CounterFlow Heat Exchanger - Gas + Liquid

This version of the counterflow heat exchanger connects two kinds of line: gas runs from Input to Output, liquid from Input2 to Output2. Both streams stay separate and exchange heat in counterflow.

The big advantage lies in heat capacity. According to the game data water stores 72 J per mole and kelvin and takes up 0.018 litres per mole. So a litre of water holds about 4,000 J per kelvin. A litre of nitrogen at 100 kPa and 20 °C is only 0.041 mol and stores 0.85 J per kelvin – about 4,700 times less. Even at 10,000 kPa gas pressure the liquid still carries about 47 times as much heat per litre.

That leads to the typical layout: a hot gas stream, such as exhaust or a cooling loop fed by wall coolers, hands its heat to a water loop here. The water loop carries it to large radiators such as the Large Extendable Radiator.

Watch the liquid:

• Water freezes at 273.15 K. Cool too hard and it solidifies in the pipe.
• At 100 kPa water boils at about 384 K in the game; above that part of it can evaporate.
• Liquid lines hold at most 6,079.5 kPa.

Like the gas version it is passive: both streams only flow while the respective input has more pressure or more filling than the output. So a pump in the water loop and one in the gas loop belong to the setup. The gas side transfers correspondingly less below 101.325 kPa; the liquid side counts in full as soon as 0.1 % of its volume is liquid. Setting (0 to 10) does appear in the logic list, but the exchanger never reads it. It is built from the Kit (CounterFlow Heat Exchanger) plus one steel sheet with the welding torch. More in Heat exchangers and heat transport: pipe to pipe, gas to liquid.