The Lemon Fool

Mike4 wrote:

servodude wrote:
Sounds a bit dodgy geezer?

Dunnit just!!!

Getting a cavern of 0.1 cubic kilometres in volume totally pressure-tight sounds like quite a project.

Out of interest, can you or anyone post up the calcs to work out the pressure required for the boiling point of water to reach 140C?

I'd imagine most of the difficult bit is at the top (given how giant holes work)

I think this https://www.engineeringtoolbox.com/water-vapor-saturation-pressure-d_599.html?vA=140&units=C# suggests 3.6bar (52.5psi)
- which isn't all that high
I've had to seal irrigation outlets at 5 bar before - using battery powered linear actuators pushing plate steel against concrete and they were capable of 7bar (granted though closing the last half an inch would probably have stripped your ankles off if you'd been standing too close)

Mike4 wrote:

servodude wrote:
Sounds a bit dodgy geezer?

Dunnit just!!!

Getting a cavern of 0.1 cubic kilometres in volume totally pressure-tight sounds like quite a project.

Out of interest, can you or anyone post up the calcs to work out the pressure required for the boiling point of water to reach 140C?

4 bar absolute (400kPa absolute). Or higher of course.

Not sure what to think about that. It's a lot lower than the pressures I work with, but my pressure vessels are measured in litres.
FWIW an over burden of about 12m of rock would at least keep the roof of the cavern in compression.

Isn't 4 bar about 30m of water? Dams cope with ten times that and you don't see them leaking, so shouldn't be much of an engineering problem surely?

GS

GoSeigen wrote:Isn't 4 bar about 30m of water? Dams cope with ten times that and you don't see them leaking, so shouldn't be much of an engineering problem surely?

GS

I think the challenge is as much the strength testing of the vessel, given the vast surface areas having 4 bar applied to them. The magnitude of the forces involved will be astounding.

Mike4 wrote:

GoSeigen wrote:Isn't 4 bar about 30m of water? Dams cope with ten times that and you don't see them leaking, so shouldn't be much of an engineering problem surely?

GS

I think the challenge is as much the strength testing of the vessel, given the vast surface areas having 4 bar applied to them. The magnitude of the forces involved will be astounding.

As a boiler expert you would know better than me but can't they just pour in some of that Holt Sealit stuff that automatically finds and fixes the leaks?

GS

GoSeigen wrote:

Mike4 wrote:
I think the challenge is as much the strength testing of the vessel, given the vast surface areas having 4 bar applied to them. The magnitude of the forces involved will be astounding.

As a boiler expert you would know better than me but can't they just pour in some of that Holt Sealit stuff that automatically finds and fixes the leaks?

GS

"Yeah mate dunno! I'll have to drain and power flush your cavern to be sure"

An example of a smaller scale heat battery in an industrial process.

https://www.msn.com/en-us/lifestyle/lifestyle-buzz/alcoholic-drinks-giant-to-power-its-production-sites-with-giant-brick-toaster-battery-here-s-why-it-s-important/ar-AA1nzTJr