...another one from my series of ideas and concepts I doubt I will live long enough to enact!!!
This is a concept for a solid fuel internal combustion Carnot cycle engine (or at least a variation on the Carnot cycle).
There is a cylinder on the left which acts as a simple air pump and is shown with two flap valves.
The cylinder on the right is the power cylinder and is somewhat bigger than the air pump cylinder. The exhaust valve is shown as a poppet valve and is in the head of the piston which would allow the valve to be operated by a cam on the crank pin.
The centre vessel is the combustion chamber which is double walled. Solid fuel such as charcoal is loaded into the combustion chamber through a removable lid.
Cold inducted air passes through holes into the inner chamber.
Hot expanded air moves from the inner chamber and acts on the power piston.
Starting the engine would require the a small amount of fuel to be lit and dropped into the inner chamber and the chamber filled with more fuel then the lid clamped in place. The engine would then be turned forcing fresh air into the inner chamber fanning the fire and the resulting heated combustion gasses would be passed to the power cylinder.
The engine would be throttled by restricting air intake.
I dont really know if this would work and I have no idea how long it might run between refueling and relighting. More importantly I dont know what the ratio should be between the volume of the air pump and the power cylinder.
The choice of solid fuel is partly for the simplicity compared to managing a liquid fuel system and of course partly for the novelty value.
The principle of operation is akin to that of a jet engine.