Tommey Reed Rocket Mass Heater Project

[TommeyLReed]

Hi Mark,


I disagree with a strirling engine efficiency due to the fact it's not a sealed piston ring setup.

This design is a sealed unit and water that will expand 1:1700 times makes a good design.

Tom..

[MarkE]

Hi Mark,


I disagree with a strirling engine efficiency due to the fact it's not a sealed piston ring setup.

This design is a sealed unit and water that will expand 1:1700 times makes a good design.

Tom..

Tommey the 1700:1 expansion is only a factor if the volume change actually allows for that.  A typical steam engine does not have either a high expansion ratio or temperature drop leading to a low efficiency.  Rudolph Diesel made his fortune because his engine has a decent power band like a steam engine but much higher efficiency.  The limitations of Stirling engines is that they have narrow operating ranges.  That can be fixed by outputting the power into an electrical power converter that performs maximum power tracking.

[Rigel4]

This is to everyone if they have any answers!
What would be the effect if the stove was twice as tall and wide ? Would it be more or less efficient?
What is the largest size wood that would work for an unattended burn? Can you stuff a 8 foot long  6 in diameter tree like poplar in it and expect a clean burn for overnight?

Your next step seems to be putting something LIKE a boiler on it, I have not found if people convert these things so I wonder if converting an existing boiler is feasible, or if you have to break new ground.
My oil bill last winter was over 800 every 2-3 weeks I am just asking for a friend

As always you build the most useful and practical stuff. Hats off to you sir.

[MarkE]

What the rocket stoves do very well is use draft to get lots of oxygen while maintaining a high temperature in the combustion area.  This yields a very clean burn and low ash.  What the better rocket stoves do is to also exchange the heat effectively without sending most of it out the exhaust flue, yielding good efficiency.  The inverted tank design that Tommey has built which has similarities to the design that zero fossil fuel build do that pretty well.  My intuition tells me that if taken to the limit the best efficiency will require a condensing design, which means there will be water to dispose.  Condensing versus non-condensing may make up to about a 20% difference in fuel use.

[Rigel4]

Thanks Mark, I am not sure what you mean about condensate on the existing unit. You mean from temperature differential? or his future design?
The existing ones I have seen use earth as a heat sink so moisture is not an issue. The one that Z has shown may not be legal or safe inside a house. I just don't know.
If Tommey can get a boiler or whatever he has in mind and a steam engine going, it would be interesting.