Stirling engine fan for top of woodstove
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aloneagain55
- Posts: 9
- Joined: Sat Jan 27, 2024 2:52 pm
Re: Stirling engine fan for top of woodstove
Sounds great...keep me / us informed on possible woodstove fans you make/sell.
Re: Stirling engine fan for top of woodstove
One disadvantage of a Stirling stove fan is not being self starting.
Perhaps some heat activated electric starter that doubles as a small generator (night light/phone charger ?) could be incorporated.
Though, probably charging a phone over a hot wood stove wouldn't be the smartest thing to do.
Perhaps some heat activated electric starter that doubles as a small generator (night light/phone charger ?) could be incorporated.
Though, probably charging a phone over a hot wood stove wouldn't be the smartest thing to do.
Re: Stirling engine fan for top of woodstove
This is a Moriya Stirling engine fan. Detailed plans are readily available.
https://youtu.be/Q6AJLq8bKKI?si=4T4JTOiM2bsT66bP
A pretty lot of these have been built from the plans by machinists as it is a pretty popular project and Senft's design has been published in the book "Steam And Stirling Engine You Can Build" By William C. Fitt
The book is archived online: First page of the Moriya plans:
It is, infact, patterned after the KyKo:
The plans have been successfully used as the basis for a wood stove fan as well:
The only modification to the plans for a wood stove fan, apparently, is to leave off the long legs and make a heavy base.
https://www.chaski.org/homemachinist/vi ... p?t=110374
I wouldn't be surprised if I were to find out that the Vulcan originated from the same Senft/Ky-Ko plans/design. It is at least very similar and of the same basic high temperature Gamma configuration.
https://youtu.be/ATUYB_vFjic?si=_SJr0ANxNGFyX3L1
An LTD "pancake" type design is also Gamma but the wide flat displacer allows the LTD to operate with a much lower temperature difference.
It seems perfectly obvious that the heat input on a gamma is primarily the circular bottom of the displacer chamber. Make the diameter bigger and the engine can take in more, or just as many Joules of heat at a lower temperature, though it is not uncommon for some to insist that the only heat exchange takes place along the sides of the displacer in the narrow passage between the displacer piston and displacer cylinder walls. How they arrive at such a conclusion is something of a mystery to me, but I think it probably came from or originated with Robert Stirling himself, who considered this passage to be significant as a regenerator allowing the "reuse" of the caloric.
My point being, in this long digression, the long tall displacer tube is IMO a poor design choice for the relatively moderate heat on the top surface of a wood stove. Yes, it is hot, but nothing like the direct flame of a kerosene burner, which was the original heat source for the Ky Ko.
Probably a wider displacer cylinder, intermediate between a Ky Ko and an LTD would be more appropriate and functional for the wood stove top application.
https://youtu.be/Q6AJLq8bKKI?si=4T4JTOiM2bsT66bP
A pretty lot of these have been built from the plans by machinists as it is a pretty popular project and Senft's design has been published in the book "Steam And Stirling Engine You Can Build" By William C. Fitt
The book is archived online: First page of the Moriya plans:
- Resize_20240209_124222_2552.jpg (107.55 KiB) Viewed 3907 times
It is, infact, patterned after the KyKo:
- Resize_20240209_124222_2758.jpg (128.28 KiB) Viewed 3907 times
The plans have been successfully used as the basis for a wood stove fan as well:
The only modification to the plans for a wood stove fan, apparently, is to leave off the long legs and make a heavy base.
https://www.chaski.org/homemachinist/vi ... p?t=110374
I wouldn't be surprised if I were to find out that the Vulcan originated from the same Senft/Ky-Ko plans/design. It is at least very similar and of the same basic high temperature Gamma configuration.
https://youtu.be/ATUYB_vFjic?si=_SJr0ANxNGFyX3L1
An LTD "pancake" type design is also Gamma but the wide flat displacer allows the LTD to operate with a much lower temperature difference.
It seems perfectly obvious that the heat input on a gamma is primarily the circular bottom of the displacer chamber. Make the diameter bigger and the engine can take in more, or just as many Joules of heat at a lower temperature, though it is not uncommon for some to insist that the only heat exchange takes place along the sides of the displacer in the narrow passage between the displacer piston and displacer cylinder walls. How they arrive at such a conclusion is something of a mystery to me, but I think it probably came from or originated with Robert Stirling himself, who considered this passage to be significant as a regenerator allowing the "reuse" of the caloric.
My point being, in this long digression, the long tall displacer tube is IMO a poor design choice for the relatively moderate heat on the top surface of a wood stove. Yes, it is hot, but nothing like the direct flame of a kerosene burner, which was the original heat source for the Ky Ko.
Probably a wider displacer cylinder, intermediate between a Ky Ko and an LTD would be more appropriate and functional for the wood stove top application.
Re: Stirling engine fan for top of woodstove
A departure from the typical, it might be interesting to attempt a lower temperature version of this type of engine. This is very simply made from tin cans and rubber gloves and such but apparently requires a rather high temperature heat source and perhaps water cooling for extended operation, but I'm guessing it has enough get up and go to power a fan.
https://youtu.be/r9lYsW0Df08?si=VUnytCVaVcF5Q3b9
The design was new and experimental, but appears to have fantastic potential. Internally it has no displacer, at least not of a conventional sort, only an internal rubber diaphragm cut from a balloon, which seems like a possible Achilles' heel for a high temperature engine, but for moderate temperatures, such as a wood stove top, and, perhaps a high temperature silicone diaphragm rather than latex, I'm guessing even at moderate temperatures an engine based on the same principles could move some air.
The problem is, figuring out exactly what principle it is that such a heat engine actually operates on.
It was described as "hybrid".
There is a tear down video that reveals the inner construction:
https://youtu.be/CXsFNPmjluo?si=cTd4Z3gB6Y9woZvp
I may be wrong, but it looks like that diaphragm has had to be replaced numerous times, judging by the rainbow of colored balloon fragments.
A bit of a noise maker though. Sounds like an Indy 500 race car to me.
https://youtu.be/OPBCe6t0EwE?si=nX6uhTqJo0QCcYqP
I've talked it up so much in here, I really should try building one.
https://youtu.be/r9lYsW0Df08?si=VUnytCVaVcF5Q3b9
The design was new and experimental, but appears to have fantastic potential. Internally it has no displacer, at least not of a conventional sort, only an internal rubber diaphragm cut from a balloon, which seems like a possible Achilles' heel for a high temperature engine, but for moderate temperatures, such as a wood stove top, and, perhaps a high temperature silicone diaphragm rather than latex, I'm guessing even at moderate temperatures an engine based on the same principles could move some air.
The problem is, figuring out exactly what principle it is that such a heat engine actually operates on.
It was described as "hybrid".
There is a tear down video that reveals the inner construction:
https://youtu.be/CXsFNPmjluo?si=cTd4Z3gB6Y9woZvp
I may be wrong, but it looks like that diaphragm has had to be replaced numerous times, judging by the rainbow of colored balloon fragments.
A bit of a noise maker though. Sounds like an Indy 500 race car to me.
https://youtu.be/OPBCe6t0EwE?si=nX6uhTqJo0QCcYqP
I've talked it up so much in here, I really should try building one.