1415 Thermal Lag Engines

Link to the masters thesis I was talking about libstore.ugent.be/fulltxt/RUG...
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[@totherarf]

I am always amazed at how you get so much actually done! Simply taking this video on its own shows a shed load of background work that has gone into it, often unseen. Things like reading thesis' on the subject takes time ..... but how many other bits of information have been looked at, parsed and put into a few seconds of video? This is information dense material ..... and all this does not account for all the bits that did not make it in for whatever reason. Also there is the not so small element of running a business into the bargain! If there was an award for this you would richly deserve it! As we say up north .... Nice one mate!

[@ThinkingandTinkering]

oh wow - mate - I am really happy to see that you see all the background that goes on and goes into a few minutes of video - it really does make it worthwhile - cheers mate

[@stevenbeaumont1698]

The time you take doing investigations pays off in your designs Robert so take your time we will wait.......

[@happydrones9187]

Truth

[@ThinkingandTinkering]

cheers mate and thanks for understanding

[@al3xf103]

Hi RMS, excited to see you tackling this subject, building a rocket stove powered Stirling is something of a long term dream of mine. After reading your book on stirlings as well as Andy Ross’s book and some of the uk working group material on boat powered stirlings, it would seem pressurisation and high temps are required to generate anything close to the hundreds of watts range, and that the technical challenges to do so are not insignificant. Not familiar with these so called ‘thermal lag’ types. Looking forward to the rest of the series. Best of luck!

[@ThinkingandTinkering]

I agree mate and I am not expecting first trials to give huge amounts of power - anything would be good and we can talk it from there - I am thinking compressed nitrogen as the working gas

[@wageslaveuranus9596]

I like the way this genius is speaking.

[@ThinkingandTinkering]

oh wow - cheers mate

[@zylascope]

I'm grateful that you are investigating this. Thanks mate :)

[@danielbishop62]

You are right in the working gas heat rejection rate being a limiting factor. It plays out that, Stirling engines have low power densities. Need very large Stirling engines to generate a decent amount of power. Love your work

[@happydrones9187]

How big can you go?..im a super sizer king a guy..ha

[@danielbishop62]

@@happydrones9187 have a look at the sun pulse 500 on KZbin for reference. It's a low temp Stirling, but you can see from the size 0.7m ish diameter and only 2/3 hp. I'm not too sure how big you can get... But at some point probably better off with a different tech for max power

[@ThinkingandTinkering]

thank you mate and thank you for taking the time to say that

[@Twistedmetal-qe8kx]

Really interesting to see how you work through the engineering options before the build, nice work.

[@ThinkingandTinkering]

cheers mate - I did wonder if it would be of interest

[@edwardhughes352]

Nice. Looking forward to the build.

[@ThinkingandTinkering]

cheers mate

[@garywillis5790]

Looking forward to this development. Thanks Robert!

[@ThinkingandTinkering]

cheers mate

[@peterbarrett5829]

Strange how things go full circle. We are now watching Rob build a machine working on very similar principles to the Newcomen atmospheric engine.

[@ThinkingandTinkering]

lol - nice point mate - I didn't think about that but you are dead right

[@alaingrignon]

@rob, when I saw your heat dissipation device, I couldn’t help but think of Luke’s CPU heat sink experiment using your carbon ink. I wonder if his carbon ink based paste would help built a better heat sink for your thermal barrier. Could be a simple add on! Very interesting project. Now you’ve got me thinking I need a rocket stove in my garage so I can keep working during our -40C winter here in Canada! :)

[@kevinmcmuhammad4841]

I'm using lots of your words now in everyday talk, and some people think I know what I'm talking about, but I will keep watching and eventually I will know what this all about, thank you Robert, for the effort you put into these videos, I love this channel ❤ LETS GO BRANDON

[@ThinkingandTinkering]

lol - awesome mate - cheers

[@AndreaDingbatt]

Watching this with great interest!! Thank you Robert, I am very interested in how this is going!! AX

[@ThinkingandTinkering]

You and me both lol - cheers Andrea

[@angelusmendez5084]

Thanks mate! 👏🎉

[@ThinkingandTinkering]

cheers mate

[@fransmurati2370]

This I concider the most exciting and promising solution diy home electricity generation

[@ThinkingandTinkering]

I kind of think that too mate

[@daroniussubdeviant3869]

i made my first free piston nasa type sterling engine run today and i would like to thank you for pointing me in the right direction. thank you.

[@ThinkingandTinkering]

oh wow nice work mate - well done and cheers

[@rogerwaters6344]

Hello from the hills of TN. A lot of this stuff is over my head but you help me to understand a great deal of the material. Thank you for taking the time to make these videos. I love to learn and that's why I'm subscribed to this channel. Just a thought on the Sterling how about the wasted heat when you're cooking?

[@ThinkingandTinkering]

cheers mate and to be honest there is a lot of wasted heat around - I would think with little ingenuity we could recover a fair bit of it

[@keeperofthegood]

Of course there is more to efficiency than just power conversion. Picture the scenario: Remote Hill Top, Rustic Cabin, No Roads in/out. Now, to run an engine like a diesel will not just need a supply of diesel, it needs lubrication because it is full of parts that do wear out over time and being locked away remotely you would need to store a selection of those parts that wear out so you can maintain yourself. Watching MANY festivals go through our city every year, many of the small portable units get one summers use, some get two summers use, and the rare lucky get three (nothing sadder than a closed chippie because their generators pooched). They do not last to the extent an industrial unit lasts. So, to really work out efficiency you do need to include maintenance. The benefit of these 'off the road map' devices like the Stirling is that their maintenance is far simpler or longer between repairs and I think this adds to their value over other machines.

[@ThinkingandTinkering]

nicely put mate and I couldn't agree more

[@randomhuman1965]

Awesome!!!

[@stevetobias4890]

Really looking forward to this, imagine a small sterling engine built into your soldering iron holder to make use of the heat when your not soldering.

[@McRootbeer]

Sounds like a great desk toy!

[@ThinkingandTinkering]

that would be fun lol

[@azlandpilotcar4450]

I've always appreciated these sorts of devices as heat recovery devices for co-generation: explotation of waste heat from an appliance with a different purpose. I really like your idea, but your stove heat output should be much greater than needed for the stirling engine. You'll probably still be able to make your tea (or pizza) with the exess heat from that great stove. Looking forward to your next.

[@ThinkingandTinkering]

oh 100% the heat output is too great mate - but CHP is on my mind not just generation but I get what you mean and agree

[@SundogbuildersNet]

I'm wondering if imbedding the hot side of your engine into a modest thermal mass would help here in a couple ways. The first would be to mellow the intense heat produced by the stove and the second would be to smooth out the temperature spikes one gets with these stoves. Every loading during the firing cycle, the stove temperature will spike, then recede. When the feed is full and the fire going well, temperature will rise very quickly. When the feed clears enough to drop in another load of wood, temperature will go down by quite a lot, not really picking up again until moisture is driven off the (fresh load of) wood and the stove is running full on again. I'm thinking that a mass of some kind may ride over these bumps in temperature, provide a more consistant output and possibly extend the running time a little after the fire goes out. Does this make sense or am I possibly trying to solve an imaginary problem? ;)

[@TheKlink]

one of the most inspiring vids i've ever seen were on the solar Stirling installation at the Tamera project in portugal. That thing was massive, but then ithad a lot of heat to deal with. do you have any idea on how to size the engine based on the size of the rocket stove/rmh?

[@ile84]

I think there is still going to be room for several peltier elements to slap on the side of that rocket stove (about the coldest part so that the plastic cover of those elements wont melt) after those stirlings, which could power a small water pump to give water cooling for those elements and that stirling also. I mean you could have such a pump to be totally mechanical and one stirling would be pumping, not necessarily an electric pump.

[@ThinkingandTinkering]

I agree mate - I am nt doing Peltier devices down - what I am saying is a swing against those that only see Peltier devices

[@ferminenriquezamorapineda2832]

I was on the stirling engine project for the 3D printer contest, but failed because it's really hard to get the piston tight and frictionless enough with common materials (molten plastic or epoxy) so I want to make some variant with a kind of flexible "piston", so it won't need high tolerances in machined parts, maybe using some kind of heat resistant rubber or silicone, in a corrugated cilíndrical shape

[@daroniussubdeviant3869]

the nasa type with a diaphragm. use latex gloves or a balloon. i have just made a cast of the can lids in silicone sealant. i keep burning my inner diaphragm out. i'm hoping these will stand the test.

[@ThinkingandTinkering]

have a look at rolling seals mate - they can just be bought you know?

[@jandooms7427]

A beta configuration 'free piston' version of the sterling engine, was commercially produced by SunPower ('invented' by prof. William Beale, Ohio University, around 1964). Probably the most efficient and simple design, the EG-1000 would produce about 1000W in a very compact size. I wonder if it could be easily enough reproduced...

[@Nuts-Bolts]

I think Sterling's with 40% plus efficiency utilise helium as as working gas. Although that adds engineering challenges, I don't understand why they haven't seen wider applications. A cryogenic cooling unit for things like infrared cameras are Sterlings being run in revers.

[@ThinkingandTinkering]

yeah that was from wikipedia - the font of all truth lol

[@hootsmin]

There's a stirling fridge, it's called a stirling ultracold.

[@marksercombe3575]

How about using the diaphragm been tin design that you demonstrated on a hot plate then have the coil or magnet mounted on a frame along side to generate electricity. Rocket stoves can glow red or orange suggesting a temperature of around 1000-1200 degrees Celsius

[@jonathansgarden9128]

I still think the stirling engine needs a magnet inside of it and copper coiled around the actual chamber

[@AttilaBlade]

Dear Robert, the efficiency of thermal lag units same as standing wave thermoacoustic units, because of the similar working method. Traveling wave TA units could hit the Stirling cycle efficiency. I know you want to find a heat engine to your rocket stove. A coaxial traveling wave unit TASHE could be the optimal choice. Basically it has only one moving part as Thermal lag has, or we can combined it with an added membrane. I hope you will build good heat exchangers to increase the power range. I'm interested about this generator, so I'll be back. BLADE

[@David_Mash]

Something with continuous duty work cycle!

[@ThinkingandTinkering]

indeed

[@denniskramer9788]

Pretty common are diaphragms used for the displacer piston. Are there designs using a singldiaphragms??? working piston without seals by using a diphram???

[@ThinkingandTinkering]

diaphragms do have a problem and that relates to frequency of the engine which has to be matched

[@TheBaconWizard]

I hope you go with the thermal-lag design, I would love to know more about it (although I am of course looking on youtube and google etc)

[@ThinkingandTinkering]

have a read of that thesis I posted a link to mate

[@michaelwarbon]

Thermal bridge. Large heat sink and/or...great insulation. I would do aircrete - my recipe - diamotecous earth (with your graphene idea on sand), foaming agent (Drexel is good), Portland cement, and 1% nanocellulose, 2% iron slag. Oh and the excess heat can dry out urea which can be used to help keep the cool section cool.

[@ThinkingandTinkering]

nice idea mate - but what about making it gas tight? I am still pondering isolation of the hot and cold side - oh I was thinking dipping the completed bridge in plastic-dip - what do you think?

[@michaelwarbon]

@@ThinkingandTinkering yes, plastic dip for the metal parts. Water glass is great for non metal and even metal. Graphene is the best conductor so maybe also use it to pull of the heat too.... The aircrete around the rocket stove has been done by others on KZbin..just FYI.

[@michaelwarbon]

But the high heat is a problem. Mineral oil around the area to pull off the heat is an idea..it is great but things can get complicated and messy. The CPU pump is a good simple thing. Just get it going with the easy version then start throwing other things at it - you will have endless suggestions.

[@michaelwarbon]

@@ThinkingandTinkering I love that you are doing this. Thank you. I look forward to see your tries and all your attempts. I believe in your smarts. Finding a way to use heat better would help everyone.

[@happydrones9187]

Pondering the heat conductivity of graphene.. It transfers and releases really well..

[@TheWingnut58]

Wonder if a discarded lawn mower engine could be converted by replacing the head with a diffuser plate and heater tube.... I think removing cam to relieve friction and keep the valves closed would also be in order...

[@brianjones8673]

You seem to be working along the same track I'd like to look into. How would a thermocouple work in combination with a stirling engine?

[@ThinkingandTinkering]

a thermocouple would work well mate - but they don't generate that much tbh - so you would need a lot of the - and I mean a lot!

[@HP3.14]

Hi. Thought if you have an old moped engine then maybe you can use the cylinder and piston from it. Connect it via the spark plug hole? Have you thought about which gas to use inside? My first thought was ammonia, without checking anything 🙂

[@ThinkingandTinkering]

if I did have a couple I would certainly be using them mate - I was thinking nitrogen - ammonia can be pretty lethal if it escapes

[@C-M-E]

Hey Robert, sort of along your usual lines thematically but I have a potential video idea/request. I know it's fairly regional as well but with a lot of my projects as I'm not currently a licensed business for what I'm doing, getting ahold of lab grade materials is usually either an ebay affair at quite high cost for small quantity or making do with hardware store equivalents and trying to purify that quality. Maybe you can go into where to source some of the more common forms of things that that typically require a certain strength/grade of product without entangling yourself in legal issues? For instance, lately that potassium permengante has been tricky to source until I stumbled on one of its original uses for alleviating greensand of iron content, which a lot of roundabout hunting eventually led me to pool supply places. (As it turns out, a lot of survival people like to have it on hand for its anti-bacterial properties, too!) Same kind of issue with higher grades of hydrogen peroxide and such. I sure do miss having local brick and mortar chem supply places!

[@blackheathnick]

Have you thought of looking into compressed air for energy storage?

[@ThinkingandTinkering]

yes lots of times

[@jamest.5001]

The strange engine has me thinking of the possibly of building a sterling/steam type engine, possibly using methanol, where the hot exhaust methanol is used to heat the methanol making the engine run, it would be awesome to build a engine like this that can power a car! Small car atleast! Even if it is only used to charge batteries, making enough power only run down the highway, not accelerate quickly, the battery supply the power for peak loads, it could be fueled by almost anything, methanol or ethanol would be better, maybe propane

[@annamolly1261]

So I know the big push right now is to build the Sterling engine and use the heat generated from the combustion to power it. But I wonder if you have thought of using the flame itself to recover/distill gas (diesel kerosene petrol) from waste plastic.

[@ThinkingandTinkering]

I haven't but it is a very good point and certainly one I will think about. now - cheers

[@icebluscorpion]

Why not getting rid of the piston itself and make a Thermoacoustic one to increase efficiency to 80%?

[@errorgd]

could this work as a waste heat scavenger? one of the processes i use generates about 2kW of waste heat, so that mean i could get back about 300W? might be worth doing...

[@ThinkingandTinkering]

I would think it would mate

[@VacuumTube88]

I Don't know about the cost/simplicity to make, but maybe a Graphite meccanical seal could be good enough for the piston.?

[@ThinkingandTinkering]

I would think so mate -but I think the problem there is mostly a graphite piston is used for small models - a larger piston might need a different solution and I liked the idea of a rolling seal - anyway that's what I was thinking

[@ryanlebeck259]

Are these different from other Sterling engines in that they will self start, or do they still have that limitation?

[@ThinkingandTinkering]

don't forget mate diesel doesn't self start neither does petrol - if I think about it - you used to use a crank handle now it's a pull cord for smaller engines and a starter motor for larger engines - and they are the most widely used engines so I am not sure not self starting is a limitation per se

[@ryanlebeck259]

@@ThinkingandTinkering salient point. Sadly we live in a world where of you don't mention that kind of thing people misinterpret the facts and start talking tall over something that really doesn't exist.

[@TheBaconWizard]

Could this be simplified further by using a diaphragm rather than a piston? Air-brake chambers are very cheap (especially from a scrapyard) and would do the job handily.

[@ThinkingandTinkering]

frequency which would translate into distance of travel might have to be matched to the travel diaphragm can make might have to be matched mate - but apart from that I can't see why not

[@TheBaconWizard]

@@ThinkingandTinkering Great, I will try to learn about what factors affect frequency then :)

[@RoadRashSpirit]

Brilliant Paper, read key bits of it...they didnt seem to conclude anything on their origional investigation perameters which is a shame.

[@ThinkingandTinkering]

they ran into spend and time constraints - but yes it was very interesting

[@comi496]

Where can I get plans for making one?

[@ThinkingandTinkering]

I'll be doing a set of plans when I get the thing worked out mate - they will be free of course

[@bikerfirefarter7280]

I second Dave W; any viewer would have to be dense enough to stop a neutrino not to realise and appreciate the amount of background, research and effort you bring and put into your videos. I know I've been a bit critical sometimes, but mean no offense, god forbid it gives you any pause. Thank you for sharing, and keep on keeping on. P.S. the 'tesla-gyro/power-ball' idea is a bust so far, way too much in friction losses despite using car stub-axle bearings, it wont maintain enough gyro-resistance to milk 24hr precession worth a diddly, ;-( air resistance alone is a killer; though I can hand-crank it to increase rotation it's an exhausting workout. Back to the drawing board. ;-)

[@eloinforest6994]

Please make an engine with a toenail clipper and a banana.

[@Sacredeng]

So if a 'vin' diesel engine is 35% efficient, has anyone combined a stirling to absorb the 65% excess and feed in a bit more power to output . I think extra components would add weight against overall power output but a good hybrid might be achievable??? Anyway though project over 😅👍

[@ThinkingandTinkering]

give it a go mate

[@tamaseduard5145]

🙏👍🙏

[@ThinkingandTinkering]

cheers mate

[@karlmyers6518]

Like it

[@ThinkingandTinkering]

awesome mate

[@psychoasshole7738]

lol sorry i accidentally disliked this epidode. * goes and washes the culprit hand in sodium hydroxide*

[@ThinkingandTinkering]

lol - it happens mate lol - thanks for owning it and cheers