On 15/12/2024 03:24, gene heskett wrote:
On 12/14/24 12:31, Thomas Schmitt wrote:
Gene Heskett wrote:
Our std night shift procedure was to pump the big tank down to under
2 or 3
psi, which put the bottles up around 7400 to 7800 psi at midnight. The
morning shift at 8AM had 5200 psi to play with till the truck got there.
Around a 2500 diff. Where did the rest of it go?
The pressure of a given amount of gas in a given volume is proportional
to its absolute temperature. Pressure reduction from 7400 to 5200 would
correspond to a temperature reduction from e.g. 427 Kelvin (309 F, more
than boiling hot but not glowing) to 300 Kelvin (80 F, luke warm).
The next step would be calculation of ideal gas temperature in a vessel
after filling it from atmospheric pressure to 7500 psi (rather high
value) neglecting heat dissipation through the vessel walls.
(Side not: compressor thrust may be hot as well) +100 K difference does
not look like an overestimate from my point of view.
I've BTDT, have you?
Heating during filling was mentioned previous time as well and sounds
reasonable.
