Hi all,
I have been buzzing about the forum / TPU threads for ages now. Sort of started off down the renewable branch just lately and it's quite interesting.
So much so I just got my hands on a stirling engine and it's quite an amazing little thing. I can get it running nice and slow on 3C differential between 26C and 29C, it makes about 40RPM.
Just wondering what figures other stirling engine owners are getting with their engines.
Sweep,
I haven't actually measured the RPM on the one I built myself, but you can see it running here at:
http://www.youtube.com/v/i81RPxuTNO8
..and you can see it starting at
http://www.youtube.com/v/eUbMZZ_KtyA
If I can manage to build a rotary stirling engine I bet it will run a lot faster.
Regards
Joseph
Quote from: joegatt on March 23, 2008, 06:39:32 AM
I haven't actually measured the RPM on the one I built myself, but you can see it running here at:
http://www.youtube.com/v/i81RPxuTNO8
..and you can see it starting at
http://www.youtube.com/v/eUbMZZ_KtyA
If I can manage to build a rotary stirling engine I bet it will run a lot faster.
Regards
Joseph
Joseph are you still here?
I was looking at the picture of your sterling.
Do you still have it ?
I have an idea
gary
Hi Gary.
I had an idea myself, regarding this engine. It occurred to me that the displacer shaft lacked lubrication, and when that was taken care of, it went considerably faster. Pity we didn't film that. It is dismantled now, the meccano bits having been handed back to the kids.
This design makes a good demonstrator, but I am not really fond of it. I would like to build an engine with more pistons and less linkages, like an FCDA alpha stirling, with a swash plate, or with a wobble yoke. I am currently working on a design with a rotary displacer. I thought it would be easier to build than one with multiple pistons. But in the end, the ease of construction of the humble linear piston may prove me wrong. I mean, look at what the people from cyclonepower.com have come up with! And, irrespective of what happens on the industrial front, for the home constructor, ease of fabrication is always an issue.
Anyway, if you have some new idea, I would still like to hear about it.
Regards
Joseph.
Quote from: joegatt on July 01, 2008, 09:14:23 PM
Hi Gary.
I had an idea myself, regarding this engine. It occurred to me that the displacer shaft lacked lubrication, and when that was taken care of, it went considerably faster. Pity we didn't film that. It is dismantled now, the meccano bits having been handed back to the kids.
This design makes a good demonstrator, but I am not really fond of it. I would like to build an engine with more pistons and less linkages, like an FCDA alpha stirling, with a swash plate, or with a wobble yoke. I am currently working on a design with a rotary displacer. I thought it would be easier to build than one with multiple pistons. But in the end, the ease of construction of the humble linear piston may prove me wrong. I mean, look at what the people from cyclonepower.com have come up with! And, irrespective of what happens on the industrial front, for the home constructor, ease of fabrication is always an issue.
Anyway, if you have some new idea, I would still like to hear about it.
Regards
Joseph.
Joseph
I was hoping that you still thad the sterling in the picture .
I have been doing alot of thnking about water as fuel in the HHO section.
one thing that is growing clear is an electric arc in water releses LOTS of energy.
One of the main problems with sterlings is they are external combustion getting the heat in and out is always a big problem .
Now it looks like a couple of electrodes and some very basic electronics and you can set up an arc inside of a sterling engine and possably create alot of power .
Sterlings can be over 90% efficient .........I think electric arcs in water are over unity ....so there is some very real possibilities there .
I thought from the picture that your sterling would be perfect to test this idea
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
As far as a rotary sterling .
Think of a ring of pistons in a circle ...... with the crankshaft in the center .
If you have 2 rings of pistons like that ............connected side by side ........so they share one crankshaft ...
Then all you need is the duct work to connect them.
pick a piston and go 90 degrees one way or the other ......that is the other half of that pair
You can have as many pairs of pistons as you care to make ..........just make sure that there is always 90 degrees in between .
As long as you have one cylinder flollowing another by 90 degrees you have a sterling .
one ring of pistons will be hot ........one cold
I think I would make the cylinders stationary ........like a radial airplane engine .
gary
Hi Gary.
I'd hate to dampen your enthusiasm, but I myself am very sceptical about over-unity in electrolysis. Ordinary electrolysis is only about 2% efficient. Industrial electrolyzers may well go up to 80% efficiency but that is hard to obtain. And even harder still is getting the conditions right to enjoy a short bout of "cold fusion". However you are right in observing that there is heat in electrolysis that is usually lost. Combining a stirling with an electrolyzer may be a good way to recover some lost energy ... but not much. As far as I know, Stirling engines are only 30% efficient.
The rotary you describe looks a lot like the Cylonepower machine. On the other hand what I am working on is a rotary DISPLACER, and looks very different. Now I don't know the mechanics of the Cyclone, but it looks like it has double acting cylinders with their hot end on the inside and their cold end on the outside. I don't know anything about their fluid cycle and I suspect this device is not strictly speaking a stirling machine.
Regards
Joseph
Quote from: joegatt on July 04, 2008, 02:48:38 PM
Hi Gary.
I'd hate to dampen your enthusiasm, but I myself am very sceptical about over-unity in electrolysis. Ordinary electrolysis is only about 2% efficient. Industrial electrolyzers may well go up to 80% efficiency but that is hard to obtain. And even harder still is getting the conditions right to enjoy a short bout of "cold fusion". However you are right in observing that there is heat in electrolysis that is usually lost. Combining a stirling with an electrolyzer may be a good way to recover some lost energy ... but not much. As far as I know, Stirling engines are only 30% efficient.
The rotary you describe looks a lot like the Cylonepower machine. On the other hand what I am working on is a rotary DISPLACER, and looks very different. Now I don't know the mechanics of the Cyclone, but it looks like it has double acting cylinders with their hot end on the inside and their cold end on the outside. I don't know anything about their fluid cycle and I suspect this device is not strictly speaking a stirling machine.
Regards
Joseph
Joseph
I am not even a little interested in electrolysis
If the system makes some HHO that is ok with me .,........it will revert back to water when it is cooled enough .
This forum
http://www.overunity.com/index.php/board,104.0.html
Is all about replicating a car that runs on water .
We are still at step 1 ......but it is looking promising
A few people have got small engines to turn over using only water as fuel and a spark for heat .
Anyway ......... the spark looks like an idea way to get heat into a sterling engine .
Sterlings can be as high as 90 % efficent .......but that takes some doing .
I have never heard of this cyclonepower engine .
I would not use double acting cylinders . ..... no way to get lubrication in between ..........also it is very poor thermally if you have hot and cold that close together .
The engine I described was just off the top of my head .......
I used to spend alot of my free time trying to design engines
Learning how to make a rotary sterling took me about a year .
gary
So Gary, it turns out that you too were interested in rotary displacer stirlings! Looks like we're both thinking on similar lines. Did you keep any photos that you can share with this forum? I still haven't figured out all the details on mine.
Regards
Joseph
Quote from: joegatt on July 09, 2008, 02:16:43 PM
So Gary, it turns out that you too were interested in rotary displacer stirlings! Looks like we're both thinking on similar lines. Did you keep any photos that you can share with this forum? I still haven't figured out all the details on mine.
Regards
Joseph
Joseph
Sorry don't have any pictures .
I havn't thought much about sterlings for quite a few years ..........but years ago they were almost all that I thought about .
Designing a rotary sterling was a major goal ........it was very hard and took a long time .
Looking back it should of been easy .
I was looking at one part at a time
With sterlings it is the whole system that matters .
That is why I said that any time you have one piston following another by 90 degrees you have a sterling .
The system has less volume when most of the air is in the hot cylinder
It has more volume when most of the air is in the cool cylinder
That is all that it takes .
About efficiency ........ have you noticed that the most efficient sterlings have heat collectors in the ducts between the cylinders ? Aluminum tubes are often used for this .
As the hot air leaves the hot cylinder it contacts the heat collector
It looses heat as it passes through the heat collector . ...... the result is cooler cool cylinder
The air picks up the heat again on its way back to the hot cylinder .
The heat collector must be large enough to have a temperature gradient along its length .
One reason I lost interest in the sterling was because I found a different engine on the net .
It was called An Entropy engine ........
It was simple it had a piston in a cylinder
on top of that was a cylinder about twice the size .
In this larger cylinder was a paddle that rotated .
It was the speed of the rotation that caused the engine to run
The paddle was connected to a a pinion gear
The pinion ran of a rack gear connected to a cam follower .
The can was designed to for maximum speed difference for the paddle .
The concept seemed to be that it took less energy to use rotation to compress the air in the cylinders than it takes to compress it with a piston
So when the paddle was spun fast ......the piston was pulled up .
When the paddle was moving relatively slow the air rushed back to the center and pushed the piston back down .
The website is long gone .....but when it was up they had quite a few reports about what big companys said about it
I remember GM said that they couldn't use it . The admitted it worked .......but said it would take a motor the size of a bus to power a car .
The fact that they admitted that it worked was a revelation to me
It put me on the OU track
One of the main things that people said about the motor was " there is to much parasitic drag "
At the time I had been into designing engines as a hobby for around 15 years .
I tried to email them to let them know how to reduce the parasitic drag .........NO reply .
I never built a test model .......... not enough money .
gary
Going back to what I said about the sterling
It is the whole system that matters .
Same thing with this engine
The inventor of the Entropy engine said that the paddle worked similar to a rotary air compressor ............but a rotary air compressor will not work .
He was both right and wrong .
A rotary air compressor will not work in its normal mode .
It WILL work in a closed loop in a pulse mode .
My plan was to drive a compressor disk with a gears off the crankshaft
The disk would run about 10 times as fast as the crankshaft .
Unlike the sterling this engine requires valves
It is the valves that make this work
The valves decide if the engine is in compression mode or expansion mode .
In compression mode the valve going TO the compressor disk is open .
The air in the cylinder will be sucked to the disk .,
If all the air that the disk can pull has already been pulled the dislk will maintain that condition
It will take SOME energy to maintain .....but not as much as if it was compressing more air .
In the expansion mode the valve between the output of the compressor and the cylinder is open .
There has to be enough space behind the commpressor to hold most of the air in the system . .........this space is equivelent to the hot end of a sterling .
Heating this area more should provide extra power .
Once the expansion valve is open the air rushes back into the cylinder and pushes the piston back down .
Pressurizing the whole system should make it stronger .
I thiink of this engine as a turbo sterling
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
If you are like me , for the next few hours you are going to have smoke coming out of your ears from thinking to much .
:)
gary
I forgot a little detail about the compressor disk
It turns out that on a disk like this at the place where the air exits you have a choice to make .
The normal way to do it is to have the compressed air just flow straight out .
If you design the vanes on the disk so that they curve you can have the air exit almost parallel to the direction of motion .......... in other words you can get some free thrust from the air .
gary
Yes Gary, the heat reservoir between the hot side and the cold side is important for the efficiency of a stirling. It's called a re-generator. In the case of a gamma stirling, like the one in my picture, this function is partly fullfilled by the temperature gradient along the walls of the displacer cylinder, and those of the displacer itself.
By the way, if you want to recover web pages from a discontinued website, you may find them on www.webarchive.org , if you're lucky. But I wouldn't worry too much about it. From what you said about that O.U. design, it all sounds pretty complicated. The simplest designs are usually the best.
For example, I once toyed with the idea of using a linear motor to drive the displacer thereby eliminating leaky seals. However it turns out that, for a small machine at least, the whole setup becomes very inefficient!
Anyway, I'll try to stay focused on my rotary for now, and I promise to post pics and movies if I manage to get it running.
Regards
Joseph
Quote from: joegatt on July 12, 2008, 03:02:45 AM
Yes Gary, the heat reservoir between the hot side and the cold side is important for the efficiency of a stirling. It's called a re-generator. In the case of a gamma stirling, like the one in my picture, this function is partly fullfilled by the temperature gradient along the walls of the displacer cylinder, and those of the displacer itself.
By the way, if you want to recover web pages from a discontinued website, you may find them on www.webarchive.org , if you're lucky. But I wouldn't worry too much about it. From what you said about that O.U. design, it all sounds pretty complicated. The simplest designs are usually the best.
For example, I once toyed with the idea of using a linear motor to drive the displacer thereby eliminating leaky seals. However it turns out that, for a small machine at least, the whole setup becomes very inefficient!
Anyway, I'll try to stay focused on my rotary for now, and I promise to post pics and movies if I manage to get it running.
Regards
Joseph
Joseph
The compressor disk would take some doing .......The rest of the motor is pretty simple .
I am looking forward to seeing your progress.
gary
I've built a few Stirlings, and I have a rotary-displacer LTD unit under construction right now. The seals are the big problem for me.
Here is a video of a small coffee-cup Stirling that I built a couple of years ago. The power cylinder is graphite, the power piston is aluminum, the displacer is pink construction foam, the working gas is helium in the video, but air is fine too, just less efficient. It will do 600 RPM on a good day, and usually runs for 60-65 minutes on the heat from a cup of hot coffee.
http://www.mediafire.com/?2bmktk95xcx
I'll try to post some pictures of the rotary construction project. I'd like to see other's designs for this too.
Thanks--
Tinsel
Quote from: TinselKoala on July 12, 2008, 11:58:50 AM
I've built a few Stirlings, and I have a rotary-displacer LTD unit under construction right now. The seals are the big problem for me.
Here is a video of a small coffee-cup Stirling that I built a couple of years ago. The power cylinder is graphite, the power piston is aluminum, the displacer is pink construction foam, the working gas is helium in the video, but air is fine too, just less efficient. It will do 600 RPM on a good day, and usually runs for 60-65 minutes on the heat from a cup of hot coffee.
http://www.mediafire.com/?2bmktk95xcx
I'll try to post some pictures of the rotary construction project. I'd like to see other's designs for this too.
Thanks--
Tinsel
Tinsel
That is a really cool sterling
Very well built
I had hopes of using the heat from the water / plasma to drive a sterling .
Judging by another thread ........if it can be called cold fog there might not be enough heat there .
Is there enough heat released to capture with an engine ?
If not ...... I have seen videos of engines kicking over with water alone . What would be driving them ? just the shock wave?
gary
Thanks, resonanceman. I've got some others (no vids of those, and they are in storage, sorry) but this is my favorite. It's got tiny ball bearings on the conrod and the displacer link, that I found in a surplus store. And of course the main shaft is on ball bearings too.
The Graneau style "cold fog" water-arc explosions are produced by charging a big (physically large) capacitor bank, typically 0.3 to 3.0 microFarads, to 10-12 thousand volts, then discharging that into the water, through a Triggered Air Gap sparking switch, that is itself initiated by firing an automotive spark plug to start the gap ionization. Even though the energy per discharge may be only a few hundred Joules, it is given up in such a short time that each discharge represents kiloAmps at Kilovolts, hence megaWatts of power, over an extremely short time of course. Much of this power goes into making a big noise, fracturing the water, and blasting the water out the muzzle, so most of the efforts have been directed towards harnessing the KE of the blast directly. We tried pistons,Pelton turbines, levers, piezo transducers, reaction drives, Tesla turbines, and a bunch of other ways to extract the energy, always wondering why, if the Graneau process was so overunity as he claimed, we could never come close to break-even. Then we reanalyzed the problem, used more sophisticated modelling and better high-speed photography, and put his overunity claims to bed. But not for good, evidently, since he has chosen to ignore this work and continues to claim OU by the same tired and disproven (and circular) momentum transfer model.
Sorry, you punched the Graneau button, and it takes a while to run down.
You'd be better off, IMHO, using the input electricity to run a Meyer electrolysis cell and then burning the gas to heat your Stirling.
(In fact I think I'll try that very thing...I'll bet that baby would really go...)
Hi, I just wanted to state that its very easy to create a overunity device made of a stirling engine (at least in the theoretical approach).
As most of you here probably know, a heatpump create a temperature difference in much larger ammounts than what pure heating from electricity is capeable of (usealy the COP is around 3-5 depending on the quality).
That is in reality more energy extracted from a point in space than what it originaly did contain (inclduing the electricity used to create it).
This means, that if you want to make a bulletproof example that more energy is extracted than what was originaly put in (at least by us) you could build, say a room in a certain volume which is isolated from the temperature outside of it.
Inside this room you have both your heat pump and your stirling engine, with electricity being fed by cabels going through the walls, and ouput from the generator which is driven by the stirling engine, (the generator is also inside the room).
Allthough this procces is full of conversion inefficienses, it would be cabeable of creating a higher power output from the room than what was put into it, at least if the motor, generator and heatpump was made efficient enough.
I know that this would be a huge project with little in return if it was made to work, but I really see no problem of this feat being possible, and if proven, it would at least rock the ground of the scientists who claim that no such thing as overunity is possible, as a room which is inclosed can't provide an unlimited amount of power continiusly (at least if its only the energy in the heat we are looking at).
Btw, great work with this forum! ;)
Quote from: Nabo00o on August 21, 2008, 05:56:43 AM
Hi, I just wanted to state that its very easy to create a overunity device made of a stirling engine (at least in the theoretical approach).
As most of you here probably know, a heatpump create a temperature difference in much larger ammounts than what pure heating from electricity is capeable of (usealy the COP is around 3-5 depending on the quality).
That is in reality more energy extracted from a point in space than what it originaly did contain (inclduing the electricity used to create it).
This means, that if you want to make a bulletproof example that more energy is extracted than what was originaly put in (at least by us) you could build, say a room in a certain volume which is isolated from the temperature outside of it.
Inside this room you have both your heat pump and your stirling engine, with electricity being fed by cabels going through the walls, and ouput from the generator which is driven by the stirling engine, (the generator is also inside the room).
Allthough this procces is full of conversion inefficienses, it would be cabeable of creating a higher power output from the room than what was put into it, at least if the motor, generator and heatpump was made efficient enough.
I know that this would be a huge project with little in return if it was made to work, but I really see no problem of this feat being possible, and if proven, it would at least rock the ground of the scientists who claim that no such thing as overunity is possible, as a room which is inclosed can't provide an unlimited amount of power continiusly (at least if its only the energy in the heat we are looking at).
Btw, great work with this forum! ;)
Thanks Nabo00o.
Also has anyone seen this video? Pretty nice explanation on how it works.
http://www.youtube.com/watch?v=CDntL4GZh0E
Take a look at this stuffs! CPU fan powered by stirling engine! lol
http://global.msi.com.tw/index.php?func=newsdesc&news_no=591