Interesting Regenerative Firebox Design

[fredrosse]

With respect to this forum thread, Barts comment is right-on, and contains virtually all the meaningful information relevant to steam generation using combustion of fuels, be they gas, oil, or solid fuel firing.

I have been employed in power plant technology for over 40 years, been inside many power plant air heaters, some 50 feet in diameter (and one that could have killed me). Every one picks up heat for combustion air from the stack gasses downstream of the boiler water/steam heating surfaces, nothing different makes sense in a boiler system that seeks best efficiency.

IC (Internal Combustion) engines often seek cool intake combustion air, mainly because this cool air is more dense, and hence allows larger air and fuel mass flow in the machine, giving greater power output potential. Anyone who has owned a Diesel automobile or truck knows how much better performance is during cold ambient conditions. That is not an issue for EC (External Combustion) engines, such as virtually all steam plants, be they 1,000,000 horsepower utility plants or 1 horsepower steamboat plants.

[Lopez Mike]

All very fine but I don't see any stage in this proposed burner where any energy is extracted for external use like one of our boilers. I would think that boiling water is the goal. If the only purpose is to increase the efficiency of the burner by a few percent when the power plant efficiency is in single digits, it seems like a lot of trouble for a small gain. The energy transfer is still through a metal wall to the water and the metal wall needs to have a line of sight to the flame for radiative transfer to happen.

There is, as well, the question of cleaning combustion products out of the heat exchanger. I have enough trouble scrubbing out my boiler tubes which are easy to get to and round as well.

I'm just not cranked up very much by attempts to increase the efficiency of our launch power plants at the expense of increased complication. Seems like a lot of trouble for rather small gains.

Being an old grump. I know, I know.