Ian F
MegaDork
12/28/18 10:23 a.m.
In reply to Dr. Hess :
It's definitely interesting. I work along side steam systems all the time. One issue is they are inherently brutal systems. Even with treated water in a closed system, the high temperature can be hell on the piping.
One item not addressed in my calculations is the required pressures involved in making such a system work well. The systems we deal with for heating applications typically don't run at very high pressure as the steam isn't used to "push" anything significant other than a steam driven condensate pump. I'm not sure at all what pressure would be required to effectively turn a 20 HP PTO drive. As a point of reference, I'm working on a project where we are installing a new 800 HP boiler with an operating pressure of 50 PSI, which is considering "medium pressure" when distributed in the building.
D2W
HalfDork
12/28/18 11:08 a.m.
In a post apocalyptic event I think I will concentrate on leadership and weapon making skills. A nomadic band of marauders seems like a good way to survive.
The solar + wood idea isn't bad. I think you'd actually want to make it solar+wind+wood because wind turbines are light, highly energy-dense for a renewable energy collection system, and can fold into a small size. To keep parts cheap and easily scavengeable you'd want to stick mostly to 18650 cells (found in most EVs and laptops), with some hookups for generic 3.7V lipo packs (found in e-bikes, big RCs, some cell phones and cell power banks) and perhaps some 12v lead-acid batteries (found in every ICE car). Hydrogen fuel cells are crazy-expensive and extremely rare, and if you're pressurizing hydrogen, the fuel tank is relatively dangerous.
The solar concentrator/steam turbine could work but it may not be worth the complexity of one or more turbines and high-pressure high-temperature plumbing systems. Solar cells are dead simple, no moving parts or plumbing, let sunlight hit them and electricity comes out the wires.
Check out this thing, it's not far off:
https://www.wired.com/story/3d-printed-solar-powered-snow-rover/
In reply to Ian F :
My dream design is to use the Organic Rankin Cycle with whatever refrigerant is considered "enviro friendly" at the time of design, or propane for that matter.
We used like 800-1200F steam systems, if I recall, for 50KHP turbines. Not sure what pressures they ran at. Those were a tad dangerous, but hey, as long as you didn't submerge them in water, everything worked out. They key is having a multistage turbine, not a single stage like an automotive turbocharger. Each stage just captures a portion of the total energy, and each stage needs to be designed optimally for that portion it is to capture.
Sounds like we all need 40 acres and a mule.
I know where all the natural gas wells are in my area.
Brian
MegaDork
12/28/18 8:44 p.m.
Hungary Bill said:
Of course it has vanished, it doesn’t have pedals!