Tesla's Ambient Heat Engine revisted

[matt brown]

According to Tesla's theory...

If we first ran the Peltier module to cool the bottom plate. (Keeping it insulated of course, to preserve the cold).

The engine could then run on the surrounding ambient heat, and with perfect insulation and a 100% efficient engine, it could run indefinitely.

He recognized however, that with the technology current in his day, those two conditions could not be met, so the "cold hole" would need to be re-cooled or refrigerated from time to time.

But, be reasoned. Because the engine is actively converting the ambient heat entering into the engine to other forms of energy, less heat would reach the sink than goes in at the top.

He further reasoned, that when heat did need to be removed from the "cold hole", it could be taken out "by its own energy".

In my 100-300k OP, I ended with this...

"So, for expansion at 300k, we need 3Qin for 3Wout while for compression at 100k we need 1Win for 1Qout. In this manner, eff=.66 where (300-100)/300 is inline Carnot. Unfortunately, the compression process taxes the system twice: (1) via mechanical backwork=1Win (2) via heat sink=1Qout, thus doubling losses whereby ideal eff=.33 and Carnot laughs."

Otto sub atm.png (47.64 KiB) Viewed 4233 times

Here's a graphic described as an Otto cycle, but could also represent a Stirling cycle. If Stirling, process 3-4 will be isothermal expansion with ambient input, but then process 1-2 would be isothermal compression with heat sink filling cold hole. It really doesn't matter if ambient pressure supplies compression force, since as Fool has pointed out several times, the 'spread' between 2 isothermals or adiabats requires a heat transfer. The Stirling does this via regen, but requires heat sink during compression vs Otto does this via source and sink, but no heat transfer during compression. Without this temperature spread, there's no Wnet area.

Tom - even with your fantasy backstroke, your suck cycle would require an input temperature spread, so if pt 3 was T ambient then pt 2 would be T sub ambient, and this raises the backwork ratio.

To explain, let's say, we have a heat pipe that takes the heat generated by the Peltier unit while operating and carries that heat back up to the ambient side on top.

In this way, the heat taken out of the "cold hole" will assist in its own removal.

While heat is being removed, the temperature difference will increase and the engine will have more power to make the cold hole colder using the heat taken out of the cold hole.

After that, the engine can run steadily on the ambient heat once again.

He believed this scheme did not require a 100% efficient engine.

This is all fantasy. In my OP, I mentioned cold hole issues as "(1) via mechanical backwork=1Win (2) via heat sink=1Qout" but ignored that compensating for "sink=1Qout" would only tax the system .33 when maintaining cold hole was achieved at 1.0 eff. What your suggesting is transforming any sink heat above 100k into greater heat (300k ?) AND at 1.0 eff !!!

[Tom Booth]

...Many decades ago, I lived in Phoenix for a couple years when everyone had these, but they're worthless there today (there's a clue in there). So yeah, I know how they work and not from bad internet buzz.

...

"Worthless" how?

https://www.azcoolersonly.com/swamp-cooler-installation

https://www.rainforestplumbingandair.co ... hoenix-az/

https://www.air-conditioning-arizona.co ... ooler.html

https://coolblew.com/services/air-condi ... e-coolers/

https://www.desertcomfortmechanical.com ... r_services

https://coolerguytucson.com/

https://www.allstateairandheating.com/a ... tallation/

The swamp cooler business in Arizona appears to be thriving.

I doubt any of these business owners in Arizona would agree with you

My swamp cooler worked wonderfully, but I serviced it myself. Sounds like yours needed servicing. You probably needed to clean out the gutters, they often get clogged.

https://youtu.be/hS7Aaqwjv7o

[matt brown]

caught it prior edit...Your a bigger blowhard than "fool".

AC units are fairly cheap these days, except for electricity. When I lived in Phoenix (early 1960s), the population was small and most people had swamp coolers and they worked great. However, as the population exploded, all the lawns, pools and golf courses drove the humidity thru the roof whereupon swamp coolers became fairly worthless. As the country urbanized, many areas that were dominated by swamp coolers were forced into AC (no big oil conspiracy). Back in the day, my dad had a cooler bag for the car which hung in a window and made a big difference on cabin temperature during road trips.

BTW Tom, here's a tidbit I'll blow your way...I was born in Rochester, NY and lived on the Erie canal as a kid. So, let's just say that I'm more than familiar with the cocky know-it-all mindset that plagues the region.

[Tom Booth]

caught it prior edit...Your a bigger blowhard than "fool".

AC units are fairly cheap these days, except for electricity. When I lived in Phoenix (early 1960s), the population was small and most people had swamp coolers and they worked great. However, as the population exploded, all the lawns, pools and golf courses drove the humidity thru the roof whereupon swamp coolers became fairly worthless. As the country urbanized, many areas that were dominated by swamp coolers were forced into AC (no big oil conspiracy). Back in the day, my dad had a cooler bag for the car which hung in a window and made a big difference on cabin temperature during road trips.

BTW Tom, here's a tidbit I'll blow your way...I was born in Rochester, NY and lived on the Erie canal as a kid. So, let's just say that I'm more than familiar with the cocky know-it-all mindset that plagues the region.

The deserts in AZ are vast and wide with frequent winds. Lawn sprinklers have done nothing to change the dry air desert conditions. I already posted a few of the swamp coolers installation and service businesses in AZ today, so what are you talking about? Who are you trying to fool?

I think 99% of the swamp coolers are roof mounted. Hardy prone to being affected by lawns that hardly ever get watered due to the water shortages.

[Tom Booth]

...
BTW Tom, here's a tidbit I'll blow your way...I was born in Rochester, NY and lived on the Erie canal as a kid. So, let's just say that I'm more than familiar with the cocky know-it-all mindset that plagues the region.

Well that explains a lot. I guess you should if you grew up there. I didn't.

[Tom Booth]

According to Tesla's theory...

If we first ran the Peltier module to cool the bottom plate. (Keeping it insulated of course, to preserve the cold).

The engine could then run on the surrounding ambient heat, and with perfect insulation and a 100% efficient engine, it could run indefinitely.

He recognized however, that with the technology current in his day, those two conditions could not be met, so the "cold hole" would need to be re-cooled or refrigerated from time to time.

But, be reasoned. Because the engine is actively converting the ambient heat entering into the engine to other forms of energy, less heat would reach the sink than goes in at the top.

He further reasoned, that when heat did need to be removed from the "cold hole", it could be taken out "by its own energy".

In my 100-300k OP, I ended with this...

"So, for expansion at 300k, we need 3Qin for 3Wout while for compression at 100k we need 1Win for 1Qout. In this manner, eff=.66 where (300-100)/300 is inline Carnot. Unfortunately, the compression process taxes the system twice: (1) via mechanical backwork=1Win (2) via heat sink=1Qout, thus doubling losses whereby ideal eff=.33 and Carnot laughs."



Otto sub atm.png


Here's a graphic described as an Otto cycle, but could also represent a Stirling cycle. If Stirling, process 3-4 will be isothermal expansion with ambient input, but then process 1-2 would be isothermal compression with heat sink filling cold hole. It really doesn't matter if ambient pressure supplies compression force, since as Fool has pointed out several times, the 'spread' between 2 isothermals or adiabats requires a heat transfer. The Stirling does this via regen, but requires heat sink during compression vs Otto does this via source and sink, but no heat transfer during compression. Without this temperature spread, there's no Wnet area.

Tom - even with your fantasy backstroke, your suck cycle would require an input temperature spread, so if pt 3 was T ambient then pt 2 would be T sub ambient, and this raises the backwork ratio.

To explain, let's say, we have a heat pipe that takes the heat generated by the Peltier unit while operating and carries that heat back up to the ambient side on top.

In this way, the heat taken out of the "cold hole" will assist in its own removal.

While heat is being removed, the temperature difference will increase and the engine will have more power to make the cold hole colder using the heat taken out of the cold hole.

After that, the engine can run steadily on the ambient heat once again.

He believed this scheme did not require a 100% efficient engine.

This is all fantasy. In my OP, I mentioned cold hole issues as "(1) via mechanical backwork=1Win (2) via heat sink=1Qout" but ignored that compensating for "sink=1Qout" would only tax the system .33 when maintaining cold hole was achieved at 1.0 eff. What your suggesting is transforming any sink heat above 100k into greater heat (300k ?) AND at 1.0 eff !!!

No clue what you're talking about.

This is my setup:

Compress_20240517_233716_6977.jpg (82.82 KiB) Viewed 4214 times

My statement begins:

If we first ran the Peltier module to cool the bottom plate. (Keeping it insulated of course, to preserve the cold).

You quoted this above so... You should know.

Nothing to do with Wneg Wpos nonsense.

It's an ordinary, unmodified Kontax model Stirling engine running on the cold produced by a Peltier module from the little helmet beer cooler.

Maintaining the "cold hole" has nothing to do with the engine, other than, could the engine run long enough on the cold produced by the Peltier module to do something like charge a 9 volt battery to run the module intermittently.

Anyway, this is your thread, It seemed you had abandoned it.

I'm still not clear why you even started it since you 1) don't seem to understand Tesla's work on his ambient heat engine at all, and 2) are still bent on debunking the concept, though apparently without having the slightest clue what Tesla was talking about.

[Tom Booth]

Just BTW, I sent for some of these little 6 volt 2 amp copper Peltier chips.

Faster response time, better cooling.

Compress_20240518_223413_3506.jpg (18.08 KiB) Viewed 4211 times

https://youtu.be/zGS3HX8wIdg

12 volt even 9 volt charging for a little model LTD Stirling is a pretty tall order. 5 volts will be a challenge.

Oooo... I just noticed there are 2 volt modules as well.

[Tom Booth]

My my, there are even 0.85 volt peltier modules.

How low can you go?

They can also be "stacked" for greater ∆T and better heat separation.

Also running them briefly gives better efficiency as each module can only create a certain ∆T, once reached they quit working, still consume power, but are so thin the heat will conduct through them backwards.

[Fool]

...
I just have one more question, how does ipoo get -32 degrees C out of a chemical that boils at 10 degrees F, in a system that is running at atmospheric pressure?
...

Funny how you believe the video can be easily faked by letting butane evaporate on the outside of the pipe, but can't believe the same thing can happen if the butane is made to evaporate inside the pipe.

You obviously do not know the difference between boiling and evaporating.

[Tom Booth]

...
I just have one more question, how does ipoo get -32 degrees C out of a chemical that boils at 10 degrees F, in a system that is running at atmospheric pressure?
...

Funny how you believe the video can be easily faked by letting butane evaporate on the outside of the pipe, but can't believe the same thing can happen if the butane is made to evaporate inside the pipe.

You obviously do not know the difference between boiling and evaporating.

How about this "fool"

In the following image, after you identify the "orifice" and explain it's function maybe you could also identify the "BOILER".

Then perhaps you could explain the significance of your question and how the "BOILER" in a refrigeration system functions.

Resize_20240519_124651_1729.jpg (109.73 KiB) Viewed 4184 times

.

[Fool]

The capillary tube is the "orifice". It's diameter and length must be sized to the pressure difference, and flow rate. Longer and narrower for lower flows and higher pressure drops. Shorter and wider for higher flows an lower pressure drops. Higher pressure drops are needed for higher temperature differences. Those fake ones were claiming a large temperature drop, so a high pressure differential is needed. It appears to have a very small pump so very low flow are possible at the pressure needed. So a small diameter and long length is needed. Neither were installed.

The boiler is called an evaporator, but it isn't evaporation it is boiling. Get it? See through the errors. Figure it out for yourself. In the "evaporator" any liquid it will boil until the temperature reaches the boiling point pressure. The boiling will stop, zero evaporation will happen as the vapor is already saturated. I thought this was obvious.

Evaporation only happens if the partial pressure is below the boiling point. The pressure and partial pressure is always the same in a refrigerator system. In a dry desert the humidity is low meaning the partial pressure of water is lower than atmospheric. Water boils at a lower temperature when at a lower pressure or partial pressure. The bulk water won't boil, but the vapour coming off is low temperature steam at lower partial pressure.

Shall I continue with standard refrigerator thermodynamics lecture?


I challenge you to prove that the tiny little pump operating with that tiny little battery, with those loose fitting silicone hoses, can produce enough pressure on that tiny mix of butane and air, to liquify anything at 30° C, with the tiny length of not small enough tube to be an orifice for the flow maximum of that pump at that needed pressure differential for that claimed temperature drop. Please provide reliable numbers so we can verify you aren't just giving us opinion.

[Tom Booth]

For butane the vacuum side is below 1 atmosphere.

To get to -30°C the vacuum would need to be about 0.5 ATM

From looking at the specs of similar small vacuum pumps sold on Amazon, it looks to me like that might just be possible.

Anyway, I don't see any major theoretical flaws in the design but the proof is in the pudding.

I do however see a number of rather uninformed erroneous statements in your above "standard refrigerator thermodynamics lecture".

Congratulations on identifying the cap tube as an orifice! Quite a milestone. You've come a long way.

[matt brown]

The capillary tube is the "orifice". It's diameter and length must be sized to the pressure difference, and flow rate. Longer and narrower for lower flows and higher pressure drops. Shorter and wider for higher flows an lower pressure drops. Higher pressure drops are needed for higher temperature differences. Those fake ones were claiming a large temperature drop, so a high pressure differential is needed. It appears to have a very small pump so very low flow are possible at the pressure needed. So a small diameter and long length is needed. Neither were installed.

xlnt catch

Evaporation only happens if the partial pressure is below the boiling point.

You mean, swamp coolers aren't magic lol

I challenge you to prove that the tiny little pump operating with that tiny little battery, with those loose fitting silicone hoses, can produce enough pressure on that tiny mix of butane and air, to liquify anything at 30° C, with the tiny length of not small enough tube to be an orifice for the flow maximum of that pump at that needed pressure differential for that claimed temperature drop. Please provide reliable numbers so we can verify you aren't just giving us opinion.

There's a lot of Indy/Paki pseudo-science videos on youtube. Many are very well done which leads me to think these are done by engineers where youtube pays better than their day job ("moonlighting" on steroids). Most have a distinct DIY flavor which sucks in the newbies with an innocent "and tell a friend theme" but hokey enough that any engineer would sink such. Overall, I view these as creative entertainment as long as there's no moola pitch. I often scan the comments in these videos where some are priceless.

[Tom Booth]

The capillary tube is the "orifice". It's diameter and length must be sized to the pressure difference, and flow rate. Longer and narrower for lower flows and higher pressure drops. Shorter and wider for higher flows an lower pressure drops. Higher pressure drops are needed for higher temperature differences. Those fake ones were claiming a large temperature drop, so a high pressure differential is needed. It appears to have a very small pump so very low flow are possible at the pressure needed. So a small diameter and long length is needed. Neither were installed.

xlnt catch
...

Butane systems are very LOW pressure, The vacuum side is a literal vacuum (about 1/2 atmospheric pressure).

Anyone can verify that such a low pressure Butane refrigerator requires a LESS restrictive rather than a more restrictive metering device because the pressure is so low, that what the two of you glibly suggest, "a small diameter and long length" cap tube is the opposite of what would be needed in reality and this can be verified by any and all available data pertaining to the subject.

Such a restriction would cause such a small low pressure system to cease operating or fail entirely.

You two are clowns passing completely bogus opinion you cannot possibly substantiate.

[Fool]

The name calling is against forum rules. Please stop.

Main Board Rules: General Rules
A) Please treat everyone with respect. If you have a point, then make it. Driving it on and on will not be tolerated.

You post to nearly all the threads, and you drive in over and over the same anti Carnot and education point, often using naming slurs. That is against the rules. Please stop.

You get more belligerent when people kindly point out a scientific reason opposing yours. Please be more kind.

You only feel like you are being tracked, it is not so. You've asked for input, you have to expect it. This does apply to every thread you soapbox your anti conventional thermodynamics theory. This is a problem mostly because it is unsubstantial. Please accept our input graciously. Please stop soapboxing.

Please stop driving posters away.

Butane systems are very LOW pressure, The vacuum side is a literal vacuum (about 1/2 atmospheric pressure).

You seem to avoid 1/2 the cycle, often. The low pressure in a real butane refrigerator cycle, is not the working pressure. The high pressure is.

What pressure is needed to condense butane at ambient temperatures 20 30° C? 20 30 PSI?

The orifice works by the pressure drop from flow. What flow rate is needed at the working PSI differential for the claimed pressure/temperature drop? Please start considering the whole cycle.

What power is needed to reduce the temperature of the open air boiler tube to -32° C? Probably more than a 9 Volt battery can put out, Watts, let alone long enough to cool that mass of tubbing, Joules?

Your lack of a complete description leaves open lots of engineering questions. I still contend, am skeptical, that the reduced size tube is insufficient for the pump and claimed performance. Pinching the tube to make a smaller orifice might help, but the tiny energy supply and pump still put the kibosh on any expectation of noticable performance.

P.S., orifices need liquid to work properly. It takes more pressure to push liquid through an orifice than gas. There wasn't enough butane put into the system to get liquefaction.