Search found 28 matches

by dlaliberte
Thu Apr 06, 2023 5:28 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Stirling cycle machines, appropriate technology and design ideas
Replies: 42
Views: 11093

Re: Stirling cycle machines, appropriate technology and design ideas

I'm speculating that, even though the pressure would tend to equalize, any small motion of the ring would change that stability because that motion would be caused by converting some amount of the heat to mechanical force, and the motion itself would amplify the instability if it goes too far.
by dlaliberte
Thu Apr 06, 2023 2:23 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Stirling cycle machines, appropriate technology and design ideas
Replies: 42
Views: 11093

Re: Stirling cycle machines, appropriate technology and design ideas

Here is an image without the debugger selection overlay.
rotary-stirling.png
rotary-stirling.png (206.47 KiB) Viewed 4182 times
by dlaliberte
Thu Apr 06, 2023 2:01 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Stirling cycle machines, appropriate technology and design ideas
Replies: 42
Views: 11093

Re: Stirling cycle machines, appropriate technology and design ideas

I've been thinking about a rotary Stirling engine with a design that is very similar in having a synchronized rotating central structure, but quite different in that I am trying to do away with most of the moving parts, all the cylinders, pistons, and displacers. Basically, there is only a moving ri...
by dlaliberte
Sat Feb 25, 2023 10:21 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: My contribution to the ECE
Replies: 120
Views: 19069

Re: My contribution to the ECE

Hey guys. (I've been reading all new posts the past few months... Still very interested in all this.) Regarding the idea of making timing adjustments on a running engine, that would be a great way to enable doing many more experiments. But even if you have to restart the engine after a quick adjustm...
by dlaliberte
Sat Dec 03, 2022 7:33 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: NASA Stirling Engines (Stirling "convertors")
Replies: 42
Views: 32464

Re: NASA Stirling Engines (Stirling "convertors")

I did read the air-cycle previously, and again. Thanks for bringing it up. Each time I reread these docs I get more out of them. Still learning lots. Seems a cold storage unit would be as useful as a thermal storage unit, depending on individual needs. Could sand be used for both? So it sounds like ...
by dlaliberte
Sat Dec 03, 2022 9:30 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: NASA Stirling Engines (Stirling "convertors")
Replies: 42
Views: 32464

Re: NASA Stirling Engines (Stirling "convertors")

Heating up a thermal storage unit with direct heat, if it is hot enough to do the job, makes a lot more sense than heating with electrical resistance, unless you are going to otherwise throw away the electricity. This is simply because an electric powered heat pump system can move several times more...
by dlaliberte
Sun Nov 27, 2022 5:53 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: ∆T, Another Sacred Cow?
Replies: 4
Views: 2089

Re: ∆T, Another Sacred Cow?

I should have said that the current belief is the efficiency number is a fraction (or percentage) of the energy that is transferred into the hot side of the engine, not a fraction of all the energy that is available to be transferred through. And the belief is that only that fraction of the energy t...
by dlaliberte
Sat Nov 26, 2022 7:26 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: ∆T, Another Sacred Cow?
Replies: 4
Views: 2089

Re: ∆T, Another Sacred Cow?

Maybe the efficiency, based on the heat difference, is a rate of transfer of energy from the hot side to the cold side, or to work. And with lower temperature on the hot side, there is less energy that can be transferred, so even if two engines have the same efficiency, the one running with less ene...
by dlaliberte
Fri Nov 25, 2022 7:38 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Residential Stirling - why we don't have it
Replies: 19
Views: 6355

Re: Residential Stirling - why we don't have it

I just tripped over info about Sunamp, and their "heat battery" which is a phase change material thermal storage unit. https://www.youtube.com/watch?v=OETqG5PCz_o I talked with their New York office, and it appears I could get a 4 ton system for about $3500. The heat input is either electr...
by dlaliberte
Tue Nov 22, 2022 3:59 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Superheated heat engines
Replies: 15
Views: 3866

Re: Superheated heat engines

Lol, not sure how I posted twice, but that's better than losing a post. Can't figure out how to delete one. In terms of product ideas, and related to the subject of the thread, this machine converts air pressure or the opposite, a vacuum, in the context of a heat difference, into mechanical force, a...
by dlaliberte
Tue Nov 22, 2022 6:21 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Superheated heat engines
Replies: 15
Views: 3866

Re: Superheated heat engines

I watched several more of their videos, and this one is perhaps the best one to explain what he is doing.

https://youtu.be/ysCV3dbzzWE

Seems like he's got several possible practical products that could come out of this that could fund the effort further.
by dlaliberte
Tue Nov 22, 2022 6:19 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Superheated heat engines
Replies: 15
Views: 3866

Re: Superheated heat engines

I watched several more of their their, and this one is perhaps the best one to understand what he is doing.

https://youtu.be/ysCV3dbzzWE

Seems like he's got several possible practical products that could come out of this that could help fund the effort further.
by dlaliberte
Mon Nov 21, 2022 9:46 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Superheated heat engines
Replies: 15
Views: 3866

Re: Superheated heat engines

Thanks for posting the talk by Peter Lindemann. He came up with a design very similar to what we were talking about, I.e. integrating a heat pump with a heat engine.

Here is another video you may know about, which appears to be confirming some of your arguments.
https://youtu.be/hm8m_0rzyMo
by dlaliberte
Fri Nov 18, 2022 10:54 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Absurdly simple thermoacoustic-steam "rice" engine – What's going on here?
Replies: 136
Views: 48061

Re: Absurdly simple thermoacoustic-steam "rice" engine – What's going on here?

Maybe the way to think about thermoacoustics is to observe that the random motion of particles holding a certain amount of heat energy is basically equivalent to noise, and vice versa. So if we can organize the noise by amplifying any resonance of motion of the particles, then we can take advantage ...
by dlaliberte
Sun Nov 13, 2022 11:22 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: How much power possible from a LTD Stirling generator
Replies: 24
Views: 4530

Re: How much power possible from a LTD Stirling generator

I'm guessing you may be trying to overcome the objections raised that a heat pump has greater efficiency with a small temperature difference, whereas a Stirling engine requires a high temperature difference. Yes, I am concerned about those objections. But I'm also not so concerned given the fact th...