Large Heat Exchanger is a item from Modern Industrialization, crafted from Invar Gear, Small Heat Exchanger, Aluminum Rotor, and Large Advanced Pump.
Crafting using Invar Gear, Small Heat Exchanger, Invar Gear, Aluminum Rotor, Large Advanced Pump, Aluminum Rotor, Invar Gear, Small Heat Exchanger and Invar Gear, arranged in the pattern shown. Produces Large Heat Exchanger.
Crafting 
Large Heat Exchanger guaranteedCrafting using Superconductor Coil, Large Heat Exchanger, Superconductor Coil, Nuclear Alloy Large Plate, Plasma Handling Iridium Machine Casing, Nuclear Alloy Large Plate, Superconductor Coil, Large Heat Exchanger and Superconductor Coil, arranged in the pattern shown. Produces Fusion Chamber.
Crafting 
modern_industrialization:large_heat_exchangermodern_industrializationmodern_industrializationRecipe JSON (1):
{
"recipe_type": "minecraft:crafting_shaped",
"pattern": [
"ghg",
"RLR",
"ghg"
],
"ingredients": {
"L": {
"item": "modern_industrialization:large_advanced_pump"
},
"R": {
"item": "modern_industrialization:aluminum_rotor"
},
"g": {
"tag": "c:invar_gears"
},
"h": {
"item": "modern_industrialization:small_heat_exchanger"
}
},
"conditions": [],
"sequence": null,
"group_name": null,
"experience": null,
"cooking_time": null
}