Cryogenic Tanks

A mod pack for Kerbal Space Program, specifically supporting my other mods Kerbal Atomics and Cryogenic Engines, dealing with cryogenic fuels, their storage and their properties

• Features
• Config Documentation
• Contributing
• Changelog

Features

Fuel Switching

This mod contains patches that enables fuel switching on most parts, stock and modded, that contain LiquidFuel/Oxidizer. The parts will be able to contain the following fuel settings with correct dry mass

• LiquidFuel/Oxidizer
• LqdHydrogen/Oxidizer
• LiquidFuel
• Oxidizer
• LqdHydrogen

Hydrogen Boiloff

The mod contains a plugin that causes LiquidHydrogen to evaporate from improperly cooled tanks. The boiloff rate is quite low so there is only a need to deal with it if you are storing fuel on orbit or doing long interplanetary transfers.

Orbital Zero-boiloff (ZBO) Fuel Tanks

This mod adds several ZBO tanks that use electricity to halt boiloff. These are provided in 1.25m to 5m size classes as well as several radial mount models. They have the same mass properties, but take less power to cool

Disabling Boiloff

Either remove the SimpleBoiloff.dll file from GameData/CryoTanks/Plugins/ or remove the following code block from GameData/CryoTanks/Patches/CryoTanksFuelSwitcher.cfg:

MODULE
{
  name =  ModuleCryoTank
  ... stuff
}

Contributing

I certainly accept pull requests. Please target all such thing to the dev branch though!

Translations

For translation instructions please see Localization Instructions

• Spanish: KSP forum user fitiales
• Russian: KSP forum user vladmir_v, Sooll3
• German: KSP forum user Three_Pounds
• French: KSP forum user Aodh4n

Config Documentation

Basic

Adding boiloff support to a fuel or fuel tank is simple. Specify the following MODULE block:

MODULE
{
  name =  ModuleCryoTank
  // in Ec per 1000 units per second
  CoolingCost = 0.08
  CoolingEnabled = True
  BOILOFFCONFIG
  {
    FuelName = LqdHydrogen
    // in % per hr
    BoiloffRate = 0.05
  }
}

Any number of BOILOFFCONFIGs can be used to boil off multiple fuels, though the CoolingCost is shared per tank.

Resource Generation

It is possible to set things so that boiloff creates another resource instead of venting into the ether. Do do this, specify an OUTPUT_RESOURCE in the BOILOFFCONFIG. You can set ratio, flow mode and resource name. With this option set, an amount of ResourceName will be produced according to the Ratio field, with the specified FlowMode.

BOILOFFCONFIG
{
  FuelName = Hydrogen
  // in % per hr
  BoiloffRate = 0.05
  OUTPUT_RESOURCE
  {
    ResourceName = Hydrogen
    Ratio = 1.0
    FlowMode = ALL_VESSEL
  }
}

Heating Effects

It is also possible to configure such that there is a boiloff dependence on energy input from planets and the sun. This does not affect cooling cost, but allows more interesting boiloff mitigation strategies, like hiding behind planets and being in the outer solar system.

MODULE
{
  name =  ModuleCryoTank
  // in Ec per 1000 units per second
  CoolingCost = 0.08
  CoolingEnabled = True

  Albedo = 0.5
  LongwaveFluxAffectsBoiloff = True
  LongwaveFluxBaseline = 0.5
  ShortwaveFluxAffectsBoiloff = True
  ShortwaveFluxBaseline = 0.5

  MaximumBoiloffScale = 5
  MinimumBoiloffScale = 0.001
  BOILOFFCONFIG
  {
    FuelName = LqdHydrogen
    // in % per hr
    BoiloffRate = 0.05
  }
}

Setting LongwaveFluxAffectsBoiloff will cause emission from planets to affect boiloff. This depends on the part's emissiveConstant, so ensure it is configured correctly. High emissiveConstant will increase boiloff. Modifying LongwaveFluxBaseline allows the scale of this to be changed - it defaults to a value of 0.1231, which is the flux received by an object in Low Kerbin Orbit with an emissiveConstant of 0.2. If the baseline is unchanged, the boiloff in LKO should be approximately the same as if LongwaveFluxAffectsBoiloff was disabled.

Setting ShortwaveFluxAffectsBoiloff will cause emission from the sun to affect boiloff. This depends on the Albedo field, so ensure it is configured correctly. High Albedo will decrease boiloff. Modifying ShortwaveFluxBaseline allows the scale of this to be changed - it defaults to a value of 0.7047, which is the flux received by an object in Low Kerbin Orbit with an Albedo of 0.5. If the baseline is unchanged, the boiloff in LKO should be approximately the same as if ShortwaveFluxAffectsBoiloff was disabled.

The DebugMode flag can also be set in order to observe solar input and planetary input as UI fields ingame.

Finally, the MaximumBoiloffScale and MinimumBoiloffScale fields can be configured to cap the modifier to boiloff from these modifications.