[RO] Preventing boiloff with radiators

[Human Person]

Who plays RO knows that cryogenic fuels (especially liquid Hydrogen) boil off pretty fast over time. You can reduce the rate of boiloff by using insulated tanks, but I was told you could also use thermal control systems to actively cool the propellants.

How to prevent boiloff efficiently?

   - wich Tank-type has the best insulation (is balloon cryo as good as cryo?)

   - does the shape of the tank or the utilization matter? (Are spherical tanks best or does it not matter in the game?)

   - should I have extra tanks (extra parts) for the liquid Hydrogen? 

   - How many radiators do need to stop boiloff completely (I don't want to use more than I need). Is that even possible?

 

Here's my latest test. Boiloff is very low now, but still not zero. I want this stage to be able to stay fully fueled in orbit for months.

   6 Days later, more than half of the Hydrogen is gone, even though 4 of the biggest radiators are constantly pumping.

 

Edited September 20, 2017 by Physics Student

[Laie]

I haven't (couldn't) play RO for months now. Last time I did, boiloff was a moving target (too much, too little, somehow odd, changing with every release of RealHeat). It didn't properly work at warp, or (especially) when coming out of warp. Which isn't the mods fault, btw, but a side effect from how heat ceases to exist at higher warp, only to come back with vengeance when you return to real time.

However... exposed surface was very much taken into account since, like, forever. Pointing your Centaur into or away from the sun mattered. Earth itself also radiates heat, though. The best way to store your hydrogen would be a long stick, far from earth (at least GEO, preferably translunar), showing the smallest possible profile to the sun.

Radiators were ill-configured for the purpose. My understanding is that @stratochief66 has been working on it in the meantime, so I won't get into details.

As to tank types, plain "Cryo" used to be the better option throughout, sometimes only slightly better, sometimes by a lot. "ServiceModule" was better still but not supposed to be used on a cubic meter scale.

At one time it was good to use separate tanks for LH and LOX and point it LOX-first towards the sun; at other times such a setup would ferociously boil off your hydrogen until all the LOX was cooled to 20K (repeat every time you drop out of warp).

For what you want to do, probably the best way of doing it would be to turn off boiloff entirely (configure yourself a magic tank or uninstall RealHeat) and to just roleplay it by sticking on however many radiators you think is the right amount.