Shop projects 4/24 - Testing a homemade monotube boiler for a steam turbine generator

The end-goal of this project is to make a cheap, efficient steam-driven generator that can be powered by pretty much anything that burns.

Due to the differences in the steam cycle vs internal-combustion cycle, it should be possible to make a generator that watt-for-watt is roughly twice as efficient as a diesel/gas generator.  Rather than wasting excess heat out the exhaust, this heat can be recirculated in a steam plant.

The first mod I need to make is to replace the hose outlet with an NPT threaded pipe outlet.  This will make it easier to prevent leaks and be easier to use at higher temperatures.

I also fashioned a couple short mockup tests with a copper monotube and a few plumbing fittings.  I wanted to see how fast the water heats up, how it boils/flashes inside the monotube, and how the pressure+flow acts as heat is added/removed.

Warm-up time from room temperature seems to be about 5-8 seconds, with pressure rapidly exceeding beyond 100psi when a propane torch is focused down the coil.

There were some odd water-hammer effects when the burner was focused unevenly.  Water likely flashes in one part of the tube causing a rapid pressure 'kick' in both directions.  Nothing that hurts the project, it's just something that needs to be accounted for.

For today, all that's left is to wait for the JB-weld to set so I can hopefully continue testing with a proper pump tomorrow.

Hope you enjoyed the update😌