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In this video I'll use a steam turbine to generate electricity using a BLDC motor as a generator to create 3phase alternating current. The turbine is machined from a brass block, with a 2" x 2" x 1" housing and 46mm diameter / 19mm wide rotor. As a nozzle, it has a 1mm orifice. The steam is generated by a flash boiler that's heated with a propane flame and fed from a pressurized water tank. A unique feature about this boiler design is that the feedwater pressurization comes from the propane fuel.

The boiler evaporates approximately ~1 gram/sec of water, meaning it's absorbing about 2.6 kW of heat. The generator puts out a peak power of 17 watts, making it 0.65% efficient in a best case. In reality, a large portion of the heat is probably lost to the surroundings instead of heating the boiler, so the efficiency is probably even less than that. The average steam pressure right before the nozzle exit was about 60 psi (~4 bar) for the tests in this video.

Huge losses were probably caused by the relatively large gaps between the turbine rotor and the housing wall. Also, the lack of a convergingdiverging nozzle is probably another source of inefficiency, but I don't think I currently have the ability to machine one at such a small scale. The burner itself was probably drawing in much more air than was neccesary for combustion, meaning a large volume of air was probably just acting as a parasitic load on the burner.

The power output of this thing was pretty small, but large enough to charge a phone / tablet or power a small radio, which could actually make it useful in an emergency if nothing else was available.

The idea for this turbine is a development on some compressedair turbine designs i experimented with in two videos published in 2022:

   • 3d Printed Compressed Air Turbine  

   • Comparing Turbine Rotors  

Machining this thing out of metal was a lot of work, so maybe if i make a future video on steam turbines, I'll try one of those Tesla Turbine things, since those just require a big stack of thin plates.