely counterproductive.

Go ahead and do it then. That's the best way to learn physics. Most of the folks responding to you have likely already spent enough time in the lab to know this exercise is futile. Tesla doesn't support your theory, and his remarks do not repeal the laws of nature.

It's the laws of nature that govern reality, not your opinion of why people are advising you what those laws are.

 

Except as soon as you say "air" you are invariably talking about a Stirling engine, which does not have an external sink. It has an external source and an internal sink.

Some of it. Never all of it.

The piston starts at ambient temperature. Cold air is injected and it expands upon heating to the ambient temperature. The air does not give up energy. It gains energy and this is why it expands.

No, the cold air is now expanded by the addition of ambient heat, so it will not contract.

The heat sink is the cold air that was injected into the Stirling engine.

In the Stirling engine, heat is "removed" by the cold air injected into the cylinder.

The numbers become important in order to understand whether the engine will even run. By now you realize that at the bottom of the efficiency analysis is a dipping bird. You need to do better than that to run a Stirling engine.

In the case of the Stirling engine, no more heat will be absorbed by the cold air than it lacks (below ambient). So you have to reformulate this, because your design is now entirely limited by the volume and temperature of the cold air in the cylinder.

In the Stirling engine you're not moving heat to an external sink. It's an internal sink. And for efficiency, all of that cold air needs to be brought to ambient temperature very quickly. That's part of the design challenge.

You have made quite a few mistakes already. And you've admitted that you don't know the math or science involved. Additionally, you've discounted the laws and the people who understand them.

No, heat energy in a Stirling engine is converted into pneumatic energy, which converts to work, and that energy never flows across the thermal circuit.

If that were true, no work would be done and the engine would not operate.

The Stirling engine needs cold air. The potential energy of the ambient, minus the potential energy of the cold air, must be higher than the amount used for work plus the amount wasted. The refrigerator that can move that much heat out of the ambient requires even more energy. So the perpetual machine won't work.

True curiosity can only be satisfied by exploring the best evidence. That can't be done with blinders on.

 

Really ?

I've been studying Stirling engines for the past ten years of so and even built a couple out of tin cans and have never come across any such thing as a Stirling engine with an internal heat sink.

Cold air injected into a Stirling engine ?

What planet are you from ? If such a thing as a Stirling engine with some sort of cold air injector exists I'd have to challenge you to provide some sort of reference to prove it.

Ummm... assuming the Stirling engine is using ambient heat as a heat source, where did this "cold" (presumably below ambient) air come from ? How did it manage to get cold ? What made it cold ? At what point in the cycle was it "injected" and how was it injected into what, in a Stirling engine is typically a hermetically sealed air chamber ?

Let's think about this. Heat expands the air in a sealed chamber with an attached piston cylinder and piston (typically). The expanding air pushes the piston down the cylinder. This is the "power stroke".

I say that in expanding and pushing the piston there is a transfer of energy. The energy has to come from somewhere. In a Gas, the only kind of energy available is heat so in expanding and pushing the piston the gas/air gives up heat. This all happens very quickly, in a fraction of a second. Heat > expansion > power stroke > energy transfer > the air/gas looses energy/heat cools and contracts. This giving up of heat/energy to the piston causes the air to cool and contract sufficiently to relieve the pressure and allow the piston to return to its starting point.

If the air only heats and expands, then what happens ?

You say the air/gas does not get cold and so does not contract. If that were true the engine would come to a screeching halt at the end of the power stroke as the pressure of the heat expanded air would prevent the piston from returning back down the cylinder. Presumably it is at this point that cold air is "injected" ???

OK so you have a sealed chamber. Heat it up to expand the air, this drives a piston down a cylinder. The heated air does not lose energy get cold and contract but now we are going to inject more air ?

Wrong, impossible, nonsense.

Wrong, impossible, nonsense. No such animal. Please provide some kind of reference to back up this claim.

An internal heat sink ?

A Stirling engine can run on ice (external) dry ice (external) snow (external) or if heat is applied (externally) ambient can be used as a sink (external). even if cold air were injected as a "sink", I know of no such Stirling engine configuration, but for the sake of argument we can assume that if such a thing existed the cold air so injected would have to be pre-cooled before injection or come from some reservoir of cold air somewhere external. You can call that internal if you like, I suppose, but it is a fantasy. If such a thing exists, which I strongly doubt, It certainly doesn't sound like any kind of Stirling engine I've ever heard of and you would have to prove it.

I'll pause at this point because whatever else you have to say about the operation of a Stirling engine, as far as I can tell, is based on some kind of fantasy. There is no point in further debate in regard to what appears to be something concocted entirely out of your own imagination with no basis in reality. If I'm wrong, please post some kind of link or reference to this type of Stirling engine where there is an "internal" heat sink consisting of "injected" cold air.

Perhaps you are talking about a liquid air engine or something. There has been some talk of developing such a thing but as far as I know none are currently in production and even if it were that is not a Stirling.

 

I didn't say it drives evaporation itself, I said it drives an evaporative cooler. The bird dipping its felt beak in the water and then swinging back and forth accelerates the process of evaporation.

A swamp cooler uses a mesh of some fiber saturated with water and a fan to draw air through the mesh greatly accelerating the process of evaporation to reach much colder temperatures much faster than any mere natural process of evaporation by itself such as water sitting in a pan.

I doubt you could overcome the friction of the drinking bird, as little as it may be, with natural evaporation. The felt on the birds head, the mechanical movement to continually and repeatedly wet the felt, these contribute to and accelerate the natural process by artificial means.

You may doubt it could work, an ambient heat engine driving an evaporative cooling system but I would say that until someone actually tries it we will never know.

I disagree. The bird is doing work. The energy to do the work is derived from ambient heat. It is not harvesting power from evaporation. Energy flows from a heat source to a sink and is intercepted by the heat engine. Energy is not coming from evaporation it is leaving.

Tesla's remarks about decomposing gases was merely an analogy to represent heat conversion into other forms of energy.

I've been working on that but don't have the required privileges here as yet to post the links.

 

To Tom Booth:

You are just beating your gums together spouting impossible nonsense. Why?
Post 97, with no complex math, PROVES what you believe is IMPOSSIBLE.

The Carnot engine takes every calorie in from the highest thermal energy level (temperature) available and rejects every calorie at the lowest thermal energy available - Better is impossible. (To produce work from thermal energy)

Yet even it, even if it were ideal (no frictions), cannot drive the best possible real refrigerator (just a tiny amount of friction) to pump the heat deposited in the cold sink back up to the hot source (restoring the initial conditions -closing the cycle) even if 100% of the energy produced by the Carnot engine is used to drive the refrigerator - no energy available for other uses.

Why don´t you try to learn, instead of just be stubborn and stupidly hold on to your impossible beliefs?

Tesla was very clever in one area, (AC motors, which Edison never understood) but very ignorant in several other areas and wrote stupid, easily refuted papers, back in an age when many were equally ignorant. That is the age you are still in, as you refuse to learn. Again, Why?

Yes, but that is not much of an explanation of how it works.

What the bird´s beak gains (takes) from the water is heat to bring the beak, previously cooled by evaporation, back up to warmer conditions and drive the internal fluid out of beak back into body. This shift the center of gravity, making the motion that removes the wet beak from the water and it begins to cool (reject heat to the air). As beak cools below the bird´s body temperature some of the internal liquid´s vapor condense in the beak again, moving the center of gravity forward, so down into the warm water the cooled beak goes again, etc.

Summary: The bird is low efficiency (no net work / energy produced) heat engine taking heat from water and rejecting heat to the air as it evaporatively cools.

 

I'm surprised in 10 years you never came across the Carnot cycle and the explanations Billy T and rpenner have given here, among others.

My discussion of the Stirling cycle was without any preconception of how you would design it, since you didn't say so. It was your proposal but you didn't specify it. You just launched into some faulty statements about thermodynamics, for which I offered additional explanations since neither rpenner nor Billy T got through to you.

In the simplest realization, at the moment of the power stroke, cold air is transmitted into the cylinder and heated. I used the word injected; use any other verb you like. Cold air is forced towards the heat, is immersed in heat, and this begins the power phase. At the moment of the stroke, without further definition of what components lie beyond the power cylinder, the cold air becomes the sink, absorbing heat and expanding. At that moment, the potential energy in that sink completely defines the ideal upper limit on power. This fact seems to be escaping you, so I have given you another way to look at it, expecting that it would trigger the proper recognition of how and why it's impossible for the engine to power its own power source, the chiller. You would need to recognize that the cold air is sinking the heat at the moment power develops.

Cold air is injected into the power cylinder and heated, causing the power stroke.

That's up to you. You're the person who proposed it. You already know you need refrigeration to produce cold air, that is, you know you need cold air - colder than ambient - in order to cause it to expand upon application of ambient heat.

OK now you need to understand where the power comes from, and how much is available. For that, you need to treat the injected cold air as the sink, since it establishes the maximum amount of energy that will cross into the cylinder at the onset of the stroke .

Careful how you say this. It's the difference in energy, between the mass of cold air in the power cylinder at the outset of the stroke, and the energy level of the cylinder wall, which we are (apparently) assuming is maintaining itself at ambient. That "delta" is your max. energy available to develop power from.

Not true, insofar as you are probably associating heat with temperature of the gas exclusively. Ideally, PV=nRT, where the units of both sides of the equation (obviously) are units of energy (Joules). Compressed air at room temperature is an example of a gas storing energy in a form other than heat (as temperature). Any volume V of a gas at pressure P holds (ideally) PV Joules of potential energy.

How fast it happens depends on the design, particulaly the rate of heat exchange, and, in this case, the temperature of the refrigerated air you are producing, versus ambient. The air does not lose energy. It passes excess energy (the amount that would pressurize it above the equivalent force of the load in the piston) to the load in the form of work. When the piston tops out, it does so because the air is hot and "full of energy", not depleted.

Not sure what you mean by "only". It expands while transfering energy (constantly available from the ambient) to the load. It does work.

You tell me how you design your engine. By some means not defined by you the hot air we are left with is displaced as a new puff of cold air is injected (or moved, conveyed or transferred). I did imagine you were probably assuming a displacer that would do the cold air injection, but that part of the design isn't very relevant to your error.

Displace, if you prefer. You didn't specify.

At the moment the power stroke begins the cold air in the power cylinder sinks the heat, expands and develops power. You just need to understand that this is where your limit on power arises.

The internal sinking is reference to the flow of heat outside the engine and into the cold air that has been injected/conveyed/put into the power cylinder at the beginning of the stroke. That volume of air has potential energy nRT (or PV if you prefer) and that's the size of the sink that establishes the max power (ideally) that your engine can develop. You seem to be missing this very fundamental point.

It really doesn't matter to me how the rest of your Stirling engine works. Until you can properly address the sinking of heat by the cold air inside the power cylinder at the beginning of the stroke, you're shooting without bullets.

Nope. I was just addressing the unspecified engine, and only referring to the power stroke so you could understand how to deal with calculating power, since you have the erroneous belief that the engine can power its own chiller.

 

If you take away any other meaning than this - that the energy of evaporation is being harnessed by the machine - then you're only misleading yourself. The same process you think is accelerating evaporation - increasing air flow - is counteracted by air friction.

Which is pretty wasteful since you can increase the rate of evaporation for free simply by increasing the surface area.

That's impossible. You can't "amplify" energy. This looks like another foray into perpetual motion.

Actually I was telling you you won't develop enough cooling by evaporation to overcome the friction in your Stirling engine. But the way you pose this is ludicrous, since no engine can power the source from which it derives energy. This gets us back to perpetual motion and violating the laws of nature.

Here's where the math comes in. A spot check, or a little figuring, can save you the effort and waste of time. Considering the fragile bearing that supports the bird, it's pretty evident you can't overcome the friction in a Stirling engine

You mean the machine converts energy into work.

More directly, ambient heat does work on the liquid water, causing it to evaporate.

Sure it is. As the mass of water on the beak evaporates, the machine transfers the delta in force to the opposite end of the fulcrum, causing the lever to move, thereby developing mechanical power.

The source energy is harnessed and converted by the machine into other energy forms, including work.

The machine converts the usable energy into work and develops power. The usable energy is the delta in weight between wet and dry states of the wick, times the height of the stroke.

You mean you want to link us to something you built?

 

Actually it is worse than just a "foray into perpetual motion," PM. It is an attempt to make an "Over Unity" Device, OUD. - Get more energy out than put in or get an energy "free lunch."

PMs are not impossible, but very hard to realize as there is almost always some friction and wear. Only man made exception is the perpetual motion of electrons in a supper conductor, but at present, except in Antartica´s winter, they require cooling. Perhaps some day higher temperature supper conductor will exist and not require cooling. Already in a currently existing super conductor the electrons could "run forever" (producing an observable and useful magnetic field)*, on any planet more distant from the sun than Mars.

OUDs are impossible, any where in this universe as energy must be conserved.

* but you can not take any of magnetic field´s stored energy out as doing that would reduce or kill the electrons´ motion. I´m nearly sure you could, with careful design, push the super conduction loop with its magnetic field thru a regular coil of wire and generate electrical power and energy, but if that is possible that energy comes from the work done by the "pushing device" not the super conducting current.

 

Couldn't you use a two metal sandwich (bi-metallic strip), where each metal has a different expansion coefficient as a function of temperature. These are often used for thermometers.

As we heat the bi-metal (heat reservoir) it bends one way and as we cool it (heat sink) the unit straightens or bends the other way. We use this for a work cycle. We take advantage of different material properties as a function of temperature instead of heat flow.

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Good point. Over-unity is the fundamental flaw in Tom's thinking, but he had already dismissed the First and Second Laws and your and rpenner's explanations of them, so I took the lighter tack. He seems to be receptive to the idea that perpetual motion is problematic. But over course over-unity is the reason everyone saw the flaw in his thinking from the outset.

Right. On the issue of friction alone, there's a huge obstacle to overcome for a glorified "dipping bird". The bearings and rings in the Stirling engine are far more substantial than the hair fulcrum the toy uses. Additionally he would need to take mass effects into consideration (weight, inertia) when he scales his dipping bird to some colossal proportions.

That's the main point throughout this thread. The dipping bird isn't truly free because it wastes water - although if placed where water is abundant, it would seem to be free.

Geothermal is the source I would have expected for the source heat (in cold weather) or the sink (in hot weather) since it's truly free once you pay for the installation. Here of course there are two levels of heat, except during mild weather. Of course temperature variability is the other obstacle to this idea of developing electricity from the ambient.

A couple of other free sources that Tom could exploit include changes in barometric pressure (as with weather), in the way it will lift a column of mercury, and the rotation of the Earth, as in the Foucault pendulum, where some free rotation is available, for the cost of powering the pendulum.

 

Not to mention it efficiency, E, is less than 4%!

Like all heat engines E is Carnot limited by (Th-Tc) / Th. Where Th is room temperature, say 300K and Tc, is produced by evaporation so is only about 10 degrees Kelvin cooler at best on a very dry day. I.e. the bird´s efficiency is less than ~10 / 300 but I was generous and said 4%.

 

Well, aside from your insulting way of putting it. I persist because:

a.) I generally consider the idea of "Laws" in science to be just a bit medieval. Is it THE LAW of Gravity or the THEORY of gravity ? I prefer to think in terms of theory. It allows for exceptions, contingencies, corrections, an open door to eventual better understanding and discovery. When something is framed as a "LAW" such as "The 2nd LAW of Thermodynamics" well, it tends to stonewall any inquiry that might challenge "The Law".

Something similar happens when ideas are framed in mathematical terms.

1 + 1 = 2 therefore: If I pour one jar of apple sauce into another jar and then pour in one more, How many jars of apple sauce do I get?

If I add 2 pints of water to 2 pints of alcohol How many pints of fluid does that make ?

Nature or Reality doesn't always cooperate with the math or conform to our definitions. There can be misunderstandings and wrong answers when we cling to mental constructs and mathematical abstractions and ignore the obvious or rely on our own suppositions or conceptualizations and neglect experiment.

Take for example your explanation

:

This is entirely wrong and backwards. A conclusion based on supposition rather than experiment and can easily be proven wrong by one simple experiment.

Remove the felt from the birds head. Take away the glass of water altogether. Paint the head or top bulb a light color and the tail or bottom bulb black. set the contraption in the sun and it will still go through the motions of dipping its heat, swinging back and forth etc. On and on as long as the sun shines on its tail.

It is a temperature differential engine or heat engine. What you describe is only apparent. coincidental. The beak of the bird is NOT both the heat source and sink alternatively as you suggest. The wet head effects cooling only, regardless of the birds position, (beak in or out of water, body vertical or horizontal.)

Proof: The bird goes through the same motions with no water, no evaporation, no "drinking" just a constant relative temperature difference between the top and bottom bulbs effected by sunlight or by any other means. It is this temperature difference between the top bulb and the bottom bulb that drives the engine and keeps the bird going through its gyrations.

Under normal operation it is ambient heat > in at the bottom that powers the engine, or the temperature differential between the relatively hot bottom bulb and the cool head.

If that is true than a "Carnot engine" is a piece of junk from which no usable energy or "work" can be extracted. All the heat goes in one side and out the other and none is converted into any other form of useable energy.

This is the problem or misunderstanding that Tesla was trying to point out. Heat is not like water. It doesn't pass through a heat engine like water passing through a water wheel or turbine - all of it going in one end and all of it coming out the other.

The description of the so-called ideal or perfect or as-good-as-it-gets "Carnot" engine is apparently based on the fallacy that heat is a fluid substance like water that goes in one side and somehow turns a wheel inside a heat engine and comes out the other side. Tesla recognized the fallacy and IMO it is indeed a fallacy.

If the math is based on a false assumption than you get wrong answers.

Like:

Such a statement is based on the fallacy that Heat is a fluid that passes through a heat engine. All of it going in one side and out the other making the engine turn like water over a water wheel. Tesla tried in vain to explain how this just isn't so, and now I try in vain. The world is apparently blind and Tesla's insight is apparently still ahead of its time.

A case of the pot calling the kettle black ?

ditto.

BTW that is about the most arrogant and self assuming statement I ever heard. Tesla stupid, ignorant and easily refuted. My oh my.

Utterly and completely WRONG. Sorry. Do the experiment, or just watch it on YouTube. Look for "Solar drinking birds"
( YouTube URL + /watch?v=zpp3-e4gVs0 )

 

The Kelvin reference to absolute zero is the killer, or our small diurnal variations in ambient temperature could pay off big. That 4% upper limit might apply for some locales that see wide daily excursions. And come to think of it, it's probably one of the better ways to answer the thread topic. You could try a very good heat exchanger that could cool, say, a tank of water to the near the nighttime low temperature, then transfer the water to a very well insulated tank, while the ambient rises during the day, and a second tank that lags by 12 hours, so you have a warm and cool tank almost all the time. Then you could place a thermoelectric generator between them and ouila! Electricity from the ambient. A small amount of manual energy to switch the heat exchanger back and forth might help. It's sounds like an excruciatingly difficult way to do it, considering alternatives, but it seems to more or less answer the mail.

 

Tom,

Wow. Get down. You just dissed a PhD physicist for getting physics wrong.

You are operating under a rack of false assumptions and fallacies well known to freshman science students. Your overriding error arises from the false belief that human law constitutes science. You fail to understand that the only thing humans have done is to collect the best evidence of what nature is actually doing, and to categorize and formulate these into the principles that answer questions such as the one posed by the OP.

You may think that the Carnot cycle is medieval, but its nothing more than a concise way to describe how nature works. You know that a gas expands when heated. Your belief in that principle is not fairly called medieval, even though an alchemist may have understood it. It's fairly called a property of thermodynamics, which we all agree on and which is easily proven.

The Carnot cycle is merely a composite of all such proofs over all states of the engine, for each incremental position of the piston.

No one likes to be proven wrong, but one of the things you will need in order to succeed in your quest is what folks here call intellectual honesty. At some point you need to concede to your errors or you will never never advance to any realizable solution. That may not matter to you, but for the purposes of advancing in the discussion here, and the possibility that some other person similarly situated may gain from your recognition of error, and, more importantly, the recognition of what's real and what's not, you ought to consider intellectual honesty as the best way forward.

You may not like the Carnot cycle because it quickly reveals that you are proposing a machine that can not work. That's not a human revelation, or the result of Byzantine thinking. It's a proclamation coming down from nature itself.

You've distanced yourself from the particulars by saying you don't do math. That's OK. It's the hardest way imaginable to work through the physics, but it's not impossible. The handicap it presents you is that you're left to deal with all the concepts in prose where formulas would be more concise and more precise.

Unfortunately you have already mangled some of the science concepts pretty badly so you're hanging by a thread right now. If you want more help I can probably provide it. You would just need to be a little more receptive to following a structured approach to this dialogue, in order to give you the consistency and continuity of thought that the math provides.

 

I'm sorry but you obviously have no practical knowledge or understanding of how a Stirling engine operates or the principles involved or the definition of terms like "heat sink". I see no point in debating abstract made-up concepts and ideas of yours that bear no resemblance to reality or how a real Stirling engine actually works.

Sorry but your conceptualizations are so predominantly backwards... The "power source" is "the chiller" ????

"The potential energy in that sink defines the ideal upper limit on power"

"You would need to recognize that the cold air is sinking the heat at the moment power develops."

OK, so the cold air absorbs (sinks) heat. It is, however, not injected, not a "power source" and not considered by anyone I know who commonly discusses such matters a "heat sink" or the heat sink of such an engine.

The air conveys energy. Absorbs heat and expands, conveying energy to the piston. Whatever energy the piston does not or cannot utilize is excess heat.

The excess heat will be absorbed by the actual "sink" which in a Stirling engine is generally the cold end of the displacer chamber opposite the hot end. But this takes place at the end of the power stroke. The air intercepts the heat flowing from the hot to the cold end of the displacer chamber. In the process some of the heat/energy is diverted to power the piston. This heat/energy powering the piston is CONVERTED into something other than "heat". Whatever energy is converted to electricity or to some other form leaves the system and never passes through the displacer chamber and so never reaches the actual "sink" - (the other end of the displacer chamber).

It is rather strenuous I admit, but I can follow your logic.

The "chilled" air in the chamber when it is made to contact the hot end of the chamber can only absorb as much heat as it lacks or as much as has been taken away by the cooling system. I follow that.

That is why you have to "dig your cold hole" to make an "ambient heat engine" a reality. You have to do this first. Create an artificial sink. That takes energy to begin with. You have to dunk the birds head in some water as a practical example. Now you have a "cold hole" for the ambient heat to flow into and you can now intercept the flow and to one degree or another divert it for other purposes.

Fine, you can look at it that way, but that does not make the cold air the ultimate "sink".

If it were the sink, it would be a dead end. The cold air absorbs heat and expands pushing the piston. The "cold hole" has been filled. Dead end. End of story. At best it is a kind of temporary "sink".

Now you fancy that there is some necessity to "inject" more cold air for power. Marvelous. But wrong. Bordering I think, on some form of delusional.

I think I follow your reasoning here. You can only fill your "cold hole" as deep as you dig it in the first place. You can't put more energy into the sink than what you took out in the first place.

But what Tesla was trying to say is that if you dig your "cold hole" first. Now you drop a shovel full of heat energy into the hole. But in the hole you have a heat engine that converts the heat into electricity. The heat that gets shoveled in is converted and goes out some wires, so shovel and shovel for as long as you like the "cold hole" will not fill back up. If the engine doesn't at first convert all the heat and the hole begins to fill up, well the engine runs on heat so you can just recycle the "waste" heat or drive a heat pump to dig the hole even deeper.

 

But not all the heat being shoveled into the "cold hole" is being used to do useful work (like being converted into energy electricity); some of it heats up the "cold hole" -- a finite resource which is consumed by the attempt to exploit it.

For the drinking bird, either enough of the water evaporates until the head stays dry or the relative humidity goes to 100%. In either case the bird stops moving.

For a generic heat engine, running between a hot summer's day and a block of ice, the maximum efficiency is less than 15%. That means of every 20 joules of heat that leave the ambient, less than 3 joules of heat can be used usefully, and the remainder goes to the cold reservoir, melting the ice and heating it up. That's fun as a laboratory novelty, but it's an intrinsically finite demonstration only made possible by the human labor it went into procuring ice on such a hot day.

(This was calculated using \(T_{\tiny \textrm{Hot}}\) at 45°C = 113°F = 318.15 K. On a less oppressively hot day, the efficiency will be lower. On the other hand, using a colder "cold hole" will result in more efficiency at progressively more expensive cost and does not remove the finiteness of the "cold hole." )