- #1
steves1080
- 65
- 1
Hi everybody,
I am an entry-level engineer working on a launch pad and so far I have little experience with cryogenics. We have a 80,000 gallon capacity liquid oxygen tank on site, and it is generally filled to about 75% full, but varies depending on what is going on. What I am wondering is a couple of different things:
1- I understand that if the liquid oxygen has reached its saturation point, it is going to be warmer than liquid below its saturation temp due to a higher heat flux. What I do not understand is how to determine the time it takes to reach this saturation temperature. If the pressure inside the vessel never exceeds 3 psig in standby conditions and there is no temp sensor, is there even any way to know this?
2- How would one determine the amount of liquid that would be lost if the vent was opened to atmosphere to rid some of this excess boil-off and effectively "cool" the liquid to a lower temperature? In addition, how could you determine the amount of time this takes? I know it will have something to do with energy/heat transfer, size of the outlet piping of the vent, and ullage space above the liquid inside the tank, but I can't seem to make sense enough of it to figure out where to start.
Thanks in advance for any help on either of these questions!
I am an entry-level engineer working on a launch pad and so far I have little experience with cryogenics. We have a 80,000 gallon capacity liquid oxygen tank on site, and it is generally filled to about 75% full, but varies depending on what is going on. What I am wondering is a couple of different things:
1- I understand that if the liquid oxygen has reached its saturation point, it is going to be warmer than liquid below its saturation temp due to a higher heat flux. What I do not understand is how to determine the time it takes to reach this saturation temperature. If the pressure inside the vessel never exceeds 3 psig in standby conditions and there is no temp sensor, is there even any way to know this?
2- How would one determine the amount of liquid that would be lost if the vent was opened to atmosphere to rid some of this excess boil-off and effectively "cool" the liquid to a lower temperature? In addition, how could you determine the amount of time this takes? I know it will have something to do with energy/heat transfer, size of the outlet piping of the vent, and ullage space above the liquid inside the tank, but I can't seem to make sense enough of it to figure out where to start.
Thanks in advance for any help on either of these questions!