New wood-fired electric generator

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MivilleAndré
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New wood-fired electric generator




by MivilleAndré » 02/04/22, 02:48

Hello,

I would like to join forces with equipped self-builders (or motivated people with dreams in their heads) to create a new engine. It will be used as a boiler at home instead of oil/gas and will produce electricity for you at the same time.
Brief description:
It is a linear electric generator excited by magnets connected to the pistons of an external combustion engine. The working fluid is dry steam and fuel from small charcoal-sized wood briquettes. It is a two-stroke with opposed piston without segmentation with labyrinth seal whose return movement is carried out thanks to a spring guided on a friction slide.

Here are some advantages of this engine:
-two-stroke -> better weight/power ratio and better efficiency than four-stroke
- acts as an electric generator and boiler
-electricity is an energy of better value (more useful) than movement
-no crankshaft -> no radial force of the piston on the cylinder -> less heating -> less wear -> better efficiency (8% more efficiency)
-The lights are located at the ends of the cylinders and do not require valves
-external combustion engines can use any fuel that "burns" (the high temperature boiler burns the fumes)
-continuous combustion -> no need for an intake chamber -> higher volumetric ratio -> simpler -> less loss of loss in the pipes -> better efficiency
-variable compression ratio
- no engine oil
- no piston and cylinder wear
-Dry steam is not (or very slightly) corrosive
-If transposed in a car with axial flow motors on each wheel that means no gearbox, no drive shaft, no starter, no alternator -> weight gain -> fuel economy
-Braking energy can be recovered up to motor efficiency via a coil which heats the water again
-independent cylinders, extremely useful at low loads
-Opposed piston motor generates less vibration
-Simple design, can be done by do it yourself unlike a much more complicated diesel engine

-Disadvantages:
-High overall temperature for good carnot efficiency limits machine size due to cost/insulation losses
-Thermal inertia, requires significant preheating
-Large footprint
- precision of the alignment of the slide and the piston in the cylinder which has a major influence on the performance (the tolerance between the piston and the cylinder must be less than 30 microns and if possible close to 10 microns, 50 microns is already too much and leads to a significant loss of yield)


The machine is exceptionally simple to build for an engine but I don't have the space or all the tools or the time, I have to call on professional machinists and strippers...
There is no mold or foundry required. But only conventional machine tool operations, plus a laser cutting operation and of course a lot of assembly and welding.

The machine has an efficiency of 40% if only electricity is used, the 60% of heat is used for domestic hot water

I already have the sizing equations, materials and grades, and general topology in mind. I miss the equations characterizing the linear electric generator. I will focus on the axial flow type (magnets along the piston with alternating polarity). I'm going to design a linear generator that produces a sudden force at the high engine point (and low during piston return) to maximize the reciprocating frequency and therefore the power-to-weight ratio. Luckily I know how to use/program macroscopic maxwell equations.

Please feel free to ask questions and challenge the design, I have drawn inspiration from many posts on motors and what has been tried to validate my topology. An essential site is zlibrary which allows you to access most scientific publications for free.

Best regards

Miville Andre
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Re: New wood-fired electric generator




by izentrop » 02/04/22, 03:08

Otherwise you buy a Stirling engine cogeneration boiler, it is studied for, but not sure that there are still many manufacturers https://www.totalenergies.fr/particulie ... ion-atouts
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Re: New wood-fired electric generator




by MivilleAndré » 02/04/22, 03:38

No, because individual cogeneration boilers do not have an efficiency of 40%, large sizes are necessarily needed to reach 40% and a double cycle with two turbines to obtain 60% is unaffordable.

The interest of the engine is its high efficiency and its relatively simple design, if you want it's like a stirling where you use water instead of air

It is true that I disguise the 60% of my engine's heat as boiler use, but in reality we want to reduce the heat fraction as much as possible because electricity is 100% convertible into heat.
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Re: New wood-fired electric generator




by izentrop » 02/04/22, 11:14

How does dry steam work :?:
Maybe a diagram :?:
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Re: New wood-fired electric generator




by MivilleAndré » 02/04/22, 16:15

Dry steam is purely gaseous steam, it does not wet.

DEMO dry steam:


It looks like a 2hp engine but with a single combustion chamber in the center instead of two on the sides and without a crankshaft and with a single cylinder but two opposed pistons.
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Re: New wood-fired electric generator




by sicetaitsimple » 02/04/22, 17:14

Wouldn't there be synergies to be sought through integration with a liquid nitrogen storage-generator as presented here:
inventions, innovations / motor-generator-liquid-nitrogen-t15588.html
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Re: New wood-fired electric generator




by izentrop » 02/04/22, 18:12

MivilleAndre wrote:The interest of the motor is its high efficiency and its relatively simple design
If I understand correctly, your DIY steam engine in his garage would be more efficient than a stirling engine tested by engineers.

Why ask others to make it for you so that they steal the idea? It's absurd, isn't it? : roll:

Tiens Okofen offered a granulated one.
Image As it dates from 2012, nothing indicates that they still market it? https://conseils.xpair.com/recherche_de ... ricite.htm

They seem to be moving more towards photovoltaic cogeneration https://www.oekofen.com/assets/france/p ... L_2019.pdf

The engine manufacturer gives 26% efficiency ... 40% for your DIY, holy pretension : Mrgreen:
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Re: New wood-fired electric generator




by MivilleAndré » 03/04/22, 01:45

"If I understand correctly, your DIY steam engine in his garage would perform better than an engineer-proven stirling engine."
Yes otherwise the engine has no interest

"Why ask others to make it for you so that they steal your idea? It's absurd isn't it?"

There have been many tests of motors and this topology in the past and present:

https://www.freikolben.ch/lineargeneratoren.shtml

the important thing is to combine what is best. Mine will be on this list if it turns out not to exceed 40%. As there is necessarily a risk taking in this kind of adventure, it is easier to associate (the loss is less great) especially when you have few means. There is no diagram yet because there are still problems to solve and I do not yet have the sizing equations for the magnets and coils.

Many teams of researchers are working on these engines...but still nothing

26% efficiency is not terrible, it takes 40%!
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Re: New wood-fired electric generator




by izentrop » 03/04/22, 10:45

There have been many tests of motors and this topology in the past and present: https://www.freikolben.ch/lineargeneratoren.shtml
In 1930 we did not know but today there is the linear stirling engine : Wink:
MivilleAndre wrote:26% efficiency is not terrible, it takes 40%!
It is not specified but I suppose that 26% is the overall thermal > mechanical > electrical energy efficiency and in cogeneration this is not a problem since the rest of the heat is used for heating a dwelling and a small bit to run the water circulation pump.

40% would be the thermal/mechanical efficiency which would correspond to the maximum achievable in small systems of the Carnot cycle efficiency for a dithermal heat engine, right?
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Re: New wood-fired electric generator




by izentrop » 03/04/22, 12:18

MivilleAndre wrote: not terrible, it takes 40%!
We are still waiting for the plans to match your claims : Wink:
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