Large Boiler

The Large Boiler is an MV tier multiblock for burning combustible fuels to evaporate water into steam or superheated steam. There are four tiers of the Large Boiler to further improve its efficiency and throughput as better materials are unlocked. Higher density fuels not only burn for longer, but they also receive bonus ticks proportional to their total burn time. Supplying both solid and liquid fuel at the same time boosts both the maximum water consumption and steam production by 25%. The Large Boiler ultimately supersedes the Railcraft Boiler, but the bronze version has slightly less maximum throughput.

Spreadsheet: GTNH Power Planner 2.9

The Large Boiler is available in four tiers but the only structural difference between them is the type of casings and the controller itself. Buses/hatches may replace any machine casing or firebox casing anywhere on the structure. Both liquid fuel and water may enter through the same input hatch if necessary. There is no energy hatch because it does not consume power. Use the Multiblock Structure Hologram Projector to visualize/build the structure.

Assuming plates are made in a bending machine and rods are made with a file, a Large Bronze Boiler requires 368 bronze ingots and 28 brick blocks to build if there are five buses/hatches all replacing the more expensive firebox casings. Similarly, a Large Steel Boiler requires 376 steel ingots to build if rods are made in an extruder.

Structure

• Controller: Front center, 2nd layer
• 20-28 Machine Casing^[1]
• 5-15 Firebox Casing^[1]
• 4 Pipe Casing^[1]
• 1 Maintenance Hatch: Any machine or firebox casing
• 1 Muffler Hatch: Any machine or firebox casing
• 0+ Input Bus: Any machine or firebox casing
• 1+ Input Hatch: Any machine or firebox casing
• 1+ Output Hatch: Any machine or firebox casing

Wallsharing

Large Boilers may wallshare each of their sides to save on casings and buses/hatches. That includes the input bus/hatch for fuel and water as well as the output hatch for steam if it is large enough to hold the combined output of all shared machines.

The Large Boiler burns combustible fuels to evaporate water into steam or superheated (SH) steam. Higher density fuels naturally burn for longer, but they also receive bonus ticks proportional to their total burn time. Solid fuels with less than 480 burn time are not allowed in the Large Bronze Boiler and solid fuels with less than 1,200 burn time are not allowed in the Large Steel Boiler. Only a few specific fuels are allowed in the Large Titanium Boiler or Large Tungstensteel Boiler. The solid burn times are per item and the fluid burn times are per 1,000L in the following tables.

The maximum rate that water is consumed and that steam is produced is fixed based on the tier of the machine. The Large Bronze Boiler and Large Steel Boiler produce only regular steam while the Large Titanium Boiler and Large Tungstensteel Boiler produce only supersheated (SH) steam. See the following section on power for the difference between the two. Both the consumption rate of water and the output rate of steam scales linearly with runtime during the warm-up phase, which is a short period that the Large Boiler must go through every time it starts. Distilled water may be used in place of regular water if looping the output of the Large Steam Turbine (LST) back into the Large Boiler. Maintenance issues reduce the amount of steam produced by 10% each.

Supplying both solid and liquid fuel at the same time boosts the throughput of the Large Boiler by 25%, allowing it to consume more water and produce more steam than normal. The burn times of both fuels are "doubled" in the GUI of the controller when doing this but that is only because the machine alternates which fuel to subtract from every tick. They are being used half as often so they last twice as long--they are not twice as effective. In the following table, one fuel refers to using either solid or liquid fuel while both fuels refers to using both solid and liquid fuel together in the same machine.

Optionally, a programmed circuit can be placed inside the controller to reduce the total steam output by 1,000 L/s per value. For example, a programmed circuit of 3 reduces the steam output by 3,000 L/s. This is rarely ever useful since more steam always produces more power in the LST, even if above the optimal flow rate of the turbine.

Feeding high tier boilers may prove to be difficult or potentially confusing, as many different recipes exist producing both standard and magic super fuel and their components.

Super Fuel Binder is required in both Super Fuel types, and has eight recipes.

• Wood Pulp can be easily sourced from bonsai tree crops or a Farming Station
• Sulfur can be obtained from various processes, including Hydrogen Sulfide from oil processing or from crops like Red Stonelilly
• The Sodium Dust recipe can be used with a renewable source of Salt such as Salty Root, but is not recommended for mass-scale set ups due to requiring massive amounts of Advanced Glue and Sodium Dust
• Lithium Dust can be obtained in large quantities from the Lithium or Salt Bee, which are relatively early in the bee breeding tree and can supply the lithium required to make enough Super Fuel Binder
• Advanced Glue can be produced from Ethylene and some other chemicals and automated
• Ethyl Cyanoacrylate (Super Glue) can be used instead of Advanced Glue in the Lithium recipe, quadrupling the amount of binder produced, but requires a complicated Chemical Plant chain; players may find it easier to upscale overall production

• Using the Cetane-Boosted Diesel (CBD) recipe is recommended over the High Octane Gasoline (HOG) recipe is preferred as if the player is already producing HOG, using the Extreme Combustion Engine or Universal Chemical Fuel Engine would be more effective
• Using the Charcoal or Lignite block recipes are not recommended due to requiring an extreme amount of Super Fuel Binder as well as CBD or HOG; instead, the Coal Coke recipe should be used, being the most efficient recipe
• Coal can be sourced in multiple ways:
  • It can be mass produced in the Extreme Entity Crusher from mobs such as the Redcap Sapper. While this is very easy to scale due to its perfect overclock, it can be extremely energy intensive
  • Charcoal can be transmuted into Coal using the Alchemic Chemistry Set, requiring 20LP per piece of coal
  • Coal Bees are capable of producing Coal at a solid rate

• First, Magic Super Fuel Binder must be obtained:
  • Redcap Sappers can produce Balanced Shards and other Thaumcraft Shards. If the player has defeated the Twilight Forest Hydra, using the Fiery Blood recipes can be effective
  • Blaze Powder and Ender Pearls can be automated for the Endereye Dust recipe, and Mercury can be sourced from redstone produced by Red Stonelilly (which also produces sulfur) or other methods
• Lastly, the binder must be mixed with CBD or HOG, a coal block variant, and another material:
  • The Diamond Dust recipe is preferred as while it is less CBD/HOG efficient, Diamonds are another drop the Redcap Sapper gives
  • The Alumentum recipe can also be used if the player has automated their crucible and/or essentia generation, though four Alumentum per Magic Super Fuel may be a steep price

The steam produced by the Large Boiler is used to generate power with singleblock steam turbines or a series of Large Steam Turbines in the order listed below. Both types of steam have the same conversion ratio so the output of one can feed directly into the input of the next. At maximum efficiency, 100% of the steam is recycled back into distilled water--forming a sustainable closed loop system. SH steam generates 2x more EU than regular steam at the same optimal flow rate.

• The Large HP Steam Turbine generates power from SH steam and converts it to regular steam at a 1:1 ratio.
• The Large Steam Turbine generates power from regular steam and converts it to distilled water at a 160:1 ratio.

If the steam throughput is too high for steam valves or fluid pipes, use fluid P2P tunnels instead. They have no transfer limit and evenly distribute all fluids between all output connections.

The following are some example setups for various turbine materials. These all assume the maximum steam production which means there is both solid and liquid fuel being burned in the same Large Boiler at the same time. Use the planner linked at the top for a complete list of turbine materials and full setup breakdowns.