A system for providing electricity and running water using only a mass heater

This is a system concept that I made up, not a finished design. It *should* work like this: rocket mass heater is fired, it heats the “hot” end of the Stirling engine, the Stirling engine generates electricity, the battery collects the electricity, the pump uses electricity to pump water from the well through the “cold” end of the Stirling engine and up to the cold tank, which feeds the hot tank, which is heated by the “self-flowing” system, (самотёчная система) which together with the RMH heats the house. Extra electricity from the battery powers household appliances. Please excuse the messiness of the diagrams. The pump can alternatively be powered by an air line. Input? Criticism? Comments?

By the way, does anyone know of a similar system? If so, what’s it called?

Myron,

Instead of using a sterling engine, you might consider a Thermal Electrical Generator or a TEG.  TEG’s are designed to be applied directly to hot surfaces and have no moving parts.  

Overall I like the basic concept.  It would be interesting to check the overall efficiency between a Sterling engine and a TEG.

Cool idea!

Eric

Well...

Stirling engines larger than tabletop models are not available and actively discouraged from being marketed, in the USA, so you need to be a machinist to bring this to fruition.

But the idea is sound. Added efficiency could be found by putting the cold end in a heat sink, (pond) or having a water source cascade over it, sort of creating a vacuum engine.
Another scenario is using hot glycol in a boiler configuration and having a Sterling engine as the first heat sink, then running it through a domestic water heat exchanger, as a second, and finally through a radiator in a green house, or as a glycol to air heat exchanger in a forced air furnace, or into a concrete flooring, set the flow so it scrubs heat from 200 Fahrenheit to 80 at the end of the process, and then cycle the cooler fluid across the cool end.

Twenty five years ago there was a five hp unit marketed out of Kennewick WA. but they would not sell it here and for info on it they referred you to a chinese firm.
Do they sell them in Russia? or anywhere else for that matter?.....All I find on the net is fractional hp units

Bill Haynes wrote:Well...

Stirling engines larger than tabletop models are not available and actively discouraged from being marketed, in the USA, so you need to be a machinist to bring this to fruition.

But the idea is sound. Added efficiency could be found by putting the cold end in a heat sink, (pond) or having a water source cascade over it, sort of creating a vacuum engine.
Another scenario is using hot glycol in a boiler configuration and having a Sterling engine as the first heat sink, then running it through a domestic water heat exchanger, as a second, and finally through a radiator in a green house, or as a glycol to air heat exchanger in a forced air furnace, or into a concrete flooring, set the flow so it scrubs heat from 200 Fahrenheit to 80 at the end of the process, and then cycle the cooler fluid across the cool end.

Twenty five years ago there was a five hp unit marketed out of Kennewick WA. but they would not sell it here and for info on it they referred you to a chinese firm.
Do they sell them in Russia? or anywhere else for that matter?.....All I find on the net is fractional hp units

Bill, I do know a machinist, which is nearly as good.
I’m also really curious why Stirling engines are so discouraged.
I don’t know where they might be sold. Here, the answer to that question is always: “Probably in Moscow!”.
This system needs at least a couple horsepower.
I had thought of using a sterling engine to directly power a glycol heating system before, but then I found out about a brilliant Soviet system that uses the natural thermal expansion to carry the fluid through the system, so the Stirling engine would not be warranted in that function.
I wrote up above that the cold flow of well water goes over the “cold” face of the Stirling engine.

Myron,

Sterling engines can be quite effective but at higher temperatures and pressures.  There was a Sterling engine built in the US in the 60s? That was designed for undeveloped countries lacking infrastructure.  Essentially, the idea was that they could be plopped on a fire and generate electricity.  The idea was sound but failed due to a number of technical difficulties.  

It is an interesting idea though.

I suggest the TEGs because of their lack of moving parts and ease of installation and operation.  Your overall concept can be achieved using TEGs.  You can buy TEGs for reasonable prices at a website I found called Tegmart.com (I am sure there are other sources as well).

TEGs do not have the same inherent efficacy of a Sterling engine, but their ease of setup can sometimes make up the difference.  Also, TEGs are presently commercially available as opposed to Sterling engines.  However, if you the ability to make a Sterling engine, you might be able to do some interesting stuff.

This is an interesting thread and I would love to hear how your plans develop.  Please keep us informed.

Eric  

The engine I spoke of earlier is the ST5 and you can still find info on the web....but nobody's selling it!!

I've wondered about a fire-eater engine. I believe the downfall of them was the wear in the cylinder/piston from the exhaust gasses. I'd like to see how one would work with modern zirconia ceramics for the cylinder and piston.

https://www.youtube.com/watch?v=GqIapDKtvzc
https://www.youtube.com/watch?v=GFfMruoRMGo
Brilliant design for a stirling engine here.

Eric Hanson wrote:Myron,

Sterling engines can be quite effective but at higher temperatures and pressures.  There was a Sterling engine built in the US in the 60s? That was designed for undeveloped countries lacking infrastructure.  Essentially, the idea was that they could be plopped on a fire and generate electricity.  The idea was sound but failed due to a number of technical difficulties.  

It is an interesting idea though.

I suggest the TEGs because of their lack of moving parts and ease of installation and operation.  Your overall concept can be achieved using TEGs.  You can buy TEGs for reasonable prices at a website I found called Tegmart.com (I am sure there are other sources as well).

TEGs do not have the same inherent efficacy of a Sterling engine, but their ease of setup can sometimes make up the difference.  Also, TEGs are presently commercially available as opposed to Sterling engines.  However, if you the ability to make a Sterling engine, you might be able to do some interesting stuff.

This is an interesting thread and I would love to hear how your plans develop.  Please keep us informed.

Eric  

Eric, TEGs have something like a 5-8% efficiency. They are also less versitle than Stirling engines, although the lack of moving parts is super attractive. I will look into this. BTW, I just remembered a system that uses infrared light and water to generate electricity, using a phenomenon unique to water called an "EZ" or "Exclusion Zone". Radiant heat is infrared light, and RMH's generate heaps of it, so...

Myron,

Glad you can appreciate the shortcomings of TEGs.  You are right in that they do have miserable efficiency, though that can be mitigated a bit with a water backing as you intend to do.  A Sterling engine can theoretically get much higher efficiency.  The only real problem I see with the Sterling engine is acquiring one.  I am not aware of any commercially for sale for a homeowner.  If you intend to fabricate one, that would be really fascinating.  Out of curiosity, if you do intend to fabricate one, what do you intend to use as a working fluid?  Supercritical CO2 has some really interesting properties, but that means keeping it under some pretty intense pressure.  But then again, basically any working fluid likes to work under relatively high pressures.

If you are planning to fabricate a Sterling engine, I would love to know how you intend to engineer/plan/build the device.  They are pretty interesting machines.

Eric

Myron,

I just stumbled on this site.  I think that is a great idea!  As others pointed out one could go with TEGs, off the shelf, no moving parts but at a cost to efficiency.  One might go with something like a Tesla turbine or other turbine which might even be more efficient than the Stirling motor, but you would need steam to drive the rotor.  I have read that Stirling motors are efficient but am used to seeing them only as novelty items for a coffee table.  If there is either an off the shelf solution or one could build without great difficulty a Stirling motor that produced more power than a coffee table novelty, that scales, as I said, that's a winner.  I have just started reading and I get it, rocket stoves/masonry stoves are a better deal. that said such a Stirling engine could go on every wood stove in the world. Not joking, you should start a crowd sourced, go fund me, or whatever they call it, if you don't in six months or less I might! For the cost of having moving parts, and who doesn't like a conversation piece on the hearth, you could have something 5-10x more efficient than TEGs for producing electricity and people already market TEGs for this.

Myron,

GE used to make a Stirling engine called the ST-5.  It was aimed partially at a 3rd world market, though it had applications in the United States as well.  

If I recall correctly it was not a commercial success.  It could generate up to 5hp under ideal conditions, but the device was expensive.  Again, if memory serves, it was too expensive for the 3rd world market and underpowered for the domestic market.  I did find an online manual for one HERE:

https://www.ohio.edu/mechanical/stirling/engines/ST-5_Engine.pdf

This might be interesting if you could find one used or might make a useful template if you decide to build one.  Frankly, I would love to see someone actually build a practical Stirling engine as despite their promise, relatively few have been built.

Good Luck,

Eric

I believe the theory is sound but the problem you will run into is the inefficiencies of each part leaving no surplus. As mentioned above stirlings can be very efficient as long as they operate at high pressure with highly conductive materials and high temperature differentials between hot and cold. The whispergen from a decade ago was a good attempt at a commercial unit it used a sealed free piston design similar to spacecraft stirlings. It had promise then the cost of solar dropped like a stone. You mentioned a 2 hp engine which with losses will produce at best 1.25hp or roughly 1 kW per hour of electricity at full temperature production. By unpressurized Stirling standards that engine would weight several hundred pounds and require continuous maintenance. For roughly 1000 dollars you can do the same with solar and have no moving parts or maintenance... Not to be discouraging but it might go some way into explaining why you dont see stirlings around much. I would try it with tegs myself. Their efficiency is not great but would be similar to a homebuilt stirling. All opinions of course but I did chase the stirling rabbit down the hole for a while.
Cheers,  NF

I was also just thinking about this possibility over TEGs and I have found a german shop: https://www.stirlingshop.de - here you can buy as set:  where they say that will produce on average 200w when there is sun in central europe. They also have the individual building sets: https://www.stirlingshop.de/epages/61267352.sf/de_DE/?ObjectPath=/Shops/61267352/Products/%22Motor/Generator-Einheit_Bausatz_Modellbau%22 and https://www.stirlingshop.de/epages/61267352.sf/de_DE/?ObjectPath=/Shops/61267352/Products/GT03_Acryl_Bauteilesatz. I would be very curios to see how much energy this could produce and how this would work out efficiency wise compared to a TEG.

Even found one specifically looking at combining woodstoves with stirling engines: http://www.kufner-stirling.de/

Another one here: https://www.oekofen.com/en-gb/myenergy365/ though that looks more commercial and is only in combination with a pellet heater.

Found another seller of stirling ovens and this one looks actually very interesting: https://www.microgen-engine.com/

Markus Padourek wrote:Found another seller of stirling ovens and this one looks actually very interesting: https://www.microgen-engine.com/

I would be interested in what they have to say, if they have a free piston stirling for sale and at what price. I could never get a straight answer myself. At the time they were interested in building a complete project as one offs not just selling the guts of it for experimentation.
Cheers,  David

I recently came across this one. Low temperature differential stirlings would be a good diy kind of approach using your rocket stove to heat water fast, then generate power slowly...
https://youtu.be/9Cy__Xsog2o

That looks very interesting indeed. I just found another company that is working on an energy solution that is making use of a sterling engine: https://www.azelio.com/